1 files changed, 1182 insertions, 0 deletions
diff --git a/js/src/wasm/WasmConstants.h b/js/src/wasm/WasmConstants.h
new file mode 100644
index 0000000000..0ce741b2d0
--- /dev/null
+++ b/js/src/wasm/WasmConstants.h
@@ -0,0 +1,1182 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ *
+ * Copyright 2015 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef wasm_constants_h
+#define wasm_constants_h
+
+#include <stdint.h>
+
+#include "wasm/WasmBuiltinModuleGenerated.h"
+#include "wasm/WasmSerialize.h"
+
+namespace js {
+namespace wasm {
+
+static const uint32_t MagicNumber = 0x6d736100;  // "\0asm"
+static const uint32_t EncodingVersion = 0x01;
+
+enum class SectionId {
+  Custom = 0,
+  Type = 1,
+  Import = 2,
+  Function = 3,
+  Table = 4,
+  Memory = 5,
+  Global = 6,
+  Export = 7,
+  Start = 8,
+  Elem = 9,
+  Code = 10,
+  Data = 11,
+  DataCount = 12,
+  Tag = 13,
+};
+
+// WebAssembly type encodings are all single-byte negative SLEB128s, hence:
+//  forall tc:TypeCode. ((tc & SLEB128SignMask) == SLEB128SignBit
+static const uint8_t SLEB128SignMask = 0xc0;
+static const uint8_t SLEB128SignBit = 0x40;
+
+enum class TypeCode {
+
+  // If more "simple primitive" (non-reference, non-constructor,
+  // non-special-purpose) types are added here then you MUST update
+  // LowestPrimitiveTypeCode, below.
+
+  I32 = 0x7f,   // SLEB128(-0x01)
+  I64 = 0x7e,   // SLEB128(-0x02)
+  F32 = 0x7d,   // SLEB128(-0x03)
+  F64 = 0x7c,   // SLEB128(-0x04)
+  V128 = 0x7b,  // SLEB128(-0x05)
+
+  I8 = 0x78,   // SLEB128(-0x08)
+  I16 = 0x77,  // SLEB128(-0x09)
+
+  // A function pointer with any signature
+  FuncRef = 0x70,  // SLEB128(-0x10)
+
+  // A reference to any host value.
+  ExternRef = 0x6f,  // SLEB128(-0x11)
+
+  // A reference to any wasm gc value.
+  AnyRef = 0x6e,  // SLEB128(-0x12)
+
+  // A reference to a struct/array value.
+  EqRef = 0x6d,  // SLEB128(-0x13)
+
+  // Type constructor for nullable reference types.
+  NullableRef = 0x63,  // SLEB128(-0x1D)
+
+  // Type constructor for non-nullable reference types.
+  Ref = 0x64,  // SLEB128(-0x1C)
+
+  // A reference to an unboxed 31-bit integer.
+  I31Ref = 0x6c,  // SLEB128(-0x14)
+
+  // A null reference in the extern hierarchy.
+  NullExternRef = 0x72,  // SLEB128(-0x0E)
+
+  // A null reference in the func hierarchy.
+  NullFuncRef = 0x73,  // SLEB128(-0x0D)
+
+  // A reference to any struct value.
+  StructRef = 0x6b,  // SLEB128(-0x15)
+
+  // A reference to any array value.
+  ArrayRef = 0x6a,  // SLEB128(-0x16)
+
+  // A reference to an exception value.
+  ExnRef = 0x69,  // SLEB128(-0x17)
+
+  // A null reference in the any hierarchy.
+  NullAnyRef = 0x71,  // SLEB128(-0x0F)
+
+  // Type constructor for function types
+  Func = 0x60,  // SLEB128(-0x20)
+
+  // Type constructor for structure types - gc proposal
+  Struct = 0x5f,  // SLEB128(-0x21)
+
+  // Type constructor for array types - gc proposal
+  Array = 0x5e,  // SLEB128(-0x22)
+
+  // Value for non-nullable type present.
+  TableHasInitExpr = 0x40,
+
+  // The 'empty' case of blocktype.
+  BlockVoid = 0x40,  // SLEB128(-0x40)
+
+  // Type constructor for recursion groups - gc proposal
+  RecGroup = 0x4e,  // SLEB128(-0x31)
+
+  // Type prefix for parent types - gc proposal
+  SubNoFinalType = 0x50,  // SLEB128(-0x30)
+
+  // Type prefix for final types - gc proposal
+  SubFinalType = 0x4f,  // SLEB128(-0x32)
+
+  Limit = 0x80
+};
+
+// This is the lowest-valued TypeCode that is a primitive type, used in
+// UnpackTypeCodeTypeAbstracted().  If primitive typecodes are added below any
+// reference typecode then the logic in that function MUST change.
+
+static constexpr TypeCode LowestPrimitiveTypeCode = TypeCode::I16;
+
+// An arbitrary reference type used as the result of
+// UnpackTypeCodeTypeAbstracted() when a value type is a reference.
+
+static constexpr TypeCode AbstractReferenceTypeCode = TypeCode::ExternRef;
+
+// A type code used to represent (ref null? T) whether or not the type
+// is encoded with 'Ref' or 'NullableRef'.
+
+static constexpr TypeCode AbstractTypeRefCode = TypeCode::Ref;
+
+// wasm traps are machine instructions that can fail to execute for reasons
+// that have to do with some condition in the wasm that they were compiled
+// from.  The failure manifests as a (machine-level) exception of some sort,
+// which leads execution to a signal handler, and is eventually reported as a
+// WebAssembly.RuntimeError.  Generated code may also jump to a Trap
+// symbolically, passing the bytecode offset to report as the trap offset.
