openreliant/src/engine/vm/opcodes.zig at main · OpenReliant/openreliant · GitHub

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//! The mission script VM's instruction set.
//!
//! Generated by `src/tools/tablegen` from the payload executable's dispatch table at
//! 0x004F6350, which holds 86 entries. Do not edit by hand; run `make vm-opcodes`.

const assert = @import("std").debug.assert;

const dte = @import("../../formats/dte.zig");

/// What an instruction does to the instruction pointer.
pub const Form = enum {
    /// Execution continues at the instruction after the operands.
    sequential,
    /// The operand bytes hold a displacement, relative to their own position, to where
    /// execution resumes. The instruction itself still ends after them.
    branch,
    /// The one operand byte is a total length, covering itself: `length - 1` bytes of
    /// inline data follow it, and execution resumes after them.
    inline_data,
    /// Control passes somewhere a linear decoder cannot follow.
    transfer,
};

pub const Info = struct {
    /// The opcode, by its name (`dte.Opcode`).
    opcode: dte.Opcode,
    /// Operand bytes between the opcode and the next instruction. For `inline_data` this
    /// counts only the length byte.
    operands: u8,
    form: Form,
    /// Whether execution can continue at the instruction after the operands. Where it
    /// cannot, the bytes that follow are reached only by a branch, so a linear sweep
    /// would decode whatever happens to sit there.
    falls_through: bool,
    /// Whether the instruction starts a statement, which a step of the editor link stops before
    /// (`vm_starts_statement`, 0x004575C0).
    starts_statement: bool,
    /// Address of the handler in the payload executable.
    handler: u32,
};

/// Every opcode the VM implements, in order.
pub const table = [_]Info{
    .{ .opcode = .equal, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BAD0 },
    .{ .opcode = .not_equal, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BB00 },
    .{ .opcode = .greater, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BB30 },
    .{ .opcode = .greater_equal, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BB60 },
    .{ .opcode = .less, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BB90 },
    .{ .opcode = .less_equal, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BBC0 },
    .{ .opcode = .in_flight_group, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BBF0 },
    .{ .opcode = .not_in_flight_group, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BC30 },
    .{ .opcode = .assign, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045BC70 },
    .{ .opcode = .add_assign, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045BCA0 },
    .{ .opcode = .sub_assign, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045BCD0 },
    .{ .opcode = .mul_assign, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045BD00 },
    .{ .opcode = .div_assign, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045BD30 },
    .{ .opcode = .add, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BD60 },
    .{ .opcode = .sub, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BD90 },
    .{ .opcode = .mul, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BDC0 },
    .{ .opcode = .div, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BDF0 },
    .{ .opcode = .logical_and, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BE20 },
    .{ .opcode = .logical_or, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BE60 },
    .{ .opcode = .command, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045BEA0 },
    .{ .opcode = .call_part, .operands = 1, .form = .transfer, .falls_through = true, .starts_statement = true, .handler = 0x0045BFA0 },
    .{ .opcode = .branch_if_zero, .operands = 2, .form = .branch, .falls_through = true, .starts_statement = true, .handler = 0x0045C270 },
    .{ .opcode = .branch_if_zero_alt, .operands = 2, .form = .branch, .falls_through = true, .starts_statement = true, .handler = 0x0045C270 },
    .{ .opcode = .return_alt, .operands = 0, .form = .transfer, .falls_through = true, .starts_statement = true, .handler = 0x0045C6E0 },
    .{ .opcode = .push_array, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C2D0 },
    .{ .opcode = .push_global, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C300 },
    .{ .opcode = .push_constant, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C340 },
    .{ .opcode = .push_constant_wide, .operands = 2, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C370 },
    .{ .opcode = .push_string, .operands = 1, .form = .inline_data, .falls_through = true, .starts_statement = false, .handler = 0x0045C3B0 },
    .{ .opcode = .push_string_alt, .operands = 1, .form = .inline_data, .falls_through = true, .starts_statement = false, .handler = 0x0045C3B0 },
    .{ .opcode = .push_ship, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C3E0 },
    .{ .opcode = .push_flight_group, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C560 },
    .{ .opcode = .push_byte_alt, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C6B0 },
    .{ .opcode = .push_percent, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DA50 },
    .{ .opcode = .push_local, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C5A0 },
    .{ .opcode = .push_argument, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C680 },
    .{ .opcode = .push_byte, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C6B0 },
    .{ .opcode = .greater_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DAB0 },
    .{ .opcode = .greater_equal_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DB10 },
    .{ .opcode = .less_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DB70 },
    .{ .opcode = .less_equal_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DBD0 },
    .{ .opcode = .add_assign_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045DC30 },
    .{ .opcode = .sub_assign_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045DC70 },
    .{ .opcode = .mul_assign_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045DCB0 },
    .{ .opcode = .div_assign_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045DCF0 },
    .{ .opcode = .add_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DD30 },
    .{ .opcode = .sub_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DD80 },
    .{ .opcode = .mul_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DDD0 },
    .{ .opcode = .div_f, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045DE20 },
    .{ .opcode = .select_array, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C790 },
    .{ .opcode = .select_global, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C7D0 },
    .{ .opcode = .select_argument, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C810 },
    .{ .opcode = .jump, .operands = 2, .form = .branch, .falls_through = false, .starts_statement = false, .handler = 0x0045C2B0 },
    .{ .opcode = .@"return", .operands = 0, .form = .transfer, .falls_through = true, .starts_statement = false, .handler = 0x0045C6E0 },
    .{ .opcode = .push_squad, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C850 },
    .{ .opcode = .in_squad, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C890 },
    .{ .opcode = .not_in_squad, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C8D0 },
    .{ .opcode = .push_component, .operands = 2, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C460 },
    .{ .opcode = .push_null, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C4B0 },
    .{ .opcode = .push_curve, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C4D0 },
    .{ .opcode = .call_part_b, .operands = 1, .form = .transfer, .falls_through = false, .starts_statement = true, .handler = 0x0045C110 },
    .{ .opcode = .push_event_value, .operands = 3, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C5E0 },
    .{ .opcode = .push_result, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C650 },
    .{ .opcode = .spawn_part, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045C070 },
    .{ .opcode = .spawn_part_b, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = true, .handler = 0x0045C1E0 },
    .{ .opcode = .command_b, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045BF20 },
    .{ .opcode = .random_branch, .operands = 0, .form = .transfer, .falls_through = false, .starts_statement = false, .handler = 0x0045C910 },
    .{ .opcode = .push_ship_wide, .operands = 2, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C420 },
    .{ .opcode = .nop, .operands = 0, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C510 },
    .{ .opcode = .push_section_19, .operands = 1, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C520 },
    .{ .opcode = .push_component_alt, .operands = 2, .form = .sequential, .falls_through = true, .starts_statement = false, .handler = 0x0045C460 },
};

comptime {
    // `find` relies on the order.
    for (table[1..], table[0 .. table.len - 1]) |next, previous| assert(@backingInt(next.opcode) > @backingInt(previous.opcode));
}

/// Looks up `opcode`, or null when the VM has no handler for it.
pub fn find(opcode: dte.Opcode) ?Info {
    // The table is sorted, and short enough that a scan beats anything cleverer.
    for (table) |info| {
        if (info.opcode == opcode) return info;
        if (@backingInt(info.opcode) > @backingInt(opcode)) break;
    }
    return null;
}

test find {
    const std = @import("std");
    try std.testing.expect(find(table[0].opcode) != null);
    try std.testing.expect(find(@fromBackingInt(0x00)) == null);
}