summaryrefslogtreecommitdiffstats
path: root/js/src/jit/MIR.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'js/src/jit/MIR.cpp')
-rw-r--r--js/src/jit/MIR.cpp7261
1 files changed, 7261 insertions, 0 deletions
diff --git a/js/src/jit/MIR.cpp b/js/src/jit/MIR.cpp
new file mode 100644
index 0000000000..a4b2191a82
--- /dev/null
+++ b/js/src/jit/MIR.cpp
@@ -0,0 +1,7261 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "jit/MIR.h"
+
+#include "mozilla/CheckedInt.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/FloatingPoint.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/ScopeExit.h"
+
+#include <array>
+#include <utility>
+
+#include "jslibmath.h"
+#include "jsmath.h"
+#include "jsnum.h"
+
+#include "builtin/RegExp.h"
+#include "jit/AtomicOperations.h"
+#include "jit/CompileInfo.h"
+#include "jit/KnownClass.h"
+#include "jit/MIRGraph.h"
+#include "jit/RangeAnalysis.h"
+#include "jit/VMFunctions.h"
+#include "jit/WarpBuilderShared.h"
+#include "js/Conversions.h"
+#include "js/experimental/JitInfo.h" // JSJitInfo, JSTypedMethodJitInfo
+#include "js/ScalarType.h" // js::Scalar::Type
+#include "util/Text.h"
+#include "util/Unicode.h"
+#include "vm/Iteration.h" // js::NativeIterator
+#include "vm/PlainObject.h" // js::PlainObject
+#include "vm/Uint8Clamped.h"
+#include "wasm/WasmCode.h"
+
+#include "vm/JSAtom-inl.h"
+#include "wasm/WasmInstance-inl.h"
+
+using namespace js;
+using namespace js::jit;
+
+using JS::ToInt32;
+
+using mozilla::CheckedInt;
+using mozilla::DebugOnly;
+using mozilla::IsFloat32Representable;
+using mozilla::IsPowerOfTwo;
+using mozilla::Maybe;
+using mozilla::NumbersAreIdentical;
+
+NON_GC_POINTER_TYPE_ASSERTIONS_GENERATED
+
+#ifdef DEBUG
+size_t MUse::index() const { return consumer()->indexOf(this); }
+#endif
+
+template <size_t Op>
+static void ConvertDefinitionToDouble(TempAllocator& alloc, MDefinition* def,
+ MInstruction* consumer) {
+ MInstruction* replace = MToDouble::New(alloc, def);
+ consumer->replaceOperand(Op, replace);
+ consumer->block()->insertBefore(consumer, replace);
+}
+
+template <size_t Arity, size_t Index>
+static void ConvertOperandToDouble(MAryInstruction<Arity>* def,
+ TempAllocator& alloc) {
+ static_assert(Index < Arity);
+ auto* operand = def->getOperand(Index);
+ if (operand->type() == MIRType::Float32) {
+ ConvertDefinitionToDouble<Index>(alloc, operand, def);
+ }
+}
+
+template <size_t Arity, size_t... ISeq>
+static void ConvertOperandsToDouble(MAryInstruction<Arity>* def,
+ TempAllocator& alloc,
+ std::index_sequence<ISeq...>) {
+ (ConvertOperandToDouble<Arity, ISeq>(def, alloc), ...);
+}
+
+template <size_t Arity>
+static void ConvertOperandsToDouble(MAryInstruction<Arity>* def,
+ TempAllocator& alloc) {
+ ConvertOperandsToDouble<Arity>(def, alloc, std::make_index_sequence<Arity>{});
+}
+
+template <size_t Arity, size_t... ISeq>
+static bool AllOperandsCanProduceFloat32(MAryInstruction<Arity>* def,
+ std::index_sequence<ISeq...>) {
+ return (def->getOperand(ISeq)->canProduceFloat32() && ...);
+}
+
+template <size_t Arity>
+static bool AllOperandsCanProduceFloat32(MAryInstruction<Arity>* def) {
+ return AllOperandsCanProduceFloat32<Arity>(def,
+ std::make_index_sequence<Arity>{});
+}
+
+static bool CheckUsesAreFloat32Consumers(const MInstruction* ins) {
+ if (ins->isImplicitlyUsed()) {
+ return false;
+ }
+ bool allConsumerUses = true;
+ for (MUseDefIterator use(ins); allConsumerUses && use; use++) {
+ allConsumerUses &= use.def()->canConsumeFloat32(use.use());
+ }
+ return allConsumerUses;
+}
+
+#ifdef JS_JITSPEW
+static const char* OpcodeName(MDefinition::Opcode op) {
+ static const char* const names[] = {
+# define NAME(x) #x,
+ MIR_OPCODE_LIST(NAME)
+# undef NAME
+ };
+ return names[unsigned(op)];
+}
+
+void MDefinition::PrintOpcodeName(GenericPrinter& out, Opcode op) {
+ const char* name = OpcodeName(op);
+ size_t len = strlen(name);
+ for (size_t i = 0; i < len; i++) {
+ out.printf("%c", unicode::ToLowerCase(name[i]));
+ }
+}
+
+uint32_t js::jit::GetMBasicBlockId(const MBasicBlock* block) {
+ return block->id();
+}
+#endif
+
+static MConstant* EvaluateInt64ConstantOperands(TempAllocator& alloc,
+ MBinaryInstruction* ins) {
+ MDefinition* left = ins->getOperand(0);
+ MDefinition* right = ins->getOperand(1);
+
+ if (!left->isConstant() || !right->isConstant()) {
+ return nullptr;
+ }
+
+ MOZ_ASSERT(left->type() == MIRType::Int64);
+ MOZ_ASSERT(right->type() == MIRType::Int64);
+
+ int64_t lhs = left->toConstant()->toInt64();
+ int64_t rhs = right->toConstant()->toInt64();
+ int64_t ret;
+
+ switch (ins->op()) {
+ case MDefinition::Opcode::BitAnd:
+ ret = lhs & rhs;
+ break;
+ case MDefinition::Opcode::BitOr:
+ ret = lhs | rhs;
+ break;
+ case MDefinition::Opcode::BitXor:
+ ret = lhs ^ rhs;
+ break;
+ case MDefinition::Opcode::Lsh:
+ ret = lhs << (rhs & 0x3F);
+ break;
+ case MDefinition::Opcode::Rsh:
+ ret = lhs >> (rhs & 0x3F);
+ break;
+ case MDefinition::Opcode::Ursh:
+ ret = uint64_t(lhs) >> (uint64_t(rhs) & 0x3F);
+ break;
+ case MDefinition::Opcode::Add:
+ ret = lhs + rhs;
+ break;
+ case MDefinition::Opcode::Sub:
+ ret = lhs - rhs;
+ break;
+ case MDefinition::Opcode::Mul:
+ ret = lhs * rhs;
+ break;
+ case MDefinition::Opcode::Div:
+ if (rhs == 0) {
+ // Division by zero will trap at runtime.
+ return nullptr;
+ }
+ if (ins->toDiv()->isUnsigned()) {
+ ret = int64_t(uint64_t(lhs) / uint64_t(rhs));
+ } else if (lhs == INT64_MIN || rhs == -1) {
+ // Overflow will trap at runtime.
+ return nullptr;
+ } else {
+ ret = lhs / rhs;
+ }
+ break;
+ case MDefinition::Opcode::Mod:
+ if (rhs == 0) {
+ // Division by zero will trap at runtime.
+ return nullptr;
+ }
+ if (!ins->toMod()->isUnsigned() && (lhs < 0 || rhs < 0)) {
+ // Handle all negative values at runtime, for simplicity.
+ return nullptr;
+ }
+ ret = int64_t(uint64_t(lhs) % uint64_t(rhs));
+ break;
+ default:
+ MOZ_CRASH("NYI");
+ }
+
+ return MConstant::NewInt64(alloc, ret);
+}
+
+static MConstant* EvaluateConstantOperands(TempAllocator& alloc,
+ MBinaryInstruction* ins,
+ bool* ptypeChange = nullptr) {
+ MDefinition* left = ins->getOperand(0);
+ MDefinition* right = ins->getOperand(1);
+
+ MOZ_ASSERT(IsTypeRepresentableAsDouble(left->type()));
+ MOZ_ASSERT(IsTypeRepresentableAsDouble(right->type()));
+
+ if (!left->isConstant() || !right->isConstant()) {
+ return nullptr;
+ }
+
+ MConstant* lhs = left->toConstant();
+ MConstant* rhs = right->toConstant();
+ double ret = JS::GenericNaN();
+
+ switch (ins->op()) {
+ case MDefinition::Opcode::BitAnd:
+ ret = double(lhs->toInt32() & rhs->toInt32());
+ break;
+ case MDefinition::Opcode::BitOr:
+ ret = double(lhs->toInt32() | rhs->toInt32());
+ break;
+ case MDefinition::Opcode::BitXor:
+ ret = double(lhs->toInt32() ^ rhs->toInt32());
+ break;
+ case MDefinition::Opcode::Lsh:
+ ret = double(uint32_t(lhs->toInt32()) << (rhs->toInt32() & 0x1F));
+ break;
+ case MDefinition::Opcode::Rsh:
+ ret = double(lhs->toInt32() >> (rhs->toInt32() & 0x1F));
+ break;
+ case MDefinition::Opcode::Ursh:
+ ret = double(uint32_t(lhs->toInt32()) >> (rhs->toInt32() & 0x1F));
+ break;
+ case MDefinition::Opcode::Add:
+ ret = lhs->numberToDouble() + rhs->numberToDouble();
+ break;
+ case MDefinition::Opcode::Sub:
+ ret = lhs->numberToDouble() - rhs->numberToDouble();
+ break;
+ case MDefinition::Opcode::Mul:
+ ret = lhs->numberToDouble() * rhs->numberToDouble();
+ break;
+ case MDefinition::Opcode::Div:
+ if (ins->toDiv()->isUnsigned()) {
+ if (rhs->isInt32(0)) {
+ if (ins->toDiv()->trapOnError()) {
+ return nullptr;
+ }
+ ret = 0.0;
+ } else {
+ ret = double(uint32_t(lhs->toInt32()) / uint32_t(rhs->toInt32()));
+ }
+ } else {
+ ret = NumberDiv(lhs->numberToDouble(), rhs->numberToDouble());
+ }
+ break;
+ case MDefinition::Opcode::Mod:
+ if (ins->toMod()->isUnsigned()) {
+ if (rhs->isInt32(0)) {
+ if (ins->toMod()->trapOnError()) {
+ return nullptr;
+ }
+ ret = 0.0;
+ } else {
+ ret = double(uint32_t(lhs->toInt32()) % uint32_t(rhs->toInt32()));
+ }
+ } else {
+ ret = NumberMod(lhs->numberToDouble(), rhs->numberToDouble());
+ }
+ break;
+ default:
+ MOZ_CRASH("NYI");
+ }
+
+ if (ins->type() == MIRType::Float32) {
+ return MConstant::NewFloat32(alloc, float(ret));
+ }
+ if (ins->type() == MIRType::Double) {
+ return MConstant::New(alloc, DoubleValue(ret));
+ }
+
+ Value retVal;
+ retVal.setNumber(JS::CanonicalizeNaN(ret));
+
+ // If this was an int32 operation but the result isn't an int32 (for
+ // example, a division where the numerator isn't evenly divisible by the
+ // denominator), decline folding.