+// The generated jump will be bound to a tiny stub which fills the offset and
+// then jumps to a per-Trap shared stub at the end of the module.
+//
+// Traps are described by a value from Trap and, in debug builds only, a value
+// from TrapInsn.
+//
+// * A Trap indicates why the trap has happened and is used to construct the
+//   WebAssembly.Runtime message.
+//
+// * A TrapMachineInsn (not defined in this file) describes roughly what kind
+//   of machine instruction has caused the trap.  This is used only for
+//   validation of trap placement in debug builds, in
+//   ModuleGenerator::finishMetadataTier, and is not necessary for execution
+//   of wasm code.
+
+enum class Trap {
+  // The Unreachable opcode has been executed.
+  Unreachable,
+  // An integer arithmetic operation led to an overflow.
+  IntegerOverflow,
+  // Trying to coerce NaN to an integer.
+  InvalidConversionToInteger,
+  // Integer division by zero.
+  IntegerDivideByZero,
+  // Out of bounds on wasm memory accesses.
+  OutOfBounds,
+  // Unaligned on wasm atomic accesses; also used for non-standard ARM
+  // unaligned access faults.
+  UnalignedAccess,
+  // call_indirect to null.
+  IndirectCallToNull,
+  // call_indirect signature mismatch.
+  IndirectCallBadSig,
+  // Dereference null pointer in operation on (Ref T)
+  NullPointerDereference,
+  // Failed to cast a (Ref T) in a ref.cast instruction
+  BadCast,
+
+  // The internal stack space was exhausted. For compatibility, this throws
+  // the same over-recursed error as JS.
+  StackOverflow,
+
+  // The wasm execution has potentially run too long and the engine must call
+  // CheckForInterrupt(). This trap is resumable.
+  CheckInterrupt,
+
+  // Signal an error that was reported in C++ code.
+  ThrowReported,
+
+  Limit
+};
+
+enum class DefinitionKind {
+  Function = 0x00,
+  Table = 0x01,
+  Memory = 0x02,
+  Global = 0x03,
+  Tag = 0x04,
+};
+
+enum class GlobalTypeImmediate { IsMutable = 0x1, AllowedMask = 0x1 };
+
+enum class LimitsFlags {
+  Default = 0x0,
+  HasMaximum = 0x1,
+  IsShared = 0x2,
+  IsI64 = 0x4,
+};
+
+enum class LimitsMask {
+  Table = uint8_t(LimitsFlags::HasMaximum),
+#ifdef ENABLE_WASM_MEMORY64
+  Memory = uint8_t(LimitsFlags::HasMaximum) | uint8_t(LimitsFlags::IsShared) |
+           uint8_t(LimitsFlags::IsI64),
+#else
+  Memory = uint8_t(LimitsFlags::HasMaximum) | uint8_t(LimitsFlags::IsShared),
+#endif
+};
+
+enum class DataSegmentKind {
+  Active = 0x00,
+  Passive = 0x01,
+  ActiveWithMemoryIndex = 0x02
+};
+
+enum class ElemSegmentKind : uint32_t {
+  Active = 0x0,
+  Passive = 0x1,
+  ActiveWithTableIndex = 0x2,
+  Declared = 0x3,
+};
+
+enum class ElemSegmentPayload : uint32_t {
+  Indices = 0x0,
+  Expressions = 0x4,
+};
+
+enum class TagKind {
+  Exception = 0x0,
+};
+
+enum class Op {
+  // Control flow operators
+  Unreachable = 0x00,
+  Nop = 0x01,
+  Block = 0x02,
+  Loop = 0x03,
+  If = 0x04,
+  Else = 0x05,
+  Try = 0x06,
+  Catch = 0x07,
+  Throw = 0x08,
+  Rethrow = 0x09,
+  ThrowRef = 0x0a,
+  End = 0x0b,
+  Br = 0x0c,
+  BrIf = 0x0d,
+  BrTable = 0x0e,
+  Return = 0x0f,
+
+  // Call operators
+  Call = 0x10,
+  CallIndirect = 0x11,
+  ReturnCall = 0x12,
+  ReturnCallIndirect = 0x13,
+  CallRef = 0x14,
+  ReturnCallRef = 0x15,
+
+  // Additional exception operators
+  Delegate = 0x18,
+  CatchAll = 0x19,
+
+  // Parametric operators
+  Drop = 0x1a,
+  SelectNumeric = 0x1b,
+  SelectTyped = 0x1c,
+
+  // Additional exception operators
+  TryTable = 0x1f,
+
+  // Variable access
+  LocalGet = 0x20,
+  LocalSet = 0x21,
+  LocalTee = 0x22,
+  GlobalGet = 0x23,
+  GlobalSet = 0x24,
+  TableGet = 0x25,  // Reftypes,
+  TableSet = 0x26,  //   per proposal as of February 2019
+
+  // Memory-related operators
+  I32Load = 0x28,
+  I64Load = 0x29,
