BytecodeInterpreter.java

package org.perlonjava.backend.bytecode;

import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.BitSet;
import java.util.Set;

import org.perlonjava.runtime.HintHashRegistry;
import org.perlonjava.runtime.NamedCharacterExpansionMap;
import org.perlonjava.runtime.WarningBitsRegistry;
import org.perlonjava.runtime.debugger.DebugHooks;
import org.perlonjava.runtime.operators.CompareOperators;
import org.perlonjava.runtime.operators.ModuleOperators;
import org.perlonjava.runtime.operators.ReferenceOperators;
import org.perlonjava.runtime.operators.WarnDie;
import org.perlonjava.runtime.regex.RegexQuoteMeta;
import org.perlonjava.runtime.regex.RuntimeRegex;
import org.perlonjava.runtime.runtimetypes.*;

/**
 * Bytecode interpreter with switch-based dispatch and pure register architecture.
 * <p>
 * Key design principles:
 * 1. Pure register machine (NO expression stack) - required for control flow correctness
 * 2. 3-address code format: rd = rs1 op rs2 (explicit register operands)
 * 3. Call same org.perlonjava.runtime.operators.* methods as compiler (100% code reuse)
 * 4. Share GlobalVariable maps with compiled code (same global state)
 * 5. Handle RuntimeControlFlowList for last/next/redo/goto/tail-call
 * 6. Switch-based dispatch (JVM optimizes to tableswitch - O(1) jump table)
 */
public class BytecodeInterpreter {

    /** A loop-entry restriction belongs to the resolved destination, not to
     * every unrelated label with the same spelling elsewhere in the frame. */
    private static boolean jumpsIntoUnenteredLoopBody(InterpretedCode code, String label, int targetPc,
                                                       int sourcePc) {
        if (code.gotoLabelLoopRanges == null) return false;
        int[] range = code.gotoLabelLoopRanges.get(label);
        // A computed goto may target a label in the current foreach body. Its
        // iterator and control-block state are already active in that case;
        // only an entry from outside the range is forbidden.
        return range != null && targetPc >= range[0] && targetPc < range[1]
                && (sourcePc < range[0] || sourcePc >= range[1]);
    }

    private static void rejectGotoIntoGiven(InterpretedCode code, String label) {
        if (code.gotoLabelsInsideGiven != null && code.gotoLabelsInsideGiven.contains(label)) {
            throw new PerlCompilerException("Can't \"goto\" into a \"given\" block");
        }
    }

    private static void enterGotoLabelPackage(InterpretedCode code, int targetPc) {
        if (code.gotoLabelPackages == null) return;
        String packageName = code.gotoLabelPackages.get(targetPc);
        if (packageName != null) InterpreterState.setCurrentPackageStatic(packageName);
    }

    // Debug flag for regex compilation (set at class load time)
    private static final boolean DEBUG_REGEX = System.getenv("DEBUG_REGEX") != null;

    static RuntimeScalar ensureMutableScalar(RuntimeBase val) {
        if (val instanceof RuntimeScalarReadOnly ro) {
            RuntimeScalar copy = new RuntimeScalar();
            copy.type = ro.type;
            copy.value = ro.value;
            copy.numericLiteralText = ro.numericLiteralText;
            copy.numericContextSeen = ro.numericContextSeen;
            return copy;
        }
        if (val instanceof ScalarSpecialVariable sv) {
            RuntimeScalar src = sv.getValueAsScalar();
            return new RuntimeScalar(src);
        }
        return (RuntimeScalar) val;
    }

    static boolean isImmutableProxy(RuntimeBase val) {
        // ReadOnlyAlias is a deliberate exception: it extends
        // RuntimeScalarReadOnly so utf8::upgrade/downgrade and similar
        // paths treat it as read-only (skip in-place mutation), but the
        // interpreter's mutating opcodes must NOT silently strip it --
        // we want `for (3) { ++$_ }` to throw, not silently succeed.
        if (val instanceof ReadOnlyAlias) return false;
        if (val instanceof ScalarSpecialVariable specialVariable
                && specialVariable.hasSpecialAssignmentBehavior()) {
            return false;
        }
        return val instanceof RuntimeScalarReadOnly || val instanceof ScalarSpecialVariable;
    }

    private static RuntimeScalar conditionScalar(RuntimeBase value) {
        if (value == null) {
            // A lexical whose initializer is skipped by short-circuit control
            // flow still has Perl's undef value.  Registers use Java null for
            // that not-yet-materialized state, so boolean branches must treat
            // it exactly like LOAD_UNDEF.
            return new RuntimeScalar();
        }
        return value instanceof RuntimeScalar scalar ? scalar : value.scalar();
    }

    private static boolean lexicalAssignmentMustPreserveSlot(RuntimeBase val) {
        if (!(val instanceof RuntimeScalar scalar)) return false;
        return scalar instanceof ReadOnlyAlias
                || scalar.threadShared
                || scalar.captureCount > 0
                || scalar.captureRefCountOwned() > 0
                || scalar.referencedByScalarReference
                || scalar.hasLiveSubstrLvalueObservers()
                || scalar.hasWatchers()
                || scalar.type == RuntimeScalarType.TIED_SCALAR
                || scalar.type == RuntimeScalarType.READONLY_SCALAR;
    }

    private static boolean returnListContainsTrackedReference(RuntimeList retList) {
        if (retList == null || retList instanceof RuntimeControlFlowList) return true;
        for (RuntimeBase elem : retList.elements) {
            if (runtimeBaseIsTrackedReference(elem)) {
                return true;
            }
        }
        return false;
    }

    private static boolean runtimeBaseIsTrackedReference(RuntimeBase elem) {
        if (elem == null) return false;
        if (elem instanceof RuntimeScalar scalar) {
            if (!RuntimeScalarType.isReference(scalar)) {
                return false;
            }
            if (!(scalar.value instanceof RuntimeBase base)) {
                return false;
            }
            return base.blessId != 0 || base.refCount >= 0;
        }
        return elem.blessId != 0 || elem.refCount >= 0;
    }

    private static void releaseConsumedTemp(RuntimeBase temp, RuntimeBase target) {
        if (!(temp instanceof RuntimeScalar tempScalar)
                || !(target instanceof RuntimeScalar targetScalar)
                || tempScalar == targetScalar
                || !tempScalar.refCountOwned
                || !RuntimeScalarType.isReference(tempScalar)
                || tempScalar.type != targetScalar.type
                || tempScalar.value != targetScalar.value
                || !(tempScalar.value instanceof RuntimeBase base)
                || base.refCount <= 0) {
            return;
        }

        tempScalar.refCountOwned = false;
        if (base.refCountTrace) {
            base.traceRefCount(-1, "BytecodeInterpreter.releaseConsumedTemp");
            base.releaseOwner(tempScalar, "releaseConsumedTemp");
        }
        base.releaseActiveOwner(tempScalar);
        base.refCount--;
    }

    private static java.util.Set<RuntimeCode> collectReturnedClosures(RuntimeBase value) {
        java.util.IdentityHashMap<RuntimeCode, Boolean> closures = new java.util.IdentityHashMap<>();
        collectReturnedClosures(value, closures);
        return closures.isEmpty() ? null : closures.keySet();
    }

    private static void collectReturnedClosures(RuntimeBase value, java.util.IdentityHashMap<RuntimeCode, Boolean> closures) {
        if (value == null) {
            return;
        }
        if (value instanceof RuntimeScalar scalar) {
            if (scalar.type == RuntimeScalarType.CODE && scalar.value instanceof RuntimeCode code) {
                closures.put(code, Boolean.TRUE);
            }
            return;
        }
        if (value instanceof RuntimeControlFlowList flow && flow.returnValue != null) {
            collectReturnedClosures(flow.returnValue, closures);
            return;
        }
        if (value instanceof RuntimeList list) {
            for (RuntimeBase element : list.elements) {
                collectReturnedClosures(element, closures);
            }
        }
    }

    /**
     * Execute interpreted bytecode.
     *
     * @param code        The InterpretedCode to execute
     * @param args        The arguments array (@_)
     * @param callContext The calling context (VOID/SCALAR/LIST/RUNTIME)
     * @return RuntimeList containing the result (may be RuntimeControlFlowList)
     */
    public static RuntimeList execute(InterpretedCode code, RuntimeArray args, int callContext) {
        return execute(code, args, callContext, null);
    }

    /**
     * Execute interpreted bytecode with subroutine name for stack traces.
     *
     * @param code           The InterpretedCode to execute
     * @param args           The arguments array (@_)
     * @param callContext    The calling context
     * @param subroutineName Subroutine name for stack traces (may be null)
     * @return RuntimeList containing the result (may be RuntimeControlFlowList)
     */
    public static RuntimeList execute(InterpretedCode code, RuntimeArray args, int callContext, String subroutineName) {
        RuntimeBase[] registers = code.getRegisters();
        SuspendedInterpreterFrame frame = new SuspendedInterpreterFrame(
                code, registers, callContext, subroutineName);

        // Initialize special registers (same as compiler).
        registers[0] = code;
        registers[1] = args;
        registers[2] = RuntimeScalarCache.getScalarInt(callContext);
        if (code.capturedVars != null && code.capturedVars.length > 0) {
            System.arraycopy(code.capturedVars, 0, registers, 3, code.capturedVars.length);
        }
        return execute(frame);
    }

    /** Resume a heap-owned interpreter frame after an await callback. */
    static RuntimeList resume(SuspendedInterpreterFrame frame) {
        return execute(frame);
    }

    /** Release lexical and closure ownership for a suspended frame that is cancelled. */
    static void abandon(SuspendedInterpreterFrame frame) {
        if (!frame.suspended) return;
        frame.suspended = false;
        frame.suspendedRuntimeDisabledWarningCategories = null;

        for (RuntimeCode closure : frame.createdClosures) {
            if ((closure.capturedScalars != null || closure.capturedAggregates != null)
                    && closure.refCount == 0
                    && closure.stashRefCount <= 0
                    && (frame.returnedClosures == null
                        || !frame.returnedClosures.contains(closure))) {
                closure.releaseCaptures();
            }
        }

        InterpretedCode code = frame.code;
        RuntimeBase[] registers = frame.registers;
        int firstMyVarReg = 3 + (code.capturedVars != null ? code.capturedVars.length : 0);
        BitSet myVars = code.myVarRegisters;
        boolean needsFlush = false;
        for (int i = myVars.nextSetBit(firstMyVarReg);
             i >= 0 && i < registers.length;
             i = myVars.nextSetBit(i + 1)) {
            RuntimeBase reg = registers[i];
            if (reg == null) continue;
            if (reg instanceof RuntimeScalar rs) {
                RuntimeScalar.scopeExitCleanup(rs);
                needsFlush = true;
            } else if (reg instanceof RuntimeHash rh) {
                MortalList.scopeExitCleanupHash(rh);
                needsFlush = true;
            } else if (reg instanceof RuntimeArray ra) {
                MortalList.scopeExitCleanupArray(ra);
                needsFlush = true;
            }
            MyVarCleanupStack.unregister(reg);
            registers[i] = null;
        }
        if (needsFlush) {
            MortalList.flush();
        }
        code.releaseRegisters();
    }

    /**
     * Result of a call whose non-local last/next/redo was consumed by an enclosing
     * labeled block.  Control has left the block, so the marker must not stay in the
     * call's result register: a sub whose last statement is that block returns the
     * register as its value, and the caller would otherwise see an unmatched marker.
     */
    private static RuntimeBase consumedControlFlowResult(int context) {
        return context == RuntimeContextType.SCALAR || context == RuntimeContextType.LVALUE
                || context == RuntimeContextType.OBJECT ? new RuntimeScalar() : new RuntimeList();
    }

    private static boolean matchesInterpreterControlBlock(RuntimeControlFlowList flow, String blockLabel) {
        boolean switchContinueBoundary = RuntimeControlFlowList.SWITCH_CONTINUE_BLOCK_LABEL.equals(blockLabel);
        if (flow.isSwitchContinue()) {
            return switchContinueBoundary;
        }
        return !switchContinueBoundary && flow.matchesLabel(blockLabel);
    }

    /**
     * Dispatches non-local control-flow markers returned by map/grep in the
     * current interpreted frame. Returns the target PC, or {@code -1} when
     * this frame does not own the target and the marker must propagate.
     */
    private static int dispatchListOperatorControlFlow(
            RuntimeControlFlowList flow, InterpretedCode code, int context, int resultReg,
            int sourcePc, RuntimeBase[] registers, ArrayList<int[]> controlBlockStack,
            ArrayList<int[]> labeledBlockStack) {
        if (flow.getControlFlowType() == ControlFlowType.GOTO) {
            String label = flow.getControlFlowLabel();
            Integer targetPc = code.gotoLabelPcs == null ? null : code.gotoLabelPcs.get(label);
            if (targetPc == null) {
                return -1;
            }
            if (jumpsIntoUnenteredLoopBody(code, label, targetPc, sourcePc)) {
                throw new PerlCompilerException("Can't \"goto\" into the middle of a foreach loop");
            }
            rejectGotoIntoGiven(code, label);
            if (code.gotoLabelsInsideConstruct != null
                    && code.gotoLabelsInsideConstruct.contains(label)) {
                throw new PerlCompilerException(
                        "Use of \"goto\" to jump into a construct is no longer permitted");
            }
            enterGotoLabelPackage(code, targetPc);
            registers[resultReg] = consumedControlFlowResult(context);
            return targetPc;
        }

        if (flow.getControlFlowType() != ControlFlowType.LAST
                && flow.getControlFlowType() != ControlFlowType.NEXT
                && flow.getControlFlowType() != ControlFlowType.REDO) {
            return -1;
        }

        for (int i = controlBlockStack.size() - 1; i >= 0; i--) {
            int[] entry = controlBlockStack.get(i);
            String blockLabel = code.stringPool[entry[0]];
            if (matchesInterpreterControlBlock(flow, blockLabel)) {
                while (controlBlockStack.size() > i + 1) {
                    controlBlockStack.removeLast();
                }
                int targetPc = switch (flow.getControlFlowType()) {
                    case LAST -> entry[1];
                    case NEXT -> entry[2];
                    case REDO -> entry[3];
                    default -> -1;
                };
                if (targetPc >= 0) {
                    registers[resultReg] = consumedControlFlowResult(context);
                    return targetPc;
                }
            }
        }

        for (int i = labeledBlockStack.size() - 1; i >= 0; i--) {
            int[] entry = labeledBlockStack.get(i);
            String blockLabel = code.stringPool[entry[0]];
            if (matchesInterpreterControlBlock(flow, blockLabel)) {
                while (labeledBlockStack.size() > i) {
                    labeledBlockStack.removeLast();
                }
                registers[resultReg] = consumedControlFlowResult(context);
                return entry[1];
            }
        }
        return -1;
    }

    private static RuntimeList execute(SuspendedInterpreterFrame frame) {
        InterpretedCode code = frame.code;
        int callContext = frame.callContext;
        // Track interpreter state for stack traces
        String framePackageName = code.packageName != null ? code.packageName : "main";
        if (code.isQuotedRegexCallback) {
            String callbackPackage = PerlRuntime.current().executionState()
                    .activeRegexCallbackPackages.peek();
            if (callbackPackage != null && !callbackPackage.isEmpty()) {
                framePackageName = callbackPackage;
            }
        }
        // Prefer code.subName (set by set_subname) over passed subroutineName
        // This ensures caller() returns the name set by set_subname()
        String frameSubName = code.subName != null ? code.subName
                : (frame.subroutineName != null ? frame.subroutineName : "(eval)");
        // Get PC holder for direct updates (avoids ThreadLocal lookups in hot loop)
        int[] pcHolder = InterpreterState.push(code, framePackageName, frameSubName);

        RuntimeBase[] registers = frame.registers;
        int pc = frame.pc;
        // Tight bytecode loops can otherwise execute only GOTO instructions and
        // never reach an operation that polls for queued Perl signals.  Poll on
        // a modest instruction cadence so alarm handlers run without making the
        // no-signal fast path part of every dispatch.
        int signalPollCountdown = 256;
        final int[] bytecode = code.bytecode;
        String savedRuntimeWarningBits = WarningBitsRegistry.getRuntimeWarningBits();
        Set<String> savedRuntimeDisabledWarningCategories =
                WarningBitsRegistry.getRuntimeDisabledWarningCategories();
        WarningBitsRegistry.setRuntimeWarningBits(
                frame.pc > 0 ? frame.suspendedRuntimeWarningBits : code.warningBitsString);
        WarningBitsRegistry.setRuntimeDisabledWarningCategories(
                frame.pc > 0
                        ? frame.suspendedRuntimeDisabledWarningCategories
                        : savedRuntimeDisabledWarningCategories);

        // Eval block exception handling: stack of catch PCs
        // When EVAL_TRY is executed, push the catch PC onto this stack
        // When exception occurs, pop from stack and jump to catch PC
        // Use ArrayDeque instead of Stack for better performance (no synchronization)
        java.util.ArrayDeque<Integer> evalCatchStack = frame.evalCatchStack;
        java.util.ArrayDeque<Boolean> evalCallerFrameStack = frame.evalCallerFrameStack;

        // Parallel stack tracking the frame-relative DynamicVariableManager level at
        // eval entry. A suspended frame can resume from a Future callback whose
        // dynamic stack has a different absolute depth, so absolute levels cannot be
        // retained across AWAIT_WAIT. On eval exit (both normal EVAL_END and exception
        // catch), add savedLocalLevel to restore the invocation-relative level.
        java.util.ArrayDeque<Integer> evalLocalLevelStack = frame.evalLocalLevelStack;

        // Parallel stack tracking the first register allocated inside the eval body.
        // When an exception is caught, my-variable registers from this index onward
        // receive scope cleanup so DESTROY fires for lexicals that went out of scope.
        // Expression temporaries must not be cleaned as lexicals: a temporary may be
        // a CODE ref loaded from the stash, and scopeExitCleanup would release that
        // installed subroutine's captures.
        java.util.ArrayDeque<Integer> evalBaseRegStack = frame.evalBaseRegStack;

        // Parallel eval stack for chained method-invocant holds. A method-chain
        // temporary is evaluated before the outer call's arguments and must remain
        // alive while those arguments run tied FETCH/DESTROY code. Eval exceptions
        // unwind only holds acquired inside that eval, preserving an enclosing call.
        java.util.ArrayDeque<Integer> evalMethodInvocantHoldDepthStack =
                frame.evalMethodInvocantHoldDepthStack;
        java.util.ArrayList<RuntimeBase> methodInvocantHolds = frame.methodInvocantHolds;

        // Interpreted eval BLOCKs execute inline, so caller() needs a virtual
        // frame for each active EVAL_TRY. Track the depth explicitly so normal,
        // exceptional, and non-local exits all unwind the synthetic frames.
        // Labeled block stack for non-local last/next/redo handling.
        // When a function call returns a RuntimeControlFlowList, we check this stack
        // to see if the label matches an enclosing labeled block.
        // Uses ArrayList for O(1) indexed access when searching for labels
        java.util.ArrayList<int[]> labeledBlockStack = frame.labeledBlockStack;
        // Each entry is [labelStringPoolIdx, exitPc]

        // Each entry is [labelStringPoolIdx, lastPc, nextPc, redoPc].  Unlike
        // the label stack this records the real runtime loop nesting, so a
        // marker returned from a nested closure can resume the correct loop.
        java.util.ArrayList<int[]> controlBlockStack = frame.controlBlockStack;

        java.util.ArrayDeque<RegexState> regexStateStack = frame.regexStateStack;

        // Only ordinary localized variables are conditional. Regex capture variables
        // ($1, $&, @-, etc.) are dynamically scoped for every subroutine call, even
        // when the callee does not use `local`.
        // Record DVM level so the finally block can clean up everything pushed
        // by this subroutine (local variables AND regex state snapshot).
        int savedLocalLevel = DynamicVariableManager.getLocalLevel();
        if (frame.suspendedDynamicStates != null) {
            DynamicVariableManager.resumeSuspended(frame.suspendedDynamicStates);
            frame.suspendedDynamicStates = null;
        }
        // Cache the currentPackage RuntimeScalar to avoid ThreadLocal lookups in hot loop
        RuntimeScalar currentPackageScalar = InterpreterState.currentPackage.get();
        String savedPackage = currentPackageScalar.toString();
        RegexState.save();
        if (frame.suspendedRegexState != null) {
            frame.suspendedRegexState.restore();
        }
        currentPackageScalar.set(frame.suspendedPackage != null
                ? frame.suspendedPackage : framePackageName);
        frame.suspended = false;
        if (frame.pc > 0 && !frame.evalCatchStack.isEmpty()) {
            RuntimeCode.adjustEvalDepth(frame.evalCatchStack.size());
            for (java.util.Iterator<Boolean> it = frame.evalCallerFrameStack.descendingIterator(); it.hasNext(); ) {
                boolean visibleEvalFrame = it.next();
                if (visibleEvalFrame && InterpreterState.pushEvalFrameForCurrentInterpreter()) {
                    frame.virtualEvalFrameDepth++;
                }
            }
        }

        // First my-variable register index (skip reserved + captured vars).
        int firstMyVarReg = 3 + (code.capturedVars != null ? code.capturedVars.length : 0);

        // Track closures created by CREATE_CLOSURE in this frame.
        // At frame exit, we release captures for closures that were never stored
        // via set() (refCount stayed at 0). This handles eval STRING map/grep
        // block closures that over-capture all visible variables but are temporary.
        // This matches the JVM-compiled path where scopeExitCleanup releases
        // captures for CODE refs with refCount=0 (RuntimeScalar.java line ~2185).
        java.util.List<RuntimeCode> createdClosures = frame.createdClosures;

        // Scope-exit cleanup emitted by BytecodeCompiler is bracketed by
        // MORTAL_PUSH_MARK / MORTAL_POP_FLUSH. Defer unregister/null-store
        // until the POP so interpreted code matches the JVM backend:
        // cleanup all lexicals first, unregister/null them second, then flush.
        java.util.ArrayDeque<java.util.ArrayList<Integer>> scopeCleanupBatches =
                frame.scopeCleanupBatches;

        // Structure: try { while(true) { try { ...dispatch... } catch { handle eval/die } } } finally { cleanup }
        //
        // Outer try/finally — cleanup only, no catch.
        //   Restores local variables, package name, and call stack on ANY exit (return, throw, etc.)
        //
        // Inner try/catch — implements Perl's eval { BLOCK } / die semantics.
        //   When Perl code calls `die` inside `eval { ... }`, the catch block sets $@ and
        //   uses `continue outer` to jump back to the top of the while(true) loop, resuming
        //   the bytecode dispatch at the eval's catch target PC. Without the while(true),
        //   `continue` would have nowhere to go after the catch block.
        try {
            outer:
            while (true) {
                try {
                    if (frame.resumeException != null) {
                        Throwable resumeException = frame.resumeException;
                        frame.resumeException = null;
                        if (resumeException instanceof RuntimeException runtimeException) {
                            throw runtimeException;
                        }
                        if (resumeException instanceof Error error) {
                            throw error;
                        }
                        throw new RuntimeException(resumeException);
                    }
                    // Main dispatch loop - JVM JIT optimizes switch to tableswitch (O(1) jump)
                    while (pc < bytecode.length) {
                        if (--signalPollCountdown <= 0) {
                            signalPollCountdown = 256;
                            PerlSignalQueue.checkPendingSignals();
                        }
                        // Update current PC for caller()/stack trace reporting.
                        // This allows ExceptionFormatter to map pc->tokenIndex->line using code.errorUtil,
                        // which also honors #line directives inside eval strings.
                        // Uses cached pcHolder to avoid ThreadLocal lookups in hot loop.
                        pcHolder[0] = pc;
                        int opcode = bytecode[pc++];

                        switch (opcode) {
                            // =================================================================
                            // CONTROL FLOW
                            // =================================================================

                            case Opcodes.NOP -> {
                                // No operation
                            }

                            case Opcodes.MORTAL_FLUSH -> {
                                // Statement-boundary FREETMPS for the current function scope.
                                MortalList.flushAboveMark();
                            }

                            case Opcodes.MORTAL_PUSH_MARK -> {
                                // Push mark before scope-exit cleanup (SAVETMPS equivalent)
                                MortalList.pushMark();
                                scopeCleanupBatches.push(new java.util.ArrayList<>());
                            }

                            case Opcodes.MORTAL_POP_FLUSH -> {
                                if (!scopeCleanupBatches.isEmpty()) {
                                    for (int cleanupReg : scopeCleanupBatches.pop()) {
                                        RuntimeBase slot = registers[cleanupReg];
                                        MyVarCleanupStack.unregister(slot);
                                        registers[cleanupReg] = null;
                                    }
                                }
                                // Pop mark and flush only entries added since it (scoped FREETMPS)
                                MortalList.popAndFlush();
                            }

                            case Opcodes.SCOPE_EXIT_CLEANUP -> {
                                // Scope-exit cleanup for a my-scalar register.
                                //
                                // Root cause for the defensive `instanceof` check
                                // below: a my-scalar declared inside a
                                // short-circuiting expression
                                //   if (COND_A and COND_B and defined((my $x = ...)->{k})) {...}
                                // may never run its MY_SCALAR initialisation if
                                // COND_A or COND_B short-circuits. The compiler
                                // has already allocated a register for `$x`, but
                                // that register may be holding a temp value left
                                // over from an earlier statement (e.g. a
                                // CREATE_LIST result from an unrelated block
                                // whose register was later recycled). When the
                                // enclosing scope exits, SCOPE_EXIT_CLEANUP runs
                                // on `$x`'s register and finds a non-scalar.
                                //
                                // This is safe to ignore because the user never
                                // observes `$x` in that short-circuit path (their
                                // code is inside the same block and also skipped).
                                // `scopeExitCleanup` only has work to do on real
                                // RuntimeScalars (IO-owner fd recycling,
                                // refCount decrement for blessed refs with
                                // DESTROY, and captureCount tracking for
                                // closures); a non-scalar slot simply has no
                                // cleanup obligation.
                                int reg = bytecode[pc++];
                                RuntimeBase slot = registers[reg];
                                if (slot instanceof RuntimeScalar rs) {
                                    RuntimeScalar.scopeExitCleanup(rs);
                                }
                                if (!scopeCleanupBatches.isEmpty()) {
                                    scopeCleanupBatches.peek().add(reg);
                                } else {
                                    MyVarCleanupStack.unregister(slot);
                                    registers[reg] = null;
                                }
                            }

                            case Opcodes.UNBIND_ACTIVE_LEXICAL -> {
                                int reg = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                code.unbindActiveLexical(code.stringPool[nameIdx], registers[reg]);
                            }

                            case Opcodes.RETURN_SCOPE_CLEANUP -> {
                                int reg = bytecode[pc++];
                                int returnReg = bytecode[pc++];
                                RuntimeBase slot = registers[reg];
                                if (slot instanceof RuntimeScalar rs) {
                                    RuntimeScalar.releaseOrTransferSocketIoOwnerOnReturn(
                                            rs, registers[returnReg]);
                                    MortalList.deferDecrementIfNotCaptured(rs);
                                }
                            }