+ MOZ_ASSERT(ins->type() == MIRType::Int32);
+ if (!retVal.isInt32()) {
+ if (ptypeChange) {
+ *ptypeChange = true;
+ }
+ return nullptr;
+ }
+
+ return MConstant::New(alloc, retVal);
+}
+
+static MMul* EvaluateExactReciprocal(TempAllocator& alloc, MDiv* ins) {
+ // we should fold only when it is a floating point operation
+ if (!IsFloatingPointType(ins->type())) {
+ return nullptr;
+ }
+
+ MDefinition* left = ins->getOperand(0);
+ MDefinition* right = ins->getOperand(1);
+
+ if (!right->isConstant()) {
+ return nullptr;
+ }
+
+ int32_t num;
+ if (!mozilla::NumberIsInt32(right->toConstant()->numberToDouble(), &num)) {
+ return nullptr;
+ }
+
+ // check if rhs is a power of two
+ if (mozilla::Abs(num) & (mozilla::Abs(num) - 1)) {
+ return nullptr;
+ }
+
+ Value ret;
+ ret.setDouble(1.0 / double(num));
+
+ MConstant* foldedRhs;
+ if (ins->type() == MIRType::Float32) {
+ foldedRhs = MConstant::NewFloat32(alloc, ret.toDouble());
+ } else {
+ foldedRhs = MConstant::New(alloc, ret);
+ }
+
+ MOZ_ASSERT(foldedRhs->type() == ins->type());
+ ins->block()->insertBefore(ins, foldedRhs);
+
+ MMul* mul = MMul::New(alloc, left, foldedRhs, ins->type());
+ mul->setMustPreserveNaN(ins->mustPreserveNaN());
+ return mul;
+}
+
+#ifdef JS_JITSPEW
+const char* MDefinition::opName() const { return OpcodeName(op()); }
+
+void MDefinition::printName(GenericPrinter& out) const {
+ PrintOpcodeName(out, op());
+ out.printf("%u", id());
+}
+#endif
+
+HashNumber MDefinition::valueHash() const {
+ HashNumber out = HashNumber(op());
+ for (size_t i = 0, e = numOperands(); i < e; i++) {
+ out = addU32ToHash(out, getOperand(i)->id());
+ }
+ if (MDefinition* dep = dependency()) {
+ out = addU32ToHash(out, dep->id());
+ }
+ return out;
+}
+
+HashNumber MNullaryInstruction::valueHash() const {
+ HashNumber hash = HashNumber(op());
+ if (MDefinition* dep = dependency()) {
+ hash = addU32ToHash(hash, dep->id());
+ }
+ MOZ_ASSERT(hash == MDefinition::valueHash());
+ return hash;
+}
+
+HashNumber MUnaryInstruction::valueHash() const {
+ HashNumber hash = HashNumber(op());
+ hash = addU32ToHash(hash, getOperand(0)->id());
+ if (MDefinition* dep = dependency()) {
+ hash = addU32ToHash(hash, dep->id());
+ }
+ MOZ_ASSERT(hash == MDefinition::valueHash());
+ return hash;
+}
+
+HashNumber MBinaryInstruction::valueHash() const {
+ HashNumber hash = HashNumber(op());
+ hash = addU32ToHash(hash, getOperand(0)->id());
+ hash = addU32ToHash(hash, getOperand(1)->id());
+ if (MDefinition* dep = dependency()) {
+ hash = addU32ToHash(hash, dep->id());
+ }
+ MOZ_ASSERT(hash == MDefinition::valueHash());
+ return hash;
+}
+
+HashNumber MTernaryInstruction::valueHash() const {
+ HashNumber hash = HashNumber(op());
+ hash = addU32ToHash(hash, getOperand(0)->id());
+ hash = addU32ToHash(hash, getOperand(1)->id());
+ hash = addU32ToHash(hash, getOperand(2)->id());
+ if (MDefinition* dep = dependency()) {
+ hash = addU32ToHash(hash, dep->id());
+ }
+ MOZ_ASSERT(hash == MDefinition::valueHash());
+ return hash;
+}
+
+HashNumber MQuaternaryInstruction::valueHash() const {
+ HashNumber hash = HashNumber(op());
+ hash = addU32ToHash(hash, getOperand(0)->id());
+ hash = addU32ToHash(hash, getOperand(1)->id());
+ hash = addU32ToHash(hash, getOperand(2)->id());
+ hash = addU32ToHash(hash, getOperand(3)->id());
+ if (MDefinition* dep = dependency()) {
+ hash = addU32ToHash(hash, dep->id());
+ }
+ MOZ_ASSERT(hash == MDefinition::valueHash());
+ return hash;
+}
+
+const MDefinition* MDefinition::skipObjectGuards() const {
+ const MDefinition* result = this;
+ // These instructions don't modify the object and just guard specific
+ // properties.
+ while (true) {
+ if (result->isGuardShape()) {
+ result = result->toGuardShape()->object();
+ continue;
+ }
+ if (result->isGuardNullProto()) {
+ result = result->toGuardNullProto()->object();
+ continue;
+ }
+ if (result->isGuardProto()) {
+ result = result->toGuardProto()->object();
+ continue;
+ }
+
+ break;
+ }
+
+ return result;
+}
+
+bool MDefinition::congruentIfOperandsEqual(const MDefinition* ins) const {
+ if (op() != ins->op()) {
+ return false;
+ }
+
+ if (type() != ins->type()) {
+ return false;
+ }
+
+ if (isEffectful() || ins->isEffectful()) {
+ return false;
+ }
+
+ if (numOperands() != ins->numOperands()) {
+ return false;
+ }
+
+ for (size_t i = 0, e = numOperands(); i < e; i++) {
+ if (getOperand(i) != ins->getOperand(i)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+MDefinition* MDefinition::foldsTo(TempAllocator& alloc) {
+ // In the default case, there are no constants to fold.
+ return this;
+}
+
+bool MDefinition::mightBeMagicType() const {
+ if (IsMagicType(type())) {
+ return true;
+ }
+
+ if (MIRType::Value != type()) {
+ return false;
+ }
+
+ return true;
+}
+
+bool MDefinition::definitelyType(std::initializer_list<MIRType> types) const {
+#ifdef DEBUG
+ // Only support specialized, non-magic types.
+ auto isSpecializedNonMagic = [](MIRType type) {
+ return type <= MIRType::Object;
+ };
+#endif
+
+ MOZ_ASSERT(types.size() > 0);
+ MOZ_ASSERT(std::all_of(types.begin(), types.end(), isSpecializedNonMagic));
+
+ if (type() == MIRType::Value) {
+ return false;
+ }
+
+ return std::find(types.begin(), types.end(), type()) != types.end();
+}
+
+MDefinition* MInstruction::foldsToStore(TempAllocator& alloc) {
+ if (!dependency()) {
+ return nullptr;
+ }
+
+ MDefinition* store = dependency();
+ if (mightAlias(store) != AliasType::MustAlias) {
+ return nullptr;
+ }
+
+ if (!store->block()->dominates(block())) {
+ return nullptr;
+ }
+
+ MDefinition* value;
+ switch (store->op()) {
+ case Opcode::StoreFixedSlot:
+ value = store->toStoreFixedSlot()->value();
+ break;
+ case Opcode::StoreDynamicSlot:
+ value = store->toStoreDynamicSlot()->value();
+ break;
+ case Opcode::StoreElement:
+ value = store->toStoreElement()->value();
+ break;
+ default:
+ MOZ_CRASH("unknown store");
+ }
+
+ // If the type are matching then we return the value which is used as
+ // argument of the store.
+ if (value->type() != type()) {
+ // If we expect to read a type which is more generic than the type seen
+ // by the store, then we box the value used by the store.
+ if (type() != MIRType::Value) {
+ return nullptr;
+ }
+
+ MOZ_ASSERT(value->type() < MIRType::Value);
+ MBox* box = MBox::New(alloc, value);
+ value = box;
+ }
+
+ return value;
+}
+
+void MDefinition::analyzeEdgeCasesForward() {}
+
+void MDefinition::analyzeEdgeCasesBackward() {}
+
+void MInstruction::setResumePoint(MResumePoint* resumePoint) {
+ MOZ_ASSERT(!resumePoint_);
+ resumePoint_ = resumePoint;
+ resumePoint_->setInstruction(this);
+}
+
+void MInstruction::stealResumePoint(MInstruction* other) {
+ MResumePoint* resumePoint = other->resumePoint_;
+ other->resumePoint_ = nullptr;
+
+ resumePoint->resetInstruction();
+ setResumePoint(resumePoint);
+}
+
+void MInstruction::moveResumePointAsEntry() {
+ MOZ_ASSERT(isNop());
+ block()->clearEntryResumePoint();
+ block()->setEntryResumePoint(resumePoint_);
+ resumePoint_->resetInstruction();
+ resumePoint_ = nullptr;
+}
+
+void MInstruction::clearResumePoint() {
+ resumePoint_->resetInstruction();
+ block()->discardPreAllocatedResumePoint(resumePoint_);
+ resumePoint_ = nullptr;
+}
+
+MDefinition* MTest::foldsDoubleNegation(TempAllocator& alloc) {
+ MDefinition* op = getOperand(0);
+
+ if (op->isNot()) {
+ // If the operand of the Not is itself a Not, they cancel out.