+  F32Load = 0x2a,
+  F64Load = 0x2b,
+  I32Load8S = 0x2c,
+  I32Load8U = 0x2d,
+  I32Load16S = 0x2e,
+  I32Load16U = 0x2f,
+  I64Load8S = 0x30,
+  I64Load8U = 0x31,
+  I64Load16S = 0x32,
+  I64Load16U = 0x33,
+  I64Load32S = 0x34,
+  I64Load32U = 0x35,
+  I32Store = 0x36,
+  I64Store = 0x37,
+  F32Store = 0x38,
+  F64Store = 0x39,
+  I32Store8 = 0x3a,
+  I32Store16 = 0x3b,
+  I64Store8 = 0x3c,
+  I64Store16 = 0x3d,
+  I64Store32 = 0x3e,
+  MemorySize = 0x3f,
+  MemoryGrow = 0x40,
+
+  // Constants
+  I32Const = 0x41,
+  I64Const = 0x42,
+  F32Const = 0x43,
+  F64Const = 0x44,
+
+  // Comparison operators
+  I32Eqz = 0x45,
+  I32Eq = 0x46,
+  I32Ne = 0x47,
+  I32LtS = 0x48,
+  I32LtU = 0x49,
+  I32GtS = 0x4a,
+  I32GtU = 0x4b,
+  I32LeS = 0x4c,
+  I32LeU = 0x4d,
+  I32GeS = 0x4e,
+  I32GeU = 0x4f,
+  I64Eqz = 0x50,
+  I64Eq = 0x51,
+  I64Ne = 0x52,
+  I64LtS = 0x53,
+  I64LtU = 0x54,
+  I64GtS = 0x55,
+  I64GtU = 0x56,
+  I64LeS = 0x57,
+  I64LeU = 0x58,
+  I64GeS = 0x59,
+  I64GeU = 0x5a,
+  F32Eq = 0x5b,
+  F32Ne = 0x5c,
+  F32Lt = 0x5d,
+  F32Gt = 0x5e,
+  F32Le = 0x5f,
+  F32Ge = 0x60,
+  F64Eq = 0x61,
+  F64Ne = 0x62,
+  F64Lt = 0x63,
+  F64Gt = 0x64,
+  F64Le = 0x65,
+  F64Ge = 0x66,
+
+  // Numeric operators
+  I32Clz = 0x67,
+  I32Ctz = 0x68,
+  I32Popcnt = 0x69,
+  I32Add = 0x6a,
+  I32Sub = 0x6b,
+  I32Mul = 0x6c,
+  I32DivS = 0x6d,
+  I32DivU = 0x6e,
+  I32RemS = 0x6f,
+  I32RemU = 0x70,
+  I32And = 0x71,
+  I32Or = 0x72,
+  I32Xor = 0x73,
+  I32Shl = 0x74,
+  I32ShrS = 0x75,
+  I32ShrU = 0x76,
+  I32Rotl = 0x77,
+  I32Rotr = 0x78,
+  I64Clz = 0x79,
+  I64Ctz = 0x7a,
+  I64Popcnt = 0x7b,
+  I64Add = 0x7c,
+  I64Sub = 0x7d,
+  I64Mul = 0x7e,
+  I64DivS = 0x7f,
+  I64DivU = 0x80,
+  I64RemS = 0x81,
+  I64RemU = 0x82,
+  I64And = 0x83,
+  I64Or = 0x84,
+  I64Xor = 0x85,
+  I64Shl = 0x86,
+  I64ShrS = 0x87,
+  I64ShrU = 0x88,
+  I64Rotl = 0x89,
+  I64Rotr = 0x8a,
+  F32Abs = 0x8b,
+  F32Neg = 0x8c,
+  F32Ceil = 0x8d,
+  F32Floor = 0x8e,
+  F32Trunc = 0x8f,
+  F32Nearest = 0x90,
+  F32Sqrt = 0x91,
+  F32Add = 0x92,
+  F32Sub = 0x93,
+  F32Mul = 0x94,
+  F32Div = 0x95,
+  F32Min = 0x96,
+  F32Max = 0x97,
+  F32CopySign = 0x98,
+  F64Abs = 0x99,
+  F64Neg = 0x9a,
+  F64Ceil = 0x9b,
+  F64Floor = 0x9c,
+  F64Trunc = 0x9d,
+  F64Nearest = 0x9e,
+  F64Sqrt = 0x9f,
+  F64Add = 0xa0,
+  F64Sub = 0xa1,
+  F64Mul = 0xa2,
+  F64Div = 0xa3,
+  F64Min = 0xa4,
+  F64Max = 0xa5,
+  F64CopySign = 0xa6,
+
+  // Conversions
+  I32WrapI64 = 0xa7,
+  I32TruncF32S = 0xa8,
+  I32TruncF32U = 0xa9,
+  I32TruncF64S = 0xaa,
+  I32TruncF64U = 0xab,
+  I64ExtendI32S = 0xac,
+  I64ExtendI32U = 0xad,
+  I64TruncF32S = 0xae,
+  I64TruncF32U = 0xaf,
+  I64TruncF64S = 0xb0,
+  I64TruncF64U = 0xb1,
+  F32ConvertI32S = 0xb2,
+  F32ConvertI32U = 0xb3,
+  F32ConvertI64S = 0xb4,
+  F32ConvertI64U = 0xb5,
+  F32DemoteF64 = 0xb6,
+  F64ConvertI32S = 0xb7,
+  F64ConvertI32U = 0xb8,
+  F64ConvertI64S = 0xb9,
+  F64ConvertI64U = 0xba,
+  F64PromoteF32 = 0xbb,
+
+  // Reinterpretations
+  I32ReinterpretF32 = 0xbc,
+  I64ReinterpretF64 = 0xbd,
+  F32ReinterpretI32 = 0xbe,
+  F64ReinterpretI64 = 0xbf,
+
+  // Sign extension
+  I32Extend8S = 0xc0,
+  I32Extend16S = 0xc1,
+  I64Extend8S = 0xc2,
+  I64Extend16S = 0xc3,
+  I64Extend32S = 0xc4,
+
+  // Reference types
+  RefNull = 0xd0,
+  RefIsNull = 0xd1,
+  RefFunc = 0xd2,
+
+  // Function references
+  RefAsNonNull = 0xd4,
+  BrOnNull = 0xd5,
+
+  // GC (experimental)
+  RefEq = 0xd3,
+
+  // Function references
+  BrOnNonNull = 0xd6,
+
+  FirstPrefix = 0xfa,
+  GcPrefix = 0xfb,
+  MiscPrefix = 0xfc,
+  SimdPrefix = 0xfd,
+  ThreadPrefix = 0xfe,
+  MozPrefix = 0xff,
+
+  Limit = 0x100
+};
+
+inline bool IsPrefixByte(uint8_t b) { return b >= uint8_t(Op::FirstPrefix); }
+
+// Opcodes in the GC opcode space.