                            case Opcodes.SCOPE_EXIT_CLEANUP_HASH -> {
                                // Scope-exit cleanup for a my-hash register.
                                //
                                // !!! DO NOT REMOVE THE `instanceof` CHECK BELOW !!!
                                //
                                // Reverting to a blind `(RuntimeHash) registers[reg]`
                                // cast WILL bring back the bug fixed by this code:
                                // a `ClassCastException: RuntimeScalar cannot be
                                // cast to RuntimeHash` thrown at scope/sub exit.
                                //
                                // Why a register slot for a `my %h` can hold a
                                // RuntimeScalar:
                                //
                                //   1. The JIT (JVM) backend can fall back to the
                                //      bytecode interpreter for individual subs
                                //      that use features it doesn't support — e.g.
                                //      dynamic `goto $coderef` / `goto \&sub`. See
                                //      SubroutineParser interpreter-fallback path
                                //      and JPERL_SHOW_FALLBACK=1 for diagnostics.
                                //
                                //   2. The same register file is shared across
                                //      every basic block in the sub. The compiler
                                //      reuses (recycles) registers between
                                //      independent statements, so a slot that the
                                //      compiler later reserves for `my %h` may
                                //      previously have been used as the
                                //      destination of an unrelated CREATE_LIST,
                                //      assignment or arithmetic op which leaves a
                                //      RuntimeScalar in it.
                                //
                                //   3. Any control-flow path that *skips* the
                                //      MY_HASH initialisation for that slot
                                //      (e.g. an early `return`, `last`, `goto`,
                                //      or a short-circuited `&&`/`||` guarding
                                //      the `my %h = (...)` declaration) will
                                //      leave the stale RuntimeScalar behind.
                                //
                                //   4. SCOPE_EXIT_CLEANUP_HASH runs
                                //      unconditionally for every declared
                                //      my-hash, regardless of whether step 3 was
                                //      taken. With a blind cast this throws
                                //      ClassCastException and unwinds out of the
                                //      sub even when the user's logic completed
                                //      normally.
                                //
                                // Why ignoring the slot is correct:
                                //
                                //   The user can never have observed `%h` on a
                                //   path that skipped its initialisation, so
                                //   there is nothing user-visible to clean up.
                                //   `MortalList.scopeExitCleanupHash` only has
                                //   real work to do on actual RuntimeHash
                                //   instances (releasing tied magic, decrementing
                                //   tracked-element ref counts, etc.); a non-hash
                                //   slot simply has no cleanup obligation.
                                //
                                // Minimal regression test (must keep passing):
                                //
                                //   sub t {
                                //       my %h = (a=>1);   # SCOPE_EXIT_CLEANUP_HASH emitted
                                //       print "ok\n";
                                //       return;            # exits before goto -> JIT fallback
                                //       my $f = sub {1};
                                //       goto $f;           # forces interpreter fallback
                                //   }
                                //   t();
                                //
                                // Originally surfaced by `use Moose;` ->
                                // Sub::Exporter::Progressive::import (uses
                                // `goto \&Exporter::import`).
                                int reg = bytecode[pc++];
                                RuntimeBase slot = registers[reg];
                                if (slot instanceof RuntimeHash rh) {
                                    MortalList.scopeExitCleanupHash(rh);
                                }
                                if (!scopeCleanupBatches.isEmpty()) {
                                    scopeCleanupBatches.peek().add(reg);
                                } else {
                                    MyVarCleanupStack.unregister(slot);
                                    registers[reg] = null;
                                }
                            }

                            case Opcodes.RETURN_SCOPE_CLEANUP_HASH -> {
                                int reg = bytecode[pc++];
                                RuntimeBase slot = registers[reg];
                                if (slot instanceof RuntimeHash rh) {
                                    MortalList.scopeExitCleanupHash(rh);
                                }
                            }

                            case Opcodes.SCOPE_EXIT_CLEANUP_ARRAY -> {
                                // Scope-exit cleanup for a my-array register.
                                //
                                // !!! DO NOT REMOVE THE `instanceof` CHECK BELOW !!!
                                //
                                // See the long comment on SCOPE_EXIT_CLEANUP_HASH
                                // above — the exact same reasoning applies here,
                                // just with RuntimeArray instead of RuntimeHash.
                                // Reverting to a blind `(RuntimeArray) registers[reg]`
                                // cast will reintroduce ClassCastException at
                                // sub/scope exit for any my-array whose
                                // initialisation was skipped by control flow on
                                // an interpreter-fallback sub.
                                //
                                // Minimal regression test (must keep passing):
                                //
                                //   sub t {
                                //       my @a = ('x');     # SCOPE_EXIT_CLEANUP_ARRAY emitted
                                //       print "ok\n";
                                //       return;
                                //       my $f = sub {1};
                                //       goto $f;            # forces JIT->interpreter fallback
                                //   }
                                //   t();
                                int reg = bytecode[pc++];
                                RuntimeBase slot = registers[reg];
                                if (slot instanceof RuntimeArray ra) {
                                    MortalList.scopeExitCleanupArray(ra);
                                }
                                if (!scopeCleanupBatches.isEmpty()) {
                                    scopeCleanupBatches.peek().add(reg);
                                } else {
                                    MyVarCleanupStack.unregister(slot);
                                    registers[reg] = null;
                                }
                            }

                            case Opcodes.RETURN_SCOPE_CLEANUP_ARRAY -> {
                                int reg = bytecode[pc++];
                                int returnReg = bytecode[pc++];
                                RuntimeBase slot = registers[reg];
                                if (slot instanceof RuntimeArray ra) {
                                    MortalList.scopeExitCleanupArray(ra, registers[returnReg]);
                                }
                            }

                            case Opcodes.RETURN -> {
                                // Return from subroutine: return rd
                                int retReg = bytecode[pc++];
                                RuntimeBase retVal = registers[retReg];

                                if (retVal == null) {
                                    retVal = new RuntimeList();
                                }
                                // A switch-only control is normalized to a
                                // NEXT/LAST marker.  It must fail at the eval
                                // boundary rather than return from the whole
                                // interpreter frame and bypass EVAL_CATCH.
                                if (retVal instanceof RuntimeControlFlowList flow
                                        && flow.isSwitchControl() && !evalCatchStack.isEmpty()) {
                                    GlobalVariable.setGlobalVariable(
                                            "main::@", flow.marker.buildErrorMessage() + ".\n");
                                    if (!evalLocalLevelStack.isEmpty()) {
                                        int relativeLevel = evalLocalLevelStack.pop();
                                        DynamicVariableManager.popToLocalLevel(
                                                savedLocalLevel + relativeLevel);
                                    }
                                    unwindEvalMethodInvocantHolds(
                                            evalMethodInvocantHoldDepthStack, methodInvocantHolds);
                                    pc = evalCatchStack.pop();
                                    RuntimeCode.decrementEvalDepth();
                                    popEvalCallerFrame(frame);
                                    break;
                                }
                                RuntimeCode.requireInterpreterLvalueReturn(code, retVal, callContext);
                                RuntimeList retList = RuntimeCode.returnList(
                                        retVal, callContext, !RuntimeCode.isLvalueCode(code));
                                RuntimeCode.materializeSpecialVarsInResult(
                                        retList, RuntimeCode.currentRawCallContext());
                                frame.returnedClosures = collectReturnedClosures(retList);
                                if (!returnListContainsTrackedReference(retList)) {
                                    MortalList.flushAboveMark();
                                }

                                return retList;
                            }

                            case Opcodes.RETURN_NONLOCAL -> {
                                // Non-local return from map/grep block (explicit 'return' statement):
                                // wrap in RETURN marker so it propagates to enclosing subroutine
                                int retReg = bytecode[pc++];
                                RuntimeBase retVal = registers[retReg];

                                if (retVal == null) {
                                    retVal = new RuntimeList();
                                }
                                RuntimeList retList = RuntimeCode.returnList(
                                        retVal, callContext, !RuntimeCode.isLvalueCode(code));
                                RuntimeCode.materializeSpecialVarsInResult(
                                        retList, RuntimeCode.currentRawCallContext());
                                frame.returnedClosures = collectReturnedClosures(retList);

                                return new RuntimeControlFlowList(retList, code.sourceName, code.sourceLine);
                            }

                            case Opcodes.GOTO -> {
                                // Unconditional jump: pc = offset
                                int offset = readInt(bytecode, pc);
                                enterGotoLabelPackage(code, offset);
                                pc = offset;  // Registers persist across jump (unlike stack-based!)
                            }

                            case Opcodes.GOTO_DYNAMIC -> {
                                // Dynamic goto: evaluate register to get label name, look up PC
                                int rs = bytecode[pc++];
                                int evalScopeIdx = bytecode[pc++];
                                String evalScope = evalScopeIdx >= 0 ? code.stringPool[evalScopeIdx] : null;
                                RuntimeScalar target = (RuntimeScalar) registers[rs];
                                if (target.type == RuntimeScalarType.TIED_SCALAR) {
                                    target = target.tiedFetch();
                                }
                                // While DB::sub is running, its public
                                // $DB::sub value is a debugger-visible name.
                                // `goto $DB::sub` must still tail-call the
                                // lexical CV behind that name.
                                RuntimeScalar debuggerTarget = DebugHooks.debuggerTargetCode(target);
                                if (debuggerTarget != null) {
                                    target = debuggerTarget;
                                }
                                // Dereference if target is a reference to CODE (e.g., goto \&sub)
                                if (target.type == RuntimeScalarType.REFERENCE) {
                                    RuntimeScalar deref = (RuntimeScalar) target.value;
                                    if (deref.type == RuntimeScalarType.CODE) {
                                        target = deref;
                                    }
                                }
                                // If target is a CODE reference, treat as goto &sub (tail call)
                                ErrorMessageUtil.SourceLocation gotoLocation =
                                        InlineOpcodeHandler.sourceLocation(code, pcHolder[0]);
                                if (target.type == RuntimeScalarType.CODE) {
                                    // Create a TAILCALL marker - pass current @_ (register 1)
                                    RuntimeArray currentArgs = registers[1].getTailCallArrayOfAlias();
                                    RuntimeControlFlowList marker = new RuntimeControlFlowList(
                                            target, currentArgs, gotoLocation.fileName(), gotoLocation.lineNumber(),
                                            evalScope);
                                    if (evalScope != null) {
                                        RuntimeCode.resolveTailCalls(marker, callContext);
                                    }
                                    return marker;
                                }
                                String labelName = target.toString();
                                if (labelName.startsWith("\u0000invalid-goto-into-foreach:")) {
                                    throw new PerlCompilerException(
                                            "Can't \"goto\" into the middle of a foreach loop");
                                }
                                if (labelName.startsWith("\u0000invalid-goto-into-construct:")) {
                                    throw new PerlCompilerException(
                                            "Use of \"goto\" to jump into a construct is no longer permitted");
                                }
                                if (labelName.isEmpty()) {
                                    // Bare `goto` without label - runtime error like Perl 5
                                    throw new PerlCompilerException("goto must have label");
                                }
                                rejectGotoIntoGiven(code, labelName);
                                if (!org.perlonjava.runtime.runtimetypes.DynamicVariableManager.isExecutingDefer()
                                        && code.gotoLabelsInsideDefer != null
                                        && code.gotoLabelsInsideDefer.contains(labelName)) {
                                    throw new PerlCompilerException("Can't \"goto\" into a \"defer\" block at "
                                            + code.sourceName + " line " + code.sourceLine + ".\n");
                                }
                                if (code.gotoLabelPcs != null) {
                                    Integer targetPc = code.gotoLabelPcs.get(labelName);
                                    if (targetPc != null) {
                                        if (jumpsIntoUnenteredLoopBody(code, labelName, targetPc, pc)) {
                                            throw new PerlCompilerException(
                                                    "Can't \"goto\" into the middle of a foreach loop");
                                        }
                                        if (code.gotoLabelsInsideConstruct != null
                                                && code.gotoLabelsInsideConstruct.contains(labelName)) {
                                            throw new PerlCompilerException(
                                                    "Use of \"goto\" to jump into a construct is no longer permitted");
                                        }
                                        enterGotoLabelPackage(code, targetPc);
                                        pc = targetPc;
                                        break;
                                    }
                                }
                                // Parser-attached statement labels can be classified as
                                // loop-body labels before they acquire an executable PC.
                                // Preserve the foreach-entry diagnostic when no target PC
                                // is available to establish that this jump is already inside.
                                if (code.gotoLabelsInsideLoop != null
                                        && code.gotoLabelsInsideLoop.contains(labelName)) {
                                    throw new PerlCompilerException(
                                            "Can't \"goto\" into the middle of a foreach loop");
                                }
                                if (code.isSortComparator) {
                                    throw new PerlCompilerException(
                                            "Can't \"goto\" out of a pseudo block at "
                                            + gotoLocation.fileName() + " line " + gotoLocation.lineNumber() + ".\n");
                                }
                                // Label not found locally - create GOTO marker and propagate
                                RuntimeControlFlowList marker = new RuntimeControlFlowList(
                                        ControlFlowType.GOTO, labelName, gotoLocation.fileName(), gotoLocation.lineNumber(),
                                        evalScope);
                                // A missing label is a runtime error caught by the innermost
                                // eval BLOCK. Returning the marker here bypasses this frame's
                                // eval handler when the frame itself was entered by eval STRING.
                                if (!evalCatchStack.isEmpty()) {
                                    throw new PerlCompilerException(marker.marker.buildErrorMessage());
                                }
                                return marker;
                            }

                            case Opcodes.LAST, Opcodes.NEXT, Opcodes.REDO -> {
                                // Loop control: jump to target PC
                                // Format: opcode, target (absolute PC as int)
                                int target = readInt(bytecode, pc);
                                releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
                                pc = target;
                            }

                            case Opcodes.GOTO_IF_FALSE -> {
                                // Conditional jump: if (!rs) pc = offset
                                int condReg = bytecode[pc++];
                                int target = readInt(bytecode, pc);
                                pc += 1;

                                // Convert to scalar if needed for boolean test
                                RuntimeScalar cond = conditionScalar(registers[condReg]);

                                if (!cond.getBoolean()) {
                                    pc = target;  // Jump - all registers stay valid!
                                }
                            }

                            case Opcodes.GOTO_IF_TRUE -> {
                                // Conditional jump: if (rs) pc = offset
                                int condReg = bytecode[pc++];
                                int target = readInt(bytecode, pc);
                                pc += 1;

                                // Convert to scalar if needed for boolean test
                                RuntimeScalar cond = conditionScalar(registers[condReg]);

                                if (cond.getBoolean()) {
                                    pc = target;
                                }
                            }

                            case Opcodes.GOTO_IF_FALSE_NO_OVERLOAD -> {
                                int condReg = bytecode[pc++];
                                int target = readInt(bytecode, pc);
                                pc += 1;
                                RuntimeScalar cond = conditionScalar(registers[condReg]);
                                if (!cond.getBooleanNoOverload()) {
                                    pc = target;
                                }
                            }

                            case Opcodes.GOTO_IF_TRUE_NO_OVERLOAD -> {
                                int condReg = bytecode[pc++];
                                int target = readInt(bytecode, pc);
                                pc += 1;
                                RuntimeScalar cond = conditionScalar(registers[condReg]);
                                if (cond.getBooleanNoOverload()) {
                                    pc = target;
                                }
                            }

                            // =================================================================
                            // REGISTER OPERATIONS
                            // =================================================================

                            case Opcodes.ALIAS -> {
                                // Register alias: rd = rs (shares reference, does NOT copy value)
                                // Must unwrap RuntimeScalarReadOnly to prevent read-only values in variable registers
                                int dest = bytecode[pc++];
                                int src = bytecode[pc++];
                                RuntimeBase srcVal = registers[src];
                                registers[dest] = isImmutableProxy(srcVal) ? ensureMutableScalar(srcVal) : srcVal;
                            }

                            case Opcodes.ALIAS_LVALUE_REFERENCE -> {
                                int target = bytecode[pc++];
                                int reference = bytecode[pc++];
                                registers[target] = registers[target].getFirst()
                                        .aliasLvalueReference(registers[reference].getFirst());
                            }

                            case Opcodes.ALIAS_AGGREGATE_LVALUE_REFERENCE -> {
                                int target = bytecode[pc++];
                                int reference = bytecode[pc++];
                                boolean hashTarget = bytecode[pc++] != 0;
                                registers[target] = registers[target].getFirst()
                                        .aliasAggregateLvalueReference(
                                                registers[reference].getFirst(), hashTarget);
                            }

                            case Opcodes.ALIAS_GLOBAL_SCALAR -> {
                                int nameIdx = bytecode[pc++];
                                int scalarReg = bytecode[pc++];
                                GlobalVariable.aliasGlobalVariable(code.stringPool[nameIdx],
                                        registers[scalarReg].getFirst());
                            }

                            case Opcodes.ALIAS_GLOBAL_ARRAY -> {
                                int nameIdx = bytecode[pc++];
                                int arrayReg = bytecode[pc++];
                                GlobalVariable.aliasGlobalArray(code.stringPool[nameIdx],
                                        (RuntimeArray) registers[arrayReg]);
                            }

                            case Opcodes.ALIAS_GLOBAL_HASH -> {
                                int nameIdx = bytecode[pc++];
                                int hashReg = bytecode[pc++];
                                GlobalVariable.aliasGlobalHash(code.stringPool[nameIdx],
                                        (RuntimeHash) registers[hashReg]);
                            }

                            case Opcodes.LOAD_CONST -> {
                                // Load from constant pool: rd = constants[index]
                                int rd = bytecode[pc++];
                                int constIndex = bytecode[pc++];
                                registers[rd] = (RuntimeBase) code.constants[constIndex];
                            }

                            case Opcodes.REGISTER_FORMAT -> {
                                int constIndex = bytecode[pc++];
                                RuntimeFormat format = (RuntimeFormat) code.constants[constIndex];
                                GlobalVariable.warnIfFormatRedefined(format.formatName);
                                // A FORMAT slot can already be aliased through a
                                // localized typeglob.  Populate its existing
                                // RuntimeFormat object rather than replacing it.
                                RuntimeFormat target = GlobalVariable.getGlobalFormatRef(format.formatName);
                                target.replaceDefinition(format);
                                target.setLexicalDeclaringCode(RuntimeCode.getActiveCodeAt(0));
                                int captureCount = bytecode[pc++];
                                for (int capture = 0; capture < captureCount; capture++) {
                                    String name = code.stringPool[bytecode[pc++]];
                                    RuntimeBase value = registers[bytecode[pc++]];
                                    target.bindLexicalVariable(name, value);
                                    RuntimeCode.registerCurrentActiveLexical(name, value);
                                }
                            }

                            case Opcodes.LOAD_INT -> {
                                // Load integer: rd = immediate (create NEW mutable scalar, not cached)
                                int rd = bytecode[pc++];
                                int value = readInt(bytecode, pc);
                                pc += 1;
                                // Create NEW RuntimeScalar (mutable) instead of using cache
                                // This is needed for local variables that may be modified (++/--)
                                registers[rd] = new RuntimeScalar(value);
                            }

                            case Opcodes.LOAD_STRING -> {
                                int rd = bytecode[pc++];
                                int strIndex = bytecode[pc++];
                                registers[rd] = new RuntimeScalar(code.stringPool[strIndex]);
                            }

                            case Opcodes.LOAD_BYTE_STRING -> {
                                int rd = bytecode[pc++];
                                int strIndex = bytecode[pc++];
                                RuntimeScalar bs = new RuntimeScalar(code.stringPool[strIndex]);
                                bs.type = RuntimeScalarType.BYTE_STRING;
                                registers[rd] = bs;
                            }

                            case Opcodes.LOAD_VSTRING -> {
                                int rd = bytecode[pc++];
                                int strIndex = bytecode[pc++];
                                RuntimeScalar vs = new RuntimeScalar(code.stringPool[strIndex]);
                                vs.type = RuntimeScalarType.VSTRING;
                                registers[rd] = vs;
                            }

                            case Opcodes.GLOB_OP -> {
                                pc = InlineOpcodeHandler.executeGlobOp(bytecode, pc, registers);
                            }

                            case Opcodes.LOAD_UNDEF -> {
                                // Load undef: rd = new RuntimeScalar()
                                int rd = bytecode[pc++];
                                registers[rd] = new RuntimeScalar();
                            }

                            case Opcodes.LOAD_UNDEF_READONLY -> {
                                // Load the shared read-only undef singleton into rd.
                                // Used as a placeholder in list assignments like
                                // my (undef, $x) = (...), where the read-only
                                // property is what marks the slot as "skip me".
                                int rd = bytecode[pc++];
                                registers[rd] = RuntimeScalarCache.scalarUndef;
                            }

                            case Opcodes.MATERIALIZE_LEXICAL_SCALAR -> {
                                int register = bytecode[pc++];
                                // This is lexical storage, not an expression
                                // result.  Centralize the writable-cell test:
                                // a skipped declaration may inherit a pooled
                                // read-only literal through register reuse.
                                registers[register] = RuntimeScalar.materializeLexicalCell(
                                        (RuntimeScalar) registers[register]);
                            }

                            case Opcodes.INITIALIZE_LEXICAL_SCALAR -> {
                                int register = bytecode[pc++];
                                // A temporary list register can be recycled for this
                                // declaration. Only an existing scalar cell can carry a
                                // forward refalias binding; any other value is replaced by
                                // a fresh lexical scalar.
                                registers[register] = registers[register] instanceof RuntimeScalar scalar
                                        ? RuntimeScalar.initializeLexicalCell(scalar)
                                        : new RuntimeScalar();
                            }

                            case Opcodes.FOREACH_ALIAS_RETAIN -> {
                                int register = bytecode[pc++];
                                registers[register] = registers[register] instanceof RuntimeScalar scalar
                                        ? GlobalVariable.retainForeachAliasHold(scalar) : null;
                            }

                            case Opcodes.FOREACH_ALIAS_RELEASE -> {
                                int register = bytecode[pc++];
                                GlobalVariable.releaseForeachAliasHold(registers[register]);
                                registers[register] = null;
                            }

                            case Opcodes.UNDEFINE_SCALAR -> {
                                pc = InlineOpcodeHandler.executeUndefineScalar(bytecode, pc, registers);
                            }

                            case Opcodes.UNDEFINE_SCALAR_LVALUE -> {
                                // `undef EXPR` on a scalar lvalue. A stash entry is a
                                // typeglob, so undefining it empties the whole glob.
                                int rd = bytecode[pc++];
                                RuntimeGlob.undefineScalarLvalue(registers[rd]);
                            }

                            case Opcodes.MY_SCALAR -> {
                                // Lexical scalar assignment: rd = new RuntimeScalar(); rd.set(rs)
                                int rd = bytecode[pc++];
                                int rs = bytecode[pc++];
                                RuntimeScalar newScalar = new RuntimeScalar();
                                registers[rs].addToScalar(newScalar);
                                registers[rd] = newScalar;
                                MyVarCleanupStack.register(newScalar);
                            }

                            case Opcodes.REGISTER_MY_VAR -> {
                                int reg = bytecode[pc++];
                                MyVarCleanupStack.register(registers[reg]);
                            }

                            case Opcodes.APPLY_LEXICAL_ALIAS -> {
                                int reg = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                String variableName = code.stringPool[nameIdx];
                                registers[reg] = code.resolveLexicalAlias(
                                        variableName, registers[reg]);
                                if (registers[reg] instanceof RuntimeScalar scalar
                                        && variableName.startsWith("$")) {
                                    scalar.setLexicalDisplayName(variableName);
                                }
                            }

                            case Opcodes.BIND_ACTIVE_LEXICAL -> {
                                int reg = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                String variableName = code.stringPool[nameIdx];
                                code.bindActiveLexical(variableName, registers[reg]);
                                if (registers[reg] instanceof RuntimeScalar scalar
                                        && variableName.startsWith("$")) {
                                    scalar.setLexicalDisplayName(variableName);
                                }
                            }

                            // =================================================================
                            // VARIABLE ACCESS - GLOBAL
                            // =================================================================

                            case Opcodes.LOAD_GLOBAL_SCALAR -> {
                                // Load global scalar through this code's pin for the name
                                int rd = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                registers[rd] = code.scalarPin(nameIdx).scalar();
                            }

                            case Opcodes.STORE_GLOBAL_SCALAR -> {
                                // Store global scalar through this code's pin for the name
                                int nameIdx = bytecode[pc++];
                                int srcReg = bytecode[pc++];

                                // Convert to scalar if needed
                                RuntimeBase value = registers[srcReg];
                                RuntimeScalar scalarValue = value == null
                                        ? RuntimeScalarCache.scalarUndef
                                        : (value instanceof RuntimeScalar)
                                        ? (RuntimeScalar) value
                                        : value.scalar();

                                code.scalarPin(nameIdx).scalar().set(scalarValue);
                            }

                            case Opcodes.LOCAL_SCALAR_SAVE_LEVEL -> {
                                // Superinstruction: save dynamic level BEFORE makeLocal, then localize.
                                // Atomically: levelReg = getLocalLevel(), rd = makeLocal(name).
                                // The pre-push level in levelReg is used by POP_LOCAL_LEVEL after the loop.
                                int rd = bytecode[pc++];
                                int levelReg = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                String name = code.stringPool[nameIdx];

                                registers[levelReg] = new RuntimeScalar(
                                        DynamicVariableManager.getLocalLevel() - savedLocalLevel);
                                registers[rd] = GlobalRuntimeScalar.makeLocalForForeach(name);
                            }

                            case Opcodes.POP_LOCAL_LEVEL -> {
                                // Restore DynamicVariableManager to a previously saved local level.
                                // Matches JVM compiler's DynamicVariableManager.popToLocalLevel(savedLevel) call.
                                int rs = bytecode[pc++];
                                int relativeLevel = ((RuntimeScalar) registers[rs]).getInt();
                                DynamicVariableManager.popToLocalLevel(savedLocalLevel + relativeLevel);
                            }

                            case Opcodes.RESTORE_FOREACH_GLOBAL_SCALAR -> {
                                int nameIdx = bytecode[pc++];
                                int valueReg = bytecode[pc++];
                                GlobalVariable.restoreForeachGlobalVariable(
                                        code.stringPool[nameIdx], (RuntimeScalar) registers[valueReg]);
                            }

                            case Opcodes.REJECT_READONLY_CAPTURE_ASSIGNMENT ->
                                    GlobalRuntimeScalar.rejectReadonlyCaptureAssignment();

                            case Opcodes.SAVE_REGEX_STATE -> {
                                int rd = bytecode[pc++];
                                registers[rd] = new RuntimeScalar(regexStateStack.size());
                                regexStateStack.push(new RegexState());
                            }

                            case Opcodes.RESTORE_REGEX_STATE -> {
                                int rs = bytecode[pc++];
                                int savedDepth = ((RuntimeScalar) registers[rs]).getInt();
                                // A non-local jump may skip nested block
                                // teardowns. Discard those abandoned snapshots,
                                // then restore only this scope's state.
                                while (regexStateStack.size() > savedDepth + 1) {
                                    regexStateStack.pop();
                                }
                                if (regexStateStack.size() > savedDepth) {
                                    regexStateStack.pop().restore();
                                }
                            }

                            case Opcodes.RESTORE_LOOP_REGEX_STATE -> {
                                int rs = bytecode[pc++];
                                int savedDepth = ((RuntimeScalar) registers[rs]).getInt();
                                while (regexStateStack.size() > savedDepth + 1) {
                                    regexStateStack.pop();
                                }
                                if (regexStateStack.size() > savedDepth) {
                                    regexStateStack.pop().restore();
                                }
                                // Keep a fresh baseline at this loop depth so
                                // eventual loop exit restores the same state.
                                regexStateStack.push(new RegexState());
                            }