+ MDefinition* opop = op->getOperand(0);
+ if (opop->isNot()) {
+ return MTest::New(alloc, opop->toNot()->input(), ifTrue(), ifFalse());
+ }
+ return MTest::New(alloc, op->toNot()->input(), ifFalse(), ifTrue());
+ }
+ return nullptr;
+}
+
+MDefinition* MTest::foldsConstant(TempAllocator& alloc) {
+ MDefinition* op = getOperand(0);
+ if (MConstant* opConst = op->maybeConstantValue()) {
+ bool b;
+ if (opConst->valueToBoolean(&b)) {
+ return MGoto::New(alloc, b ? ifTrue() : ifFalse());
+ }
+ }
+ return nullptr;
+}
+
+MDefinition* MTest::foldsTypes(TempAllocator& alloc) {
+ MDefinition* op = getOperand(0);
+
+ switch (op->type()) {
+ case MIRType::Undefined:
+ case MIRType::Null:
+ return MGoto::New(alloc, ifFalse());
+ case MIRType::Symbol:
+ return MGoto::New(alloc, ifTrue());
+ default:
+ break;
+ }
+ return nullptr;
+}
+
+class UsesIterator {
+ MDefinition* def_;
+
+ public:
+ explicit UsesIterator(MDefinition* def) : def_(def) {}
+ auto begin() const { return def_->usesBegin(); }
+ auto end() const { return def_->usesEnd(); }
+};
+
+static bool AllInstructionsDeadIfUnused(MBasicBlock* block) {
+ for (auto* ins : *block) {
+ // Skip trivial instructions.
+ if (ins->isNop() || ins->isGoto()) {
+ continue;
+ }
+
+ // All uses must be within the current block.
+ for (auto* use : UsesIterator(ins)) {
+ if (use->consumer()->block() != block) {
+ return false;
+ }
+ }
+
+ // All instructions within this block must be dead if unused.
+ if (!DeadIfUnused(ins)) {
+ return false;
+ }
+ }
+ return true;
+}
+
+MDefinition* MTest::foldsNeedlessControlFlow(TempAllocator& alloc) {
+ // All instructions within both successors need be dead if unused.
+ if (!AllInstructionsDeadIfUnused(ifTrue()) ||
+ !AllInstructionsDeadIfUnused(ifFalse())) {
+ return nullptr;
+ }
+
+ // Both successors must have the same target successor.
+ if (ifTrue()->numSuccessors() != 1 || ifFalse()->numSuccessors() != 1) {
+ return nullptr;
+ }
+ if (ifTrue()->getSuccessor(0) != ifFalse()->getSuccessor(0)) {
+ return nullptr;
+ }
+
+ // The target successor's phis must be redundant. Redundant phis should have
+ // been removed in an earlier pass, so only check if any phis are present,
+ // which is a stronger condition.
+ if (ifTrue()->successorWithPhis()) {
+ return nullptr;
+ }
+
+ return MGoto::New(alloc, ifTrue());
+}
+
+MDefinition* MTest::foldsTo(TempAllocator& alloc) {
+ if (MDefinition* def = foldsDoubleNegation(alloc)) {
+ return def;
+ }
+
+ if (MDefinition* def = foldsConstant(alloc)) {
+ return def;
+ }
+
+ if (MDefinition* def = foldsTypes(alloc)) {
+ return def;
+ }
+
+ if (MDefinition* def = foldsNeedlessControlFlow(alloc)) {
+ return def;
+ }
+
+ return this;
+}
+
+AliasSet MThrow::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ExceptionState);
+}
+
+AliasSet MNewArrayDynamicLength::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ExceptionState);
+}
+
+AliasSet MNewTypedArrayDynamicLength::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ExceptionState);
+}
+
+#ifdef JS_JITSPEW
+void MDefinition::printOpcode(GenericPrinter& out) const {
+ PrintOpcodeName(out, op());
+ for (size_t j = 0, e = numOperands(); j < e; j++) {
+ out.printf(" ");
+ if (getUseFor(j)->hasProducer()) {
+ getOperand(j)->printName(out);
+ out.printf(":%s", StringFromMIRType(getOperand(j)->type()));
+ } else {
+ out.printf("(null)");
+ }
+ }
+}
+
+void MDefinition::dump(GenericPrinter& out) const {
+ printName(out);
+ out.printf(":%s", StringFromMIRType(type()));
+ out.printf(" = ");
+ printOpcode(out);
+ out.printf("\n");
+
+ if (isInstruction()) {
+ if (MResumePoint* resume = toInstruction()->resumePoint()) {
+ resume->dump(out);
+ }
+ }
+}
+
+void MDefinition::dump() const {
+ Fprinter out(stderr);
+ dump(out);
+ out.finish();
+}
+
+void MDefinition::dumpLocation(GenericPrinter& out) const {
+ MResumePoint* rp = nullptr;
+ const char* linkWord = nullptr;
+ if (isInstruction() && toInstruction()->resumePoint()) {
+ rp = toInstruction()->resumePoint();
+ linkWord = "at";
+ } else {
+ rp = block()->entryResumePoint();
+ linkWord = "after";
+ }
+
+ while (rp) {
+ JSScript* script = rp->block()->info().script();
+ uint32_t lineno = PCToLineNumber(rp->block()->info().script(), rp->pc());
+ out.printf(" %s %s:%u\n", linkWord, script->filename(), lineno);
+ rp = rp->caller();
+ linkWord = "in";
+ }
+}
+
+void MDefinition::dumpLocation() const {
+ Fprinter out(stderr);
+ dumpLocation(out);
+ out.finish();
+}
+#endif
+
+#ifdef DEBUG
+bool MDefinition::trackedSiteMatchesBlock(const BytecodeSite* site) const {
+ return site == block()->trackedSite();
+}
+#endif
+
+#if defined(DEBUG) || defined(JS_JITSPEW)
+size_t MDefinition::useCount() const {
+ size_t count = 0;
+ for (MUseIterator i(uses_.begin()); i != uses_.end(); i++) {
+ count++;
+ }
+ return count;
+}
+
+size_t MDefinition::defUseCount() const {
+ size_t count = 0;
+ for (MUseIterator i(uses_.begin()); i != uses_.end(); i++) {
+ if ((*i)->consumer()->isDefinition()) {
+ count++;
+ }
+ }
+ return count;
+}
+#endif
+
+bool MDefinition::hasOneUse() const {
+ MUseIterator i(uses_.begin());
+ if (i == uses_.end()) {
+ return false;
+ }
+ i++;
+ return i == uses_.end();
+}
+
+bool MDefinition::hasOneDefUse() const {
+ bool hasOneDefUse = false;
+ for (MUseIterator i(uses_.begin()); i != uses_.end(); i++) {
+ if (!(*i)->consumer()->isDefinition()) {
+ continue;
+ }
+
+ // We already have a definition use. So 1+
+ if (hasOneDefUse) {
+ return false;
+ }
+
+ // We saw one definition. Loop to test if there is another.
+ hasOneDefUse = true;
+ }
+
+ return hasOneDefUse;
+}
+
+bool MDefinition::hasDefUses() const {
+ for (MUseIterator i(uses_.begin()); i != uses_.end(); i++) {
+ if ((*i)->consumer()->isDefinition()) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+bool MDefinition::hasLiveDefUses() const {
+ for (MUseIterator i(uses_.begin()); i != uses_.end(); i++) {
+ MNode* ins = (*i)->consumer();
+ if (ins->isDefinition()) {
+ if (!ins->toDefinition()->isRecoveredOnBailout()) {
+ return true;
+ }
+ } else {
+ MOZ_ASSERT(ins->isResumePoint());
+ if (!ins->toResumePoint()->isRecoverableOperand(*i)) {
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+MDefinition* MDefinition::maybeSingleDefUse() const {
+ MUseDefIterator use(this);
+ if (!use) {
+ // No def-uses.
+ return nullptr;
+ }
+
+ MDefinition* useDef = use.def();
+
+ use++;
+ if (use) {
+ // More than one def-use.
+ return nullptr;
+ }
+
+ return useDef;
+}
+
+MDefinition* MDefinition::maybeMostRecentlyAddedDefUse() const {
+ MUseDefIterator use(this);
+ if (!use) {
+ // No def-uses.
+ return nullptr;
+ }
+
+ MDefinition* mostRecentUse = use.def();
+
+#ifdef DEBUG
+ // This function relies on addUse adding new uses to the front of the list.
+ // Check this invariant by asserting the next few uses are 'older'. Skip this
+ // for phis because setBackedge can add a new use for a loop phi even if the
+ // loop body has a use with an id greater than the loop phi's id.
+ if (!mostRecentUse->isPhi()) {
+ static constexpr size_t NumUsesToCheck = 3;
+ use++;
+ for (size_t i = 0; use && i < NumUsesToCheck; i++, use++) {
+ MOZ_ASSERT(use.def()->id() <= mostRecentUse->id());
+ }
+ }
+#endif
+
+ return mostRecentUse;
+}
+
+void MDefinition::replaceAllUsesWith(MDefinition* dom) {
+ for (size_t i = 0, e = numOperands(); i < e; ++i) {
+ getOperand(i)->setImplicitlyUsedUnchecked();
+ }
+
+ justReplaceAllUsesWith(dom);
+}
+
+void MDefinition::justReplaceAllUsesWith(MDefinition* dom) {
+ MOZ_ASSERT(dom != nullptr);
+ MOZ_ASSERT(dom != this);
+
+ // Carry over the fact the value has uses which are no longer inspectable
+ // with the graph.