+enum class GcOp {
+  // Structure operations
+  StructNew = 0x0,
+  StructNewDefault = 0x1,
+  StructGet = 0x02,
+  StructGetS = 0x03,
+  StructGetU = 0x04,
+  StructSet = 0x05,
+
+  // Array operations
+  ArrayNew = 0x6,
+  ArrayNewDefault = 0x7,
+  ArrayNewFixed = 0x8,
+  ArrayNewData = 0x9,
+  ArrayNewElem = 0xa,
+  ArrayGet = 0xb,
+  ArrayGetS = 0xc,
+  ArrayGetU = 0xd,
+  ArraySet = 0xe,
+  ArrayLen = 0xf,
+  ArrayFill = 0x10,
+  ArrayCopy = 0x11,
+  ArrayInitData = 0x12,
+  ArrayInitElem = 0x13,
+
+  // Ref operations
+  RefTest = 0x14,
+  RefTestNull = 0x15,
+  RefCast = 0x16,
+  RefCastNull = 0x17,
+  BrOnCast = 0x18,
+  BrOnCastFail = 0x19,
+
+  // Extern/any coercion operations
+  AnyConvertExtern = 0x1a,
+  ExternConvertAny = 0x1b,
+
+  // I31 operations
+  RefI31 = 0x1c,
+  I31GetS = 0x1d,
+  I31GetU = 0x1e,
+
+  Limit
+};
+
+// Opcode list from the SIMD proposal post-renumbering in May, 2020.
+
+// Opcodes with suffix 'Experimental' are proposed but not standardized, and are
+// compatible with those same opcodes in V8.  No opcode labeled 'Experimental'
+// will ship in a Release build where SIMD is enabled by default.
+
+enum class SimdOp {
+  V128Load = 0x00,
+  V128Load8x8S = 0x01,
+  V128Load8x8U = 0x02,
+  V128Load16x4S = 0x03,
+  V128Load16x4U = 0x04,
+  V128Load32x2S = 0x05,
+  V128Load32x2U = 0x06,
+  V128Load8Splat = 0x07,
+  V128Load16Splat = 0x08,
+  V128Load32Splat = 0x09,
+  V128Load64Splat = 0x0a,
+  V128Store = 0x0b,
+  V128Const = 0x0c,
+  I8x16Shuffle = 0x0d,
+  I8x16Swizzle = 0x0e,
+  I8x16Splat = 0x0f,
+  I16x8Splat = 0x10,
+  I32x4Splat = 0x11,
+  I64x2Splat = 0x12,
+  F32x4Splat = 0x13,
+  F64x2Splat = 0x14,
+  I8x16ExtractLaneS = 0x15,
+  I8x16ExtractLaneU = 0x16,
+  I8x16ReplaceLane = 0x17,
+  I16x8ExtractLaneS = 0x18,
+  I16x8ExtractLaneU = 0x19,
+  I16x8ReplaceLane = 0x1a,
+  I32x4ExtractLane = 0x1b,
+  I32x4ReplaceLane = 0x1c,
+  I64x2ExtractLane = 0x1d,
+  I64x2ReplaceLane = 0x1e,
+  F32x4ExtractLane = 0x1f,
+  F32x4ReplaceLane = 0x20,
+  F64x2ExtractLane = 0x21,
+  F64x2ReplaceLane = 0x22,
+  I8x16Eq = 0x23,
+  I8x16Ne = 0x24,
+  I8x16LtS = 0x25,
+  I8x16LtU = 0x26,
+  I8x16GtS = 0x27,
+  I8x16GtU = 0x28,
+  I8x16LeS = 0x29,
+  I8x16LeU = 0x2a,
+  I8x16GeS = 0x2b,
+  I8x16GeU = 0x2c,
+  I16x8Eq = 0x2d,
+  I16x8Ne = 0x2e,
+  I16x8LtS = 0x2f,
+  I16x8LtU = 0x30,
+  I16x8GtS = 0x31,
+  I16x8GtU = 0x32,
+  I16x8LeS = 0x33,
+  I16x8LeU = 0x34,
+  I16x8GeS = 0x35,
+  I16x8GeU = 0x36,
+  I32x4Eq = 0x37,
+  I32x4Ne = 0x38,
+  I32x4LtS = 0x39,
+  I32x4LtU = 0x3a,
+  I32x4GtS = 0x3b,
+  I32x4GtU = 0x3c,
+  I32x4LeS = 0x3d,
+  I32x4LeU = 0x3e,
+  I32x4GeS = 0x3f,
+  I32x4GeU = 0x40,
+  F32x4Eq = 0x41,
+  F32x4Ne = 0x42,
+  F32x4Lt = 0x43,
+  F32x4Gt = 0x44,
+  F32x4Le = 0x45,
+  F32x4Ge = 0x46,
+  F64x2Eq = 0x47,
+  F64x2Ne = 0x48,
+  F64x2Lt = 0x49,
+  F64x2Gt = 0x4a,
+  F64x2Le = 0x4b,