                            case Opcodes.FOREACH_GLOBAL_NEXT_OR_EXIT -> {
                                // Superinstruction: foreach loop step for a global loop variable (e.g. $_).
                                // Combines: hasNext check, next() into varReg, aliasGlobalVariable, conditional jump.
                                // Do-while layout: if hasNext jump to bodyTarget, else fall through to exit.
                                int rd = bytecode[pc++];
                                int iterReg = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                int bodyTarget = readInt(bytecode, pc);
                                pc += 1;

                                String name = code.stringPool[nameIdx];
                                RuntimeScalar iterScalar = (RuntimeScalar) registers[iterReg];
                                if (!(iterScalar.value instanceof java.util.Iterator<?>)) {
                                    throw new PerlCompilerException(!evalCatchStack.isEmpty()
                                            ? "Can't \"goto\" into the middle of a foreach loop"
                                            : "Use of \"goto\" to jump into a construct is no longer permitted");
                                }
                                @SuppressWarnings("unchecked")
                                java.util.Iterator<RuntimeScalar> iterator =
                                        (java.util.Iterator<RuntimeScalar>) iterScalar.value;

                                if (iterator.hasNext()) {
                                    // See FOREACH_NEXT_OR_EXIT above for the rationale.
                                    RuntimeScalar element = ReadOnlyAlias.forForeach(iterator.next());
                                    registers[rd] = element;
                                    GlobalVariable.aliasForeachGlobalVariable(name, element);
                                    pc = bodyTarget;  // ABSOLUTE jump back to body start
                                } else {
                                    registers[rd] = new RuntimeScalar();
                                }
                            }

                            case Opcodes.STORE_GLOBAL_ARRAY -> {
                                // Store global array: GlobalVariable.getGlobalArray(name).setFromList(list)
                                int nameIdx = bytecode[pc++];
                                int srcReg = bytecode[pc++];
                                String name = code.stringPool[nameIdx];

                                RuntimeArray globalArray = GlobalVariable.getGlobalArray(name);
                                RuntimeBase value = registers[srcReg];

                                if (value == null) {
                                    // Output disassembly around the error
                                    String disasm = Disassemble.disassemble(code);
                                    throw new PerlCompilerException("STORE_GLOBAL_ARRAY: Register r" + srcReg +
                                            " is null when storing to @" + name + " at pc=" + (pc - 3) + "\n\nDisassembly:\n" + disasm);
                                }

                                // Clear and populate the global array from the source
                                if (value instanceof RuntimeArray) {
                                    globalArray.elements.clear();
                                    globalArray.elements.addAll(((RuntimeArray) value).elements);
                                } else if (value instanceof RuntimeList) {
                                    globalArray.setFromList((RuntimeList) value);
                                } else {
                                    globalArray.setFromList(value.getList());
                                }
                            }

                            case Opcodes.STORE_GLOBAL_HASH -> {
                                // Store global hash: GlobalVariable.getGlobalHash(name).setFromList(list)
                                int nameIdx = bytecode[pc++];
                                int srcReg = bytecode[pc++];
                                String name = code.stringPool[nameIdx];

                                RuntimeHash globalHash = GlobalVariable.getGlobalHash(name);
                                RuntimeBase value = registers[srcReg];

                                // Clear and populate the global hash from the source
                                if (value instanceof RuntimeHash) {
                                    globalHash.elements.clear();
                                    globalHash.elements.putAll(((RuntimeHash) value).elements);
                                } else if (value instanceof RuntimeList) {
                                    globalHash.setFromList((RuntimeList) value);
                                } else {
                                    globalHash.setFromList(value.getList());
                                }
                            }

                            case Opcodes.LOAD_GLOBAL_ARRAY -> {
                                // Load global array: rd = GlobalVariable.getGlobalArray(name)
                                int rd = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                String name = code.stringPool[nameIdx];
                                registers[rd] = GlobalVariable.getGlobalArray(name);
                            }

                            case Opcodes.LOAD_GLOBAL_HASH -> {
                                // Load global hash: rd = GlobalVariable.getGlobalHash(name)
                                int rd = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                String name = code.stringPool[nameIdx];
                                registers[rd] = GlobalVariable.getGlobalHash(name);
                            }

                            case Opcodes.LOAD_GLOBAL_CODE -> {
                                // Load global code: rd = GlobalVariable.getGlobalCodeRef(name)
                                int rd = bytecode[pc++];
                                int nameIdx = bytecode[pc++];
                                String name = code.stringPool[nameIdx];
                                if (name.equals("__SUB__")) {
                                    // __SUB__ returns the current subroutine being executed
                                    RuntimeScalar selfReference = code.__SUB__;
                                    if (code.isQuotedRegexCallback) {
                                        // A qr// callback is compiled once but can be invoked by
                                        // different enclosing CVs.  At execution time the active
                                        // stack is [callback, enclosing, ...], so derive __SUB__
                                        // from the current owner rather than retaining the owner
                                        // from the first match.
                                        RuntimeCode enclosing = RuntimeCode.getActiveCodeAt(1);
                                        if (enclosing != null) {
                                            selfReference = enclosing.__SUB__ != null
                                                    ? enclosing.__SUB__
                                                    : new RuntimeScalar(enclosing);
                                        }
                                    }
                                    registers[rd] = RuntimeCode.selfReferenceMaybeNull(selfReference);
                                } else if (name.equals("__CLASS__")) {
                                    registers[rd] = RuntimeCode.currentClassName();
                                } else {
                                    registers[rd] = GlobalVariable.getGlobalCodeRefForDirectCall(name);
                                }
                            }

                            case Opcodes.STORE_GLOBAL_CODE -> {
                                // Store global code: GlobalVariable.globalCodeRefs.put(name, codeRef)
                                int nameIdx = bytecode[pc++];
                                int codeReg = bytecode[pc++];
                                String name = code.stringPool[nameIdx];
                                RuntimeScalar codeRef = (RuntimeScalar) registers[codeReg];
                                // Store the code reference in the global namespace
                                GlobalVariable.globalCodeRefs.put(name, codeRef);
                            }

                            case Opcodes.UNDEFINE_GLOBAL_CODE -> {
                                int nameIdx = bytecode[pc++];
                                GlobalVariable.undefineVisibleGlobalCodeRef(code.stringPool[nameIdx]);
                            }

                            case Opcodes.UNDEFINE_CODE_REF -> {
                                int codeRefReg = bytecode[pc++];
                                RuntimeCode.undefineCodeReference((RuntimeScalar) registers[codeRefReg]);
                            }

                            case Opcodes.CREATE_CLOSURE -> {
                                // Create closure with captured variables
                                // Format: CREATE_CLOSURE rd template_idx num_captures reg1 reg2 ...
                                int closureRd = bytecode[pc]; // peek at destination register
                                pc = OpcodeHandlerExtended.executeCreateClosure(bytecode, pc, registers, code);
                                // Track closure for frame-exit capture release.
                                // The interpreter's BytecodeCompiler captures ALL visible
                                // variables for closures (for eval STRING compatibility),
                                // inflating captureCount on variables the closure doesn't
                                // actually use. When the closure is temporary (map/grep
                                // block), releaseCaptures must fire to decrement captureCount.
                                RuntimeBase closureVal = registers[closureRd];
                                if (closureVal instanceof RuntimeScalar crs
                                        && crs.value instanceof RuntimeCode ic
                                        && (ic.capturedScalars != null
                                                || ic.capturedAggregates != null)) {
                                    createdClosures.add(ic);
                                }
                                if (closureVal instanceof RuntimeScalar crs
                                        && crs.value instanceof RuntimeCode ic) {
                                    RuntimeCode.emitDeferredClosureWarning(crs,
                                            ic.deferredClosureWarning,
                                            ic.deferredClosureWarningLocation);
                                    RuntimeCode.throwDeferredConstantCvError(crs,
                                            ic.deferredConstantCvError);
                                }
                            }

                            case Opcodes.SET_SCALAR -> {
                                // Set scalar value: registers[rd] = registers[rs]
                                // Use addToScalar which properly handles special variables like $&
                                // addToScalar calls getValueAsScalar() for ScalarSpecialVariable
                                int rd = bytecode[pc++];
                                int rs = bytecode[pc++];
                                RuntimeBase rdVal = registers[rd];
                                RuntimeScalar rdScalar;
                                if (rdVal == null || isImmutableProxy(rdVal)) {
                                    rdScalar = new RuntimeScalar();
                                    registers[rd] = rdScalar;
                                } else if (rdVal instanceof RuntimeScalar) {
                                    rdScalar = (RuntimeScalar) rdVal;
                                } else {
                                    rdScalar = rdVal.scalar();
                                    // Lists and other aggregate expression
                                    // results can scalarize to a cached
                                    // read-only constant. SET_SCALAR replaces
                                    // the destination register; it must not
                                    // attempt to mutate that shared constant.
                                    if (isImmutableProxy(rdScalar)) {
                                        rdScalar = new RuntimeScalar();
                                        registers[rd] = rdScalar;
                                    }
                                }
                                RuntimeScalar.assignTo(registers[rs], rdScalar);
                            }

                            case Opcodes.COPY_DO_BLOCK_RESULT -> {
                                int rd = bytecode[pc++];
                                int rs = bytecode[pc++];
                                registers[rd] = RuntimeCode.copyDoBlockListResult(registers[rs]);
                            }

                            case Opcodes.REGEX_CALLBACK -> {
                                int rd = bytecode[pc++];
                                int codeReg = bytecode[pc++];
                                int kindIdx = bytecode[pc++];
                                int packageIdx = bytecode[pc++];
                                int sourceIdx = bytecode[pc++];
                                boolean uninitializedWarningsEnabled = bytecode[pc++] != 0;
                                if (DEBUG_REGEX) {
                                    RuntimeCode callbackCode =
                                            (RuntimeCode) registers[codeReg].scalar().value;
                                    System.err.println("REGEX_CALLBACK package="
                                            + code.stringPool[packageIdx]
                                            + " codePackage=" + callbackCode.packageName
                                            + " source=" + callbackCode.cvStartFile
                                            + ":" + callbackCode.cvStartLine);
                                }
                                registers[rd] = org.perlonjava.runtime.regex.RuntimeRegexCallback.wrap(
                                        registers[codeReg].scalar(), code.stringPool[kindIdx],
                                        code.stringPool[packageIdx], code.stringPool[sourceIdx],
                                        uninitializedWarningsEnabled);
                            }

                            case Opcodes.REGEX_TEMPLATE -> {
                                int rd = bytecode[pc++];
                                int partsReg = bytecode[pc++];
                                registers[rd] = org.perlonjava.runtime.regex.RuntimeRegexTemplate.build(
                                        (RuntimeList) registers[partsReg]);
                            }

                            case Opcodes.ASSIGN_LEXICAL_SCALAR -> {
                                int rd = bytecode[pc++];
                                int rs = bytecode[pc++];
                                RuntimeBase target = registers[rd];
                                RuntimeScalar targetScalar;
                                RuntimeScalar sourceScalar = registers[rs].scalar();
                                // Undef assignment must release the value through
                                // the existing scalar cell. Replacing the cell
                                // defers weakly observed aggregate cleanup until
                                // a later sweep, after Perl code can observe it.
                                if (sourceScalar.type == RuntimeScalarType.UNDEF
                                        || lexicalAssignmentMustPreserveSlot(target)
                                        || (sourceScalar.type == RuntimeScalarType.GLOBREFERENCE
                                            && target instanceof RuntimeScalar)) {
                                    targetScalar = (RuntimeScalar) target;
                                    RuntimeScalar.assignTo(sourceScalar, targetScalar);
                                } else {
                                    RuntimeBase source = registers[rs];
                                    targetScalar = new RuntimeScalar();
                                    RuntimeScalar.assignTo(source, targetScalar);
                                    // Replacing the register object must still
                                    // release the value owned by the old lexical
                                    // slot. This is especially important for
                                    // `my $x = $object; $x = "$x"`, where a
                                    // stale owner otherwise delays DESTROY.
                                    if (target instanceof RuntimeScalar oldTarget) {
                                        MyVarCleanupStack.replace(oldTarget, targetScalar);
                                        MortalList.deferDecrementIfNotCaptured(oldTarget);
                                    }
                                    registers[rd] = targetScalar;
                                }
                            }

                            case Opcodes.RELEASE_CONSUMED_TEMP -> {
                                int tempReg = bytecode[pc++];
                                int targetReg = bytecode[pc++];
                                releaseConsumedTemp(registers[tempReg], registers[targetReg]);
                            }

                            // =================================================================
                            // ARITHMETIC OPERATORS
                            // =================================================================

                            case Opcodes.ADD_SCALAR -> {
                                pc = InlineOpcodeHandler.executeAddScalar(bytecode, pc, registers);
                            }

                            case Opcodes.ADD_SCALAR_WARN -> {
                                pc = InlineOpcodeHandler.executeAddScalarWarn(bytecode, pc, registers);
                            }

                            case Opcodes.ADD_ASSIGN_SCALAR_WARN -> {
                                pc = InlineOpcodeHandler.executeAddScalarAssignWarn(bytecode, pc, registers);
                            }

                            case Opcodes.SUB_SCALAR -> {
                                pc = InlineOpcodeHandler.executeSubScalar(bytecode, pc, registers);
                            }

                            case Opcodes.MUL_SCALAR -> {
                                pc = InlineOpcodeHandler.executeMulScalar(bytecode, pc, registers);
                            }

                            case Opcodes.DIV_SCALAR -> {
                                pc = InlineOpcodeHandler.executeDivScalar(bytecode, pc, registers);
                            }

                            case Opcodes.MOD_SCALAR -> {
                                pc = InlineOpcodeHandler.executeModScalar(bytecode, pc, registers);
                            }

                            case Opcodes.POW_SCALAR -> {
                                pc = InlineOpcodeHandler.executePowScalar(bytecode, pc, registers);
                            }

                            case Opcodes.NEG_SCALAR -> {
                                pc = InlineOpcodeHandler.executeNegScalar(bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_ADD, Opcodes.INTEGER_SUBTRACT, Opcodes.INTEGER_MULTIPLY,
                                 Opcodes.INTEGER_BITWISE_AND, Opcodes.INTEGER_BITWISE_OR,
                                 Opcodes.INTEGER_BITWISE_XOR -> {
                                pc = InlineOpcodeHandler.executeIntegerBinary(opcode, bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_NEGATE -> {
                                pc = InlineOpcodeHandler.executeIntegerNegate(bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_ADD_ASSIGN -> {
                                pc = InlineOpcodeHandler.executeIntegerArithmeticAssign(bytecode, pc, registers, 0);
                            }

                            case Opcodes.INTEGER_SUBTRACT_ASSIGN -> {
                                pc = InlineOpcodeHandler.executeIntegerArithmeticAssign(bytecode, pc, registers, 1);
                            }

                            case Opcodes.INTEGER_MULTIPLY_ASSIGN -> {
                                pc = InlineOpcodeHandler.executeIntegerArithmeticAssign(bytecode, pc, registers, 2);
                            }

                            // Arithmetic without overload dispatch (no overloading pragma)
                            case Opcodes.ADD_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executeAddNoOverload(bytecode, pc, registers);
                            }
                            case Opcodes.SUB_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executeSubNoOverload(bytecode, pc, registers);
                            }
                            case Opcodes.MUL_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executeMulNoOverload(bytecode, pc, registers);
                            }
                            case Opcodes.DIV_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executeDivNoOverload(bytecode, pc, registers);
                            }
                            case Opcodes.MOD_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executeModNoOverload(bytecode, pc, registers);
                            }
                            case Opcodes.POW_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executePowNoOverload(bytecode, pc, registers);
                            }
                            case Opcodes.NEG_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executeNegNoOverload(bytecode, pc, registers);
                            }

                            // Specialized unboxed operations (rare optimizations)
                            case Opcodes.ADD_SCALAR_INT -> {
                                pc = InlineOpcodeHandler.executeAddScalarInt(bytecode, pc, registers);
                            }

                            // =================================================================
                            // STRING OPERATORS
                            // =================================================================

                            case Opcodes.CONCAT -> {
                                pc = InlineOpcodeHandler.executeConcat(bytecode, pc, registers);
                            }

                            case Opcodes.REPEAT -> {
                                pc = InlineOpcodeHandler.executeRepeat(bytecode, pc, registers);
                            }

                            case Opcodes.LENGTH -> {
                                pc = InlineOpcodeHandler.executeLength(bytecode, pc, registers);
                            }

                            // =================================================================
                            // COMPARISON AND LOGICAL OPERATORS (opcodes 31-39) - Delegated
                            // =================================================================

                            case Opcodes.COMPARE_NUM, Opcodes.COMPARE_STR, Opcodes.EQ_NUM, Opcodes.NE_NUM,
                                 Opcodes.LT_NUM, Opcodes.GT_NUM, Opcodes.LE_NUM, Opcodes.GE_NUM, Opcodes.EQ_STR,
                                 Opcodes.NE_STR, Opcodes.EQU_STR, Opcodes.NEU_STR,
                                 Opcodes.STRICT_EQ_NUM, Opcodes.STRICT_NE_NUM,
                                 Opcodes.INTEGER_STRICT_EQ_NUM, Opcodes.INTEGER_STRICT_NE_NUM,
                                 Opcodes.NOT, Opcodes.NOT_NO_OVERLOAD -> {
                                pc = executeComparisons(opcode, bytecode, pc, registers);
                            }

                            // =================================================================
                            // TYPE AND REFERENCE OPERATORS (opcodes 102-105) - Delegated
                            // =================================================================

                            case Opcodes.DEFINED, Opcodes.DEFINED_CODE, Opcodes.DEFINED_CODE_DYNAMIC, Opcodes.EXISTS_CODE_DYNAMIC, Opcodes.DEFINED_GLOB, Opcodes.DEFINED_SCALAR_DEREF, Opcodes.REF, Opcodes.BLESS, Opcodes.BLESS_CLASS_INSTANCE, Opcodes.ISA, Opcodes.SMARTMATCH, Opcodes.INTEGER_SMARTMATCH, Opcodes.PROTOTYPE,
                                 Opcodes.QUOTE_REGEX, Opcodes.QUOTE_REGEX_O -> {
                                pc = executeTypeOps(opcode, bytecode, pc, registers, code);
                            }

                            // =================================================================
                            // ITERATOR OPERATIONS - For efficient foreach loops
                            // =================================================================

                            case Opcodes.ITERATOR_CREATE -> {
                                // Create iterator: rd = rs.iterator()
                                // Format: ITERATOR_CREATE rd rs
                                pc = OpcodeHandlerExtended.executeIteratorCreate(bytecode, pc, registers);
                            }

                            case Opcodes.ITERATOR_HAS_NEXT -> {
                                // Check iterator: rd = iterator.hasNext()
                                // Format: ITERATOR_HAS_NEXT rd iterReg
                                pc = OpcodeHandlerExtended.executeIteratorHasNext(bytecode, pc, registers);
                            }

                            case Opcodes.ITERATOR_NEXT -> {
                                // Get next element: rd = iterator.next()
                                // Format: ITERATOR_NEXT rd iterReg
                                pc = OpcodeHandlerExtended.executeIteratorNext(bytecode, pc, registers);
                            }

                            case Opcodes.FOREACH_NEXT_OR_EXIT -> {
                                // Superinstruction for foreach loops (do-while layout).
                                // Combines: hasNext check, next() call, and conditional jump to body.
                                // Format: FOREACH_NEXT_OR_EXIT rd, iterReg, bodyTarget
                                // If hasNext: rd = iterator.next(), jump to bodyTarget (backward)
                                // Else: fall through to exit (iterator exhausted)
                                int rd = bytecode[pc++];
                                int iterReg = bytecode[pc++];
                                int bodyTarget = readInt(bytecode, pc);  // Absolute target address
                                pc += 1;  // Skip the int we just read

                                RuntimeScalar iterScalar = (RuntimeScalar) registers[iterReg];
                                if (!(iterScalar.value instanceof java.util.Iterator<?>)) {
                                    throw new PerlCompilerException(!evalCatchStack.isEmpty()
                                            ? "Can't \"goto\" into the middle of a foreach loop"
                                            : "Use of \"goto\" to jump into a construct is no longer permitted");
                                }
                                @SuppressWarnings("unchecked")
                                java.util.Iterator<RuntimeScalar> iterator =
                                        (java.util.Iterator<RuntimeScalar>) iterScalar.value;

                                if (iterator.hasNext()) {
                                    // Get next element and jump back to body.
                                    // For literal rvalues (RuntimeScalarReadOnly), wrap in
                                    // ReadOnlyAlias so the loop variable can be stored as
                                    // a regular RuntimeScalar (not an "immutable proxy" the
                                    // mutating opcodes would silently strip), but mutation
                                    // attempts still throw "Modification of a read-only
                                    // value". Fixes op/ref.t 232-234, op/for.t 130-134.
                                    // Keep ScalarSpecialVariable cells live.  Foreach aliases
                                    // to match variables such as $' must observe later matches,
                                    // just like the JVM backend and Perl do.
                                    RuntimeScalar elem = ReadOnlyAlias.forForeach(iterator.next());
                                    registers[rd] = elem;
                                    pc = bodyTarget;  // ABSOLUTE jump back to body start
                                } else {
                                    registers[rd] = new RuntimeScalar();
                                }
                            }

                            // =================================================================
                            // COMPOUND ASSIGNMENT OPERATORS (with overload support)
                            // =================================================================

                            case Opcodes.SUBTRACT_ASSIGN -> {
                                // Compound assignment: rd -= rs
                                // Format: SUBTRACT_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeSubtractAssign(bytecode, pc, registers);
                            }

                            case Opcodes.MULTIPLY_ASSIGN -> {
                                // Compound assignment: rd *= rs
                                // Format: MULTIPLY_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeMultiplyAssign(bytecode, pc, registers);
                            }

                            case Opcodes.DIVIDE_ASSIGN -> {
                                // Compound assignment: rd /= rs
                                // Format: DIVIDE_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeDivideAssign(bytecode, pc, registers);
                            }

                            case Opcodes.MODULUS_ASSIGN -> {
                                // Compound assignment: rd %= rs
                                // Format: MODULUS_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeModulusAssign(bytecode, pc, registers);
                            }

                            case Opcodes.REPEAT_ASSIGN -> {
                                // Compound assignment: rd x= rs
                                // Format: REPEAT_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeRepeatAssign(bytecode, pc, registers);
                            }

                            case Opcodes.POW_ASSIGN -> {
                                // Compound assignment: rd **= rs
                                // Format: POW_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executePowAssign(bytecode, pc, registers);
                            }

                            case Opcodes.LEFT_SHIFT_ASSIGN -> {
                                // Compound assignment: rd <<= rs
                                // Format: LEFT_SHIFT_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeLeftShiftAssign(bytecode, pc, registers);
                            }

                            case Opcodes.RIGHT_SHIFT_ASSIGN -> {
                                pc = OpcodeHandlerExtended.executeRightShiftAssign(bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_LEFT_SHIFT_ASSIGN -> {
                                pc = InlineOpcodeHandler.executeIntegerLeftShiftAssign(bytecode, pc, registers);
                            }
                            case Opcodes.INTEGER_RIGHT_SHIFT_ASSIGN -> {
                                pc = InlineOpcodeHandler.executeIntegerRightShiftAssign(bytecode, pc, registers);
                            }
                            case Opcodes.INTEGER_DIV_ASSIGN -> {
                                pc = InlineOpcodeHandler.executeIntegerDivAssign(bytecode, pc, registers);
                            }
                            case Opcodes.INTEGER_MOD_ASSIGN -> {
                                pc = InlineOpcodeHandler.executeIntegerModAssign(bytecode, pc, registers);
                            }

                            case Opcodes.LOGICAL_AND_ASSIGN -> {
                                // Compound assignment: rd &&= rs (short-circuit)
                                // Format: LOGICAL_AND_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeLogicalAndAssign(bytecode, pc, registers);
                            }

                            case Opcodes.LOGICAL_OR_ASSIGN -> {
                                // Compound assignment: rd ||= rs (short-circuit)
                                // Format: LOGICAL_OR_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeLogicalOrAssign(bytecode, pc, registers);
                            }

                            case Opcodes.DEFINED_OR_ASSIGN -> {
                                // Compound assignment: rd //= rs (short-circuit)
                                // Format: DEFINED_OR_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeDefinedOrAssign(bytecode, pc, registers);
                            }

                            // =================================================================
                            // SHIFT OPERATIONS
                            // =================================================================

                            case Opcodes.LEFT_SHIFT -> {
                                pc = InlineOpcodeHandler.executeLeftShift(bytecode, pc, registers);
                            }

                            case Opcodes.RIGHT_SHIFT -> {
                                pc = InlineOpcodeHandler.executeRightShift(bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_LEFT_SHIFT -> {
                                pc = InlineOpcodeHandler.executeIntegerLeftShift(bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_RIGHT_SHIFT -> {
                                pc = InlineOpcodeHandler.executeIntegerRightShift(bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_DIV -> {
                                pc = InlineOpcodeHandler.executeIntegerDiv(bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_MOD -> {
                                pc = InlineOpcodeHandler.executeIntegerMod(bytecode, pc, registers);
                            }

                            // =================================================================
                            // ARRAY OPERATIONS
                            // =================================================================

                            case Opcodes.ARRAY_GET -> {
                                pc = InlineOpcodeHandler.executeArrayGet(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_GET_LVALUE -> {
                                pc = InlineOpcodeHandler.executeArrayGetLvalue(bytecode, pc, registers);
                            }
                            case Opcodes.ARRAY_GET_FOR_LOCAL -> {
                                pc = InlineOpcodeHandler.executeArrayGetForLocal(bytecode, pc, registers);
                            }
                            case Opcodes.ARRAY_GET_FOR_LOCAL_DEREFERENCE -> {
                                pc = InlineOpcodeHandler.executeArrayGetForLocalDereference(
                                        bytecode, pc, registers);
                            }
                            case Opcodes.ARRAY_GET_FOR_DEFINED_PROBE -> {
                                pc = InlineOpcodeHandler.executeArrayGetForDefinedProbe(
                                        bytecode, pc, registers);
                            }
                            case Opcodes.MARK_MODULE_TRUE_RETURN -> {
                                ModuleOperators.markModuleTrueReturn();
                            }
                            case Opcodes.ARRAY_KEYVALUE_SLICE -> {
                                int rd = bytecode[pc++];
                                RuntimeBase array = registers[bytecode[pc++]];
                                RuntimeList indices = (RuntimeList) registers[bytecode[pc++]];
                                if (array instanceof RuntimeScalar scalar) array = scalar.arrayDeref();
                                registers[rd] = ((RuntimeArray) array).getKeyValueSlice(indices);
                            }

                            case Opcodes.ARRAY_SET -> {
                                pc = InlineOpcodeHandler.executeArraySet(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_PUSH -> {
                                pc = InlineOpcodeHandler.executeArrayPush(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_POP -> {
                                pc = InlineOpcodeHandler.executeArrayPop(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_SHIFT -> {
                                pc = InlineOpcodeHandler.executeArrayShift(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_UNSHIFT -> {
                                pc = InlineOpcodeHandler.executeArrayUnshift(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_SIZE -> {
                                pc = InlineOpcodeHandler.executeArraySize(bytecode, pc, registers);
                            }