+ if (isImplicitlyUsed()) {
+ dom->setImplicitlyUsedUnchecked();
+ }
+
+ for (MUseIterator i(usesBegin()), e(usesEnd()); i != e; ++i) {
+ i->setProducerUnchecked(dom);
+ }
+ dom->uses_.takeElements(uses_);
+}
+
+bool MDefinition::optimizeOutAllUses(TempAllocator& alloc) {
+ for (MUseIterator i(usesBegin()), e(usesEnd()); i != e;) {
+ MUse* use = *i++;
+ MConstant* constant = use->consumer()->block()->optimizedOutConstant(alloc);
+ if (!alloc.ensureBallast()) {
+ return false;
+ }
+
+ // Update the resume point operand to use the optimized-out constant.
+ use->setProducerUnchecked(constant);
+ constant->addUseUnchecked(use);
+ }
+
+ // Remove dangling pointers.
+ this->uses_.clear();
+ return true;
+}
+
+void MDefinition::replaceAllLiveUsesWith(MDefinition* dom) {
+ for (MUseIterator i(usesBegin()), e(usesEnd()); i != e;) {
+ MUse* use = *i++;
+ MNode* consumer = use->consumer();
+ if (consumer->isResumePoint()) {
+ continue;
+ }
+ if (consumer->isDefinition() &&
+ consumer->toDefinition()->isRecoveredOnBailout()) {
+ continue;
+ }
+
+ // Update the operand to use the dominating definition.
+ use->replaceProducer(dom);
+ }
+}
+
+MConstant* MConstant::New(TempAllocator& alloc, const Value& v) {
+ return new (alloc) MConstant(alloc, v);
+}
+
+MConstant* MConstant::New(TempAllocator::Fallible alloc, const Value& v) {
+ return new (alloc) MConstant(alloc.alloc, v);
+}
+
+MConstant* MConstant::NewFloat32(TempAllocator& alloc, double d) {
+ MOZ_ASSERT(std::isnan(d) || d == double(float(d)));
+ return new (alloc) MConstant(float(d));
+}
+
+MConstant* MConstant::NewInt64(TempAllocator& alloc, int64_t i) {
+ return new (alloc) MConstant(MIRType::Int64, i);
+}
+
+MConstant* MConstant::NewIntPtr(TempAllocator& alloc, intptr_t i) {
+ return new (alloc) MConstant(MIRType::IntPtr, i);
+}
+
+MConstant* MConstant::New(TempAllocator& alloc, const Value& v, MIRType type) {
+ if (type == MIRType::Float32) {
+ return NewFloat32(alloc, v.toNumber());
+ }
+ MConstant* res = New(alloc, v);
+ MOZ_ASSERT(res->type() == type);
+ return res;
+}
+
+MConstant* MConstant::NewObject(TempAllocator& alloc, JSObject* v) {
+ return new (alloc) MConstant(v);
+}
+
+MConstant* MConstant::NewShape(TempAllocator& alloc, Shape* s) {
+ return new (alloc) MConstant(s);
+}
+
+static MIRType MIRTypeFromValue(const js::Value& vp) {
+ if (vp.isDouble()) {
+ return MIRType::Double;
+ }
+ if (vp.isMagic()) {
+ switch (vp.whyMagic()) {
+ case JS_OPTIMIZED_OUT:
+ return MIRType::MagicOptimizedOut;
+ case JS_ELEMENTS_HOLE:
+ return MIRType::MagicHole;
+ case JS_IS_CONSTRUCTING:
+ return MIRType::MagicIsConstructing;
+ case JS_UNINITIALIZED_LEXICAL:
+ return MIRType::MagicUninitializedLexical;
+ default:
+ MOZ_ASSERT_UNREACHABLE("Unexpected magic constant");
+ }
+ }
+ return MIRTypeFromValueType(vp.extractNonDoubleType());
+}
+
+MConstant::MConstant(TempAllocator& alloc, const js::Value& vp)
+ : MNullaryInstruction(classOpcode) {
+ setResultType(MIRTypeFromValue(vp));
+
+ MOZ_ASSERT(payload_.asBits == 0);
+
+ switch (type()) {
+ case MIRType::Undefined:
+ case MIRType::Null:
+ break;
+ case MIRType::Boolean:
+ payload_.b = vp.toBoolean();
+ break;
+ case MIRType::Int32:
+ payload_.i32 = vp.toInt32();
+ break;
+ case MIRType::Double:
+ payload_.d = vp.toDouble();
+ break;
+ case MIRType::String:
+ MOZ_ASSERT(!IsInsideNursery(vp.toString()));
+ MOZ_ASSERT(vp.toString()->isLinear());
+ payload_.str = vp.toString();
+ break;
+ case MIRType::Symbol:
+ payload_.sym = vp.toSymbol();
+ break;
+ case MIRType::BigInt:
+ MOZ_ASSERT(!IsInsideNursery(vp.toBigInt()));
+ payload_.bi = vp.toBigInt();
+ break;
+ case MIRType::Object:
+ MOZ_ASSERT(!IsInsideNursery(&vp.toObject()));
+ payload_.obj = &vp.toObject();
+ break;
+ case MIRType::MagicOptimizedOut:
+ case MIRType::MagicHole:
+ case MIRType::MagicIsConstructing:
+ case MIRType::MagicUninitializedLexical:
+ break;
+ default:
+ MOZ_CRASH("Unexpected type");
+ }
+
+ setMovable();
+}
+
+MConstant::MConstant(JSObject* obj) : MNullaryInstruction(classOpcode) {
+ MOZ_ASSERT(!IsInsideNursery(obj));
+ setResultType(MIRType::Object);
+ payload_.obj = obj;
+ setMovable();
+}
+
+MConstant::MConstant(Shape* shape) : MNullaryInstruction(classOpcode) {
+ setResultType(MIRType::Shape);
+ payload_.shape = shape;
+ setMovable();
+}
+
+MConstant::MConstant(float f) : MNullaryInstruction(classOpcode) {
+ setResultType(MIRType::Float32);
+ payload_.f = f;
+ setMovable();
+}
+
+MConstant::MConstant(MIRType type, int64_t i)
+ : MNullaryInstruction(classOpcode) {
+ MOZ_ASSERT(type == MIRType::Int64 || type == MIRType::IntPtr);
+ setResultType(type);
+ if (type == MIRType::Int64) {
+ payload_.i64 = i;
+ } else {
+ payload_.iptr = i;
+ }
+ setMovable();
+}
+
+#ifdef DEBUG
+void MConstant::assertInitializedPayload() const {
+ // valueHash() and equals() expect the unused payload bits to be
+ // initialized to zero. Assert this in debug builds.
+
+ switch (type()) {
+ case MIRType::Int32:
+ case MIRType::Float32:
+# if MOZ_LITTLE_ENDIAN()
+ MOZ_ASSERT((payload_.asBits >> 32) == 0);
+# else
+ MOZ_ASSERT((payload_.asBits << 32) == 0);
+# endif
+ break;
+ case MIRType::Boolean:
+# if MOZ_LITTLE_ENDIAN()
+ MOZ_ASSERT((payload_.asBits >> 1) == 0);
+# else
+ MOZ_ASSERT((payload_.asBits & ~(1ULL << 56)) == 0);
+# endif
+ break;
+ case MIRType::Double:
+ case MIRType::Int64:
+ break;
+ case MIRType::String:
+ case MIRType::Object:
+ case MIRType::Symbol:
+ case MIRType::BigInt:
+ case MIRType::IntPtr:
+ case MIRType::Shape:
+# if MOZ_LITTLE_ENDIAN()
+ MOZ_ASSERT_IF(JS_BITS_PER_WORD == 32, (payload_.asBits >> 32) == 0);
+# else
+ MOZ_ASSERT_IF(JS_BITS_PER_WORD == 32, (payload_.asBits << 32) == 0);
+# endif
+ break;
+ default:
+ MOZ_ASSERT(IsNullOrUndefined(type()) || IsMagicType(type()));
+ MOZ_ASSERT(payload_.asBits == 0);
+ break;
+ }
+}
+#endif
+
+static HashNumber ConstantValueHash(MIRType type, uint64_t payload) {
+ // Build a 64-bit value holding both the payload and the type.
+ static const size_t TypeBits = 8;
+ static const size_t TypeShift = 64 - TypeBits;
+ MOZ_ASSERT(uintptr_t(type) <= (1 << TypeBits) - 1);
+ uint64_t bits = (uint64_t(type) << TypeShift) ^ payload;
+
+ // Fold all 64 bits into the 32-bit result. It's tempting to just discard
+ // half of the bits, as this is just a hash, however there are many common
+ // patterns of values where only the low or the high bits vary, so
+ // discarding either side would lead to excessive hash collisions.