+  F64x2Ge = 0x4c,
+  V128Not = 0x4d,
+  V128And = 0x4e,
+  V128AndNot = 0x4f,
+  V128Or = 0x50,
+  V128Xor = 0x51,
+  V128Bitselect = 0x52,
+  V128AnyTrue = 0x53,
+  V128Load8Lane = 0x54,
+  V128Load16Lane = 0x55,
+  V128Load32Lane = 0x56,
+  V128Load64Lane = 0x57,
+  V128Store8Lane = 0x58,
+  V128Store16Lane = 0x59,
+  V128Store32Lane = 0x5a,
+  V128Store64Lane = 0x5b,
+  V128Load32Zero = 0x5c,
+  V128Load64Zero = 0x5d,
+  F32x4DemoteF64x2Zero = 0x5e,
+  F64x2PromoteLowF32x4 = 0x5f,
+  I8x16Abs = 0x60,
+  I8x16Neg = 0x61,
+  I8x16Popcnt = 0x62,
+  I8x16AllTrue = 0x63,
+  I8x16Bitmask = 0x64,
+  I8x16NarrowI16x8S = 0x65,
+  I8x16NarrowI16x8U = 0x66,
+  F32x4Ceil = 0x67,
+  F32x4Floor = 0x68,
+  F32x4Trunc = 0x69,
+  F32x4Nearest = 0x6a,
+  I8x16Shl = 0x6b,
+  I8x16ShrS = 0x6c,
+  I8x16ShrU = 0x6d,
+  I8x16Add = 0x6e,
+  I8x16AddSatS = 0x6f,
+  I8x16AddSatU = 0x70,
+  I8x16Sub = 0x71,
+  I8x16SubSatS = 0x72,
+  I8x16SubSatU = 0x73,
+  F64x2Ceil = 0x74,
+  F64x2Floor = 0x75,
+  I8x16MinS = 0x76,
+  I8x16MinU = 0x77,
+  I8x16MaxS = 0x78,
+  I8x16MaxU = 0x79,
+  F64x2Trunc = 0x7a,
+  I8x16AvgrU = 0x7b,
+  I16x8ExtaddPairwiseI8x16S = 0x7c,
+  I16x8ExtaddPairwiseI8x16U = 0x7d,
+  I32x4ExtaddPairwiseI16x8S = 0x7e,
+  I32x4ExtaddPairwiseI16x8U = 0x7f,
+  I16x8Abs = 0x80,
+  I16x8Neg = 0x81,
+  I16x8Q15MulrSatS = 0x82,
+  I16x8AllTrue = 0x83,
+  I16x8Bitmask = 0x84,
+  I16x8NarrowI32x4S = 0x85,
+  I16x8NarrowI32x4U = 0x86,
+  I16x8ExtendLowI8x16S = 0x87,
+  I16x8ExtendHighI8x16S = 0x88,
+  I16x8ExtendLowI8x16U = 0x89,
+  I16x8ExtendHighI8x16U = 0x8a,
+  I16x8Shl = 0x8b,
+  I16x8ShrS = 0x8c,
+  I16x8ShrU = 0x8d,
+  I16x8Add = 0x8e,
+  I16x8AddSatS = 0x8f,
+  I16x8AddSatU = 0x90,
+  I16x8Sub = 0x91,
+  I16x8SubSatS = 0x92,
+  I16x8SubSatU = 0x93,
+  F64x2Nearest = 0x94,
+  I16x8Mul = 0x95,
+  I16x8MinS = 0x96,
+  I16x8MinU = 0x97,
+  I16x8MaxS = 0x98,
+  I16x8MaxU = 0x99,
+  // Unused = 0x9a
+  I16x8AvgrU = 0x9b,
+  I16x8ExtmulLowI8x16S = 0x9c,
+  I16x8ExtmulHighI8x16S = 0x9d,
+  I16x8ExtmulLowI8x16U = 0x9e,
+  I16x8ExtmulHighI8x16U = 0x9f,
+  I32x4Abs = 0xa0,
+  I32x4Neg = 0xa1,
+  // Unused = 0xa2
+  I32x4AllTrue = 0xa3,
+  I32x4Bitmask = 0xa4,
+  // Unused = 0xa5
+  // Unused = 0xa6
+  I32x4ExtendLowI16x8S = 0xa7,
+  I32x4ExtendHighI16x8S = 0xa8,
+  I32x4ExtendLowI16x8U = 0xa9,
+  I32x4ExtendHighI16x8U = 0xaa,
+  I32x4Shl = 0xab,
+  I32x4ShrS = 0xac,
+  I32x4ShrU = 0xad,
+  I32x4Add = 0xae,
+  // Unused = 0xaf
+  // Unused = 0xb0
+  I32x4Sub = 0xb1,
+  // Unused = 0xb2
+  // Unused = 0xb3
+  // Unused = 0xb4
+  I32x4Mul = 0xb5,
+  I32x4MinS = 0xb6,
+  I32x4MinU = 0xb7,
+  I32x4MaxS = 0xb8,
+  I32x4MaxU = 0xb9,
+  I32x4DotI16x8S = 0xba,
+  // Unused = 0xbb
+  I32x4ExtmulLowI16x8S = 0xbc,
+  I32x4ExtmulHighI16x8S = 0xbd,
+  I32x4ExtmulLowI16x8U = 0xbe,
+  I32x4ExtmulHighI16x8U = 0xbf,
+  I64x2Abs = 0xc0,
