Fast validation (#1204)

This makes wasm validation parallel (the function part). This makes loading+validating tanks (a 12MB wasm file) 2.3x faster on a 4-core machine (from 3.5 to 1.5 seconds). It's a big speedup because most of loading+validating was actually validating.

It's also noticeable during compilation, since we validate by default at the end. 8% faster on -O2 and 23% on -O0. So actually fairly significant on -O0 builds.

As a bonus, this PR also moves the code from being 99% in the header to be 1% in the header.

Author: kripken

CMakeLists.txt

@@ -270,7 +270,7 @@ SET(wasm_as_SOURCES
 )
 ADD_EXECUTABLE(wasm-as
                ${wasm_as_SOURCES})
-TARGET_LINK_LIBRARIES(wasm-as passes wasm asmjs ast cfg support)
+TARGET_LINK_LIBRARIES(wasm-as wasm asmjs passes ast cfg support)
 SET_PROPERTY(TARGET wasm-as PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET wasm-as PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS wasm-as DESTINATION ${CMAKE_INSTALL_BINDIR})

src/tools/wasm-reduce.cpp

@@ -414,9 +414,7 @@ struct Reducer : public WalkerPass<PostWalker<Reducer, UnifiedExpressionVisitor<
     }
     for (auto& func : functions) {
       curr->removeFunction(func.name);
-      WasmValidator validator;
-      validator.quiet = true;
-      if (validator.validate(*curr) && writeAndTestReduction()) {
+      if (WasmValidator().validate(*curr, false, true, true /* override quiet */) && writeAndTestReduction()) {
         std::cerr << "|      removed function " << func.name << '\n';
         noteReduction();
       } else {

src/wasm-validator.h

@@ -33,6 +33,8 @@
 //                      about function B not existing yet, but we would care
 //                      if e.g. inside function A an i32.add receives an i64).
 //
+//  * quiet: Whether to log errors verbosely.
+//
 