+ return (HashNumber)bits ^ (HashNumber)(bits >> 32);
+}
+
+HashNumber MConstant::valueHash() const {
+ static_assert(sizeof(Payload) == sizeof(uint64_t),
+ "Code below assumes payload fits in 64 bits");
+
+ assertInitializedPayload();
+ return ConstantValueHash(type(), payload_.asBits);
+}
+
+HashNumber MConstantProto::valueHash() const {
+ HashNumber hash = protoObject()->valueHash();
+ const MDefinition* receiverObject = getReceiverObject();
+ if (receiverObject) {
+ hash = addU32ToHash(hash, receiverObject->id());
+ }
+ return hash;
+}
+
+bool MConstant::congruentTo(const MDefinition* ins) const {
+ return ins->isConstant() && equals(ins->toConstant());
+}
+
+#ifdef JS_JITSPEW
+void MConstant::printOpcode(GenericPrinter& out) const {
+ PrintOpcodeName(out, op());
+ out.printf(" ");
+ switch (type()) {
+ case MIRType::Undefined:
+ out.printf("undefined");
+ break;
+ case MIRType::Null:
+ out.printf("null");
+ break;
+ case MIRType::Boolean:
+ out.printf(toBoolean() ? "true" : "false");
+ break;
+ case MIRType::Int32:
+ out.printf("0x%x", uint32_t(toInt32()));
+ break;
+ case MIRType::Int64:
+ out.printf("0x%" PRIx64, uint64_t(toInt64()));
+ break;
+ case MIRType::IntPtr:
+ out.printf("0x%" PRIxPTR, uintptr_t(toIntPtr()));
+ break;
+ case MIRType::Double:
+ out.printf("%.16g", toDouble());
+ break;
+ case MIRType::Float32: {
+ float val = toFloat32();
+ out.printf("%.16g", val);
+ break;
+ }
+ case MIRType::Object:
+ if (toObject().is<JSFunction>()) {
+ JSFunction* fun = &toObject().as<JSFunction>();
+ if (fun->displayAtom()) {
+ out.put("function ");
+ EscapedStringPrinter(out, fun->displayAtom(), 0);
+ } else {
+ out.put("unnamed function");
+ }
+ if (fun->hasBaseScript()) {
+ BaseScript* script = fun->baseScript();
+ out.printf(" (%s:%u)", script->filename() ? script->filename() : "",
+ script->lineno());
+ }
+ out.printf(" at %p", (void*)fun);
+ break;
+ }
+ out.printf("object %p (%s)", (void*)&toObject(),
+ toObject().getClass()->name);
+ break;
+ case MIRType::Symbol:
+ out.printf("symbol at %p", (void*)toSymbol());
+ break;
+ case MIRType::BigInt:
+ out.printf("BigInt at %p", (void*)toBigInt());
+ break;
+ case MIRType::String:
+ out.printf("string %p", (void*)toString());
+ break;
+ case MIRType::Shape:
+ out.printf("shape at %p", (void*)toShape());
+ break;
+ case MIRType::MagicHole:
+ out.printf("magic hole");
+ break;
+ case MIRType::MagicIsConstructing:
+ out.printf("magic is-constructing");
+ break;
+ case MIRType::MagicOptimizedOut:
+ out.printf("magic optimized-out");
+ break;
+ case MIRType::MagicUninitializedLexical:
+ out.printf("magic uninitialized-lexical");
+ break;
+ default:
+ MOZ_CRASH("unexpected type");
+ }
+}
+#endif
+
+bool MConstant::canProduceFloat32() const {
+ if (!isTypeRepresentableAsDouble()) {
+ return false;
+ }
+
+ if (type() == MIRType::Int32) {
+ return IsFloat32Representable(static_cast<double>(toInt32()));
+ }
+ if (type() == MIRType::Double) {
+ return IsFloat32Representable(toDouble());
+ }
+ MOZ_ASSERT(type() == MIRType::Float32);
+ return true;
+}
+
+Value MConstant::toJSValue() const {
+ // Wasm has types like int64 that cannot be stored as js::Value. It also
+ // doesn't want the NaN canonicalization enforced by js::Value.
+ MOZ_ASSERT(!IsCompilingWasm());
+
+ switch (type()) {
+ case MIRType::Undefined:
+ return UndefinedValue();
+ case MIRType::Null:
+ return NullValue();
+ case MIRType::Boolean:
+ return BooleanValue(toBoolean());
+ case MIRType::Int32:
+ return Int32Value(toInt32());
+ case MIRType::Double:
+ return DoubleValue(toDouble());
+ case MIRType::Float32:
+ return Float32Value(toFloat32());
+ case MIRType::String:
+ return StringValue(toString());
+ case MIRType::Symbol:
+ return SymbolValue(toSymbol());
+ case MIRType::BigInt:
+ return BigIntValue(toBigInt());
+ case MIRType::Object:
+ return ObjectValue(toObject());
+ case MIRType::Shape:
+ return PrivateGCThingValue(toShape());
+ case MIRType::MagicOptimizedOut:
+ return MagicValue(JS_OPTIMIZED_OUT);
+ case MIRType::MagicHole:
+ return MagicValue(JS_ELEMENTS_HOLE);
+ case MIRType::MagicIsConstructing:
+ return MagicValue(JS_IS_CONSTRUCTING);
+ case MIRType::MagicUninitializedLexical:
+ return MagicValue(JS_UNINITIALIZED_LEXICAL);
+ default:
+ MOZ_CRASH("Unexpected type");
+ }
+}
+
+bool MConstant::valueToBoolean(bool* res) const {
+ switch (type()) {
+ case MIRType::Boolean:
+ *res = toBoolean();
+ return true;
+ case MIRType::Int32:
+ *res = toInt32() != 0;
+ return true;
+ case MIRType::Int64:
+ *res = toInt64() != 0;
+ return true;
+ case MIRType::Double:
+ *res = !std::isnan(toDouble()) && toDouble() != 0.0;
+ return true;
+ case MIRType::Float32:
+ *res = !std::isnan(toFloat32()) && toFloat32() != 0.0f;
+ return true;
+ case MIRType::Null:
+ case MIRType::Undefined:
+ *res = false;
+ return true;
+ case MIRType::Symbol:
+ *res = true;
+ return true;
+ case MIRType::BigInt:
+ *res = !toBigInt()->isZero();
+ return true;
+ case MIRType::String:
+ *res = toString()->length() != 0;
+ return true;
+ case MIRType::Object:
+ // TODO(Warp): Lazy groups have been removed.
+ // We have to call EmulatesUndefined but that reads obj->group->clasp
+ // and so it's racy when the object has a lazy group. The main callers
+ // of this (MTest, MNot) already know how to fold the object case, so
+ // just give up.
+ return false;
+ default:
+ MOZ_ASSERT(IsMagicType(type()));
+ return false;
+ }
+}
+
+HashNumber MWasmFloatConstant::valueHash() const {
+#ifdef ENABLE_WASM_SIMD
+ return ConstantValueHash(type(), u.bits_[0] ^ u.bits_[1]);
+#else
+ return ConstantValueHash(type(), u.bits_[0]);
+#endif
+}
+
+bool MWasmFloatConstant::congruentTo(const MDefinition* ins) const {
+ return ins->isWasmFloatConstant() && type() == ins->type() &&
+#ifdef ENABLE_WASM_SIMD
+ u.bits_[1] == ins->toWasmFloatConstant()->u.bits_[1] &&
+#endif
+ u.bits_[0] == ins->toWasmFloatConstant()->u.bits_[0];
+}
+
+HashNumber MWasmNullConstant::valueHash() const {
+ return ConstantValueHash(MIRType::RefOrNull, 0);
+}
+
+#ifdef JS_JITSPEW
+void MControlInstruction::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ for (size_t j = 0; j < numSuccessors(); j++) {
+ if (getSuccessor(j)) {
+ out.printf(" block%u", getSuccessor(j)->id());
+ } else {
+ out.printf(" (null-to-be-patched)");
+ }
+ }
+}
+
+void MCompare::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" %s", CodeName(jsop()));
+}
+
+void MTypeOfIs::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" %s", CodeName(jsop()));
+
+ const char* name = "";
+ switch (jstype()) {
+ case JSTYPE_UNDEFINED:
+ name = "undefined";
+ break;
+ case JSTYPE_OBJECT:
+ name = "object";
+ break;
+ case JSTYPE_FUNCTION:
+ name = "function";
+ break;
+ case JSTYPE_STRING:
+ name = "string";
+ break;
+ case JSTYPE_NUMBER:
+ name = "number";
+ break;
+ case JSTYPE_BOOLEAN:
+ name = "boolean";
+ break;
+ case JSTYPE_SYMBOL:
+ name = "symbol";
+ break;
+ case JSTYPE_BIGINT:
+ name = "bigint";
+ break;
+# ifdef ENABLE_RECORD_TUPLE
+ case JSTYPE_RECORD:
+ case JSTYPE_TUPLE:
+# endif
+ case JSTYPE_LIMIT:
+ MOZ_CRASH("Unexpected type");
+ }
+ out.printf(" '%s'", name);
+}
+
+void MLoadUnboxedScalar::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" %s", Scalar::name(storageType()));
+}
+
+void MLoadDataViewElement::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" %s", Scalar::name(storageType()));
+}
+
+void MAssertRange::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.put(" ");
+ assertedRange()->dump(out);
+}
+
+void MNearbyInt::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ const char* roundingModeStr = nullptr;
+ switch (roundingMode_) {
+ case RoundingMode::Up:
+ roundingModeStr = "(up)";
+ break;
+ case RoundingMode::Down:
+ roundingModeStr = "(down)";
+ break;
+ case RoundingMode::NearestTiesToEven:
+ roundingModeStr = "(nearest ties even)";
+ break;
+ case RoundingMode::TowardsZero:
+ roundingModeStr = "(towards zero)";
+ break;
+ }
+ out.printf(" %s", roundingModeStr);
+}
+#endif
+
+AliasSet MRandom::getAliasSet() const { return AliasSet::Store(AliasSet::RNG); }
+
+MDefinition* MSign::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+ if (!input->isConstant() ||
+ !input->toConstant()->isTypeRepresentableAsDouble()) {
+ return this;
+ }
+
+ double in = input->toConstant()->numberToDouble();
+ double out = js::math_sign_impl(in);
+
+ if (type() == MIRType::Int32) {
+ // Decline folding if this is an int32 operation, but the result type
+ // isn't an int32.
+ Value outValue = NumberValue(out);
+ if (!outValue.isInt32()) {
+ return this;
+ }
+
+ return MConstant::New(alloc, outValue);
+ }
+
+ return MConstant::New(alloc, DoubleValue(out));
+}
+
+const char* MMathFunction::FunctionName(UnaryMathFunction function) {
+ return GetUnaryMathFunctionName(function);
+}
+
+#ifdef JS_JITSPEW
+void MMathFunction::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" %s", FunctionName(function()));
+}
+#endif
+
+MDefinition* MMathFunction::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+ if (!input->isConstant() ||
+ !input->toConstant()->isTypeRepresentableAsDouble()) {
+ return this;
+ }
+
+ UnaryMathFunctionType funPtr = GetUnaryMathFunctionPtr(function());
+
+ double in = input->toConstant()->numberToDouble();
+
+ // The function pointer call can't GC.