+  I64x2Neg = 0xc1,
+  // AnyTrue = 0xc2
+  I64x2AllTrue = 0xc3,
+  I64x2Bitmask = 0xc4,
+  // Unused = 0xc5
+  // Unused = 0xc6
+  I64x2ExtendLowI32x4S = 0xc7,
+  I64x2ExtendHighI32x4S = 0xc8,
+  I64x2ExtendLowI32x4U = 0xc9,
+  I64x2ExtendHighI32x4U = 0xca,
+  I64x2Shl = 0xcb,
+  I64x2ShrS = 0xcc,
+  I64x2ShrU = 0xcd,
+  I64x2Add = 0xce,
+  // Unused = 0xcf
+  // Unused = 0xd0
+  I64x2Sub = 0xd1,
+  // Unused = 0xd2
+  // Unused = 0xd3
+  // Unused = 0xd4
+  I64x2Mul = 0xd5,
+  I64x2Eq = 0xd6,
+  I64x2Ne = 0xd7,
+  I64x2LtS = 0xd8,
+  I64x2GtS = 0xd9,
+  I64x2LeS = 0xda,
+  I64x2GeS = 0xdb,
+  I64x2ExtmulLowI32x4S = 0xdc,
+  I64x2ExtmulHighI32x4S = 0xdd,
+  I64x2ExtmulLowI32x4U = 0xde,
+  I64x2ExtmulHighI32x4U = 0xdf,
+  F32x4Abs = 0xe0,
+  F32x4Neg = 0xe1,
+  // Unused = 0xe2
+  F32x4Sqrt = 0xe3,
+  F32x4Add = 0xe4,
+  F32x4Sub = 0xe5,
+  F32x4Mul = 0xe6,
+  F32x4Div = 0xe7,
+  F32x4Min = 0xe8,
+  F32x4Max = 0xe9,
+  F32x4PMin = 0xea,
+  F32x4PMax = 0xeb,
+  F64x2Abs = 0xec,
+  F64x2Neg = 0xed,
+  // Unused = 0xee
+  F64x2Sqrt = 0xef,
+  F64x2Add = 0xf0,
+  F64x2Sub = 0xf1,
+  F64x2Mul = 0xf2,
+  F64x2Div = 0xf3,
+  F64x2Min = 0xf4,
+  F64x2Max = 0xf5,
+  F64x2PMin = 0xf6,
+  F64x2PMax = 0xf7,
+  I32x4TruncSatF32x4S = 0xf8,
+  I32x4TruncSatF32x4U = 0xf9,
+  F32x4ConvertI32x4S = 0xfa,
+  F32x4ConvertI32x4U = 0xfb,
+  I32x4TruncSatF64x2SZero = 0xfc,
+  I32x4TruncSatF64x2UZero = 0xfd,
+  F64x2ConvertLowI32x4S = 0xfe,
+  F64x2ConvertLowI32x4U = 0xff,
+  I8x16RelaxedSwizzle = 0x100,
+  I32x4RelaxedTruncF32x4S = 0x101,
+  I32x4RelaxedTruncF32x4U = 0x102,
+  I32x4RelaxedTruncF64x2SZero = 0x103,
+  I32x4RelaxedTruncF64x2UZero = 0x104,
+  F32x4RelaxedMadd = 0x105,
+  F32x4RelaxedNmadd = 0x106,
+  F64x2RelaxedMadd = 0x107,
+  F64x2RelaxedNmadd = 0x108,
+  I8x16RelaxedLaneSelect = 0x109,
+  I16x8RelaxedLaneSelect = 0x10a,
+  I32x4RelaxedLaneSelect = 0x10b,
+  I64x2RelaxedLaneSelect = 0x10c,
+  F32x4RelaxedMin = 0x10d,
+  F32x4RelaxedMax = 0x10e,
+  F64x2RelaxedMin = 0x10f,
+  F64x2RelaxedMax = 0x110,
+  I16x8RelaxedQ15MulrS = 0x111,
+  I16x8DotI8x16I7x16S = 0x112,
+  I32x4DotI8x16I7x16AddS = 0x113,
+
+  // Reserved for Relaxed SIMD = 0x114-0x12f
+
+  // Unused = 0x130 and up
+
+  // Mozilla extensions
+  MozPMADDUBSW = 0x201,
+
+  Limit
+};
+
+// Opcodes in the "miscellaneous" opcode space.
+enum class MiscOp {
+  // Saturating float-to-int conversions
+  I32TruncSatF32S = 0x00,
+  I32TruncSatF32U = 0x01,
+  I32TruncSatF64S = 0x02,
+  I32TruncSatF64U = 0x03,
+  I64TruncSatF32S = 0x04,
+  I64TruncSatF32U = 0x05,
+  I64TruncSatF64S = 0x06,
+  I64TruncSatF64U = 0x07,
+
+  // Bulk memory operations, per proposal as of February 2019.
+  MemoryInit = 0x08,
+  DataDrop = 0x09,
+  MemoryCopy = 0x0a,
+  MemoryFill = 0x0b,
+  TableInit = 0x0c,
+  ElemDrop = 0x0d,
+  TableCopy = 0x0e,
+
+  // Reftypes, per proposal as of February 2019.