 #ifndef wasm_wasm_validator_h
 #define wasm_wasm_validator_h
@@ -46,188 +48,8 @@
 
 namespace wasm {
 
-// Print anything that can be streamed to an ostream
-template <typename T,
-  typename std::enable_if<
-    !std::is_base_of<Expression, typename std::remove_pointer<T>::type>::value
-  >::type* = nullptr>
-inline std::ostream& printModuleComponent(T curr, std::ostream& stream) {
-  stream << curr << std::endl;
-  return stream;
-}
-// Extra overload for Expressions, to print type info too
-inline std::ostream& printModuleComponent(Expression* curr, std::ostream& stream) {
-  WasmPrinter::printExpression(curr, stream, false, true) << std::endl;
-  return stream;
-}
-
-struct WasmValidator : public PostWalker<WasmValidator> {
-  bool valid = true;
-
-  // what to validate, see comment up top
-  bool validateWeb = false;
-  bool validateGlobally = true;
-
-  bool quiet = false; // whether to log errors verbosely
-
-  struct BreakInfo {
-    WasmType type;
-    Index arity;
-    BreakInfo() {}
-    BreakInfo(WasmType type, Index arity) : type(type), arity(arity) {}
-  };
-
-  std::map<Name, Expression*> breakTargets;
-  std::map<Expression*, BreakInfo> breakInfos;
-
-  WasmType returnType = unreachable; // type used in returns
-
-  std::set<Name> labelNames; // Binaryen IR requires that label names must be unique - IR generators must ensure that
-
-  std::unordered_set<Expression*> seenExpressions; // expressions must not appear twice
-
-  void noteLabelName(Name name);
-
-public:
-  // TODO: If we want the validator to be part of libwasm rather than libpasses, then
-  // Using PassRunner::getPassDebug causes a circular dependence. We should fix that,
-  // perhaps by moving some of the pass infrastructure into libsupport.
-  bool validate(Module& module, bool validateWeb_ = false, bool validateGlobally_ = true) {
-    validateWeb = validateWeb_;
-    validateGlobally = validateGlobally_;
-    // wasm logic validation
-    walkModule(&module);
-    // validate additional internal IR details when in pass-debug mode
-    if (PassRunner::getPassDebug()) {
-      validateBinaryenIR(module);
-    }
-    // print if an error occurred
-    if (!valid && !quiet) {
-      WasmPrinter::printModule(&module, std::cerr);
-    }
-    return valid;
-  }
-
-  // visitors
-
-  static void visitPreBlock(WasmValidator* self, Expression** currp) {
-    auto* curr = (*currp)->cast<Block>();
-    if (curr->name.is()) self->breakTargets[curr->name] = curr;
-  }
-
-  void visitBlock(Block *curr);
-
-  static void visitPreLoop(WasmValidator* self, Expression** currp) {
-    auto* curr = (*currp)->cast<Loop>();
-    if (curr->name.is()) self->breakTargets[curr->name] = curr;
-  }
-
-  void visitLoop(Loop *curr);
-  void visitIf(If *curr);
-
-  // override scan to add a pre and a post check task to all nodes
-  static void scan(WasmValidator* self, Expression** currp) {
-    PostWalker<WasmValidator>::scan(self, currp);
-
-    auto* curr = *currp;
-    if (curr->is<Block>()) self->pushTask(visitPreBlock, currp);
-    if (curr->is<Loop>()) self->pushTask(visitPreLoop, currp);
-  }
-
-  void noteBreak(Name name, Expression* value, Expression* curr);
-  void visitBreak(Break *curr);
-  void visitSwitch(Switch *curr);
-  void visitCall(Call *curr);
-  void visitCallImport(CallImport *curr);
-  void visitCallIndirect(CallIndirect *curr);
-  void visitGetLocal(GetLocal* curr);
-  void visitSetLocal(SetLocal *curr);
-  void visitLoad(Load *curr);
-  void visitStore(Store *curr);
-  void visitAtomicRMW(AtomicRMW *curr);
-  void visitAtomicCmpxchg(AtomicCmpxchg *curr);
-  void visitAtomicWait(AtomicWait *curr);
-  void visitAtomicWake(AtomicWake *curr);
-  void visitBinary(Binary *curr);
-  void visitUnary(Unary *curr);
-  void visitSelect(Select* curr);
-  void visitDrop(Drop* curr);
-  void visitReturn(Return* curr);
-  void visitHost(Host* curr);
-  void visitImport(Import* curr);
-  void visitExport(Export* curr);
-  void visitGlobal(Global* curr);
-  void visitFunction(Function *curr);
-
-  void visitMemory(Memory *curr);
-  void visitTable(Table* curr);
-  void visitModule(Module *curr);
-
-  void doWalkFunction(Function* func) {
-    PostWalker<WasmValidator>::doWalkFunction(func);
-  }
-
-  // helpers
- private:
-  template <typename T, typename S>
-  std::ostream& fail(S text, T curr);
-  std::ostream& printFailureHeader();
-
-  template<typename T>
-  bool shouldBeTrue(bool result, T curr, const char* text) {
-    if (!result) {
-      fail("unexpected false: " + std::string(text), curr);
-      return false;
-    }
-    return result;
-  }
-  template<typename T>
-  bool shouldBeFalse(bool result, T curr, const char* text) {
-    if (result) {
-      fail("unexpected true: " + std::string(text), curr);
-      return false;
-    }
-    return result;
-  }
-
-  template<typename T, typename S>
-  bool shouldBeEqual(S left, S right, T curr, const char* text) {
-    if (left != right) {
-      std::ostringstream ss;
-      ss << left << " != " << right << ": " << text;
-      fail(ss.str(), curr);
-      return false;
-    }
-    return true;
-  }
-
-  template<typename T, typename S>
-  bool shouldBeEqualOrFirstIsUnreachable(S left, S right, T curr, const char* text) {
-    if (left != unreachable && left != right) {
-      std::ostringstream ss;
-      ss << left << " != " << right << ": " << text;
-      fail(ss.str(), curr);
-      return false;
-    }
-    return true;
-  }
-
-  template<typename T, typename S>
-  bool shouldBeUnequal(S left, S right, T curr, const char* text) {
-    if (left == right) {
-      std::ostringstream ss;
-      ss << left << " == " << right << ": " << text;
-      fail(ss.str(), curr);
-      return false;
-    }
-    return true;
-  }
-
-  void shouldBeIntOrUnreachable(WasmType ty, Expression* curr, const char* text);
-  void validateAlignment(size_t align, WasmType type, Index bytes, bool isAtomic,
-                         Expression* curr);
-  void validateMemBytes(uint8_t bytes, WasmType type, Expression* curr);
-  void validateBinaryenIR(Module& wasm);
+struct WasmValidator {
+  bool validate(Module& module, bool validateWeb = false, bool validateGlobally = true, bool quiet = false);
 };
 
 } // namespace wasm