+ JS::AutoSuppressGCAnalysis nogc;
+ double out = funPtr(in);
+
+ if (input->type() == MIRType::Float32) {
+ return MConstant::NewFloat32(alloc, out);
+ }
+ return MConstant::New(alloc, DoubleValue(out));
+}
+
+MDefinition* MAtomicIsLockFree::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+ if (!input->isConstant() || input->type() != MIRType::Int32) {
+ return this;
+ }
+
+ int32_t i = input->toConstant()->toInt32();
+ return MConstant::New(alloc, BooleanValue(AtomicOperations::isLockfreeJS(i)));
+}
+
+// Define |THIS_SLOT| as part of this translation unit, as it is used to
+// specialized the parameterized |New| function calls introduced by
+// TRIVIAL_NEW_WRAPPERS.
+const int32_t MParameter::THIS_SLOT;
+
+#ifdef JS_JITSPEW
+void MParameter::printOpcode(GenericPrinter& out) const {
+ PrintOpcodeName(out, op());
+ if (index() == THIS_SLOT) {
+ out.printf(" THIS_SLOT");
+ } else {
+ out.printf(" %d", index());
+ }
+}
+#endif
+
+HashNumber MParameter::valueHash() const {
+ HashNumber hash = MDefinition::valueHash();
+ hash = addU32ToHash(hash, index_);
+ return hash;
+}
+
+bool MParameter::congruentTo(const MDefinition* ins) const {
+ if (!ins->isParameter()) {
+ return false;
+ }
+
+ return ins->toParameter()->index() == index_;
+}
+
+WrappedFunction::WrappedFunction(JSFunction* nativeFun, uint16_t nargs,
+ FunctionFlags flags)
+ : nativeFun_(nativeFun), nargs_(nargs), flags_(flags) {
+ MOZ_ASSERT_IF(nativeFun, isNativeWithoutJitEntry());
+
+#ifdef DEBUG
+ // If we are not running off-main thread we can assert that the
+ // metadata is consistent.
+ if (!CanUseExtraThreads() && nativeFun) {
+ MOZ_ASSERT(nativeFun->nargs() == nargs);
+
+ MOZ_ASSERT(nativeFun->isNativeWithoutJitEntry() ==
+ isNativeWithoutJitEntry());
+ MOZ_ASSERT(nativeFun->hasJitEntry() == hasJitEntry());
+ MOZ_ASSERT(nativeFun->isConstructor() == isConstructor());
+ MOZ_ASSERT(nativeFun->isClassConstructor() == isClassConstructor());
+ }
+#endif
+}
+
+MCall* MCall::New(TempAllocator& alloc, WrappedFunction* target, size_t maxArgc,
+ size_t numActualArgs, bool construct, bool ignoresReturnValue,
+ bool isDOMCall, mozilla::Maybe<DOMObjectKind> objectKind) {
+ MOZ_ASSERT(isDOMCall == objectKind.isSome());
+ MOZ_ASSERT(maxArgc >= numActualArgs);
+ MCall* ins;
+ if (isDOMCall) {
+ MOZ_ASSERT(!construct);
+ ins = new (alloc) MCallDOMNative(target, numActualArgs, *objectKind);
+ } else {
+ ins =
+ new (alloc) MCall(target, numActualArgs, construct, ignoresReturnValue);
+ }
+ if (!ins->init(alloc, maxArgc + NumNonArgumentOperands)) {
+ return nullptr;
+ }
+ return ins;
+}
+
+AliasSet MCallDOMNative::getAliasSet() const {
+ const JSJitInfo* jitInfo = getJitInfo();
+
+ // If we don't know anything about the types of our arguments, we have to
+ // assume that type-coercions can have side-effects, so we need to alias
+ // everything.
+ if (jitInfo->aliasSet() == JSJitInfo::AliasEverything ||
+ !jitInfo->isTypedMethodJitInfo()) {
+ return AliasSet::Store(AliasSet::Any);
+ }
+
+ uint32_t argIndex = 0;
+ const JSTypedMethodJitInfo* methodInfo =
+ reinterpret_cast<const JSTypedMethodJitInfo*>(jitInfo);
+ for (const JSJitInfo::ArgType* argType = methodInfo->argTypes;
+ *argType != JSJitInfo::ArgTypeListEnd; ++argType, ++argIndex) {
+ if (argIndex >= numActualArgs()) {
+ // Passing through undefined can't have side-effects
+ continue;
+ }
+ // getArg(0) is "this", so skip it
+ MDefinition* arg = getArg(argIndex + 1);
+ MIRType actualType = arg->type();
+ // The only way to reliably avoid side-effects given the information we
+ // have here is if we're passing in a known primitive value to an
+ // argument that expects a primitive value.
+ //
+ // XXXbz maybe we need to communicate better information. For example,
+ // a sequence argument will sort of unavoidably have side effects, while
+ // a typed array argument won't have any, but both are claimed to be
+ // JSJitInfo::Object. But if we do that, we need to watch out for our
+ // movability/DCE-ability bits: if we have an arg type that can reliably
+ // throw an exception on conversion, that might not affect our alias set
+ // per se, but it should prevent us being moved or DCE-ed, unless we
+ // know the incoming things match that arg type and won't throw.
+ //
+ if ((actualType == MIRType::Value || actualType == MIRType::Object) ||
+ (*argType & JSJitInfo::Object)) {
+ return AliasSet::Store(AliasSet::Any);
+ }
+ }
+
+ // We checked all the args, and they check out. So we only alias DOM
+ // mutations or alias nothing, depending on the alias set in the jitinfo.
+ if (jitInfo->aliasSet() == JSJitInfo::AliasNone) {
+ return AliasSet::None();
+ }
+
+ MOZ_ASSERT(jitInfo->aliasSet() == JSJitInfo::AliasDOMSets);
+ return AliasSet::Load(AliasSet::DOMProperty);
+}
+
+void MCallDOMNative::computeMovable() {
+ // We are movable if the jitinfo says we can be and if we're also not
+ // effectful. The jitinfo can't check for the latter, since it depends on
+ // the types of our arguments.
+ const JSJitInfo* jitInfo = getJitInfo();
+
+ MOZ_ASSERT_IF(jitInfo->isMovable,
+ jitInfo->aliasSet() != JSJitInfo::AliasEverything);
+
+ if (jitInfo->isMovable && !isEffectful()) {
+ setMovable();
+ }
+}
+
+bool MCallDOMNative::congruentTo(const MDefinition* ins) const {
+ if (!isMovable()) {
+ return false;
+ }
+
+ if (!ins->isCall()) {
+ return false;
+ }
+
+ const MCall* call = ins->toCall();
+
+ if (!call->isCallDOMNative()) {
+ return false;
+ }
+
+ if (getSingleTarget() != call->getSingleTarget()) {
+ return false;
+ }
+
+ if (isConstructing() != call->isConstructing()) {
+ return false;
+ }
+
+ if (numActualArgs() != call->numActualArgs()) {
+ return false;
+ }
+
+ if (!congruentIfOperandsEqual(call)) {
+ return false;
+ }
+
+ // The other call had better be movable at this point!
+ MOZ_ASSERT(call->isMovable());
+
+ return true;
+}
+
+const JSJitInfo* MCallDOMNative::getJitInfo() const {
+ MOZ_ASSERT(getSingleTarget()->hasJitInfo());
+ return getSingleTarget()->jitInfo();
+}
+
+MCallClassHook* MCallClassHook::New(TempAllocator& alloc, JSNative target,
+ uint32_t argc, bool constructing) {
+ auto* ins = new (alloc) MCallClassHook(target, constructing);
+
+ // Add callee + |this| + (if constructing) newTarget.
+ uint32_t numOperands = 2 + argc + constructing;
+
+ if (!ins->init(alloc, numOperands)) {
+ return nullptr;
+ }
+
+ return ins;
+}
+
+MDefinition* MStringLength::foldsTo(TempAllocator& alloc) {
+ if (string()->isConstant()) {
+ JSString* str = string()->toConstant()->toString();
+ return MConstant::New(alloc, Int32Value(str->length()));
+ }
+
+ // MFromCharCode returns a one-element string.
+ if (string()->isFromCharCode()) {
+ return MConstant::New(alloc, Int32Value(1));
+ }
+
+ return this;
+}
+
+MDefinition* MConcat::foldsTo(TempAllocator& alloc) {
+ if (lhs()->isConstant() && lhs()->toConstant()->toString()->empty()) {
+ return rhs();
+ }
+
+ if (rhs()->isConstant() && rhs()->toConstant()->toString()->empty()) {
+ return lhs();
+ }
+
+ return this;
+}
+
+MDefinition* MCharCodeAt::foldsTo(TempAllocator& alloc) {
+ MDefinition* string = this->string();
+ if (!string->isConstant() && !string->isFromCharCode()) {
+ return this;
+ }
+
+ MDefinition* index = this->index();
+ if (index->isSpectreMaskIndex()) {
+ index = index->toSpectreMaskIndex()->index();
+ }
+ if (!index->isConstant()) {
+ return this;
+ }
+ int32_t idx = index->toConstant()->toInt32();
+
+ // Handle the pattern |s[idx].charCodeAt(0)|.
+ if (string->isFromCharCode()) {
+ if (idx != 0) {
+ return this;
+ }
+
+ // Simplify |CharCodeAt(FromCharCode(CharCodeAt(s, idx)), 0)| to just
+ // |CharCodeAt(s, idx)|.