                            case Opcodes.SET_ARRAY_LAST_INDEX -> {
                                pc = InlineOpcodeHandler.executeSetArrayLastIndex(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_LAST_INDEX_LVALUE -> {
                                pc = InlineOpcodeHandler.executeArrayLastIndexLvalue(bytecode, pc, registers);
                            }

                            case Opcodes.CREATE_ARRAY -> {
                                pc = InlineOpcodeHandler.executeCreateArray(bytecode, pc, registers);
                            }

                            // =================================================================
                            // HASH OPERATIONS
                            // =================================================================

                            case Opcodes.HASH_GET -> {
                                pc = InlineOpcodeHandler.executeHashGet(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_GET_STRING_INTERPOLATION -> {
                                int rd = bytecode[pc++];
                                int hashReg = bytecode[pc++];
                                int keyReg = bytecode[pc++];
                                int hashNameIdx = bytecode[pc++];
                                RuntimeHash hash = (RuntimeHash) registers[hashReg];
                                RuntimeScalar key = (RuntimeScalar) registers[keyReg];
                                registers[rd] = hash.getForStringInterpolation(
                                        key, code.stringPool[hashNameIdx]);
                            }

                            case Opcodes.HASH_GET_FOR_LOCAL -> {
                                // Like HASH_GET but always returns a RuntimeHashProxyEntry.
                                // Used by local $hash{key} so the proxy can re-resolve
                                // the key in the parent hash on restore (survives %hash = (...)).
                                int rd = bytecode[pc++];
                                int hashReg = bytecode[pc++];
                                int keyReg = bytecode[pc++];
                                RuntimeHash hash = (RuntimeHash) registers[hashReg];
                                RuntimeScalar key = (RuntimeScalar) registers[keyReg];
                                registers[rd] = hash.getForLocal(key);
                            }

                            case Opcodes.HASH_SLICE_FOR_LOCAL -> {
                                pc = SlowOpcodeHandler.executeHashSliceForLocal(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_SET -> {
                                pc = InlineOpcodeHandler.executeHashSet(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_EXISTS -> {
                                pc = InlineOpcodeHandler.executeHashExists(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_DELETE -> {
                                pc = InlineOpcodeHandler.executeHashDelete(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_EXISTS -> {
                                pc = InlineOpcodeHandler.executeArrayExists(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_DELETE -> {
                                pc = InlineOpcodeHandler.executeArrayDelete(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_DELETE_LOCAL -> {
                                pc = InlineOpcodeHandler.executeHashDeleteLocal(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_DELETE_LOCAL -> {
                                pc = InlineOpcodeHandler.executeArrayDeleteLocal(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_KEYS -> {
                                pc = InlineOpcodeHandler.executeHashKeys(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_KEYS_SCALAR -> {
                                pc = InlineOpcodeHandler.executeHashKeysScalar(bytecode, pc, registers);
                            }

                            case Opcodes.KEYS_LVALUE -> {
                                int rd = bytecode[pc++];
                                int containerReg = bytecode[pc++];
                                registers[rd] = RuntimeCode.keysLvalue(registers[containerReg]);
                            }

                            case Opcodes.HASH_VALUES -> {
                                pc = InlineOpcodeHandler.executeHashValues(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_PREALLOCATE -> {
                                pc = InlineOpcodeHandler.executeHashPreallocate(bytecode, pc, registers);
                            }

                            // =================================================================
                            // SUBROUTINE CALLS
                            // =================================================================

                            case Opcodes.CALL_SUB, Opcodes.CALL_SUB_SHARE_ARGS -> {
                                // Call subroutine: rd = coderef->(args)
                                // CALL_SUB_SHARE_ARGS: &func (no parens) shares caller's @_ by alias
                                // May return RuntimeControlFlowList!
                                // pcHolder[0] contains the PC of this opcode (set before opcode read)
                                boolean shareArgs = (opcode == Opcodes.CALL_SUB_SHARE_ARGS);
                                // pcHolder[0] contains the PC of this opcode (set before opcode read)
                                int callSitePc = pcHolder[0];
                                int rd = bytecode[pc++];
                                int coderefReg = bytecode[pc++];
                                int argsReg = bytecode[pc++];
                                int context = bytecode[pc++];

                                // Resolve RUNTIME context from register 2 (wantarray).
                                // When a subroutine body is compiled by the interpreter,
                                // the calling context is not known at compile time, so
                                // RUNTIME is baked into the bytecode. At execution time,
                                // resolve it from the actual calling context in register 2.
                                if (context == RuntimeContextType.RUNTIME) {
                                    context = ((RuntimeScalar) registers[2]).getInt();
                                } else if (context == RuntimeContextType.INHERITED) {
                                    context = RuntimeCode.currentRawCallContext();
                                }

                                // Auto-convert coderef to scalar if needed
                                RuntimeBase codeRefBase = registers[coderefReg];
                                RuntimeScalar codeRef = (codeRefBase instanceof RuntimeScalar)
                                        ? (RuntimeScalar) codeRefBase
                                        : codeRefBase.scalar();

                                // A dynamic call through a tied scalar, `&$tied`,
                                // invokes the CODE value returned by FETCH.  Unlike
                                // an explicit &{...} expression, this parse form
                                // reaches CALL_SUB directly, so materialize the tied
                                // value before RuntimeCode.apply validates the CV.
                                if (codeRef.type == RuntimeScalarType.TIED_SCALAR) {
                                    codeRef = codeRef.tiedFetch();
                                }

                                // Dereference symbolic code references using current package
                                // This matches the JVM backend's call to codeDerefNonStrict()
                                // Only call for STRING/BYTE_STRING types (symbolic references)
                                // For CODE, REFERENCE, etc. let RuntimeCode.apply() handle errors
                                // Use cached RuntimeScalar to avoid ThreadLocal lookup
                                if (codeRef.type == RuntimeScalarType.STRING || codeRef.type == RuntimeScalarType.BYTE_STRING) {
                                    codeRef = codeRef.codeDerefNonStrict(currentPackageScalar.toString());
                                }

                                RuntimeBase argsBase = registers[argsReg];
                                RuntimeCode.CallArguments stagedArgs =
                                        argsBase instanceof RuntimeCode.CallArguments staged
                                                ? staged : null;

                                RuntimeArray callArgs;
                                if (stagedArgs != null) {
                                    callArgs = null;
                                } else if (argsBase instanceof RuntimeArray) {
                                    callArgs = (RuntimeArray) argsBase;
                                } else if (argsBase instanceof RuntimeList) {
                                    if (((RuntimeList) argsBase).elements.size() == 1
                                            && ((RuntimeList) argsBase).elements.getFirst() instanceof RuntimeArray array) {
                                        array.markDirectCallArgument();
                                    }
                                    callArgs = new RuntimeArray();
                                    argsBase.setArrayOfAlias(callArgs);
                                } else {
                                    callArgs = new RuntimeArray((RuntimeScalar) argsBase);
                                }

                                // Push lazy call site info to CallerStack for caller() to see the correct location
                                // The actual line number computation is deferred until caller() is called
                                // Capture variables needed for lazy resolution
                                final String lazyPkg = currentPackageScalar.toString();
                                final int lazyPc = callSitePc;
                                CallerStack.pushLazy(lazyPkg, () -> getCallSiteInfo(code, lazyPc, lazyPkg));
                                RuntimeList result;
                                try {
                                    // Route interpreted code through RuntimeCode.apply too. Its wrapper
                                    // establishes mortal marks, warning/hint stacks, args-stack state,
                                    // and void-result cleanup. Bypassing it keeps scope temporaries alive
                                    // in large-code interpreter fallbacks (Net::LDAP ref-loop cleanup).
                                    if (stagedArgs != null) {
                                        result = shareArgs
                                                ? RuntimeCode.apply(codeRef, stagedArgs, context)
                                                : RuntimeCode.apply(codeRef, "", stagedArgs, context);
                                    } else if (shareArgs) {
                                        result = RuntimeCode.apply(codeRef, callArgs, context);
                                    } else {
                                        result = RuntimeCode.apply(codeRef, "", callArgs, context);
                                    }

                                    // Use the same tail-call marker handoff as generated JVM code.
                                    // In particular, it resolves named targets after the abandoned
                                    // frame's cleanup and consumes marker-owned temporaries once.
                                    result = RuntimeCode.resolveTailCalls(result, context);
                                } finally {
                                    CallerStack.pop();
                                }

                                // OBJECT is a raw Wanted parent-op context, but its
                                // value semantics are the same as scalar context.
                                if (context == RuntimeContextType.SCALAR || context == RuntimeContextType.LVALUE
                                        || context == RuntimeContextType.OBJECT) {
                                    RuntimeBase scalarResult = result.scalar();
                                    registers[rd] = (context == RuntimeContextType.SCALAR
                                            || context == RuntimeContextType.OBJECT) && isImmutableProxy(scalarResult)
                                            ? ensureMutableScalar(scalarResult) : scalarResult;
                                } else {
                                    registers[rd] = result;
                                }

                                // Check for control flow (last/next/redo/goto) - TAILCALL already handled above
                                if (result.isNonLocalGoto()) {
                                    RuntimeControlFlowList flow = (RuntimeControlFlowList) result;

                                    // Handle RETURN markers: consume at non-map/grep boundaries, propagate in map/grep
                                    if (flow.getControlFlowType() == ControlFlowType.RETURN) {
                                        if (!code.isMapGrepBlock) {
                                            // Consume: unwrap and return the value from this subroutine
                                            RuntimeBase retVal = flow.getReturnValue();
                                            return retVal != null ? retVal.getList() : new RuntimeList();
                                        }
                                        return result;  // Propagate in map/grep blocks
                                    }

                                    // A returned last/next/redo must select the innermost
                                    // active loop or bare block.  GOTO continues to use
                                    // the separate named-label stack below.
                                    boolean handled = false;
                                    if (flow.getControlFlowType() == ControlFlowType.GOTO
                                            && code.gotoLabelPcs != null) {
                                        Integer targetPc = code.gotoLabelPcs.get(flow.getControlFlowLabel());
                                        if (targetPc != null) {
                                            // A propagated goto cannot enter a loop body: its iterator
                                            // and control-block state only exist after the loop prologue.
                                            // This applies equally to a marker from eval STRING and one
                                            // from eval BLOCK (the latter has no evalScope tag).
                                            if (jumpsIntoUnenteredLoopBody(code,
                                                    flow.getControlFlowLabel(), targetPc, pc)) {
                                                throw new PerlCompilerException(
                                                        "Can't \"goto\" into the middle of a foreach loop");
                                            }
                                            rejectGotoIntoGiven(code, flow.getControlFlowLabel());
                                            if (code.gotoLabelsInsideConstruct != null
                                                    && code.gotoLabelsInsideConstruct.contains(flow.getControlFlowLabel())) {
                                                throw new PerlCompilerException(
                                                        "Use of \"goto\" to jump into a construct is no longer permitted");
                                            }
                                            enterGotoLabelPackage(code, targetPc);
                                            pc = targetPc;
                                            releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
                                            handled = true;
                                        }
                                    }
                                    if (flow.getControlFlowType() != ControlFlowType.GOTO) {
                                        for (int i = controlBlockStack.size() - 1; i >= 0; i--) {
                                            int[] entry = controlBlockStack.get(i);
                                            String blockLabel = code.stringPool[entry[0]];
                                            if (matchesInterpreterControlBlock(flow, blockLabel)) {
                                                while (controlBlockStack.size() > i + 1) {
                                                    controlBlockStack.removeLast();
                                                }
                                                int targetPc = switch (flow.getControlFlowType()) {
                                                    case LAST -> entry[1];
                                                    case NEXT -> entry[2];
                                                    case REDO -> entry[3];
                                                    default -> -1;
                                                };
                                                if (targetPc >= 0) {
                                                    pc = targetPc;
                                                    registers[rd] = consumedControlFlowResult(context);
                                                    releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
                                                    handled = true;
                                                    break;
                                                }
                                            }
                                        }
                                    }
                                    for (int i = labeledBlockStack.size() - 1; i >= 0; i--) {
                                        if (handled) break;
                                        int[] entry = labeledBlockStack.get(i);
                                        String blockLabel = code.stringPool[entry[0]];
                                        if (matchesInterpreterControlBlock(flow, blockLabel)) {
                                            // Pop entries down to and including the match
                                            while (labeledBlockStack.size() > i) {
                                                labeledBlockStack.removeLast();
                                            }
                                            pc = entry[1]; // jump to block exit
                                            registers[rd] = consumedControlFlowResult(context);
                                            releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
                                            handled = true;
                                            break;
                                        }
                                    }
                                    if (!handled) {
                                        ControlFlowType cfType = flow.getControlFlowType();
                                        if ((cfType == ControlFlowType.GOTO || cfType == ControlFlowType.TAILCALL
                                                || flow.isSwitchControl())
                                                && !evalCatchStack.isEmpty()) {
                                            // Set $@ to the error message
                                            String errorMsg = flow.marker.buildErrorMessage();
                                            GlobalVariable.setGlobalVariable("main::@", errorMsg);
                                            // Restore local variables pushed inside the eval block
                                            if (!evalLocalLevelStack.isEmpty()) {
                                                int relativeLevel = evalLocalLevelStack.pop();
                                                DynamicVariableManager.popToLocalLevel(
                                                        savedLocalLevel + relativeLevel);
                                            }
                                            unwindEvalMethodInvocantHolds(
                                                    evalMethodInvocantHoldDepthStack,
                                                    methodInvocantHolds);
                                            // Jump to eval catch handler
                                            pc = evalCatchStack.pop();
                                            popEvalCallerFrame(frame);
                                            RuntimeCode.decrementEvalDepth();
                                            break;
                                        }
                                        return result;
                                    }
                                }
                            }

                            case Opcodes.CALL_METHOD -> {
                                // Call method: rd = RuntimeCode.call(invocant, method, currentSub, args, context)
                                // May return RuntimeControlFlowList!
                                // pcHolder[0] contains the PC of this opcode (set before opcode read)
                                int callSitePc = pcHolder[0];
                                int rd = bytecode[pc++];
                                int invocantReg = bytecode[pc++];
                                int methodReg = bytecode[pc++];
                                int currentSubReg = bytecode[pc++];
                                int argsReg = bytecode[pc++];
                                int context = bytecode[pc++];

                                // Resolve RUNTIME context from register 2 (wantarray)
                                if (context == RuntimeContextType.RUNTIME) {
                                    context = ((RuntimeScalar) registers[2]).getInt();
                                } else if (context == RuntimeContextType.INHERITED) {
                                    context = RuntimeCode.currentRawCallContext();
                                }

                                // Method operands normally compile to scalars, but a
                                // scalar-context expression can retain its one-element
                                // RuntimeList wrapper (notably during Moose's role
                                // composition). Normalize it at the call boundary.
                                RuntimeBase rawInvocant = registers[invocantReg];
                                RuntimeScalar invocant = rawInvocant.scalar();
                                // A literal class name used as a method invocant
                                // becomes $_[0].  Preserve its immutability instead
                                // of normalizing it into a writable scalar before
                                // RuntimeCode injects the argument.
                                if (rawInvocant instanceof RuntimeScalarReadOnly
                                        && !(rawInvocant instanceof ReadOnlyAlias)) {
                                    invocant = new ReadOnlyAlias(invocant);
                                }
                                RuntimeScalar method = registers[methodReg].scalar();
                                RuntimeScalar currentSub = registers[currentSubReg].scalar();
                                RuntimeBase argsBase = registers[argsReg];
                                RuntimeCode.CallArguments stagedArgs =
                                        argsBase instanceof RuntimeCode.CallArguments staged
                                                ? staged : null;

                                RuntimeArray callArgs;
                                if (stagedArgs != null) {
                                    callArgs = null;
                                } else if (argsBase instanceof RuntimeArray) {
                                    callArgs = (RuntimeArray) argsBase;
                                } else if (argsBase instanceof RuntimeList) {
                                    callArgs = new RuntimeArray();
                                    argsBase.setArrayOfAlias(callArgs);
                                } else {
                                    callArgs = new RuntimeArray((RuntimeScalar) argsBase);
                                }

                                // Push lazy call site info to CallerStack for caller() to see the correct location
                                // Capture variables needed for lazy resolution
                                final String lazyPkg = currentPackageScalar.toString();
                                final int lazyPc = callSitePc;
                                CallerStack.pushLazy(lazyPkg, () -> getCallSiteInfo(code, lazyPc, lazyPkg));
                                RuntimeList result;
                                try {
                                    result = stagedArgs == null
                                            ? RuntimeCode.call(invocant, method, currentSub, callArgs, context)
                                            : RuntimeCode.call(invocant, method, currentSub, stagedArgs, context);

                                    // Keep method calls on the shared tail-call handoff as well.
                                    result = RuntimeCode.resolveTailCalls(result, context);
                                } finally {
                                    CallerStack.pop();
                                }

                                // OBJECT is a raw Wanted parent-op context, but its
                                // value semantics are the same as scalar context.
                                if (context == RuntimeContextType.SCALAR || context == RuntimeContextType.LVALUE
                                        || context == RuntimeContextType.OBJECT) {
                                    RuntimeBase scalarResult = result.scalar();
                                    registers[rd] = (context == RuntimeContextType.SCALAR
                                            || context == RuntimeContextType.OBJECT) && isImmutableProxy(scalarResult)
                                            ? ensureMutableScalar(scalarResult) : scalarResult;
                                } else {
                                    registers[rd] = result;
                                }

                                // Check for control flow (last/next/redo/goto) - TAILCALL already handled above
                                if (result.isNonLocalGoto()) {
                                    RuntimeControlFlowList flow = (RuntimeControlFlowList) result;

                                    // Handle RETURN markers: consume at non-map/grep boundaries, propagate in map/grep
                                    if (flow.getControlFlowType() == ControlFlowType.RETURN) {
                                        if (!code.isMapGrepBlock) {
                                            RuntimeBase retVal = flow.getReturnValue();
                                            return retVal != null ? retVal.getList() : new RuntimeList();
                                        }
                                        return result;
                                    }

                                    boolean handled = false;
                                    if (flow.getControlFlowType() == ControlFlowType.GOTO
                                            && code.gotoLabelPcs != null) {
                                        Integer targetPc = code.gotoLabelPcs.get(flow.getControlFlowLabel());
                                        if (targetPc != null) {
                                            // See the equivalent marker handoff above: eval BLOCK markers
                                            // carry no evalScope, but cannot safely enter a loop either.
                                            if (jumpsIntoUnenteredLoopBody(code,
                                                    flow.getControlFlowLabel(), targetPc, pc)) {
                                                throw new PerlCompilerException(
                                                        "Can't \"goto\" into the middle of a foreach loop");
                                            }
                                            rejectGotoIntoGiven(code, flow.getControlFlowLabel());
                                            if (code.gotoLabelsInsideConstruct != null
                                                    && code.gotoLabelsInsideConstruct.contains(flow.getControlFlowLabel())) {
                                                throw new PerlCompilerException(
                                                        "Use of \"goto\" to jump into a construct is no longer permitted");
                                            }
                                            enterGotoLabelPackage(code, targetPc);
                                            pc = targetPc;
                                            releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
                                            handled = true;
                                        }
                                    }
                                    if (flow.getControlFlowType() != ControlFlowType.GOTO) {
                                        for (int i = controlBlockStack.size() - 1; i >= 0; i--) {
                                            int[] entry = controlBlockStack.get(i);
                                            String blockLabel = code.stringPool[entry[0]];
                                            if (matchesInterpreterControlBlock(flow, blockLabel)) {
                                                while (controlBlockStack.size() > i + 1) {
                                                    controlBlockStack.removeLast();
                                                }
                                                int targetPc = switch (flow.getControlFlowType()) {
                                                    case LAST -> entry[1];
                                                    case NEXT -> entry[2];
                                                    case REDO -> entry[3];
                                                    default -> -1;
                                                };
                                                if (targetPc >= 0) {
                                                    pc = targetPc;
                                                    registers[rd] = consumedControlFlowResult(context);
                                                    releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
                                                    handled = true;
                                                    break;
                                                }
                                            }
                                        }
                                    }
                                    for (int i = labeledBlockStack.size() - 1; i >= 0; i--) {
                                        if (handled) break;
                                        int[] entry = labeledBlockStack.get(i);
                                        String blockLabel = code.stringPool[entry[0]];
                                        if (matchesInterpreterControlBlock(flow, blockLabel)) {
                                            while (labeledBlockStack.size() > i) {
                                                labeledBlockStack.removeLast();
                                            }
                                            pc = entry[1];
                                            registers[rd] = consumedControlFlowResult(context);
                                            releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
                                            handled = true;
                                            break;
                                        }
                                    }
                                    if (!handled) {
                                        ControlFlowType cfType = flow.getControlFlowType();
                                        if ((cfType == ControlFlowType.GOTO || cfType == ControlFlowType.TAILCALL
                                                || flow.isSwitchControl())
                                                && !evalCatchStack.isEmpty()) {
                                            String errorMsg = flow.marker.buildErrorMessage();
                                            GlobalVariable.setGlobalVariable("main::@", errorMsg);
                                            // Restore local variables pushed inside the eval block
                                            if (!evalLocalLevelStack.isEmpty()) {
                                                int relativeLevel = evalLocalLevelStack.pop();
                                                DynamicVariableManager.popToLocalLevel(
                                                        savedLocalLevel + relativeLevel);
                                            }
                                            unwindEvalMethodInvocantHolds(
                                                    evalMethodInvocantHoldDepthStack,
                                                    methodInvocantHolds);
                                            pc = evalCatchStack.pop();
                                            popEvalCallerFrame(frame);
                                            RuntimeCode.decrementEvalDepth();
                                            break;
                                        }
                                        return result;
                                    }
                                }
                            }

                            case Opcodes.HOLD_METHOD_INVOCANT -> {
                                int invocantReg = bytecode[pc++];
                                methodInvocantHolds.add(RuntimeCode.acquireMethodInvocantHold(
                                        (RuntimeScalar) registers[invocantReg]));
                            }

                            case Opcodes.RELEASE_METHOD_INVOCANT -> {
                                if (!methodInvocantHolds.isEmpty()) {
                                    RuntimeCode.releaseMethodInvocantHold(
                                            methodInvocantHolds.removeLast());
                                }
                            }

                            // =================================================================
                            // CONTROL FLOW - SPECIAL (RuntimeControlFlowList)
                            // =================================================================

                            case Opcodes.CREATE_LAST -> {
                                pc = InlineOpcodeHandler.executeCreateLast(bytecode, pc, registers, code, pcHolder[0]);
                            }

                            case Opcodes.CREATE_NEXT -> {
                                pc = InlineOpcodeHandler.executeCreateNext(bytecode, pc, registers, code, pcHolder[0]);
                            }

                            case Opcodes.CREATE_SWITCH_CONTINUE, Opcodes.CREATE_SWITCH_BREAK,
                                    Opcodes.CREATE_SWITCH_BREAK_LOOP_TOPICALIZER -> {
                                int rd = bytecode[pc++];
                                int labelIdx = bytecode[pc++];
                                String label = labelIdx == 255 ? null : code.stringPool[labelIdx];
                                boolean isContinue = opcode == Opcodes.CREATE_SWITCH_CONTINUE;
                                String switchControl = isContinue ? "continue"
                                        : opcode == Opcodes.CREATE_SWITCH_BREAK_LOOP_TOPICALIZER
                                        ? "break-loop-topicalizer" : "break";
                                ErrorMessageUtil.SourceLocation location =
                                        InlineOpcodeHandler.sourceLocation(code, pcHolder[0]);
                                RuntimeControlFlowList marker = new RuntimeControlFlowList(
                                        isContinue ? ControlFlowType.NEXT : ControlFlowType.LAST,
                                        label, location.fileName(), location.lineNumber(), null,
                                        switchControl);
                                registers[rd] = marker;
                            }

                            case Opcodes.CREATE_REDO -> {
                                pc = InlineOpcodeHandler.executeCreateRedo(bytecode, pc, registers, code, pcHolder[0]);
                            }

                            case Opcodes.CREATE_LAST_DYNAMIC, Opcodes.CREATE_NEXT_DYNAMIC, Opcodes.CREATE_REDO_DYNAMIC -> {
                                int rd = bytecode[pc++];
                                int labelReg = bytecode[pc++];
                                String label = ((RuntimeScalar) registers[labelReg]).toString();
                                ControlFlowType type = opcode == Opcodes.CREATE_LAST_DYNAMIC ? ControlFlowType.LAST
                                        : opcode == Opcodes.CREATE_NEXT_DYNAMIC ? ControlFlowType.NEXT
                                        : ControlFlowType.REDO;
                                ErrorMessageUtil.SourceLocation location =
                                        InlineOpcodeHandler.sourceLocation(code, pcHolder[0]);
                                RuntimeControlFlowList marker = new RuntimeControlFlowList(
                                        type, label, location.fileName(), location.lineNumber());
                                InlineOpcodeHandler.rejectSortComparatorLoopControl(code, marker);
                                registers[rd] = marker;
                            }

                            case Opcodes.CREATE_GOTO -> {
                                pc = InlineOpcodeHandler.executeCreateGoto(bytecode, pc, registers, code, pcHolder[0]);
                            }

                            case Opcodes.GOTO_TAILCALL -> {
                                // Create TAILCALL marker for goto &sub
                                // Format: GOTO_TAILCALL rd coderef_reg args_reg context evalScopeIdx
                                int rd = bytecode[pc++];
                                int coderefReg = bytecode[pc++];
                                int argsReg = bytecode[pc++];
                                int context = bytecode[pc++];  // unused in marker, but consumed
                                int evalScopeIdx = bytecode[pc++]; // -1 = not in eval
                                int namedTargetIdx = bytecode[pc++]; // -1 = dynamic target

                                // A tail call may not escape sort's pseudo
                                // block. Do this at marker creation because
                                // direct interpreter call paths can resolve a
                                // marker before the caller sees it.
                                RuntimeCode.checkSortTailCall();

                                // Get coderef
                                RuntimeBase codeRefBase = registers[coderefReg];
                                RuntimeScalar codeRef = (codeRefBase instanceof RuntimeScalar)
                                        ? (RuntimeScalar) codeRefBase
                                        : codeRefBase.scalar();

                                // Dereference symbolic code references
                                // Use cached RuntimeScalar to avoid ThreadLocal lookup
                                if (codeRef.type == RuntimeScalarType.STRING || codeRef.type == RuntimeScalarType.BYTE_STRING) {
                                    codeRef = codeRef.codeDerefNonStrict(currentPackageScalar.toString());
                                }

                                RuntimeArray callArgs = argsReg < 0
                                        ? RuntimeCode.getGotoArgs((RuntimeArray) registers[1], currentPackageScalar.toString())
                                        : registers[argsReg].getTailCallArrayOfAlias();
                                RuntimeArray localizedArgs = RuntimeGlob.localizedUnderscoreArrayForCurrentCall();
                                if (localizedArgs != null) {
                                    callArgs = localizedArgs;
                                }

                                RuntimeScalar debuggerGotoTarget = DebugHooks.dispatchGoto(codeRef, context);
                                boolean debuggerHandledGoto = debuggerGotoTarget != null;
                                if (debuggerHandledGoto) {
                                    codeRef = debuggerGotoTarget;
                                }