+  TableGrow = 0x0f,
+  TableSize = 0x10,
+  TableFill = 0x11,
+
+  MemoryDiscard = 0x12,
+
+  Limit
+};
+
+// Opcodes from threads proposal as of June 30, 2017
+enum class ThreadOp {
+  // Wait and wake
+  Wake = 0x00,
+  I32Wait = 0x01,
+  I64Wait = 0x02,
+  Fence = 0x03,
+
+  // Load and store
+  I32AtomicLoad = 0x10,
+  I64AtomicLoad = 0x11,
+  I32AtomicLoad8U = 0x12,
+  I32AtomicLoad16U = 0x13,
+  I64AtomicLoad8U = 0x14,
+  I64AtomicLoad16U = 0x15,
+  I64AtomicLoad32U = 0x16,
+  I32AtomicStore = 0x17,
+  I64AtomicStore = 0x18,
+  I32AtomicStore8U = 0x19,
+  I32AtomicStore16U = 0x1a,
+  I64AtomicStore8U = 0x1b,
+  I64AtomicStore16U = 0x1c,
+  I64AtomicStore32U = 0x1d,
+
+  // Read-modify-write operations
+  I32AtomicAdd = 0x1e,
+  I64AtomicAdd = 0x1f,
+  I32AtomicAdd8U = 0x20,
+  I32AtomicAdd16U = 0x21,
+  I64AtomicAdd8U = 0x22,
+  I64AtomicAdd16U = 0x23,
+  I64AtomicAdd32U = 0x24,
+
+  I32AtomicSub = 0x25,
+  I64AtomicSub = 0x26,
+  I32AtomicSub8U = 0x27,
+  I32AtomicSub16U = 0x28,
+  I64AtomicSub8U = 0x29,
+  I64AtomicSub16U = 0x2a,
+  I64AtomicSub32U = 0x2b,
+
+  I32AtomicAnd = 0x2c,
+  I64AtomicAnd = 0x2d,
+  I32AtomicAnd8U = 0x2e,
+  I32AtomicAnd16U = 0x2f,
+  I64AtomicAnd8U = 0x30,
+  I64AtomicAnd16U = 0x31,
+  I64AtomicAnd32U = 0x32,
+
+  I32AtomicOr = 0x33,
+  I64AtomicOr = 0x34,
+  I32AtomicOr8U = 0x35,
+  I32AtomicOr16U = 0x36,
+  I64AtomicOr8U = 0x37,
+  I64AtomicOr16U = 0x38,
+  I64AtomicOr32U = 0x39,
+
+  I32AtomicXor = 0x3a,
+  I64AtomicXor = 0x3b,
+  I32AtomicXor8U = 0x3c,
+  I32AtomicXor16U = 0x3d,
+  I64AtomicXor8U = 0x3e,
+  I64AtomicXor16U = 0x3f,
+  I64AtomicXor32U = 0x40,
+
+  I32AtomicXchg = 0x41,
+  I64AtomicXchg = 0x42,
+  I32AtomicXchg8U = 0x43,
+  I32AtomicXchg16U = 0x44,
+  I64AtomicXchg8U = 0x45,
+  I64AtomicXchg16U = 0x46,
+  I64AtomicXchg32U = 0x47,
+
+  // CompareExchange
+  I32AtomicCmpXchg = 0x48,
+  I64AtomicCmpXchg = 0x49,
+  I32AtomicCmpXchg8U = 0x4a,
+  I32AtomicCmpXchg16U = 0x4b,
+  I64AtomicCmpXchg8U = 0x4c,
+  I64AtomicCmpXchg16U = 0x4d,
+  I64AtomicCmpXchg32U = 0x4e,
+
+  Limit
+};
+
+enum class BuiltinModuleFuncId {
+// ------------------------------------------------------------------------
+// These are part/suffix of the MozOp::CallBuiltinModuleFunc operators that are
+// emitted internally when compiling intrinsic modules and are rejected by wasm
+// validation.
+// See wasm/WasmBuiltinModule.yaml for the list.
+#define VISIT_BUILTIN_FUNC(op, export, sa_name, abitype, entry, has_memory, \
+                           idx)                                             \
+  op = idx,  // NOLINT
+  FOR_EACH_BUILTIN_MODULE_FUNC(VISIT_BUILTIN_FUNC)
+#undef VISIT_BUILTIN_FUNC
+
+  // Op limit.
+  Limit
+};
+
+enum class BuiltinModuleId {
+  SelfTest = 0,
+  IntGemm,
+  JSString,
+};
+
+struct BuiltinModuleIds {
+  BuiltinModuleIds() = default;
+
+  bool selfTest = false;
+  bool intGemm = false;
+  bool jsString = false;
+
+  bool hasNone() const { return !selfTest && !intGemm && !jsString; }
+
+  WASM_CHECK_CACHEABLE_POD(selfTest, intGemm, jsString)
+};
+
+WASM_DECLARE_CACHEABLE_POD(BuiltinModuleIds)
+
+enum class MozOp {
+  // ------------------------------------------------------------------------
+  // These operators are emitted internally when compiling asm.js and are
+  // rejected by wasm validation.  They are prefixed by MozPrefix.
+
+  // asm.js-specific operators.  They start at 1 so as to check for
+  // uninitialized (zeroed) storage.
+  TeeGlobal = 0x01,
+  I32Min,
+  I32Max,
+  I32Neg,
+  I32BitNot,
+  I32Abs,
+  F32TeeStoreF64,
+  F64TeeStoreF32,
+  I32TeeStore8,
+  I32TeeStore16,
+  I64TeeStore8,
+  I64TeeStore16,
+  I64TeeStore32,
+  I32TeeStore,
+  I64TeeStore,
+  F32TeeStore,
+  F64TeeStore,
+  F64Mod,
+  F64SinNative,
+  F64SinFdlibm,
+  F64CosNative,
+  F64CosFdlibm,
+  F64TanNative,
+  F64TanFdlibm,
+  F64Asin,
+  F64Acos,
+  F64Atan,
+  F64Exp,
+  F64Log,
+  F64Pow,
+  F64Atan2,
+
+  // asm.js-style call_indirect with the callee evaluated first.