+ auto* charCode = string->toFromCharCode()->code();
+ if (!charCode->isCharCodeAt()) {
+ return this;
+ }
+
+ return charCode;
+ }
+
+ JSLinearString* str = &string->toConstant()->toString()->asLinear();
+ if (idx < 0 || uint32_t(idx) >= str->length()) {
+ return this;
+ }
+
+ char16_t ch = str->latin1OrTwoByteChar(idx);
+ return MConstant::New(alloc, Int32Value(ch));
+}
+
+template <size_t Arity>
+[[nodiscard]] static bool EnsureFloatInputOrConvert(
+ MAryInstruction<Arity>* owner, TempAllocator& alloc) {
+ MOZ_ASSERT(!IsFloatingPointType(owner->type()),
+ "Floating point types must check consumers");
+
+ if (AllOperandsCanProduceFloat32(owner)) {
+ return true;
+ }
+ ConvertOperandsToDouble(owner, alloc);
+ return false;
+}
+
+template <size_t Arity>
+[[nodiscard]] static bool EnsureFloatConsumersAndInputOrConvert(
+ MAryInstruction<Arity>* owner, TempAllocator& alloc) {
+ MOZ_ASSERT(IsFloatingPointType(owner->type()),
+ "Integer types don't need to check consumers");
+
+ if (AllOperandsCanProduceFloat32(owner) &&
+ CheckUsesAreFloat32Consumers(owner)) {
+ return true;
+ }
+ ConvertOperandsToDouble(owner, alloc);
+ return false;
+}
+
+void MFloor::trySpecializeFloat32(TempAllocator& alloc) {
+ MOZ_ASSERT(type() == MIRType::Int32);
+ if (EnsureFloatInputOrConvert(this, alloc)) {
+ specialization_ = MIRType::Float32;
+ }
+}
+
+void MCeil::trySpecializeFloat32(TempAllocator& alloc) {
+ MOZ_ASSERT(type() == MIRType::Int32);
+ if (EnsureFloatInputOrConvert(this, alloc)) {
+ specialization_ = MIRType::Float32;
+ }
+}
+
+void MRound::trySpecializeFloat32(TempAllocator& alloc) {
+ MOZ_ASSERT(type() == MIRType::Int32);
+ if (EnsureFloatInputOrConvert(this, alloc)) {
+ specialization_ = MIRType::Float32;
+ }
+}
+
+void MTrunc::trySpecializeFloat32(TempAllocator& alloc) {
+ MOZ_ASSERT(type() == MIRType::Int32);
+ if (EnsureFloatInputOrConvert(this, alloc)) {
+ specialization_ = MIRType::Float32;
+ }
+}
+
+void MNearbyInt::trySpecializeFloat32(TempAllocator& alloc) {
+ if (EnsureFloatConsumersAndInputOrConvert(this, alloc)) {
+ specialization_ = MIRType::Float32;
+ setResultType(MIRType::Float32);
+ }
+}
+
+MGoto* MGoto::New(TempAllocator& alloc, MBasicBlock* target) {
+ return new (alloc) MGoto(target);
+}
+
+MGoto* MGoto::New(TempAllocator::Fallible alloc, MBasicBlock* target) {
+ MOZ_ASSERT(target);
+ return new (alloc) MGoto(target);
+}
+
+MGoto* MGoto::New(TempAllocator& alloc) { return new (alloc) MGoto(nullptr); }
+
+#ifdef JS_JITSPEW
+void MUnbox::printOpcode(GenericPrinter& out) const {
+ PrintOpcodeName(out, op());
+ out.printf(" ");
+ getOperand(0)->printName(out);
+ out.printf(" ");
+
+ switch (type()) {
+ case MIRType::Int32:
+ out.printf("to Int32");
+ break;
+ case MIRType::Double:
+ out.printf("to Double");
+ break;
+ case MIRType::Boolean:
+ out.printf("to Boolean");
+ break;
+ case MIRType::String:
+ out.printf("to String");
+ break;
+ case MIRType::Symbol:
+ out.printf("to Symbol");
+ break;
+ case MIRType::BigInt:
+ out.printf("to BigInt");
+ break;
+ case MIRType::Object:
+ out.printf("to Object");
+ break;
+ default:
+ break;
+ }
+
+ switch (mode()) {
+ case Fallible:
+ out.printf(" (fallible)");
+ break;
+ case Infallible:
+ out.printf(" (infallible)");
+ break;
+ default:
+ break;
+ }
+}
+#endif
+
+MDefinition* MUnbox::foldsTo(TempAllocator& alloc) {
+ if (input()->isBox()) {
+ MDefinition* unboxed = input()->toBox()->input();
+
+ // Fold MUnbox(MBox(x)) => x if types match.
+ if (unboxed->type() == type()) {
+ if (fallible()) {
+ unboxed->setImplicitlyUsedUnchecked();
+ }
+ return unboxed;
+ }
+
+ // Fold MUnbox(MBox(x)) => MToDouble(x) if possible.
+ if (type() == MIRType::Double &&
+ IsTypeRepresentableAsDouble(unboxed->type())) {
+ if (unboxed->isConstant()) {
+ return MConstant::New(
+ alloc, DoubleValue(unboxed->toConstant()->numberToDouble()));
+ }
+
+ return MToDouble::New(alloc, unboxed);
+ }
+
+ // MUnbox<Int32>(MBox<Double>(x)) will always fail, even if x can be
+ // represented as an Int32. Fold to avoid unnecessary bailouts.
+ if (type() == MIRType::Int32 && unboxed->type() == MIRType::Double) {
+ auto* folded = MToNumberInt32::New(alloc, unboxed,
+ IntConversionInputKind::NumbersOnly);
+ folded->setGuard();
+ return folded;
+ }
+ }
+
+ return this;
+}
+
+#ifdef DEBUG
+void MPhi::assertLoopPhi() const {
+ // getLoopPredecessorOperand and getLoopBackedgeOperand rely on these
+ // predecessors being at known indices.
+ if (block()->numPredecessors() == 2) {
+ MBasicBlock* pred = block()->getPredecessor(0);
+ MBasicBlock* back = block()->getPredecessor(1);
+ MOZ_ASSERT(pred == block()->loopPredecessor());
+ MOZ_ASSERT(pred->successorWithPhis() == block());
+ MOZ_ASSERT(pred->positionInPhiSuccessor() == 0);
+ MOZ_ASSERT(back == block()->backedge());
+ MOZ_ASSERT(back->successorWithPhis() == block());
+ MOZ_ASSERT(back->positionInPhiSuccessor() == 1);
+ } else {
+ // After we remove fake loop predecessors for loop headers that
+ // are only reachable via OSR, the only predecessor is the
+ // loop backedge.
+ MOZ_ASSERT(block()->numPredecessors() == 1);
+ MOZ_ASSERT(block()->graph().osrBlock());
+ MOZ_ASSERT(!block()->graph().canBuildDominators());
+ MBasicBlock* back = block()->getPredecessor(0);
+ MOZ_ASSERT(back == block()->backedge());
+ MOZ_ASSERT(back->successorWithPhis() == block());
+ MOZ_ASSERT(back->positionInPhiSuccessor() == 0);
+ }
+}
+#endif
+
+MDefinition* MPhi::getLoopPredecessorOperand() const {
+ // This should not be called after removing fake loop predecessors.
+ MOZ_ASSERT(block()->numPredecessors() == 2);
+ assertLoopPhi();
+ return getOperand(0);
+}
+
+MDefinition* MPhi::getLoopBackedgeOperand() const {
+ assertLoopPhi();
+ uint32_t idx = block()->numPredecessors() == 2 ? 1 : 0;
+ return getOperand(idx);
+}
+
+void MPhi::removeOperand(size_t index) {
+ MOZ_ASSERT(index < numOperands());
+ MOZ_ASSERT(getUseFor(index)->index() == index);
+ MOZ_ASSERT(getUseFor(index)->consumer() == this);
+
+ // If we have phi(..., a, b, c, d, ..., z) and we plan
+ // on removing a, then first shift downward so that we have
+ // phi(..., b, c, d, ..., z, z):
+ MUse* p = inputs_.begin() + index;
+ MUse* e = inputs_.end();
+ p->producer()->removeUse(p);
+ for (; p < e - 1; ++p) {
+ MDefinition* producer = (p + 1)->producer();
+ p->setProducerUnchecked(producer);
+ producer->replaceUse(p + 1, p);
+ }
+
+ // truncate the inputs_ list:
+ inputs_.popBack();
+}
+
+void MPhi::removeAllOperands() {
+ for (MUse& p : inputs_) {
+ p.producer()->removeUse(&p);
+ }
+ inputs_.clear();
+}
+
+MDefinition* MPhi::foldsTernary(TempAllocator& alloc) {
+ /* Look if this MPhi is a ternary construct.
+ * This is a very loose term as it actually only checks for
+ *
+ * MTest X
+ * / \
+ * ... ...
+ * \ /
+ * MPhi X Y
+ *
+ * Which we will simply call:
+ * x ? x : y or x ? y : x
+ */
+
+ if (numOperands() != 2) {
+ return nullptr;
+ }
+
+ MOZ_ASSERT(block()->numPredecessors() == 2);
+
+ MBasicBlock* pred = block()->immediateDominator();
+ if (!pred || !pred->lastIns()->isTest()) {
+ return nullptr;
+ }
+
+ MTest* test = pred->lastIns()->toTest();
+
+ // True branch may only dominate one edge of MPhi.
+ if (test->ifTrue()->dominates(block()->getPredecessor(0)) ==
+ test->ifTrue()->dominates(block()->getPredecessor(1))) {
+ return nullptr;
+ }
+
+ // False branch may only dominate one edge of MPhi.
+ if (test->ifFalse()->dominates(block()->getPredecessor(0)) ==
+ test->ifFalse()->dominates(block()->getPredecessor(1))) {
+ return nullptr;
+ }
+
+ // True and false branch must dominate different edges of MPhi.
+ if (test->ifTrue()->dominates(block()->getPredecessor(0)) ==
+ test->ifFalse()->dominates(block()->getPredecessor(0))) {
+ return nullptr;
+ }
+
+ // We found a ternary construct.
+ bool firstIsTrueBranch =
+ test->ifTrue()->dominates(block()->getPredecessor(0));
+ MDefinition* trueDef = firstIsTrueBranch ? getOperand(0) : getOperand(1);
+ MDefinition* falseDef = firstIsTrueBranch ? getOperand(1) : getOperand(0);
+
+ // Accept either
+ // testArg ? testArg : constant or
+ // testArg ? constant : testArg
+ if (!trueDef->isConstant() && !falseDef->isConstant()) {
+ return nullptr;
+ }
+
+ MConstant* c =
+ trueDef->isConstant() ? trueDef->toConstant() : falseDef->toConstant();
+ MDefinition* testArg = (trueDef == c) ? falseDef : trueDef;
+ if (testArg != test->input()) {
+ return nullptr;
+ }
+
+ // This check should be a tautology, except that the constant might be the
+ // result of the removal of a branch. In such case the domination scope of
+ // the block which is holding the constant might be incomplete. This
+ // condition is used to prevent doing this optimization based on incomplete
+ // information.