                                if (debuggerHandledGoto) {
                                    // DB::goto has already selected the target and this
                                    // goto expression immediately returns from its frame.
                                    // Apply the target through the tail-call boundary here
                                    // rather than returning a second deferred marker.
                                    registers[rd] = RuntimeCode.apply(codeRef, "tailcall", callArgs, context);
                                } else {
                                    // Create TAILCALL marker with eval scope for runtime check
                                    String evalScope = (evalScopeIdx >= 0) ? code.stringPool[evalScopeIdx] : null;
                                    String namedTarget = namedTargetIdx >= 0 ? code.stringPool[namedTargetIdx] : null;
                                    RuntimeControlFlowList marker = new RuntimeControlFlowList(
                                            codeRef, callArgs, code.sourceName, 0, evalScope, namedTarget);

                                    // A goto &sub from eval must fail at the eval
                                    // boundary.  Returning this marker would bypass
                                    // EVAL_TRY because the goto compiler emits an
                                    // immediate RETURN.  Resolve it while the eval
                                    // catcher is active: resolveTailCalls preserves
                                    // Perl's named-undefined-target-before-eval rule
                                    // and throws the diagnostic for EVAL_TRY to catch.
                                    if (evalScope != null) {
                                        registers[rd] = RuntimeCode.resolveTailCalls(marker, context);
                                    } else {
                                        registers[rd] = marker;
                                    }
                                }
                            }

                            case Opcodes.IS_CONTROL_FLOW -> {
                                pc = InlineOpcodeHandler.executeIsControlFlow(bytecode, pc, registers);
                            }

                            // =================================================================
                            // MISCELLANEOUS
                            // =================================================================

                            case Opcodes.PRINT -> {
                                // Print to filehandle
                                // Format: PRINT contentReg filehandleReg
                                pc = OpcodeHandlerExtended.executePrint(bytecode, pc, registers);
                            }

                            case Opcodes.PRINT_RESULT -> {
                                pc = OpcodeHandlerExtended.executePrintResult(bytecode, pc, registers, code, pcHolder[0]);
                            }

                            case Opcodes.SAY -> {
                                // Say to filehandle
                                // Format: SAY contentReg filehandleReg
                                pc = OpcodeHandlerExtended.executeSay(bytecode, pc, registers);
                            }

                            // =================================================================
                            // SUPERINSTRUCTIONS - Eliminate ALIAS overhead
                            // =================================================================

                            case Opcodes.INC_REG -> {
                                pc = InlineOpcodeHandler.executeIncReg(bytecode, pc, registers);
                            }

                            case Opcodes.DEC_REG -> {
                                pc = InlineOpcodeHandler.executeDecReg(bytecode, pc, registers);
                            }

                            case Opcodes.ADD_ASSIGN -> {
                                pc = InlineOpcodeHandler.executeAddAssign(bytecode, pc, registers);
                            }

                            case Opcodes.ADD_ASSIGN_INT -> {
                                pc = InlineOpcodeHandler.executeAddAssignInt(bytecode, pc, registers);
                            }

                            case Opcodes.STRING_CONCAT_ASSIGN -> {
                                // String concatenation and assign: rd .= rs
                                // Format: STRING_CONCAT_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeStringConcatAssign(bytecode, pc, registers);
                            }

                            case Opcodes.BITWISE_AND_ASSIGN -> {
                                // Bitwise AND assignment: rd &= rs
                                // Format: BITWISE_AND_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeBitwiseAndAssign(bytecode, pc, registers);
                            }

                            case Opcodes.BITWISE_OR_ASSIGN -> {
                                // Bitwise OR assignment: rd |= rs
                                // Format: BITWISE_OR_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeBitwiseOrAssign(bytecode, pc, registers);
                            }

                            case Opcodes.BITWISE_XOR_ASSIGN -> {
                                // Bitwise XOR assignment: rd ^= rs
                                // Format: BITWISE_XOR_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeBitwiseXorAssign(bytecode, pc, registers);
                            }

                            case Opcodes.STRING_BITWISE_AND_ASSIGN -> {
                                // String bitwise AND assignment: rd &.= rs
                                // Format: STRING_BITWISE_AND_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeStringBitwiseAndAssign(bytecode, pc, registers);
                            }

                            case Opcodes.STRING_BITWISE_OR_ASSIGN -> {
                                // String bitwise OR assignment: rd |.= rs
                                // Format: STRING_BITWISE_OR_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeStringBitwiseOrAssign(bytecode, pc, registers);
                            }

                            case Opcodes.STRING_BITWISE_XOR_ASSIGN -> {
                                // String bitwise XOR assignment: rd ^.= rs
                                // Format: STRING_BITWISE_XOR_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeStringBitwiseXorAssign(bytecode, pc, registers);
                            }

                            case Opcodes.BINARY_AND_ASSIGN -> {
                                // Numeric-only bitwise AND assign (use feature "bitwise")
                                // Format: BINARY_AND_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeBinaryAndAssign(bytecode, pc, registers);
                            }

                            case Opcodes.BINARY_OR_ASSIGN -> {
                                // Numeric-only bitwise OR assign (use feature "bitwise")
                                // Format: BINARY_OR_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeBinaryOrAssign(bytecode, pc, registers);
                            }

                            case Opcodes.BINARY_XOR_ASSIGN -> {
                                // Numeric-only bitwise XOR assign (use feature "bitwise")
                                // Format: BINARY_XOR_ASSIGN rd rs
                                pc = OpcodeHandlerExtended.executeBinaryXorAssign(bytecode, pc, registers);
                            }

                            case Opcodes.BITWISE_AND_BINARY -> {
                                // Numeric bitwise AND: rd = rs1 binary& rs2
                                // Format: BITWISE_AND_BINARY rd rs1 rs2
                                pc = OpcodeHandlerExtended.executeBitwiseAndBinary(bytecode, pc, registers);
                            }

                            case Opcodes.BITWISE_OR_BINARY -> {
                                // Numeric bitwise OR: rd = rs1 binary| rs2
                                // Format: BITWISE_OR_BINARY rd rs1 rs2
                                pc = OpcodeHandlerExtended.executeBitwiseOrBinary(bytecode, pc, registers);
                            }

                            case Opcodes.BITWISE_XOR_BINARY -> {
                                // Numeric bitwise XOR: rd = rs1 binary^ rs2
                                // Format: BITWISE_XOR_BINARY rd rs1 rs2
                                pc = OpcodeHandlerExtended.executeBitwiseXorBinary(bytecode, pc, registers);
                            }

                            case Opcodes.STRING_BITWISE_AND -> {
                                // String bitwise AND: rd = rs1 &. rs2
                                // Format: STRING_BITWISE_AND rd rs1 rs2
                                pc = OpcodeHandlerExtended.executeStringBitwiseAnd(bytecode, pc, registers);
                            }

                            case Opcodes.STRING_BITWISE_OR -> {
                                // String bitwise OR: rd = rs1 |. rs2
                                // Format: STRING_BITWISE_OR rd rs1 rs2
                                pc = OpcodeHandlerExtended.executeStringBitwiseOr(bytecode, pc, registers);
                            }

                            case Opcodes.STRING_BITWISE_XOR -> {
                                // String bitwise XOR: rd = rs1 ^. rs2
                                // Format: STRING_BITWISE_XOR rd rs1 rs2
                                pc = OpcodeHandlerExtended.executeStringBitwiseXor(bytecode, pc, registers);
                            }

                            case Opcodes.XOR_LOGICAL -> {
                                pc = InlineOpcodeHandler.executeXorLogical(bytecode, pc, registers);
                            }

                            case Opcodes.BITWISE_NOT_BINARY -> {
                                // Numeric bitwise NOT: rd = binary~ rs
                                // Format: BITWISE_NOT_BINARY rd rs
                                pc = OpcodeHandlerExtended.executeBitwiseNotBinary(bytecode, pc, registers);
                            }

                            case Opcodes.BITWISE_NOT_STRING -> {
                                // String bitwise NOT: rd = ~. rs
                                // Format: BITWISE_NOT_STRING rd rs
                                pc = OpcodeHandlerExtended.executeBitwiseNotString(bytecode, pc, registers);
                            }

                            // File test and stat operations
                            case Opcodes.STAT -> {
                                pc = OpcodeHandlerExtended.executeStat(bytecode, pc, registers);
                            }

                            case Opcodes.LSTAT -> {
                                pc = OpcodeHandlerExtended.executeLstat(bytecode, pc, registers);
                            }

                            case Opcodes.STAT_LASTHANDLE -> {
                                pc = OpcodeHandlerExtended.executeStatLastHandle(bytecode, pc, registers);
                            }

                            case Opcodes.LSTAT_LASTHANDLE -> {
                                pc = OpcodeHandlerExtended.executeLstatLastHandle(bytecode, pc, registers);
                            }

                            // File test operations (opcodes 190-216) - delegated to handler
                            case Opcodes.FILETEST_R, Opcodes.FILETEST_W, Opcodes.FILETEST_X, Opcodes.FILETEST_O,
                                 Opcodes.FILETEST_R_REAL, Opcodes.FILETEST_W_REAL, Opcodes.FILETEST_X_REAL,
                                 Opcodes.FILETEST_O_REAL, Opcodes.FILETEST_E, Opcodes.FILETEST_Z, Opcodes.FILETEST_S,
                                 Opcodes.FILETEST_F, Opcodes.FILETEST_D, Opcodes.FILETEST_L, Opcodes.FILETEST_P,
                                 Opcodes.FILETEST_S_UPPER, Opcodes.FILETEST_B, Opcodes.FILETEST_C, Opcodes.FILETEST_T,
                                 Opcodes.FILETEST_U, Opcodes.FILETEST_G, Opcodes.FILETEST_K, Opcodes.FILETEST_T_UPPER,
                                 Opcodes.FILETEST_B_UPPER, Opcodes.FILETEST_M, Opcodes.FILETEST_A,
                                 Opcodes.FILETEST_C_UPPER -> {
                                pc = OpcodeHandlerFileTest.executeFileTest(bytecode, pc, registers, opcode);
                            }

                            case Opcodes.PUSH_LOCAL_VARIABLE -> {
                                pc = InlineOpcodeHandler.executePushLocalVariable(bytecode, pc, registers);
                            }

                            case Opcodes.STORE_GLOB -> {
                                pc = InlineOpcodeHandler.executeStoreGlob(bytecode, pc, registers);
                            }

                            case Opcodes.GLOB_ASSIGNMENT_RESULT -> {
                                int rd = bytecode[pc++];
                                int globReg = bytecode[pc++];
                                int valueReg = bytecode[pc++];
                                registers[rd] = RuntimeGlob.scalarAssignmentResult(
                                        (RuntimeGlob) registers[globReg],
                                        (RuntimeScalar) registers[valueReg]);
                            }

                            case Opcodes.OPEN -> {
                                // Open file: rd = IOOperator.open(ctx, args...)
                                // Format: OPEN rd ctx argsReg
                                pc = OpcodeHandlerExtended.executeOpen(bytecode, pc, registers);
                            }

                            case Opcodes.READLINE -> {
                                // Read line from filehandle
                                // Format: READLINE rd fhReg ctx
                                pc = OpcodeHandlerExtended.executeReadline(bytecode, pc, registers);
                            }

                            case Opcodes.SET_LAST_READLINE_HANDLE_NAME -> {
                                int nameIndex = bytecode[pc++];
                                RuntimeIO.setLastReadlineHandleName(code.stringPool[nameIndex]);
                            }

                            case Opcodes.MATCH_REGEX -> {
                                // Match regex
                                // Format: MATCH_REGEX rd stringReg regexReg ctx bytesMode targetNameIndex
                                pc = OpcodeHandlerExtended.executeMatchRegex(bytecode, pc, registers, code);
                            }

                            case Opcodes.MATCH_REGEX_NOT -> {
                                // Negated regex match
                                // Format: MATCH_REGEX_NOT rd stringReg regexReg ctx
                                pc = OpcodeHandlerExtended.executeMatchRegexNot(bytecode, pc, registers);
                            }

                            case Opcodes.CHOMP -> {
                                // Chomp: rd = rs.chomp()
                                // Format: CHOMP rd rs
                                pc = OpcodeHandlerExtended.executeChomp(bytecode, pc, registers);
                            }

                            case Opcodes.WANTARRAY -> {
                                // Get wantarray context
                                // Format: WANTARRAY rd wantarrayReg
                                pc = OpcodeHandlerExtended.executeWantarray(bytecode, pc, registers);
                            }

                            case Opcodes.REQUIRE -> {
                                // Require module or version
                                // Format: REQUIRE rd rs
                                pc = OpcodeHandlerExtended.executeRequire(bytecode, pc, registers);
                            }

                            case Opcodes.POS -> {
                                // Get regex position
                                // Format: POS rd rs bytes
                                pc = OpcodeHandlerExtended.executePos(bytecode, pc, registers);
                            }

                            case Opcodes.INDEX -> {
                                // Find substring position
                                // Format: INDEX rd strReg substrReg posReg
                                pc = OpcodeHandlerExtended.executeIndex(bytecode, pc, registers);
                            }

                            case Opcodes.RINDEX -> {
                                // Find substring position from end
                                // Format: RINDEX rd strReg substrReg posReg
                                pc = OpcodeHandlerExtended.executeRindex(bytecode, pc, registers);
                            }

                            case Opcodes.PRE_AUTOINCREMENT -> {
                                // Pre-increment: ++rd
                                // Format: PRE_AUTOINCREMENT rd
                                pc = OpcodeHandlerExtended.executePreAutoIncrement(bytecode, pc, registers);
                            }

                            case Opcodes.POST_AUTOINCREMENT -> {
                                // Post-increment: rd = rs++
                                // Format: POST_AUTOINCREMENT rd rs
                                pc = OpcodeHandlerExtended.executePostAutoIncrement(bytecode, pc, registers);
                            }

                            case Opcodes.PRE_AUTODECREMENT -> {
                                // Pre-decrement: --rd
                                // Format: PRE_AUTODECREMENT rd
                                pc = OpcodeHandlerExtended.executePreAutoDecrement(bytecode, pc, registers);
                            }

                            case Opcodes.POST_AUTODECREMENT -> {
                                // Post-decrement: rd = rs--
                                // Format: POST_AUTODECREMENT rd rs
                                pc = OpcodeHandlerExtended.executePostAutoDecrement(bytecode, pc, registers);
                            }

                            case Opcodes.INTEGER_PRE_AUTOINCREMENT ->
                                    pc = OpcodeHandlerExtended.executeIntegerPreAutoIncrement(bytecode, pc, registers);

                            case Opcodes.INTEGER_POST_AUTOINCREMENT ->
                                    pc = OpcodeHandlerExtended.executeIntegerPostAutoIncrement(bytecode, pc, registers);

                            case Opcodes.INTEGER_PRE_AUTODECREMENT ->
                                    pc = OpcodeHandlerExtended.executeIntegerPreAutoDecrement(bytecode, pc, registers);

                            case Opcodes.INTEGER_POST_AUTODECREMENT ->
                                    pc = OpcodeHandlerExtended.executeIntegerPostAutoDecrement(bytecode, pc, registers);

                            // =================================================================
                            // ERROR HANDLING
                            // =================================================================

                            case Opcodes.DIE -> {
                                pc = InlineOpcodeHandler.executeDie(bytecode, pc, registers, code);
                            }

                            case Opcodes.WARN -> {
                                pc = InlineOpcodeHandler.executeWarn(bytecode, pc, registers, code);
                            }

                            // =================================================================
                            // REFERENCE OPERATIONS
                            // =================================================================

                            case Opcodes.CREATE_REF -> {
                                pc = InlineOpcodeHandler.executeCreateRef(bytecode, pc, registers);
                            }

                            case Opcodes.CREATE_REF_NO_VIVIFY -> {
                                pc = InlineOpcodeHandler.executeCreateRefNoVivify(bytecode, pc, registers);
                            }

                            case Opcodes.DEREF -> {
                                pc = InlineOpcodeHandler.executeDeref(bytecode, pc, registers);
                            }

                            case Opcodes.GET_TYPE -> {
                                pc = InlineOpcodeHandler.executeGetType(bytecode, pc, registers);
                            }

                            // =================================================================
                            // EVAL BLOCK SUPPORT
                            // =================================================================

                            case Opcodes.EVAL_TRY -> {
                                // Start of eval block with exception handling
                                // Format: [EVAL_TRY] [catch_target(4 bytes)] [firstBodyReg]
                                // catch_target is absolute bytecode address

                                int catchPc = readInt(bytecode, pc);  // Read 4-byte absolute address
                                pc += 1;  // Skip the int we just read

                                int encodedFirstBodyReg = bytecode[pc++];
                                boolean visibleEvalFrame = encodedFirstBodyReg >= 0;
                                int firstBodyReg = Math.abs(encodedFirstBodyReg);

                                // Push catch PC onto eval stack
                                evalCatchStack.push(catchPc);
                                frame.evalControlBlockDepthStack.push(new int[]{
                                        controlBlockStack.size(), labeledBlockStack.size()});

                                // Save first body register for scope cleanup on exception
                                evalBaseRegStack.push(firstBodyReg);

                                evalMethodInvocantHoldDepthStack.push(methodInvocantHolds.size());

                                // Save local level so we can restore local variables on eval exit
                                evalLocalLevelStack.push(
                                        DynamicVariableManager.getLocalLevel() - savedLocalLevel);

                                // Track eval depth for $^S
                                RuntimeCode.incrementEvalDepth();

                                boolean pushedCallerFrame = visibleEvalFrame
                                        && InterpreterState.pushEvalFrameForCurrentInterpreter();
                                evalCallerFrameStack.push(pushedCallerFrame);
                                if (pushedCallerFrame) {
                                    frame.virtualEvalFrameDepth++;
                                }

                                // Clear $@ at start of eval block
                                GlobalVariable.setGlobalVariable("main::@", "");

                                // Continue execution - if exception occurs, outer catch handler
                                // will check evalCatchStack and jump to catchPc
                            }

                            case Opcodes.EVAL_END -> {
                                // A successful eval clears errors from nested evals.
                                // Operators that need eval to expose a failure throw and
                                // take the exception path below.
                                GlobalVariable.setGlobalVariable("main::@", "");

                                // Pop the catch PC from eval stack (we didn't need it)
                                if (!evalCatchStack.isEmpty()) {
                                    evalCatchStack.pop();
                                }
                                popEvalCallerFrame(frame);

                                // Pop the base register (not needed on success path)
                                if (!evalBaseRegStack.isEmpty()) {
                                    evalBaseRegStack.pop();
                                }

                                if (!evalMethodInvocantHoldDepthStack.isEmpty()) {
                                    releaseMethodInvocantHoldsAbove(methodInvocantHolds,
                                            evalMethodInvocantHoldDepthStack.pop());
                                }

                                // Restore local variables that were pushed inside the eval block
                                // e.g., `eval { local @_ = @_ }` should restore @_ on eval exit
                                if (!evalLocalLevelStack.isEmpty()) {
                                    int relativeLevel = evalLocalLevelStack.pop();
                                    DynamicVariableManager.popToLocalLevel(
                                            savedLocalLevel + relativeLevel);
                                }

                                // Track eval depth for $^S
                                RuntimeCode.decrementEvalDepth();

                            }

                            case Opcodes.EVAL_CATCH -> {
                                // Exception handler for eval block
                                // Format: [EVAL_CATCH] [rd] [context]
                                // This is only reached when an exception is caught

                                int rd = bytecode[pc++];
                                int context = bytecode[pc++];

                                // WarnDie.catchEval() should have already been called to set $@
                                // Perl returns an empty list from a failed eval in list context,
                                // but undef in scalar context.
                                registers[rd] = RuntimeContextType.isListLike(context)
                                        ? new RuntimeList()
                                        : RuntimeScalarCache.scalarUndef;
                            }

                            // =================================================================
                            // LABELED BLOCK SUPPORT
                            // =================================================================

                            case Opcodes.PUSH_LABELED_BLOCK -> {
                                int labelIdx = bytecode[pc++];
                                int exitPc = readInt(bytecode, pc);
                                pc += 1;
                                labeledBlockStack.add(new int[]{labelIdx, exitPc});
                            }

                            case Opcodes.POP_LABELED_BLOCK -> {
                                if (!labeledBlockStack.isEmpty()) {
                                    labeledBlockStack.removeLast();
                                }
                            }

                            case Opcodes.PUSH_CONTROL_BLOCK -> {
                                int labelIdx = bytecode[pc++];
                                int lastPc = readInt(bytecode, pc++);
                                int nextPc = readInt(bytecode, pc++);
                                int redoPc = readInt(bytecode, pc++);
                                controlBlockStack.add(new int[]{labelIdx, lastPc, nextPc, redoPc});
                            }

                            case Opcodes.POP_CONTROL_BLOCK -> {
                                if (!controlBlockStack.isEmpty()) {
                                    controlBlockStack.removeLast();
                                }
                            }

                            // =================================================================
                            // LIST OPERATIONS
                            // =================================================================

                            case Opcodes.LIST_TO_COUNT -> {
                                pc = InlineOpcodeHandler.executeListToCount(bytecode, pc, registers);
                            }

                            case Opcodes.LIST_TO_SCALAR -> {
                                pc = InlineOpcodeHandler.executeListToScalar(bytecode, pc, registers);
                            }

                            case Opcodes.SCALAR_TO_LIST -> {
                                pc = InlineOpcodeHandler.executeScalarToList(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_LVALUE_LIST -> {
                                pc = InlineOpcodeHandler.executeArrayLvalueList(bytecode, pc, registers);
                            }

                            case Opcodes.CREATE_LIST -> {
                                pc = InlineOpcodeHandler.executeCreateList(bytecode, pc, registers);
                            }

                            case Opcodes.NEW_CALL_ARGUMENTS -> {
                                int rd = bytecode[pc++];
                                int capacity = bytecode[pc++];
                                registers[rd] = RuntimeCode.newCallArguments(capacity);
                            }

                            case Opcodes.ADD_CALL_ARGUMENT -> {
                                int argsReg = bytecode[pc++];
                                int valueReg = bytecode[pc++];
                                ((RuntimeCode.CallArguments) registers[argsReg])
                                        .add((RuntimeBase) registers[valueReg]);
                            }

                            case Opcodes.SCALAR_IF_WANTARRAY -> {
                                pc = InlineOpcodeHandler.executeScalarIfWantarray(bytecode, pc, registers, callContext);
                            }

                            // =================================================================
                            // STRING OPERATIONS
                            // =================================================================

                            case Opcodes.JOIN -> {
                                pc = InlineOpcodeHandler.executeJoin(bytecode, pc, registers);
                            }

                            case Opcodes.JOIN_INTERPOLATION -> {
                                pc = InlineOpcodeHandler.executeJoinInterpolation(bytecode, pc, registers);
                            }

                            case Opcodes.JOIN_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executeJoinNoOverload(bytecode, pc, registers);
                            }

                            case Opcodes.CONCAT_NO_OVERLOAD -> {
                                pc = InlineOpcodeHandler.executeConcatNoOverload(bytecode, pc, registers);
                            }

                            case Opcodes.SELECT -> {
                                pc = InlineOpcodeHandler.executeSelect(bytecode, pc, registers);
                            }

                            case Opcodes.RANGE -> {
                                pc = InlineOpcodeHandler.executeRange(bytecode, pc, registers);
                            }

                            case Opcodes.CREATE_HASH -> {
                                pc = InlineOpcodeHandler.executeCreateHash(bytecode, pc, registers);
                            }

                            case Opcodes.RAND -> {
                                pc = InlineOpcodeHandler.executeRand(bytecode, pc, registers);
                            }

                            case Opcodes.MAP -> {
                                int resultReg = bytecode[pc];
                                int context = bytecode[pc + 3];
                                if (context == RuntimeContextType.RUNTIME) {
                                    context = ((RuntimeScalar) registers[2]).getInt();
                                }
                                pc = InlineOpcodeHandler.executeMap(bytecode, pc, registers);
                                if (registers[resultReg] instanceof RuntimeControlFlowList flow) {
                                    int targetPc = dispatchListOperatorControlFlow(flow, code, context,
                                            resultReg, pc, registers, controlBlockStack,
                                            labeledBlockStack);
                                    if (targetPc < 0) return flow;
                                    pc = targetPc;
                                }
                            }

                            case Opcodes.GREP -> {
                                int resultReg = bytecode[pc];
                                int context = bytecode[pc + 3];
                                if (context == RuntimeContextType.RUNTIME) {
                                    context = ((RuntimeScalar) registers[2]).getInt();
                                }
                                pc = InlineOpcodeHandler.executeGrep(bytecode, pc, registers);
                                if (registers[resultReg] instanceof RuntimeControlFlowList flow) {
                                    int targetPc = dispatchListOperatorControlFlow(flow, code, context,
                                            resultReg, pc, registers, controlBlockStack,
                                            labeledBlockStack);
                                    if (targetPc < 0) return flow;
                                    pc = targetPc;
                                }
                            }

                            case Opcodes.SORT -> {
                                pc = InlineOpcodeHandler.executeSort(bytecode, pc, registers, code);
                            }

                            case Opcodes.NEW_ARRAY -> {
                                pc = InlineOpcodeHandler.executeNewArray(bytecode, pc, registers);
                            }

                            case Opcodes.NEW_HASH -> {
                                pc = InlineOpcodeHandler.executeNewHash(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_SET_FROM_LIST -> {
                                pc = InlineOpcodeHandler.executeArraySetFromList(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_SET_FROM_REFERENCE_LIST -> {
                                pc = InlineOpcodeHandler.executeArraySetFromReferenceList(bytecode, pc, registers);
                            }

                            case Opcodes.SET_FROM_LIST -> {
                                pc = InlineOpcodeHandler.executeSetFromList(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_SET_FROM_LIST -> {
                                pc = InlineOpcodeHandler.executeHashSetFromList(bytecode, pc, registers);
                            }

                            case Opcodes.MARK_KEYVALUE_SLICE -> {
                                ((RuntimeList) registers[bytecode[pc++]]).keyValueHashSlice = true;
                            }

                            // =================================================================
                            // PHASE 2: DIRECT OPCODES (114-154) - Range delegation
                            // =================================================================
                            // These operations were promoted from SLOW_OP for better performance.
                            // Organized in CONTIGUOUS groups for JVM tableswitch optimization.