+  OldCallDirect,
+  OldCallIndirect,
+
+  // Call a builtin module funcs. The operator has argument leb u32 to specify
+  // particular operation id. See BuiltinModuleFuncId above.
+  CallBuiltinModuleFunc,
+
+  Limit
+};
+
+struct OpBytes {
+  // b0 is a byte value but has a 16-bit representation to allow for a full
+  // 256-value range plus a sentinel Limit value.
+  uint16_t b0;
+  // b1 is a LEB128 value but 32 bits is enough for now.
+  uint32_t b1;
+
+  explicit OpBytes(Op x) {
+    b0 = uint16_t(x);
+    b1 = 0;
+  }
+  OpBytes() = default;
+
+  // Whether this opcode should have a breakpoint site inserted directly before
+  // the opcode in baseline when debugging. We use this as a heuristic to
+  // reduce the number of breakpoint sites.
+  bool shouldHaveBreakpoint() const {
+    switch (Op(b0)) {
+      // Block-like instructions don't get their own breakpoint site, a
+      // breakpoint can be used on instructions in the block.
+      case Op::Block:
+      case Op::Loop:
+      case Op::If:
+      case Op::Else:
+      case Op::Try:
+      case Op::Delegate:
+      case Op::Catch:
+      case Op::CatchAll:
+      case Op::End:
+      // Effect-less instructions without inputs are leaf nodes in expressions,
+      // a breakpoint can be used on instructions that consume these values.
+      case Op::LocalGet:
+      case Op::GlobalGet:
+      case Op::I32Const:
+      case Op::I64Const:
+      case Op::F32Const:
+      case Op::F64Const:
+      case Op::RefNull:
+      case Op::Drop:
+        return false;
+      default:
+        return true;
+    }
+  }
+};
+
+static const char NameSectionName[] = "name";
+static const char SourceMappingURLSectionName[] = "sourceMappingURL";
+
+enum class NameType { Module = 0, Function = 1, Local = 2 };
+
+enum class FieldFlags { Mutable = 0x01, AllowedMask = 0x01 };
+
+enum class FieldWideningOp { None, Signed, Unsigned };
+
+// The WebAssembly spec hard-codes the virtual page size to be 64KiB and
+// requires the size of linear memory to always be a multiple of 64KiB.
+
+static const unsigned PageSize = 64 * 1024;
+static const unsigned PageBits = 16;
+static_assert(PageSize == (1u << PageBits));
+
+static const unsigned PageMask = ((1u << PageBits) - 1);
+
+// These limits are agreed upon with other engines for consistency.
+
+static const unsigned MaxRecGroups = 1000000;
+static const unsigned MaxTypes = 1000000;
+static const unsigned MaxSubTypingDepth = 63;
+static const unsigned MaxTags = 1000000;
+static const unsigned MaxFuncs = 1000000;
+static const unsigned MaxTables = 100000;
+static const unsigned MaxMemories = 100000;
+static const unsigned MaxImports = 100000;
+static const unsigned MaxExports = 100000;
+static const unsigned MaxGlobals = 1000000;
+static const unsigned MaxDataSegments = 100000;
+static const unsigned MaxDataSegmentLengthPages = 16384;
+static const unsigned MaxElemSegments = 10000000;
+static const unsigned MaxElemSegmentLength = 10000000;
+static const unsigned MaxTableLimitField = UINT32_MAX;
+static const unsigned MaxTableLength = 10000000;
+static const unsigned MaxLocals = 50000;
+static const unsigned MaxParams = 1000;
+static const unsigned MaxResults = 1000;
+static const unsigned MaxStructFields = 10000;
+static const uint64_t MaxMemory32LimitField = uint64_t(1) << 16;
+static const uint64_t MaxMemory64LimitField = uint64_t(1) << 48;
+static const unsigned MaxStringBytes = 100000;
+static const unsigned MaxModuleBytes = 1024 * 1024 * 1024;
+static const unsigned MaxFunctionBytes = 7654321;
+static const unsigned MaxArrayNewFixedElements = 10000;
+
+// Maximum payload size, in bytes, of a gc-proposal Array.  Puts it fairly
+// close to 2^31 without exposing us to potential danger at the signed-i32
+// wraparound boundary.  Note that gc-proposal Struct sizes are limited by
+// MaxStructFields above.  Some code assumes that the payload size will fit in
+// a uint32_t, hence the static assert.
+static const unsigned MaxArrayPayloadBytes = 1987654321;
+static_assert(uint64_t(MaxArrayPayloadBytes) <
+              (uint64_t(1) << (8 * sizeof(uint32_t))));
+
+// These limits pertain to our WebAssembly implementation only.
+
+static const unsigned MaxTryTableCatches = 10000;
+static const unsigned MaxBrTableElems = 1000000;
+static const unsigned MaxCodeSectionBytes = MaxModuleBytes;
+
+// 512KiB should be enough, considering how Rabaldr uses the stack and
+// what the standard limits are:
+//
+// - 1,000 parameters
+// - 50,000 locals
+// - 10,000 values on the eval stack (not an official limit)
+//
+// At sizeof(int64) bytes per slot this works out to about 480KiB.
+
+static const unsigned MaxFrameSize = 512 * 1024;
+
+// Asserted by Decoder::readVarU32.
+
+static const unsigned MaxVarU32DecodedBytes = 5;
+
+// The CompileMode controls how compilation of a module is performed (notably,
+// how many times we compile it).
+
+enum class CompileMode { Once, Tier1, Tier2 };
+
+// Typed enum for whether debugging is enabled.
+
+enum class DebugEnabled { False, True };
+
+}  // namespace wasm
+}  // namespace js
+
+#endif  // wasm_constants_h