                            // Group 1-2: Dereferencing and Slicing (114-121)
                            case Opcodes.DEREF_ARRAY, Opcodes.DEREF_HASH, Opcodes.DEREF_HASH_NONSTRICT,
                                 Opcodes.DEREF_ARRAY_NONSTRICT,
                                 Opcodes.ARRAY_SLICE, Opcodes.ARRAY_SLICE_LVALUE,
                                 Opcodes.ARRAY_SLICE_SET,
                                 Opcodes.HASH_SLICE, Opcodes.HASH_SLICE_SET, Opcodes.HASH_SLICE_DELETE,
                                 Opcodes.HASH_KEYVALUE_SLICE, Opcodes.LIST_SLICE_FROM -> {
                                pc = executeSliceOps(opcode, bytecode, pc, registers, code);
                            }

                            // Group 3-4: Array/String/Exists/Delete (122-127)
                            case Opcodes.SPLICE, Opcodes.REVERSE, Opcodes.SPLIT, Opcodes.LENGTH_OP, Opcodes.EXISTS,
                                 Opcodes.DELETE -> {
                                pc = executeArrayStringOps(opcode, bytecode, pc, registers, code);
                            }

                            // Group 5: Closure/Scope (128-131)
                            case Opcodes.RETRIEVE_BEGIN_SCALAR, Opcodes.RETRIEVE_BEGIN_ARRAY,
                                 Opcodes.RETRIEVE_BEGIN_HASH, Opcodes.LOCAL_SCALAR, Opcodes.LOCAL_ARRAY,
                                 Opcodes.LOCAL_HASH, Opcodes.STATE_INIT_SCALAR, Opcodes.STATE_INIT_ARRAY,
                                 Opcodes.STATE_INIT_HASH, Opcodes.STATE_RETRIEVE_SCALAR,
                                 Opcodes.STATE_RETRIEVE_ARRAY, Opcodes.STATE_IS_INITIALIZED,
                                 Opcodes.STATE_MARK_INITIALIZED, Opcodes.STATE_ALIAS_ARRAY,
                                 Opcodes.STATE_ALIAS_HASH, Opcodes.STATE_RETRIEVE_HASH -> {
                                pc = executeScopeOps(opcode, bytecode, pc, registers, code);
                            }

                            // Group 6-8: System Calls and IPC (132-150)
                            case Opcodes.CHOWN, Opcodes.WAITPID, Opcodes.FORK, Opcodes.GETPPID, Opcodes.GETPGRP,
                                 Opcodes.SETPGRP, Opcodes.GETPRIORITY, Opcodes.SETPRIORITY, Opcodes.GETSOCKOPT,
                                 Opcodes.SETSOCKOPT, Opcodes.SYSCALL, Opcodes.SEMGET, Opcodes.SEMOP, Opcodes.MSGGET,
                                 Opcodes.MSGSND, Opcodes.MSGRCV, Opcodes.SHMGET, Opcodes.SHMREAD, Opcodes.SHMWRITE,
                                 Opcodes.SYMLINK, Opcodes.CHROOT, Opcodes.MKDIR,
                                 Opcodes.MSGCTL, Opcodes.SHMCTL, Opcodes.SEMCTL,
                                 Opcodes.EXEC, Opcodes.FCNTL, Opcodes.IOCTL,
                                 Opcodes.GETPWENT, Opcodes.SETPWENT, Opcodes.ENDPWENT,
                                 Opcodes.GETLOGIN, Opcodes.GETPWNAM, Opcodes.GETPWUID,
                                 Opcodes.GETGRNAM, Opcodes.GETGRGID, Opcodes.GETGRENT,
                                 Opcodes.SETGRENT, Opcodes.ENDGRENT,
                                 Opcodes.GETHOSTBYNAME, Opcodes.GETHOSTBYADDR,
                                 Opcodes.GETSERVBYNAME,
                                 Opcodes.GETSERVBYPORT, Opcodes.GETPROTOBYNAME,
                                 Opcodes.GETPROTOBYNUMBER, Opcodes.ENDHOSTENT,
                                 Opcodes.ENDNETENT, Opcodes.ENDPROTOENT,
                                 Opcodes.ENDSERVENT, Opcodes.GETHOSTENT,
                                 Opcodes.GETNETBYADDR, Opcodes.GETNETBYNAME,
                                 Opcodes.GETNETENT, Opcodes.GETPROTOENT,
                                 Opcodes.GETSERVENT, Opcodes.SETHOSTENT,
                                 Opcodes.SETNETENT, Opcodes.SETPROTOENT,
                                 Opcodes.SETSERVENT -> {
                                pc = executeSystemOps(opcode, bytecode, pc, registers);
                            }

                            // Group 9: Special I/O (151-154), glob ops, strict deref
                            case Opcodes.TIME_OP -> {
                                int rd = bytecode[pc++];
                                registers[rd] = org.perlonjava.runtime.operators.Time.time();
                            }
                            case Opcodes.WAIT_OP -> {
                                int rd = bytecode[pc++];
                                registers[rd] = org.perlonjava.runtime.operators.WaitpidOperator.waitForChild();
                            }
                            case Opcodes.EVAL_STRING, Opcodes.SELECT_OP, Opcodes.LOAD_GLOB, Opcodes.LOAD_GLOB_CANONICAL, Opcodes.SLEEP_OP,
                                 Opcodes.ALARM_OP, Opcodes.DEREF_GLOB, Opcodes.DEREF_GLOB_NONSTRICT,
                                 Opcodes.LOAD_GLOB_DYNAMIC, Opcodes.DEREF_SCALAR_STRICT,
                                 Opcodes.DEREF_SCALAR_NONSTRICT, Opcodes.CODE_DEREF_NONSTRICT,
                                 Opcodes.CODE_DEREF_STRICT, Opcodes.REFALIAS_CODE_REFERENCE,
                                 Opcodes.REFALIAS_SCALAR_REFERENCE,
                                 Opcodes.NAMED_CODE_REFERENCE, Opcodes.DIRECT_NAMED_CODE_CALL,
                                 Opcodes.FOREACH_DEREF_SCALAR, Opcodes.FOREACH_DEREF_ARRAY,
                                 Opcodes.FOREACH_DEREF_HASH -> {
                                int resultReg = opcode == Opcodes.EVAL_STRING ? bytecode[pc] : -1;
                                pc = executeSpecialIO(opcode, bytecode, pc, registers, code);
                                if (opcode == Opcodes.EVAL_STRING
                                        && registers[resultReg] instanceof RuntimeControlFlowList flow
                                        && flow.getControlFlowType() == ControlFlowType.GOTO
                                        && code.gotoLabelPcs != null) {
                                    Integer targetPc = code.gotoLabelPcs.get(flow.getControlFlowLabel());
                                    if (targetPc != null) {
                                        if (jumpsIntoUnenteredLoopBody(code,
                                                flow.getControlFlowLabel(), targetPc, pc)) {
                                            throw new PerlCompilerException(
                                                    "Can't \"goto\" into the middle of a foreach loop");
                                        }
                                        rejectGotoIntoGiven(code, flow.getControlFlowLabel());
                                        if (code.gotoLabelsInsideConstruct != null
                                                && code.gotoLabelsInsideConstruct.contains(flow.getControlFlowLabel())) {
                                            throw new PerlCompilerException(
                                                    "Use of \"goto\" to jump into a construct is no longer permitted");
                                        }
                                        enterGotoLabelPackage(code, targetPc);
                                        pc = targetPc;
                                        releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
                                        break;
                                    }
                                }
                                if (opcode == Opcodes.EVAL_STRING
                                        && registers[resultReg] instanceof RuntimeControlFlowList flow
                                        && (flow.getControlFlowType() == ControlFlowType.LAST
                                        || flow.getControlFlowType() == ControlFlowType.NEXT
                                        || flow.getControlFlowType() == ControlFlowType.REDO)) {
                                    boolean handled = false;
                                    for (int i = controlBlockStack.size() - 1; i >= 0; i--) {
                                        int[] entry = controlBlockStack.get(i);
                                        if (!matchesInterpreterControlBlock(flow, code.stringPool[entry[0]])) continue;
                                        int targetPc = switch (flow.getControlFlowType()) {
                                            case LAST -> entry[1];
                                            case NEXT -> entry[2];
                                            case REDO -> entry[3];
                                            default -> -1;
                                        };
                                        if (targetPc >= 0) {
                                            while (controlBlockStack.size() > i + 1) {
                                                controlBlockStack.removeLast();
                                            }
                                            pc = targetPc;
                                            handled = true;
                                        }
                                        break;
                                    }
                                    if (!handled) {
                                        if (DynamicVariableManager.isExecutingDefer()) {
                                            int line = flow.marker.fileName != null
                                                    && flow.marker.fileName.startsWith("(eval ")
                                                    ? 1 : flow.marker.lineNumber;
                                            GlobalVariable.setGlobalVariable("main::@", "Can't \""
                                                    + flow.getControlFlowType().name().toLowerCase()
                                                    + "\" out of a \"defer\" block at "
                                                    + flow.marker.fileName + " line " + line + ".\n");
                                            registers[resultReg] = RuntimeScalarCache.scalarUndef;
                                            break;
                                        }
                                        // This marker originated in eval STRING.  No active
                                        // loop can consume it, so eval succeeds with undef and
                                        // records Perl's normal missing-label diagnostic in $@.
                                        GlobalVariable.setGlobalVariable("main::@", flow.marker.buildErrorMessage());
                                        registers[resultReg] = RuntimeScalarCache.scalarUndef;
                                    }
                                }
                            }

                            // =================================================================
                            // SLOW OPERATIONS (DEPRECATED)
                            // =================================================================

                            // DEPRECATED: SLOW_OP removed - all operations now use direct opcodes (114-154)

                            // =================================================================
                            // GENERATED BUILT-IN FUNCTION HANDLERS
                            // =================================================================
                            // Generated by dev/tools/generate_opcode_handlers.pl
                            // DO NOT EDIT MANUALLY - regenerate using the tool

                            // GENERATED_HANDLERS_START

                            // scalar_binary
                            case Opcodes.ATAN2, Opcodes.BINARY_AND, Opcodes.BINARY_OR, Opcodes.BINARY_XOR, Opcodes.EQ,
                                 Opcodes.NE, Opcodes.LT, Opcodes.LE, Opcodes.GT, Opcodes.GE, Opcodes.CMP, Opcodes.X -> {
                                pc = ScalarBinaryOpcodeHandler.execute(opcode, bytecode, pc, registers);
                            }

                            // scalar_unary
                            case Opcodes.INT, Opcodes.LOG, Opcodes.SQRT, Opcodes.COS, Opcodes.SIN, Opcodes.EXP,
                                 Opcodes.ABS, Opcodes.BINARY_NOT, Opcodes.BITWISE_NOT, Opcodes.INTEGER_BITWISE_NOT, Opcodes.ORD,
                                 Opcodes.ORD_BYTES, Opcodes.OCT, Opcodes.HEX, Opcodes.SRAND, Opcodes.CHR,
                                 Opcodes.CHR_BYTES, Opcodes.LENGTH_BYTES, Opcodes.QUOTEMETA,
                                 Opcodes.QUOTEMETA_UNICODE, Opcodes.FC, Opcodes.LC,
                                 Opcodes.LCFIRST, Opcodes.UC, Opcodes.UCFIRST, Opcodes.FC_BYTES, Opcodes.LC_BYTES,
                                 Opcodes.LCFIRST_BYTES, Opcodes.UC_BYTES, Opcodes.UCFIRST_BYTES, Opcodes.FC_UNICODE,
                                 Opcodes.LC_UNICODE, Opcodes.LCFIRST_UNICODE, Opcodes.UC_UNICODE, Opcodes.UCFIRST_UNICODE,
                                 Opcodes.TO_BYTES_STRING, Opcodes.SLEEP, Opcodes.TELL,
                                 Opcodes.RMDIR, Opcodes.CLOSEDIR, Opcodes.REWINDDIR, Opcodes.TELLDIR, Opcodes.CHDIR,
                                 Opcodes.EXIT -> {
                                pc = ScalarUnaryOpcodeHandler.execute(opcode, bytecode, pc, registers);
                            }
                            // GENERATED_HANDLERS_END

                            case Opcodes.TR_TRANSLITERATE -> {
                                pc = SlowOpcodeHandler.executeTransliterate(bytecode, pc, registers);
                            }

                            case Opcodes.STORE_SYMBOLIC_SCALAR -> {
                                pc = InlineOpcodeHandler.executeStoreSymbolicScalar(bytecode, pc, registers);
                            }

                            case Opcodes.LOAD_SYMBOLIC_SCALAR -> {
                                pc = InlineOpcodeHandler.executeLoadSymbolicScalar(bytecode, pc, registers);
                            }

                            case Opcodes.FILETEST_LASTHANDLE -> {
                                // File test on cached handle '_': rd = FileTestOperator.fileTestLastHandle(operator)
                                // Format: FILETEST_LASTHANDLE rd operator_string_idx
                                pc = SlowOpcodeHandler.executeFiletestLastHandle(bytecode, pc, registers, code);
                            }

                            case Opcodes.GLOB_SLOT_GET -> {
                                // Glob slot access: rd = glob.hashDerefGetNonStrict(key, pkg)
                                // Format: GLOB_SLOT_GET rd globReg keyReg
                                pc = SlowOpcodeHandler.executeGlobSlotGet(bytecode, pc, registers);
                            }

                            case Opcodes.SPRINTF -> {
                                // sprintf($format, @args): rd = SprintfOperator.sprintf(formatReg, argsListReg)
                                // Format: SPRINTF rd formatReg argsListReg
                                pc = OpcodeHandlerExtended.executeSprintf(bytecode, pc, registers);
                            }

                            case Opcodes.SPRINTF_BYTES -> {
                                pc = OpcodeHandlerExtended.executeSprintfBytes(bytecode, pc, registers);
                            }

                            case Opcodes.CHOP -> {
                                // chop($x): rd = StringOperators.chopScalar(scalarReg)
                                // Format: CHOP rd scalarReg
                                pc = OpcodeHandlerExtended.executeChop(bytecode, pc, registers);
                            }

                            case Opcodes.GET_REPLACEMENT_REGEX -> {
                                // Get replacement regex: rd = RuntimeRegex.getReplacementRegex(pattern, replacement, flags)
                                // Format: GET_REPLACEMENT_REGEX rd pattern_reg replacement_reg flags_reg args_reg implicit_u
                                pc = OpcodeHandlerExtended.executeGetReplacementRegex(bytecode, pc, registers);
                            }

                            case Opcodes.SUBSTR_VAR -> {
                                // substr with variable args: rd = Operator.substr(ctx, args...)
                                // Format: SUBSTR_VAR rd argsListReg ctx
                                pc = OpcodeHandlerExtended.executeSubstrVar(bytecode, pc, registers);
                            }

                            case Opcodes.SUBSTR_VAR_NO_WARN -> {
                                // substr with variable args, no warning: rd = Operator.substrNoWarn(ctx, args...)
                                // Format: SUBSTR_VAR_NO_WARN rd argsListReg ctx
                                pc = OpcodeHandlerExtended.executeSubstrVarNoWarn(bytecode, pc, registers);
                            }

                            case Opcodes.TIE -> {
                                pc = InlineOpcodeHandler.executeTie(bytecode, pc, registers);
                            }

                            case Opcodes.UNTIE -> {
                                pc = InlineOpcodeHandler.executeUntie(bytecode, pc, registers);
                            }

                            case Opcodes.TIED -> {
                                pc = InlineOpcodeHandler.executeTied(bytecode, pc, registers);
                            }

                            case Opcodes.LOCK -> {
                                pc = InlineOpcodeHandler.executeLock(bytecode, pc, registers);
                            }

                            // Miscellaneous operators with context-sensitive signatures
                            case Opcodes.CHMOD, Opcodes.UNLINK, Opcodes.UTIME, Opcodes.RENAME, Opcodes.LINK,
                                 Opcodes.READLINK, Opcodes.UMASK, Opcodes.GETC, Opcodes.FILENO, Opcodes.QX,
                                 Opcodes.SYSTEM, Opcodes.KILL, Opcodes.CALLER, Opcodes.EACH, Opcodes.PACK, Opcodes.UNPACK,
                                 Opcodes.VEC, Opcodes.LOCALTIME, Opcodes.GMTIME, Opcodes.RESET, Opcodes.TIMES, Opcodes.CRYPT,
                                 Opcodes.CLOSE, Opcodes.BINMODE, Opcodes.SEEK, Opcodes.EOF_OP, Opcodes.SYSREAD,
                                 Opcodes.SYSWRITE, Opcodes.SYSOPEN, Opcodes.SOCKET, Opcodes.BIND, Opcodes.CONNECT,
                                 Opcodes.SEND,
                                 Opcodes.RECV,
                                 Opcodes.SHUTDOWN,
                                 Opcodes.LISTEN, Opcodes.PIPE, Opcodes.SOCKETPAIR,
                                 Opcodes.GETSOCKNAME, Opcodes.GETPEERNAME,
                                 Opcodes.WRITE, Opcodes.FORMLINE, Opcodes.PRINTF, Opcodes.ACCEPT,
                                 Opcodes.SYSSEEK, Opcodes.TRUNCATE, Opcodes.FLOCK, Opcodes.READ, Opcodes.OPENDIR, Opcodes.READDIR,
                                 Opcodes.SEEKDIR -> {
                                pc = MiscOpcodeHandler.execute(opcode, bytecode, pc, registers);
                            }

                            case Opcodes.SET_PACKAGE -> {
                                // Non-scoped package declaration: package Foo;
                                // Update the runtime current-package tracker so caller() returns the right package.
                                // Uses cached RuntimeScalar reference to avoid ThreadLocal lookup
                                int nameIdx = bytecode[pc++];
                                InterpreterState.setCurrentPackageStatic(code.stringPool[nameIdx]);
                            }

                            case Opcodes.PUSH_PACKAGE -> {
                                pc = InlineOpcodeHandler.executePushPackage(bytecode, pc, registers, code);
                            }

                            case Opcodes.FLIP_FLOP -> {
                                pc = InlineOpcodeHandler.executeFlipFlop(bytecode, pc, registers);
                            }

                            case Opcodes.RUNTIME_RANGE_OR_FLIP_FLOP -> {
                                pc = InlineOpcodeHandler.executeRuntimeRangeOrFlipFlop(bytecode, pc, registers);
                            }

                            case Opcodes.LOCAL_GLOB -> {
                                pc = InlineOpcodeHandler.executeLocalGlob(bytecode, pc, registers, code);
                            }

                            case Opcodes.LOCAL_GLOB_DYNAMIC -> {
                                pc = InlineOpcodeHandler.executeLocalGlobDynamic(bytecode, pc, registers);
                            }

                            case Opcodes.LOCAL_SCALAR_DYNAMIC -> {
                                pc = InlineOpcodeHandler.executeLocalScalarDynamic(bytecode, pc, registers);
                            }

                            case Opcodes.LOCAL_GLOB_REF -> {
                                pc = InlineOpcodeHandler.executeLocalGlobRef(bytecode, pc, registers);
                            }

                            case Opcodes.GET_LOCAL_LEVEL -> {
                                int rd = bytecode[pc++];
                                registers[rd] = new RuntimeScalar(
                                        DynamicVariableManager.getLocalLevel() - savedLocalLevel);
                            }

                            case Opcodes.POP_PACKAGE -> {
                                // Scoped package block exit — restore handled by POP_LOCAL_LEVEL.
                            }

                            case Opcodes.DO_FILE -> {
                                pc = InlineOpcodeHandler.executeDoFile(bytecode, pc, registers);
                            }

                            // =================================================================
                            // DEFER SUPPORT
                            // =================================================================

                            case Opcodes.PUSH_DEFER -> {
                                pc = InlineOpcodeHandler.executePushDefer(bytecode, pc, registers);
                            }

                            case Opcodes.PUSH_CANCEL -> {
                                pc = InlineOpcodeHandler.executePushCancel(bytecode, pc, registers);
                            }

                            case Opcodes.APPLY_COMPILER_FLAGS -> {
                                int warningBitsIdx = bytecode[pc++];
                                int hints = bytecode[pc++];
                                int hintHashId = bytecode[pc++];
                                int warningScopeId = bytecode[pc++];
                                int featureFlags = bytecode[pc++];
                                WarningBitsRegistry.setCallSiteBits(code.stringPool[warningBitsIdx]);
                                WarningBitsRegistry.setCallSiteHints(hints);
                                HintHashRegistry.setCallSiteHintHashId(hintHashId);
                                org.perlonjava.runtime.FeatureFlagsRegistry
                                        .setCallSiteFeatureFlags(featureFlags);
                                if (warningScopeId > 0) {
                                    // Localize the scope before installing its
                                    // warning mask so dynamic unwind can restore
                                    // the enclosing interpreter mask.
                                    RuntimeScalar warningScope = GlobalRuntimeScalar.makeLocal(
                                            GlobalContext.WARNING_SCOPE);
                                    warningScope.set(new RuntimeScalar(warningScopeId));
                                }
                                WarningBitsRegistry.setRuntimeWarningBits(code.stringPool[warningBitsIdx]);
                            }

                            case Opcodes.SET_CALL_SITE_HINTS ->
                                WarningBitsRegistry.setCallSiteHints(bytecode[pc++]);

                            case Opcodes.SET_CALL_SITE_HINT_HASH ->
                                HintHashRegistry.setCallSiteHintHashId(bytecode[pc++]);

                            case Opcodes.SET_CALL_SITE_FEATURE_FLAGS ->
                                org.perlonjava.runtime.FeatureFlagsRegistry
                                        .setCallSiteFeatureFlags(bytecode[pc++]);

                            case Opcodes.SET_CALL_SITE_WARNING_BITS -> {
                                String warningBits = code.stringPool[bytecode[pc++]];
                                WarningBitsRegistry.setCallSiteBits(warningBits);
                                WarningBitsRegistry.setRuntimeWarningBits(warningBits);
                            }

                            // =================================================================
                            // DEBUGGER SUPPORT
                            // =================================================================

                            case Opcodes.DEBUG -> {
                                // Debug hook at statement boundary
                                // Format: DEBUG file_string_idx line_number site_index
                                int fileIdx = bytecode[pc++];
                                int line = bytecode[pc++];
                                int siteIndex = bytecode[pc++];
                                String file = code.stringPool[fileIdx];
                                DebugHooks.debug(file, line, code, registers, siteIndex);
                            }

                            // =================================================================
                            // SUPEROPERATORS - Combined instruction sequences for performance
                            // =================================================================

                            case Opcodes.HASH_DEREF_FETCH -> {
                                // Combined: DEREF_HASH + LOAD_STRING + HASH_GET
                                // Format: HASH_DEREF_FETCH rd hashref_reg key_string_idx
                                // Equivalent to: $hashref->{key}
                                int rd = bytecode[pc++];
                                int hashrefReg = bytecode[pc++];
                                int keyIdx = bytecode[pc++];

                                RuntimeBase hashrefBase = registers[hashrefReg];

                                // Dereference to get the hash
                                RuntimeHash hash;
                                if (hashrefBase instanceof RuntimeHash) {
                                    hash = (RuntimeHash) hashrefBase;
                                } else {
                                    hash = hashrefBase.scalar().hashDeref();
                                }

                                // Get the element using string key from pool
                                String key = code.stringPool[keyIdx];
                                registers[rd] = hash.get(key);
                            }

                            case Opcodes.ARRAY_DEREF_FETCH -> {
                                // Combined: DEREF_ARRAY + LOAD_INT + ARRAY_GET
                                // Format: ARRAY_DEREF_FETCH rd arrayref_reg index_immediate
                                // Equivalent to: $arrayref->[n]
                                int rd = bytecode[pc++];
                                int arrayrefReg = bytecode[pc++];
                                int index = readInt(bytecode, pc);
                                pc += 1;

                                RuntimeBase arrayrefBase = registers[arrayrefReg];

                                // Dereference to get the array
                                RuntimeArray array;
                                if (arrayrefBase instanceof RuntimeArray) {
                                    array = (RuntimeArray) arrayrefBase;
                                } else {
                                    array = arrayrefBase.scalar().arrayDeref();
                                }

                                // Get the element at index
                                registers[rd] = array.get(index);
                            }

                            case Opcodes.HASH_DEREF_FETCH_NONSTRICT -> {
                                // Combined: DEREF_HASH_NONSTRICT + LOAD_STRING + HASH_GET
                                // Format: HASH_DEREF_FETCH_NONSTRICT rd hashref_reg key_string_idx pkg_string_idx
                                // Equivalent to: $hashref->{key} without strict refs
                                int rd = bytecode[pc++];
                                int hashrefReg = bytecode[pc++];
                                int keyIdx = bytecode[pc++];
                                int pkgIdx = bytecode[pc++];

                                RuntimeBase hashrefBase = registers[hashrefReg];

                                // Dereference to get the hash (non-strict allows symbolic refs)
                                RuntimeHash hash;
                                if (hashrefBase instanceof RuntimeHash) {
                                    hash = (RuntimeHash) hashrefBase;
                                } else {
                                    hash = hashrefBase.scalar().hashDerefNonStrict(code.stringPool[pkgIdx]);
                                }

                                // Get the element using string key from pool
                                String key = code.stringPool[keyIdx];
                                registers[rd] = hash.get(key);
                            }

                            case Opcodes.HASH_DEREF_FETCH_FOR_LOCAL -> {
                                // Like HASH_DEREF_FETCH but returns a RuntimeHashProxyEntry for local() context.
                                // Format: HASH_DEREF_FETCH_FOR_LOCAL rd hashref_reg key_string_idx
                                int rd = bytecode[pc++];
                                int hashrefReg = bytecode[pc++];
                                int keyIdx = bytecode[pc++];

                                RuntimeBase hashrefBase = registers[hashrefReg];

                                RuntimeHash hash;
                                if (hashrefBase instanceof RuntimeHash) {
                                    hash = (RuntimeHash) hashrefBase;
                                } else {
                                    hash = hashrefBase.scalar().hashDeref();
                                }

                                String key = code.stringPool[keyIdx];
                                registers[rd] = hash.getForLocal(key);
                            }

                            case Opcodes.HASH_DEREF_FETCH_NONSTRICT_FOR_LOCAL -> {
                                // Like HASH_DEREF_FETCH_NONSTRICT but returns a RuntimeHashProxyEntry for local() context.
                                // Format: HASH_DEREF_FETCH_NONSTRICT_FOR_LOCAL rd hashref_reg key_string_idx pkg_string_idx
                                int rd = bytecode[pc++];
                                int hashrefReg = bytecode[pc++];
                                int keyIdx = bytecode[pc++];
                                int pkgIdx = bytecode[pc++];

                                RuntimeBase hashrefBase = registers[hashrefReg];

                                RuntimeHash hash;
                                if (hashrefBase instanceof RuntimeHash) {
                                    hash = (RuntimeHash) hashrefBase;
                                } else {
                                    hash = hashrefBase.scalar().hashDerefNonStrict(code.stringPool[pkgIdx]);
                                }

                                String key = code.stringPool[keyIdx];
                                registers[rd] = hash.getForLocal(key);
                            }

                            case Opcodes.ARRAY_DEREF_FETCH_NONSTRICT -> {
                                // Combined: DEREF_ARRAY_NONSTRICT + LOAD_INT + ARRAY_GET
                                // Format: ARRAY_DEREF_FETCH_NONSTRICT rd arrayref_reg index_immediate pkg_string_idx
                                // Equivalent to: $arrayref->[n] without strict refs
                                int rd = bytecode[pc++];
                                int arrayrefReg = bytecode[pc++];
                                int index = readInt(bytecode, pc);
                                pc += 1;
                                int pkgIdx = bytecode[pc++];

                                RuntimeBase arrayrefBase = registers[arrayrefReg];

                                // Dereference to get the array (non-strict allows symbolic refs)
                                RuntimeArray array;
                                if (arrayrefBase instanceof RuntimeArray) {
                                    array = (RuntimeArray) arrayrefBase;
                                } else {
                                    array = arrayrefBase.scalar().arrayDerefNonStrict(code.stringPool[pkgIdx]);
                                }

                                // Get the element at index
                                registers[rd] = array.get(index);
                            }

                            // =================================================================
                            // KV-SLICE DELETE OPERATIONS (390-392)
                            // =================================================================

                            case Opcodes.ARRAY_SLICE_DELETE -> {
                                pc = SlowOpcodeHandler.executeArraySliceDelete(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_SLICE_DELETE_LOCAL -> {
                                pc = SlowOpcodeHandler.executeHashSliceDeleteLocal(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_SLICE_DELETE_LOCAL -> {
                                pc = SlowOpcodeHandler.executeArraySliceDeleteLocal(bytecode, pc, registers);
                            }

                            case Opcodes.HASH_KV_SLICE_DELETE -> {
                                pc = SlowOpcodeHandler.executeHashKVSliceDelete(bytecode, pc, registers);
                            }

                            case Opcodes.ARRAY_KV_SLICE_DELETE -> {
                                pc = SlowOpcodeHandler.executeArrayKVSliceDelete(bytecode, pc, registers);
                            }

                            case Opcodes.DISPATCH_VAR_ATTRS -> {
                                pc = SlowOpcodeHandler.executeDispatchVarAttrs(bytecode, pc, registers, code.constants);
                            }

                            case Opcodes.VIVIFY_LVALUE -> {
                                // Vivify an lvalue proxy so the entry exists in the parent container.
                                // For plain scalars this is a no-op.
                                int reg = bytecode[pc++];
                                RuntimeBase val = registers[reg];
                                if (val instanceof RuntimeScalar rs) {
                                    rs.vivifyLogicalAssignmentLvalue();
                                }
                            }

                            case Opcodes.AWAIT -> {
                                int rd = bytecode[pc++];
                                int futureReg = bytecode[pc++];
                                int context = bytecode[pc++];
                                if (context == RuntimeContextType.RUNTIME) {
                                    context = ((RuntimeScalar) registers[2]).getInt();
                                }
                                RuntimeScalar awaited = registers[futureReg] instanceof RuntimeScalar scalar
                                        ? scalar : registers[futureReg].scalar();
                                if (!code.futureAsyncAwaitSub) {
                                    registers[rd] = FutureAsyncAwaitRuntime.wait(awaited, context);
                                    break;
                                }
                                if (FutureAsyncAwaitRuntime.isReady(awaited)) {
                                    registers[rd] = FutureAsyncAwaitRuntime.get(awaited, context);
                                    break;
                                }

                                frame.pc = pc;
                                frame.suspendedRegexState = new RegexState();
                                frame.suspendedPackage = currentPackageScalar.toString();
                                frame.suspended = true;
                                return new InterpreterSuspension(frame, awaited, rd, context);
                            }

                            case Opcodes.LIST_SLICE -> {
                                // List slice: rd = list.getSlice(indices)
                                // Used for (list)[indices] syntax
                                int rd = bytecode[pc++];
                                int listReg = bytecode[pc++];
                                int indicesReg = bytecode[pc++];
                                RuntimeList list = registers[listReg].getList();
                                RuntimeList indices = registers[indicesReg].getList();
                                registers[rd] = list.getSlice(indices);
                            }

                            case Opcodes.REJECT_LOCALIZE_REFERENCE -> {
                                pc = SlowOpcodeHandler.executeRejectLocalizeReference(bytecode, pc, registers);
                            }

                            default -> {
                                int opcodeInt = opcode;
                                throw new RuntimeException(
                                        "Unknown opcode: " + opcodeInt +
                                                " at pc=" + (pc - 1) +
                                                " in " + code.sourceName + ":" + code.sourceLine
                                );
                            }
                        }
                    }

                    // Fell through end of bytecode - return empty list
                    return new RuntimeList();

                } catch (ClassCastException e) {
                    // Special handling for ClassCastException to show which opcode is failing
                    // Check if we're inside an eval block first
                    if (!evalCatchStack.isEmpty()) {
                        int catchPc = evalCatchStack.pop();
                        popEvalCallerFrame(frame);
                        unwindEvalMethodInvocantHolds(
                                evalMethodInvocantHoldDepthStack, methodInvocantHolds);
                        // Restore local variables pushed inside the eval block
                        if (!evalLocalLevelStack.isEmpty()) {
                            int relativeLevel = evalLocalLevelStack.pop();
                            DynamicVariableManager.popToLocalLevel(
                                    savedLocalLevel + relativeLevel);
                        }
                        RuntimeCode.decrementEvalDepth();
                        WarnDie.catchEval(e);
                        pc = catchPc;
                        continue outer;
                    }

                    // Not in eval - show detailed error with bytecode context
                    int errorPc = Math.max(0, pc - 1);

                    // Show bytecode context (10 bytes before errorPc)
                    StringBuilder bcContext = new StringBuilder();
                    bcContext.append("\nBytecode context: [");
                    for (int i = Math.max(0, errorPc - 10); i < Math.min(bytecode.length, errorPc + 5); i++) {
                        if (i == errorPc) {
                            bcContext.append(" >>>");
                        }
                        bcContext.append(String.format(" %02X", bytecode[i] & 0xFF));
                        if (i == errorPc) {
                            bcContext.append("<<<");
                        }
                    }
                    bcContext.append(" ]");

                    StackTraceElement[] st = e.getStackTrace();
                    String javaLine = (st.length > 0) ? " [java:" + st[0].getFileName() + ":" + st[0].getLineNumber() + "]" : "";
                    String errorMessage = "ClassCastException" + bcContext + ": " + e.getMessage() + javaLine;
                    frame.propagatingException = e;
                    throw new RuntimeException(formatInterpreterError(code, errorPc, new Exception(errorMessage)), e);
                } catch (PerlExitException e) {
                    // exit() should NEVER be caught by eval{} - always propagate
                    frame.propagatingException = e;
                    throw e;
                } catch (Throwable e) {
                    // Check if we're inside an eval block
                    if (!evalCatchStack.isEmpty()) {
                        Throwable evalException = e;
                        // Inside eval block - catch the exception
                        int catchPc = evalCatchStack.pop(); // Pop the catch handler
                        popEvalCallerFrame(frame);
                        unwindEvalMethodInvocantHolds(
                                evalMethodInvocantHoldDepthStack, methodInvocantHolds);

                        // Scope exit cleanup for lexical variables allocated inside the eval body.
                        // When die throws a PerlDieException, the SCOPE_EXIT_CLEANUP opcodes
                        // between the throw site and the eval boundary are skipped. This loop
                        // ensures DESTROY fires for blessed objects that went out of scope.
                        if (!evalBaseRegStack.isEmpty()) {
                            int baseReg = evalBaseRegStack.pop();
                            boolean needsFlush = false;
                            BitSet myVars = code.myVarRegisters;
                            for (int i = myVars.nextSetBit(baseReg);
                                 i >= 0 && i < registers.length;
                                 i = myVars.nextSetBit(i + 1)) {
                                RuntimeBase reg = registers[i];
                                if (reg == null) continue;
                                if (reg instanceof RuntimeScalar rs) {
                                    RuntimeScalar.scopeExitCleanup(rs);
                                    needsFlush = true;
                                } else if (reg instanceof RuntimeHash rh) {
                                    MortalList.scopeExitCleanupHash(rh);
                                    needsFlush = true;
                                } else if (reg instanceof RuntimeArray ra) {
                                    MortalList.scopeExitCleanupArray(ra);
                                    needsFlush = true;
                                }
                                MyVarCleanupStack.unregister(reg);
                                registers[i] = null;
                            }
                            if (needsFlush) {
                                MortalList.flush();
                            }
                        }

                        // Restore local variables pushed inside the eval block
                        if (!evalLocalLevelStack.isEmpty()) {
                            int relativeLevel = evalLocalLevelStack.pop();
                            try {
                                DynamicVariableManager.popToLocalLevel(
                                        savedLocalLevel + relativeLevel);
                            } catch (Throwable cleanupException) {
                                // Restoring local tied values can itself die.
                                // This is still inside eval {}, where Perl
                                // exposes the last cleanup exception through
                                // $@ instead of letting it escape the handler.
                                evalException = cleanupException;
                            }
                        }

                        // Track eval depth for $^S
                        RuntimeCode.decrementEvalDepth();

                        // Call WarnDie.catchEval() to set $@
                        WarnDie.catchEval(evalException);

                        pc = catchPc;
                        continue outer;
                    }

                    // Not in eval block - propagate exception
                    // Re-throw RuntimeExceptions as-is (includes PerlDieException)
                    if (e instanceof RuntimeException re) {
                        re = WarnDie.maybeInvokeUnhandledDieHandler(re);
                        frame.propagatingException = re;
                        throw re;
                    }
                    frame.propagatingException = e;

                    // Check if we're running inside an eval STRING context
                    // (sourceName starts with "(eval " when code is from eval STRING)
                    // In this case, don't wrap the exception - let the outer eval handler catch it
                    boolean insideEvalString = code.sourceName != null
                            && (code.sourceName.startsWith("(eval ") || code.sourceName.endsWith("(eval)"));
                    if (insideEvalString) {
                        // Re-throw as-is - will be caught by EvalStringHandler.evalString()
                        throw e;
                    }

                    // Regex callback recursion already carries the complete
                    // Perl-facing diagnostic. Keep a RuntimeException boundary
                    // so an enclosing eval observes failure exactly as before,
                    // but omit the generic interpreter/PC decoration.
                    if (e instanceof StackOverflowError
                            && "Infinite recursion via empty pattern".equals(
                                    e.getMessage())) {
                        throw new RuntimeException(e.getMessage(), e);
                    }

                    // Wrap other exceptions with interpreter context including bytecode context
                    int debugPc = Math.max(0, pc - 3);
                    String opcodeInfo = " [opcodes at pc-3..pc: ";
                    for (int di = debugPc; di <= Math.min(pc + 2, bytecode.length - 1); di++) {
                        if (di == pc) opcodeInfo += ">>>";
                        opcodeInfo += bytecode[di] + " ";
                        if (di == pc) opcodeInfo += "<<< ";
                    }
                    opcodeInfo += "]";
                    String errorMessage = formatInterpreterError(code, pc, e) + opcodeInfo;
                    throw new RuntimeException(errorMessage, e);
                }
            } // end outer while (eval/die retry loop)
        } finally {
            if (!frame.suspended) {
                releaseMethodInvocantHoldsAbove(methodInvocantHolds, 0);
            }

            // Release captures for interpreter closures created in this frame
            // that were never stored via set() (refCount stayed at 0).
            // This handles eval STRING map/grep block closures that over-capture
            // all visible variables but are temporary and should release captures.
            // Closures stored via set() have refCount > 0 and are skipped.
            // This matches the JVM-compiled path where scopeExitCleanup releases
            // captures for CODE refs with refCount=0 (see RuntimeScalar.java
            // scopeExitCleanup special case for CODE refs).
            if (!frame.suspended && !createdClosures.isEmpty()) {
                for (RuntimeCode closure : createdClosures) {
                    if ((closure.capturedScalars != null || closure.capturedAggregates != null)
                            && closure.refCount == 0
                            && closure.stashRefCount <= 0
                            && (frame.returnedClosures == null || !frame.returnedClosures.contains(closure))) {
                        closure.releaseCaptures();
                    }
                }
            }

            // Scope-exit cleanup for my-variables when an exception propagates out
            // of this subroutine frame without being caught by an eval.
            // This ensures DESTROY fires for blessed objects going out of scope
            // during die unwinding (e.g. TxnScopeGuard in a sub called from eval).
            if (!frame.suspended && frame.propagatingException != null) {
                // Only clean up registers that are actual "my" variables.
                // Temporary registers may alias hash/array elements (via HASH_GET,
                // HASH_DEREF_FETCH, etc.) and calling scopeExitCleanup on them
                // would incorrectly decrement refCounts, causing premature DESTROY.
                BitSet myVars = code.myVarRegisters;
                boolean needsFlush = false;
                for (int i = myVars.nextSetBit(firstMyVarReg);
                     i >= 0 && i < registers.length;
                     i = myVars.nextSetBit(i + 1)) {
                    RuntimeBase reg = registers[i];
                    if (reg == null) continue;
                    if (reg instanceof RuntimeScalar rs) {
                        RuntimeScalar.scopeExitCleanup(rs);
                        needsFlush = true;
                    } else if (reg instanceof RuntimeHash rh) {
                        MortalList.scopeExitCleanupHash(rh);
                        needsFlush = true;
                    } else if (reg instanceof RuntimeArray ra) {
                        MortalList.scopeExitCleanupArray(ra);
                        needsFlush = true;
                    }
                    MyVarCleanupStack.unregister(reg);
                    registers[i] = null;
                }
                if (needsFlush) {
                    MortalList.flush();
                }
            }

            // Outer finally: restore interpreter state saved at method entry.
            // Unwinds all `local` variables pushed during this frame, restores
            // the current package, and pops the InterpreterState call stack.
            if (frame.suspended) {
                frame.suspendedRuntimeWarningBits =
                        WarningBitsRegistry.getRuntimeWarningBits();
                Set<String> disabled =
                        WarningBitsRegistry.getRuntimeDisabledWarningCategories();
                frame.suspendedRuntimeDisabledWarningCategories =
                        disabled == null ? null : Set.copyOf(disabled);
                frame.suspendedDynamicStates =
                        DynamicVariableManager.suspendAbove(savedLocalLevel);
            } else {
                DynamicVariableManager.teardownFrameToLocalLevel(savedLocalLevel);
            }
            currentPackageScalar.set(savedPackage);
            if (frame.suspended && !frame.evalCatchStack.isEmpty()) {
                RuntimeCode.adjustEvalDepth(-frame.evalCatchStack.size());
            }
            while (frame.virtualEvalFrameDepth > 0) {
                InterpreterState.pop();
                frame.virtualEvalFrameDepth--;
            }
            InterpreterState.pop();
            WarningBitsRegistry.setRuntimeWarningBits(savedRuntimeWarningBits);
            WarningBitsRegistry.setRuntimeDisabledWarningCategories(
                    savedRuntimeDisabledWarningCategories);
            if (!frame.suspended) {
                code.releaseRegisters();
            }
        }
    }

    private static void releaseMethodInvocantHoldsAbove(
            ArrayList<RuntimeBase> methodInvocantHolds, int depth) {
        boolean released = false;
        while (methodInvocantHolds.size() > depth) {
            RuntimeCode.releaseAbandonedMethodInvocantHold(
                    methodInvocantHolds.removeLast());
            released = true;
        }
        if (released) {
            MortalList.flush();
        }
    }

    private static void unwindEvalMethodInvocantHolds(
            ArrayDeque<Integer> evalMethodInvocantHoldDepthStack,
            ArrayList<RuntimeBase> methodInvocantHolds) {
        if (!evalMethodInvocantHoldDepthStack.isEmpty()) {
            releaseMethodInvocantHoldsAbove(
                    methodInvocantHolds, evalMethodInvocantHoldDepthStack.pop());
        }
    }

    /**
     * Handle comparison and logical operations (opcodes 31-41).
     * Separated to keep main execute() under JIT compilation limit.
     *
     * @return Updated program counter
     */
    private static int executeComparisons(int opcode, int[] bytecode, int pc,
                                          RuntimeBase[] registers) {
        switch (opcode) {
            case Opcodes.COMPARE_NUM -> {
                // Numeric comparison: rd = rs1 <=> rs2
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.spaceship(s1, s2);
                return pc;
            }

            case Opcodes.COMPARE_STR -> {
                // String comparison: rd = rs1 cmp rs2
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.cmp(s1, s2);
                return pc;
            }

            case Opcodes.EQ_NUM -> {
                // Numeric equality: rd = (rs1 == rs2)
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.equalTo(s1, s2);
                return pc;
            }

            case Opcodes.LT_NUM -> {
                // Less than: rd = (rs1 < rs2)
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.lessThan(s1, s2);
                return pc;
            }

            case Opcodes.GT_NUM -> {
                // Greater than: rd = (rs1 > rs2)
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.greaterThan(s1, s2);
                return pc;
            }

            case Opcodes.LE_NUM -> {
                // Less than or equal: rd = (rs1 <= rs2)
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.lessThanOrEqual(s1, s2);
                return pc;
            }

            case Opcodes.GE_NUM -> {
                // Greater than or equal: rd = (rs1 >= rs2)
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.greaterThanOrEqual(s1, s2);
                return pc;
            }

            case Opcodes.NE_NUM -> {
                // Not equal: rd = (rs1 != rs2)
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.notEqualTo(s1, s2);
                return pc;
            }

            case Opcodes.EQ_STR -> {
                // String equality: rd = (rs1 eq rs2)
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.eq(s1, s2);
                return pc;
            }

            case Opcodes.NE_STR -> {
                // String inequality: rd = (rs1 ne rs2)
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = CompareOperators.ne(s1, s2);
                return pc;
            }

            case Opcodes.EQU_STR, Opcodes.NEU_STR, Opcodes.STRICT_EQ_NUM, Opcodes.STRICT_NE_NUM,
                 Opcodes.INTEGER_STRICT_EQ_NUM, Opcodes.INTEGER_STRICT_NE_NUM -> {
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeBase val1 = registers[rs1];
                RuntimeBase val2 = registers[rs2];
                RuntimeScalar s1 = (val1 instanceof RuntimeScalar) ? (RuntimeScalar) val1 : val1.scalar();
                RuntimeScalar s2 = (val2 instanceof RuntimeScalar) ? (RuntimeScalar) val2 : val2.scalar();
                registers[rd] = switch (opcode) {
                    case Opcodes.EQU_STR -> CompareOperators.equ(s1, s2);
                    case Opcodes.NEU_STR -> CompareOperators.neu(s1, s2);
                    case Opcodes.STRICT_EQ_NUM -> CompareOperators.strictEqual(s1, s2);
                    case Opcodes.STRICT_NE_NUM -> CompareOperators.strictNotEqual(s1, s2);
                    case Opcodes.INTEGER_STRICT_EQ_NUM -> CompareOperators.strictEqualInteger(s1, s2);
                    default -> CompareOperators.strictNotEqualInteger(s1, s2);
                };
                return pc;
            }

            case Opcodes.NOT -> {
                int rd = bytecode[pc++];
                int rs = bytecode[pc++];
                RuntimeScalar val = (registers[rs] instanceof RuntimeScalar)
                        ? (RuntimeScalar) registers[rs]
                        : registers[rs].scalar();
                registers[rd] = val.getBoolean() ?
                        RuntimeScalarCache.scalarFalse : RuntimeScalarCache.scalarTrue;
                return pc;
            }
            case Opcodes.NOT_NO_OVERLOAD -> {
                int rd = bytecode[pc++];
                int rs = bytecode[pc++];
                RuntimeScalar val = (registers[rs] instanceof RuntimeScalar)
                        ? (RuntimeScalar) registers[rs] : registers[rs].scalar();
                registers[rd] = val.getBooleanNoOverload()
                        ? RuntimeScalarCache.scalarFalse : RuntimeScalarCache.scalarTrue;
                return pc;
            }

            case Opcodes.AND -> {
                // AND is short-circuit and handled in compiler typically
                // If we get here, just do boolean and
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeScalar v1 = registers[rs1].scalar();
                RuntimeScalar v2 = registers[rs2].scalar();
                registers[rd] = (v1.getBoolean() && v2.getBoolean()) ?
                        RuntimeScalarCache.scalarTrue : RuntimeScalarCache.scalarFalse;
                return pc;
            }

            case Opcodes.OR -> {
                // OR is short-circuit and handled in compiler typically
                // If we get here, just do boolean or
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                RuntimeScalar v1 = registers[rs1].scalar();
                RuntimeScalar v2 = registers[rs2].scalar();
                registers[rd] = (v1.getBoolean() || v2.getBoolean()) ?
                        RuntimeScalarCache.scalarTrue : RuntimeScalarCache.scalarFalse;
                return pc;
            }

            default -> throw new RuntimeException("Unknown comparison opcode: " + opcode);
        }
    }

    /**
     * Execute type and reference operations.
     * Handles: DEFINED, DEFINED_GLOB, REF, BLESS, ISA, PROTOTYPE, QUOTE_REGEX
     */
    private static int executeTypeOps(int opcode, int[] bytecode, int pc,
                                      RuntimeBase[] registers, InterpretedCode code) {
        switch (opcode) {
            case Opcodes.DEFINED -> {
                int rd = bytecode[pc++];
                int rs = bytecode[pc++];
                RuntimeBase v = registers[rs];
                boolean defined = v != null && v.scalar().getDefinedBoolean();
                registers[rd] = defined ? RuntimeScalarCache.scalarTrue : RuntimeScalarCache.scalarFalse;
                return pc;
            }
            case Opcodes.DEFINED_CODE -> {
                // defined(&name) - check stash via definedGlobalCodeRefAsScalar
                // This does a fresh stash lookup, matching the JVM backend and Perl 5
                // behavior where eval("defined(&name)") checks the stash, not cached CVs.
                int rd = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                String name = code.stringPool[nameIdx];
                registers[rd] = GlobalVariable.definedGlobalCodeRefAsScalar(name);
                return pc;
            }
            case Opcodes.DEFINED_CODE_DYNAMIC -> {
                int rd = bytecode[pc++];
                int nameReg = bytecode[pc++];
                int pkgIdx = bytecode[pc++];
                String pkg = code.stringPool[pkgIdx];
                RuntimeScalar name = registers[nameReg].scalar();
                registers[rd] = GlobalVariable.definedGlobalCodeRefAsScalar(name, pkg);
                return pc;
            }
            case Opcodes.EXISTS_CODE_DYNAMIC -> {
                int rd = bytecode[pc++];
                int nameReg = bytecode[pc++];
                int pkgIdx = bytecode[pc++];
                String pkg = code.stringPool[pkgIdx];
                RuntimeScalar name = registers[nameReg].scalar();
                registers[rd] = GlobalVariable.existsGlobalCodeRefAsScalar(name, pkg);
                return pc;
            }
            case Opcodes.DEFINED_GLOB -> {
                // defined *$var - check if glob is defined without throwing strict refs
                // Format: DEFINED_GLOB rd scalar_reg pkg_string_idx
                int rd = bytecode[pc++];
                int scalarReg = bytecode[pc++];
                int pkgIdx = bytecode[pc++];
                String pkg = code.stringPool[pkgIdx];
                RuntimeScalar scalar = registers[scalarReg].scalar();
                registers[rd] = GlobalVariable.definedGlob(scalar, pkg);
                return pc;
            }
            case Opcodes.DEFINED_SCALAR_DEREF -> {
                int rd = bytecode[pc++];
                int scalarReg = bytecode[pc++];
                int pkgIdx = bytecode[pc++];
                registers[rd] = GlobalVariable.definedGlobalScalarDeref(
                        registers[scalarReg].scalar(), code.stringPool[pkgIdx]);
                return pc;
            }
            case Opcodes.REF -> {
                int rd = bytecode[pc++];
                int rs = bytecode[pc++];
                registers[rd] = ReferenceOperators.ref(registers[rs].scalar());
                return pc;
            }
            case Opcodes.BLESS -> {
                int rd = bytecode[pc++];
                int refReg = bytecode[pc++];
                int pkgReg = bytecode[pc++];
                RuntimeScalar ref = registers[refReg].scalar();
                RuntimeScalar pkg = registers[pkgReg].scalar();
                registers[rd] = ReferenceOperators.bless(ref, pkg);
                return pc;
            }
            case Opcodes.BLESS_CLASS_INSTANCE -> {
                int rd = bytecode[pc++];
                int refReg = bytecode[pc++];
                int pkgReg = bytecode[pc++];
                RuntimeScalar ref = registers[refReg].scalar();
                RuntimeScalar pkg = registers[pkgReg].scalar();
                registers[rd] = ReferenceOperators.blessClassInstance(ref, pkg);
                return pc;
            }
            case Opcodes.ISA -> {
                int rd = bytecode[pc++];
                int objReg = bytecode[pc++];
                int pkgReg = bytecode[pc++];
                RuntimeScalar obj = registers[objReg].scalar();
                RuntimeScalar pkg = registers[pkgReg].scalar();
                registers[rd] = ReferenceOperators.isa(obj, pkg);
                return pc;
            }
            case Opcodes.SMARTMATCH -> {
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                registers[rd] = CompareOperators.smartmatch(registers[rs1], registers[rs2]);
                return pc;
            }
            case Opcodes.INTEGER_SMARTMATCH -> {
                int rd = bytecode[pc++];
                int rs1 = bytecode[pc++];
                int rs2 = bytecode[pc++];
                registers[rd] = CompareOperators.smartmatchInteger(registers[rs1], registers[rs2]);
                return pc;
            }
            case Opcodes.PROTOTYPE -> {
                int rd = bytecode[pc++];
                int rs = bytecode[pc++];
                int packageIdx = readInt(bytecode, pc);
                pc += 1;
                String packageName = (code.stringPool != null && packageIdx >= 0 && packageIdx < code.stringPool.length)
                        ? code.stringPool[packageIdx]
                        : "main";
                registers[rd] = RuntimeCode.prototype(registers[rs].scalar(), packageName);
                return pc;
            }
            case Opcodes.QUOTE_REGEX -> {
                int rd = bytecode[pc++];
                int patternReg = bytecode[pc++];
                int flagsReg = bytecode[pc++];
                int implicitU = bytecode[pc++];
                int warningState = bytecode[pc++];
                int warningBitsIndex = bytecode[pc++];
                int quoteConstruction = bytecode[pc++];
                int namedCharacterExpansionIndex = bytecode[pc++];
                NamedCharacterExpansionMap namedCharacterExpansions =
                        namedCharacterExpansionIndex >= 0
                                ? (NamedCharacterExpansionMap)
                                        code.constants[namedCharacterExpansionIndex]
                                : null;
                RuntimeScalar flags = registers[flagsReg].scalar();
                if (implicitU != 0) {
                    flags = RuntimeRegex.applyUnicodeStringsFeatureToModifiers(flags);
                }
                RegexQuoteMeta.setCallSiteWarning(warningState,
                        warningBitsIndex >= 0 ? code.stringPool[warningBitsIndex] : null);
                registers[rd] = RuntimeRegex.getQuotedRegex(
                        registers[patternReg].scalar(), flags,
                        namedCharacterExpansions);
                if (quoteConstruction != 0) {
                    registers[rd] = quoteConstruction == 2
                            ? RuntimeRegex.markSyntacticQuoteConstruction(registers[rd].scalar())
                            : RuntimeRegex.markQuoteConstruction(registers[rd].scalar());
                }
                return pc;
            }
            case Opcodes.QUOTE_REGEX_O -> {
                int rd = bytecode[pc++];
                int patternReg = bytecode[pc++];
                int flagsReg = bytecode[pc++];
                int callsiteId = bytecode[pc++];
                int implicitU = bytecode[pc++];
                int warningState = bytecode[pc++];
                int warningBitsIndex = bytecode[pc++];
                int quoteConstruction = bytecode[pc++];
                int namedCharacterExpansionIndex = bytecode[pc++];
                NamedCharacterExpansionMap namedCharacterExpansions =
                        namedCharacterExpansionIndex >= 0
                                ? (NamedCharacterExpansionMap)
                                        code.constants[namedCharacterExpansionIndex]
                                : null;
                RuntimeScalar flags = registers[flagsReg].scalar();
                if (implicitU != 0) {
                    flags = RuntimeRegex.applyUnicodeStringsFeatureToModifiers(flags);
                }
                RegexQuoteMeta.setCallSiteWarning(warningState,
                        warningBitsIndex >= 0 ? code.stringPool[warningBitsIndex] : null);
                registers[rd] = RuntimeRegex.getQuotedRegex(
                        registers[patternReg].scalar(), flags, callsiteId,
                        namedCharacterExpansions);
                if (quoteConstruction != 0) {
                    registers[rd] = quoteConstruction == 2
                            ? RuntimeRegex.markSyntacticQuoteConstruction(registers[rd].scalar())
                            : RuntimeRegex.markQuoteConstruction(registers[rd].scalar());
                }
                return pc;
            }
            default -> throw new RuntimeException("Unknown type opcode: " + opcode);
        }
    }

    /**
     * Execute slice operations (opcodes 114-121).
     * Handles: DEREF_ARRAY, DEREF_HASH, *_SLICE, *_SLICE_SET, *_SLICE_DELETE, LIST_SLICE_FROM
     * Direct dispatch to SlowOpcodeHandler methods (Phase 2 complete).
     */
    private static int executeSliceOps(int opcode, int[] bytecode, int pc,
                                       RuntimeBase[] registers, InterpretedCode code) {
        // Direct method calls - no SLOWOP_* constants needed!
        switch (opcode) {
            case Opcodes.DEREF_ARRAY -> {
                return SlowOpcodeHandler.executeDerefArray(bytecode, pc, registers);
            }
            case Opcodes.DEREF_HASH -> {
                return SlowOpcodeHandler.executeDerefHash(bytecode, pc, registers);
            }
            case Opcodes.DEREF_HASH_NONSTRICT -> {
                return SlowOpcodeHandler.executeDerefHashNonStrict(bytecode, pc, registers, code);
            }
            case Opcodes.DEREF_ARRAY_NONSTRICT -> {
                return SlowOpcodeHandler.executeDerefArrayNonStrict(bytecode, pc, registers, code);
            }
            case Opcodes.ARRAY_SLICE -> {
                return SlowOpcodeHandler.executeArraySlice(bytecode, pc, registers);
            }
            case Opcodes.ARRAY_SLICE_LVALUE -> {
                return SlowOpcodeHandler.executeArraySliceLvalue(bytecode, pc, registers);
            }
            case Opcodes.ARRAY_SLICE_SET -> {
                return SlowOpcodeHandler.executeArraySliceSet(bytecode, pc, registers);
            }
            case Opcodes.HASH_SLICE -> {
                return SlowOpcodeHandler.executeHashSlice(bytecode, pc, registers);
            }
            case Opcodes.HASH_SLICE_SET -> {
                return SlowOpcodeHandler.executeHashSliceSet(bytecode, pc, registers);
            }
            case Opcodes.HASH_SLICE_DELETE -> {
                return SlowOpcodeHandler.executeHashSliceDelete(bytecode, pc, registers);
            }
            case Opcodes.HASH_KEYVALUE_SLICE -> {
                return SlowOpcodeHandler.executeHashKeyValueSlice(bytecode, pc, registers);
            }
            case Opcodes.LIST_SLICE_FROM -> {
                return SlowOpcodeHandler.executeListSliceFrom(bytecode, pc, registers);
            }
            default -> throw new RuntimeException("Unknown slice opcode: " + opcode);
        }
    }

    /**
     * Execute array/string operations (opcodes 122-127).
     * Handles: SPLICE, REVERSE, SPLIT, LENGTH_OP, EXISTS, DELETE
     */
    private static int executeArrayStringOps(int opcode, int[] bytecode, int pc,
                                             RuntimeBase[] registers, InterpretedCode code) {
        switch (opcode) {
            case Opcodes.SPLICE -> {
                return SlowOpcodeHandler.executeSplice(bytecode, pc, registers);
            }
            case Opcodes.REVERSE -> {
                return SlowOpcodeHandler.executeReverse(bytecode, pc, registers);
            }
            case Opcodes.SPLIT -> {
                return SlowOpcodeHandler.executeSplit(bytecode, pc, registers);
            }
            case Opcodes.LENGTH_OP -> {
                return SlowOpcodeHandler.executeLength(bytecode, pc, registers);
            }
            case Opcodes.EXISTS -> {
                return SlowOpcodeHandler.executeExists(bytecode, pc, registers);
            }
            case Opcodes.DELETE -> {
                return SlowOpcodeHandler.executeDelete(bytecode, pc, registers);
            }
            default -> throw new RuntimeException("Unknown array/string opcode: " + opcode);
        }
    }

    /**
     * Execute closure/scope operations (opcodes 128-131).
     * Handles: RETRIEVE_BEGIN_*, LOCAL_SCALAR
     */
    private static int executeScopeOps(int opcode, int[] bytecode, int pc,
                                       RuntimeBase[] registers, InterpretedCode code) {
        switch (opcode) {
            case Opcodes.RETRIEVE_BEGIN_SCALAR -> {
                return SlowOpcodeHandler.executeRetrieveBeginScalar(bytecode, pc, registers, code);
            }
            case Opcodes.RETRIEVE_BEGIN_ARRAY -> {
                return SlowOpcodeHandler.executeRetrieveBeginArray(bytecode, pc, registers, code);
            }
            case Opcodes.RETRIEVE_BEGIN_HASH -> {
                return SlowOpcodeHandler.executeRetrieveBeginHash(bytecode, pc, registers, code);
            }
            case Opcodes.LOCAL_SCALAR -> {
                return SlowOpcodeHandler.executeLocalScalar(bytecode, pc, registers, code);
            }
            case Opcodes.LOCAL_ARRAY -> {
                int rd = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                String fullName = code.stringPool[nameIdx];

                GlobalRuntimeArray.makeLocal(fullName);
                registers[rd] = GlobalVariable.getGlobalArray(fullName);
                return pc;
            }
            case Opcodes.LOCAL_HASH -> {
                int rd = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                String fullName = code.stringPool[nameIdx];

                GlobalRuntimeHash.makeLocal(fullName);
                registers[rd] = GlobalVariable.getGlobalHash(fullName);
                return pc;
            }
            case Opcodes.STATE_INIT_SCALAR -> {
                // Format: STATE_INIT_SCALAR rd value_reg name_idx persist_id
                // Retrieves the persistent state variable (non-destructive) and
                // conditionally assigns value only on first initialization
                int rd = bytecode[pc++];
                int valueReg = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                String varName = code.stringPool[nameIdx];
                // State belongs to the executing closure, not the interpreter
                // process.  Falling back to an undefined code ref put every
                // anonymous-sub clone into the same global state cell.
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                // Retrieve without removing (unlike RETRIEVE_BEGIN_SCALAR)
                RuntimeScalar stateVar = StateVariable.retrieveStateScalar(codeRef, varName, persistId);
                registers[rd] = stateVar;
                RuntimeScalar isInit = StateVariable.isInitializedStateVariable(codeRef, varName, persistId);
                if (!isInit.getBoolean()) {
                    stateVar.set((RuntimeScalar) registers[valueReg]);
                    StateVariable.markInitializedStateVariable(codeRef, varName, persistId);
                }
                return pc;
            }
            case Opcodes.STATE_INIT_ARRAY -> {
                int rd = bytecode[pc++];
                int valueReg = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                String varName = code.stringPool[nameIdx];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                RuntimeArray stateArr = StateVariable.retrieveStateArray(codeRef, varName, persistId);
                registers[rd] = stateArr;
                RuntimeScalar isInit = StateVariable.isInitializedStateVariable(codeRef, varName, persistId);
                if (!isInit.getBoolean()) {
                    stateArr.setFromList(((RuntimeBase) registers[valueReg]).getList());
                    StateVariable.markInitializedStateVariable(codeRef, varName, persistId);
                }
                return pc;
            }
            case Opcodes.STATE_RETRIEVE_ARRAY -> {
                int rd = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                registers[rd] = StateVariable.retrieveStateArray(codeRef, code.stringPool[nameIdx], persistId);
                return pc;
            }
            case Opcodes.STATE_RETRIEVE_HASH -> {
                int rd = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                registers[rd] = StateVariable.retrieveStateHash(codeRef, code.stringPool[nameIdx], persistId);
                return pc;
            }
            case Opcodes.STATE_ALIAS_ARRAY -> {
                int rd = bytecode[pc++];
                int sourceReg = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                RuntimeBase source = registers[sourceReg];
                // Whole-array refaliasing may provide the aggregate directly
                // (for an array literal) or as the scalar array reference
                // produced by a refalias expression.  Both denote the same
                // installable state-array binding.
                RuntimeArray array = source instanceof RuntimeArray direct
                        ? direct : source.scalar().arrayDeref();
                StateVariable.aliasStateArray(codeRef, code.stringPool[nameIdx], persistId, array);
                registers[rd] = array;
                return pc;
            }
            case Opcodes.STATE_ALIAS_HASH -> {
                int rd = bytecode[pc++];
                int sourceReg = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                RuntimeBase source = registers[sourceReg];
                RuntimeHash hash = source instanceof RuntimeHash direct
                        ? direct : source.scalar().hashDeref();
                StateVariable.aliasStateHash(codeRef, code.stringPool[nameIdx], persistId, hash);
                registers[rd] = hash;
                return pc;
            }
            case Opcodes.STATE_INIT_HASH -> {
                int rd = bytecode[pc++];
                int valueReg = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                String varName = code.stringPool[nameIdx];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                RuntimeHash stateHash = StateVariable.retrieveStateHash(codeRef, varName, persistId);
                registers[rd] = stateHash;
                RuntimeScalar isInit = StateVariable.isInitializedStateVariable(codeRef, varName, persistId);
                if (!isInit.getBoolean()) {
                    stateHash.setFromList(((RuntimeBase) registers[valueReg]).getList());
                    StateVariable.markInitializedStateVariable(codeRef, varName, persistId);
                }
                return pc;
            }
            case Opcodes.STATE_RETRIEVE_SCALAR -> {
                int rd = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                String varName = code.stringPool[nameIdx];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                registers[rd] = StateVariable.retrieveStateScalar(codeRef, varName, persistId);
                return pc;
            }
            case Opcodes.STATE_IS_INITIALIZED -> {
                int rd = bytecode[pc++];
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                String varName = code.stringPool[nameIdx];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                registers[rd] = StateVariable.isInitializedStateVariable(codeRef, varName, persistId);
                return pc;
            }
            case Opcodes.STATE_MARK_INITIALIZED -> {
                int nameIdx = bytecode[pc++];
                int persistId = bytecode[pc++];
                String varName = code.stringPool[nameIdx];
                RuntimeScalar codeRef = code.__SUB__ != null ? code.__SUB__ : new RuntimeScalar();
                StateVariable.markInitializedStateVariable(codeRef, varName, persistId);
                return pc;
            }
            default -> throw new RuntimeException("Unknown scope opcode: " + opcode);
        }
    }

    /**
     * Execute system call and IPC operations (opcodes 132-150).
     * Handles: CHOWN, WAITPID, FORK, GETPPID, *PGRP, *PRIORITY, *SOCKOPT,
     * SYSCALL, SEMGET, SEMOP, MSGGET, MSGSND, MSGRCV, SHMGET, SHMREAD, SHMWRITE
     */
    private static int executeSystemOps(int opcode, int[] bytecode, int pc,
                                        RuntimeBase[] registers) {
        switch (opcode) {
            case Opcodes.CHOWN -> {
                return MiscOpcodeHandler.execute(Opcodes.CHOWN, bytecode, pc, registers);
            }
            case Opcodes.WAITPID -> {
                return MiscOpcodeHandler.execute(Opcodes.WAITPID, bytecode, pc, registers);
            }
            case Opcodes.FORK -> {
                return SlowOpcodeHandler.executeFork(bytecode, pc, registers);
            }
            case Opcodes.GETPPID -> {
                return SlowOpcodeHandler.executeGetppid(bytecode, pc, registers);
            }
            case Opcodes.GETPGRP -> {
                return MiscOpcodeHandler.execute(Opcodes.GETPGRP, bytecode, pc, registers);
            }
            case Opcodes.SETPGRP -> {
                return MiscOpcodeHandler.execute(Opcodes.SETPGRP, bytecode, pc, registers);
            }
            case Opcodes.GETPRIORITY -> {
                return MiscOpcodeHandler.execute(Opcodes.GETPRIORITY, bytecode, pc, registers);
            }
            case Opcodes.SETPRIORITY -> {
                return MiscOpcodeHandler.execute(Opcodes.SETPRIORITY, bytecode, pc, registers);
            }
            case Opcodes.GETSOCKOPT -> {
                return MiscOpcodeHandler.execute(Opcodes.GETSOCKOPT, bytecode, pc, registers);
            }
            case Opcodes.SETSOCKOPT -> {
                return MiscOpcodeHandler.execute(Opcodes.SETSOCKOPT, bytecode, pc, registers);
            }
            case Opcodes.SYSCALL -> {
                return SlowOpcodeHandler.executeSyscall(bytecode, pc, registers);
            }
            case Opcodes.SEMGET -> {
                return SlowOpcodeHandler.executeSemget(bytecode, pc, registers);
            }
            case Opcodes.SEMOP -> {
                return SlowOpcodeHandler.executeSemop(bytecode, pc, registers);
            }
            case Opcodes.MSGGET -> {
                return SlowOpcodeHandler.executeMsgget(bytecode, pc, registers);
            }
            case Opcodes.MSGSND -> {
                return SlowOpcodeHandler.executeMsgsnd(bytecode, pc, registers);
            }
            case Opcodes.MSGRCV -> {
                return SlowOpcodeHandler.executeMsgrcv(bytecode, pc, registers);
            }
            case Opcodes.SHMGET -> {
                return SlowOpcodeHandler.executeShmget(bytecode, pc, registers);
            }
            case Opcodes.SHMREAD -> {
                return SlowOpcodeHandler.executeShmread(bytecode, pc, registers);
            }
            case Opcodes.SHMWRITE -> {
                return SlowOpcodeHandler.executeShmwrite(bytecode, pc, registers);
            }
            case Opcodes.SYMLINK -> {
                return MiscOpcodeHandler.execute(Opcodes.SYMLINK, bytecode, pc, registers);
            }
            case Opcodes.CHROOT -> {
                return MiscOpcodeHandler.execute(Opcodes.CHROOT, bytecode, pc, registers);
            }
            case Opcodes.MKDIR -> {
                return MiscOpcodeHandler.execute(Opcodes.MKDIR, bytecode, pc, registers);
            }
            case Opcodes.MSGCTL -> {
                return MiscOpcodeHandler.execute(Opcodes.MSGCTL, bytecode, pc, registers);
            }
            case Opcodes.SHMCTL -> {
                return MiscOpcodeHandler.execute(Opcodes.SHMCTL, bytecode, pc, registers);
            }
            case Opcodes.SEMCTL -> {
                return MiscOpcodeHandler.execute(Opcodes.SEMCTL, bytecode, pc, registers);
            }
            case Opcodes.EXEC -> {
                return MiscOpcodeHandler.execute(Opcodes.EXEC, bytecode, pc, registers);
            }
            case Opcodes.FCNTL -> {
                return MiscOpcodeHandler.execute(Opcodes.FCNTL, bytecode, pc, registers);
            }
            case Opcodes.IOCTL -> {
                return MiscOpcodeHandler.execute(Opcodes.IOCTL, bytecode, pc, registers);
            }
            case Opcodes.GETPWENT -> {
                return MiscOpcodeHandler.execute(Opcodes.GETPWENT, bytecode, pc, registers);
            }
            case Opcodes.SETPWENT -> {
                return MiscOpcodeHandler.execute(Opcodes.SETPWENT, bytecode, pc, registers);
            }
            case Opcodes.ENDPWENT -> {
                return MiscOpcodeHandler.execute(Opcodes.ENDPWENT, bytecode, pc, registers);
            }
            case Opcodes.GETLOGIN -> {
                return MiscOpcodeHandler.execute(Opcodes.GETLOGIN, bytecode, pc, registers);
            }
            case Opcodes.GETPWNAM -> {
                return MiscOpcodeHandler.execute(Opcodes.GETPWNAM, bytecode, pc, registers);
            }
            case Opcodes.GETPWUID -> {
                return MiscOpcodeHandler.execute(Opcodes.GETPWUID, bytecode, pc, registers);
            }
            case Opcodes.GETGRNAM -> {
                return MiscOpcodeHandler.execute(Opcodes.GETGRNAM, bytecode, pc, registers);
            }
            case Opcodes.GETGRGID -> {
                return MiscOpcodeHandler.execute(Opcodes.GETGRGID, bytecode, pc, registers);
            }
            case Opcodes.GETGRENT -> {
                return MiscOpcodeHandler.execute(Opcodes.GETGRENT, bytecode, pc, registers);
            }
            case Opcodes.SETGRENT -> {
                return MiscOpcodeHandler.execute(Opcodes.SETGRENT, bytecode, pc, registers);
            }
            case Opcodes.ENDGRENT -> {
                return MiscOpcodeHandler.execute(Opcodes.ENDGRENT, bytecode, pc, registers);
            }
            case Opcodes.GETHOSTBYADDR -> {
                return MiscOpcodeHandler.execute(Opcodes.GETHOSTBYADDR, bytecode, pc, registers);
            }
            case Opcodes.GETHOSTBYNAME -> {
                return MiscOpcodeHandler.execute(Opcodes.GETHOSTBYNAME, bytecode, pc, registers);
            }
            case Opcodes.GETSERVBYNAME -> {
                return MiscOpcodeHandler.execute(Opcodes.GETSERVBYNAME, bytecode, pc, registers);
            }
            case Opcodes.GETSERVBYPORT -> {
                return MiscOpcodeHandler.execute(Opcodes.GETSERVBYPORT, bytecode, pc, registers);
            }
            case Opcodes.GETPROTOBYNAME -> {
                return MiscOpcodeHandler.execute(Opcodes.GETPROTOBYNAME, bytecode, pc, registers);
            }
            case Opcodes.GETPROTOBYNUMBER -> {
                return MiscOpcodeHandler.execute(Opcodes.GETPROTOBYNUMBER, bytecode, pc, registers);
            }
            case Opcodes.ENDHOSTENT -> {
                return MiscOpcodeHandler.execute(Opcodes.ENDHOSTENT, bytecode, pc, registers);
            }
            case Opcodes.ENDNETENT -> {
                return MiscOpcodeHandler.execute(Opcodes.ENDNETENT, bytecode, pc, registers);
            }
            case Opcodes.ENDPROTOENT -> {
                return MiscOpcodeHandler.execute(Opcodes.ENDPROTOENT, bytecode, pc, registers);
            }
            case Opcodes.ENDSERVENT -> {
                return MiscOpcodeHandler.execute(Opcodes.ENDSERVENT, bytecode, pc, registers);
            }
            case Opcodes.GETHOSTENT -> {
                return MiscOpcodeHandler.execute(Opcodes.GETHOSTENT, bytecode, pc, registers);
            }
            case Opcodes.GETNETBYADDR -> {
                return MiscOpcodeHandler.execute(Opcodes.GETNETBYADDR, bytecode, pc, registers);
            }
            case Opcodes.GETNETBYNAME -> {
                return MiscOpcodeHandler.execute(Opcodes.GETNETBYNAME, bytecode, pc, registers);
            }
            case Opcodes.GETNETENT -> {
                return MiscOpcodeHandler.execute(Opcodes.GETNETENT, bytecode, pc, registers);
            }
            case Opcodes.GETPROTOENT -> {
                return MiscOpcodeHandler.execute(Opcodes.GETPROTOENT, bytecode, pc, registers);
            }
            case Opcodes.GETSERVENT -> {
                return MiscOpcodeHandler.execute(Opcodes.GETSERVENT, bytecode, pc, registers);
            }
            case Opcodes.SETHOSTENT -> {
                return MiscOpcodeHandler.execute(Opcodes.SETHOSTENT, bytecode, pc, registers);
            }
            case Opcodes.SETNETENT -> {
                return MiscOpcodeHandler.execute(Opcodes.SETNETENT, bytecode, pc, registers);
            }
            case Opcodes.SETPROTOENT -> {
                return MiscOpcodeHandler.execute(Opcodes.SETPROTOENT, bytecode, pc, registers);
            }
            case Opcodes.SETSERVENT -> {
                return MiscOpcodeHandler.execute(Opcodes.SETSERVENT, bytecode, pc, registers);
            }
            default -> throw new RuntimeException("Unknown system opcode: " + opcode);
        }
    }

    /**
     * Execute special I/O operations (opcodes 151-154).
     * Handles: EVAL_STRING, SELECT_OP, LOAD_GLOB, SLEEP_OP, DEREF_GLOB, LOAD_GLOB_DYNAMIC,
     * DEREF_SCALAR_STRICT, DEREF_SCALAR_NONSTRICT
     */
    private static int executeSpecialIO(int opcode, int[] bytecode, int pc,
                                        RuntimeBase[] registers, InterpretedCode code) {
        switch (opcode) {
            case Opcodes.EVAL_STRING -> {
                return SlowOpcodeHandler.executeEvalString(bytecode, pc, registers, code);
            }
            case Opcodes.SELECT_OP -> {
                return SlowOpcodeHandler.executeSelect(bytecode, pc, registers);
            }
            case Opcodes.LOAD_GLOB -> {
                return SlowOpcodeHandler.executeLoadGlob(bytecode, pc, registers, code);
            }
            case Opcodes.LOAD_GLOB_CANONICAL -> {
                return SlowOpcodeHandler.executeLoadGlobCanonical(bytecode, pc, registers, code);
            }
            case Opcodes.SLEEP_OP -> {
                return SlowOpcodeHandler.executeSleep(bytecode, pc, registers);
            }
            case Opcodes.ALARM_OP -> {
                return SlowOpcodeHandler.executeAlarm(bytecode, pc, registers);
            }
            case Opcodes.DEREF_GLOB -> {
                return SlowOpcodeHandler.executeDerefGlob(bytecode, pc, registers, code);
            }
            case Opcodes.DEREF_GLOB_NONSTRICT -> {
                return SlowOpcodeHandler.executeDerefGlobNonStrict(bytecode, pc, registers, code);
            }
            case Opcodes.LOAD_GLOB_DYNAMIC -> {
                return SlowOpcodeHandler.executeLoadGlobDynamic(bytecode, pc, registers, code);
            }
            case Opcodes.DEREF_SCALAR_STRICT -> {
                return SlowOpcodeHandler.executeDerefScalarStrict(bytecode, pc, registers);
            }
            case Opcodes.REJECT_LOCALIZE_REFERENCE -> {
                return SlowOpcodeHandler.executeRejectLocalizeReference(bytecode, pc, registers);
            }
            case Opcodes.FOREACH_DEREF_SCALAR -> {
                return SlowOpcodeHandler.executeForeachDerefScalar(bytecode, pc, registers);
            }
            case Opcodes.FOREACH_DEREF_ARRAY -> {
                return SlowOpcodeHandler.executeForeachDerefArray(bytecode, pc, registers);
            }
            case Opcodes.FOREACH_DEREF_HASH -> {
                return SlowOpcodeHandler.executeForeachDerefHash(bytecode, pc, registers);
            }
            case Opcodes.REFALIAS_CODE_REFERENCE -> {
                return SlowOpcodeHandler.executeRefAliasCodeReference(bytecode, pc, registers);
            }
            case Opcodes.REFALIAS_SCALAR_REFERENCE -> {
                return SlowOpcodeHandler.executeRefAliasScalarReference(bytecode, pc, registers);
            }
            case Opcodes.DEREF_SCALAR_NONSTRICT -> {
                return SlowOpcodeHandler.executeDerefScalarNonStrict(bytecode, pc, registers, code);
            }
            case Opcodes.CODE_DEREF_NONSTRICT -> {
                return SlowOpcodeHandler.executeCodeDerefNonStrict(bytecode, pc, registers, code);
            }
            case Opcodes.CODE_DEREF_STRICT -> {
                return SlowOpcodeHandler.executeCodeDerefStrict(bytecode, pc, registers);
            }
            case Opcodes.NAMED_CODE_REFERENCE -> {
                return SlowOpcodeHandler.executeNamedCodeReference(bytecode, pc, registers, code);
            }
            case Opcodes.DIRECT_NAMED_CODE_CALL -> {
                return SlowOpcodeHandler.executeDirectNamedCodeCall(bytecode, pc, registers, code);
            }
            default -> throw new RuntimeException("Unknown special I/O opcode: " + opcode);
        }
    }

    /**
     * Read a 32-bit integer from bytecode (stored as 1 int slot).
     * With int[] storage a full int fits in a single slot.
     */
    private static int readInt(int[] bytecode, int pc) {
        return bytecode[pc];
    }

    /**
     * Get call site information (package, filename, line) for the given bytecode PC.
     * Used to push caller context before subroutine/method calls.
     *
     * @param code      The InterpretedCode containing the bytecode
     * @param callPc    The PC of the call instruction (opcode position, before operands)
     * @param currentPkg The current package name
     * @return CallerStack.CallerInfo with package, filename, and line number
     */
    private static CallerStack.CallerInfo getCallSiteInfo(InterpretedCode code, int callPc, String currentPkg) {
        String filename = code.sourceName;
        int lineNumber = code.sourceLine;

        // Try to get token index from pcToTokenIndex map
        if (code.pcToTokenIndex != null && !code.pcToTokenIndex.isEmpty()) {
            var entry = code.pcToTokenIndex.floorEntry(callPc);
            if (entry != null && code.errorUtil != null) {
                int tokenIndex = entry.getValue();
                ErrorMessageUtil.SourceLocation loc = code.errorUtil.getSourceLocationAccurate(tokenIndex);
                filename = loc.fileName();
                lineNumber = loc.lineNumber();
            }
        }

        return new CallerStack.CallerInfo(currentPkg, filename, lineNumber);
    }

    /** Restore the control stacks and virtual caller frame owned by this eval. */
    private static void popEvalCallerFrame(SuspendedInterpreterFrame frame) {
        if (!frame.evalControlBlockDepthStack.isEmpty()) {
            int[] depths = frame.evalControlBlockDepthStack.pop();
            while (frame.controlBlockStack.size() > depths[0]) {
                frame.controlBlockStack.removeLast();
            }
            while (frame.labeledBlockStack.size() > depths[1]) {
                frame.labeledBlockStack.removeLast();
            }
        }
        if (frame.evalCallerFrameStack.isEmpty()) return;
        boolean pushed = frame.evalCallerFrameStack.pop();
        if (pushed && frame.virtualEvalFrameDepth > 0) {
            InterpreterState.pop();
            frame.virtualEvalFrameDepth--;
        }
    }

    /**
     * Format an interpreter error with source location.
     * Shows the error location using the pc-to-tokenIndex mapping if available.
     */
    private static String formatInterpreterError(InterpretedCode code, int errorPc, Throwable e) {
        StringBuilder sb = new StringBuilder();

        // Try to get token index from pcToTokenIndex map
        // Use floorEntry to find the nearest token index before or at errorPc
        Integer tokenIndex = null;
        if (code.pcToTokenIndex != null && !code.pcToTokenIndex.isEmpty()) {
            var entry = code.pcToTokenIndex.floorEntry(errorPc);
            if (entry != null) {
                tokenIndex = entry.getValue();
            }
        }

        if (tokenIndex != null && code.errorUtil != null) {
            // We have token index and errorUtil - convert to line number
            int lineNumber = code.errorUtil.getLineNumber(tokenIndex);
            sb.append("Interpreter error in ").append(code.sourceName)
                    .append(" line ").append(lineNumber)
                    .append(" (pc=").append(errorPc).append("): ")
                    .append(e.getMessage());
        } else if (tokenIndex != null) {
            // We have token index but no errorUtil
            sb.append("Interpreter error in ").append(code.sourceName)
                    .append(" at token ").append(tokenIndex)
                    .append(" (pc=").append(errorPc).append("): ")
                    .append(e.getMessage());
        } else {
            // No token index available, use source line from code
            sb.append("Interpreter error in ").append(code.sourceName)
                    .append(" line ").append(code.sourceLine)
                    .append(" (pc=").append(errorPc).append("): ")
                    .append(e.getMessage());
        }

        return sb.toString();
    }
}