+ //
+ // As GVN removed a branch, it will update the dominations rules before
+ // trying to fold this MPhi again. Thus, this condition does not inhibit
+ // this optimization.
+ MBasicBlock* truePred = block()->getPredecessor(firstIsTrueBranch ? 0 : 1);
+ MBasicBlock* falsePred = block()->getPredecessor(firstIsTrueBranch ? 1 : 0);
+ if (!trueDef->block()->dominates(truePred) ||
+ !falseDef->block()->dominates(falsePred)) {
+ return nullptr;
+ }
+
+ // If testArg is an int32 type we can:
+ // - fold testArg ? testArg : 0 to testArg
+ // - fold testArg ? 0 : testArg to 0
+ if (testArg->type() == MIRType::Int32 && c->numberToDouble() == 0) {
+ testArg->setGuardRangeBailoutsUnchecked();
+
+ // When folding to the constant we need to hoist it.
+ if (trueDef == c && !c->block()->dominates(block())) {
+ c->block()->moveBefore(pred->lastIns(), c);
+ }
+ return trueDef;
+ }
+
+ // If testArg is an double type we can:
+ // - fold testArg ? testArg : 0.0 to MNaNToZero(testArg)
+ if (testArg->type() == MIRType::Double &&
+ mozilla::IsPositiveZero(c->numberToDouble()) && c != trueDef) {
+ MNaNToZero* replace = MNaNToZero::New(alloc, testArg);
+ test->block()->insertBefore(test, replace);
+ return replace;
+ }
+
+ // If testArg is a string type we can:
+ // - fold testArg ? testArg : "" to testArg
+ // - fold testArg ? "" : testArg to ""
+ if (testArg->type() == MIRType::String &&
+ c->toString() == GetJitContext()->runtime->emptyString()) {
+ // When folding to the constant we need to hoist it.
+ if (trueDef == c && !c->block()->dominates(block())) {
+ c->block()->moveBefore(pred->lastIns(), c);
+ }
+ return trueDef;
+ }
+
+ return nullptr;
+}
+
+MDefinition* MPhi::operandIfRedundant() {
+ if (inputs_.length() == 0) {
+ return nullptr;
+ }
+
+ // If this phi is redundant (e.g., phi(a,a) or b=phi(a,this)),
+ // returns the operand that it will always be equal to (a, in
+ // those two cases).
+ MDefinition* first = getOperand(0);
+ for (size_t i = 1, e = numOperands(); i < e; i++) {
+ MDefinition* op = getOperand(i);
+ if (op != first && op != this) {
+ return nullptr;
+ }
+ }
+ return first;
+}
+
+MDefinition* MPhi::foldsTo(TempAllocator& alloc) {
+ if (MDefinition* def = operandIfRedundant()) {
+ return def;
+ }
+
+ if (MDefinition* def = foldsTernary(alloc)) {
+ return def;
+ }
+
+ return this;
+}
+
+bool MPhi::congruentTo(const MDefinition* ins) const {
+ if (!ins->isPhi()) {
+ return false;
+ }
+
+ // Phis in different blocks may have different control conditions.
+ // For example, these phis:
+ //
+ // if (p)
+ // goto a
+ // a:
+ // t = phi(x, y)
+ //
+ // if (q)
+ // goto b
+ // b:
+ // s = phi(x, y)
+ //
+ // have identical operands, but they are not equvalent because t is
+ // effectively p?x:y and s is effectively q?x:y.
+ //
+ // For now, consider phis in different blocks incongruent.
+ if (ins->block() != block()) {
+ return false;
+ }
+
+ return congruentIfOperandsEqual(ins);
+}
+
+void MPhi::updateForReplacement(MPhi* other) {
+ // This function is called to fix the current Phi flags using it as a
+ // replacement of the other Phi instruction |other|.
+ //
+ // When dealing with usage analysis, any Use will replace all other values,
+ // such as Unused and Unknown. Unless both are Unused, the merge would be
+ // Unknown.
+ if (usageAnalysis_ == PhiUsage::Used ||
+ other->usageAnalysis_ == PhiUsage::Used) {
+ usageAnalysis_ = PhiUsage::Used;
+ } else if (usageAnalysis_ != other->usageAnalysis_) {
+ // this == unused && other == unknown
+ // or this == unknown && other == unused
+ usageAnalysis_ = PhiUsage::Unknown;
+ } else {
+ // this == unused && other == unused
+ // or this == unknown && other = unknown
+ MOZ_ASSERT(usageAnalysis_ == PhiUsage::Unused ||
+ usageAnalysis_ == PhiUsage::Unknown);
+ MOZ_ASSERT(usageAnalysis_ == other->usageAnalysis_);
+ }
+}
+
+/* static */
+bool MPhi::markIteratorPhis(const PhiVector& iterators) {
+ // Find and mark phis that must transitively hold an iterator live.
+
+ Vector<MPhi*, 8, SystemAllocPolicy> worklist;
+
+ for (MPhi* iter : iterators) {
+ if (!iter->isInWorklist()) {
+ if (!worklist.append(iter)) {
+ return false;
+ }
+ iter->setInWorklist();
+ }
+ }
+
+ while (!worklist.empty()) {
+ MPhi* phi = worklist.popCopy();
+ phi->setNotInWorklist();
+
+ phi->setIterator();
+ phi->setImplicitlyUsedUnchecked();
+
+ for (MUseDefIterator iter(phi); iter; iter++) {
+ MDefinition* use = iter.def();
+ if (!use->isInWorklist() && use->isPhi() && !use->toPhi()->isIterator()) {
+ if (!worklist.append(use->toPhi())) {
+ return false;
+ }
+ use->setInWorklist();
+ }
+ }
+ }
+
+ return true;
+}
+
+bool MPhi::typeIncludes(MDefinition* def) {
+ MOZ_ASSERT(!IsMagicType(def->type()));
+
+ if (def->type() == MIRType::Int32 && this->type() == MIRType::Double) {
+ return true;
+ }
+
+ if (def->type() == MIRType::Value) {
+ // This phi must be able to be any value.
+ return this->type() == MIRType::Value;
+ }
+
+ return this->mightBeType(def->type());
+}
+
+void MCallBase::addArg(size_t argnum, MDefinition* arg) {
+ // The operand vector is initialized in reverse order by WarpBuilder.
+ // It cannot be checked for consistency until all arguments are added.
+ // FixedList doesn't initialize its elements, so do an unchecked init.
+ initOperand(argnum + NumNonArgumentOperands, arg);
+}
+
+static inline bool IsConstant(MDefinition* def, double v) {
+ if (!def->isConstant()) {
+ return false;
+ }
+
+ return NumbersAreIdentical(def->toConstant()->numberToDouble(), v);
+}
+
+MDefinition* MBinaryBitwiseInstruction::foldsTo(TempAllocator& alloc) {
+ // Identity operations are removed (for int32 only) in foldUnnecessaryBitop.
+
+ if (type() == MIRType::Int32) {
+ if (MDefinition* folded = EvaluateConstantOperands(alloc, this)) {
+ return folded;
+ }
+ } else if (type() == MIRType::Int64) {
+ if (MDefinition* folded = EvaluateInt64ConstantOperands(alloc, this)) {
+ return folded;
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MBinaryBitwiseInstruction::foldUnnecessaryBitop() {
+ // It's probably OK to perform this optimization only for int32, as it will
+ // have the greatest effect for asm.js code that is compiled with the JS
+ // pipeline, and that code will not see int64 values.
+
+ if (type() != MIRType::Int32) {
+ return this;
+ }
+
+ // Fold unsigned shift right operator when the second operand is zero and
+ // the only use is an unsigned modulo. Thus, the expression
+ // |(x >>> 0) % y| becomes |x % y|.
+ if (isUrsh() && IsUint32Type(this)) {
+ MDefinition* defUse = maybeSingleDefUse();
+ if (defUse && defUse->isMod() && defUse->toMod()->isUnsigned()) {
+ return getOperand(0);
+ }
+ }
+
+ // Eliminate bitwise operations that are no-ops when used on integer
+ // inputs, such as (x | 0).
+
+ MDefinition* lhs = getOperand(0);
+ MDefinition* rhs = getOperand(1);
+
+ if (IsConstant(lhs, 0)) {
+ return foldIfZero(0);
+ }
+
+ if (IsConstant(rhs, 0)) {
+ return foldIfZero(1);
+ }
+
+ if (IsConstant(lhs, -1)) {
+ return foldIfNegOne(0);
+ }
+
+ if (IsConstant(rhs, -1)) {
+ return foldIfNegOne(1);
+ }
+
+ if (lhs == rhs) {
+ return foldIfEqual();
+ }
+
+ if (maskMatchesRightRange) {
+ MOZ_ASSERT(lhs->isConstant());
+ MOZ_ASSERT(lhs->type() == MIRType::Int32);
+ return foldIfAllBitsSet(0);
+ }
+
+ if (maskMatchesLeftRange) {
+ MOZ_ASSERT(rhs->isConstant());
+ MOZ_ASSERT(rhs->type() == MIRType::Int32);
+ return foldIfAllBitsSet(1);
+ }
+
+ return this;
+}
+
+static inline bool CanProduceNegativeZero(MDefinition* def) {
+ // Test if this instruction can produce negative zero even when bailing out
+ // and changing types.
+ switch (def->op()) {
+ case MDefinition::Opcode::Constant:
+ if (def->type() == MIRType::Double &&
+ def->toConstant()->toDouble() == -0.0) {
+ return true;
+ }
+ [[fallthrough]];
+ case MDefinition::Opcode::BitAnd:
+ case MDefinition::Opcode::BitOr:
+ case MDefinition::Opcode::BitXor:
+ case MDefinition::Opcode::BitNot:
+ case MDefinition::Opcode::Lsh:
+ case MDefinition::Opcode::Rsh:
+ return false;
+ default:
+ return true;
+ }
+}
+
+static inline bool NeedNegativeZeroCheck(MDefinition* def) {
+ if (def->isGuard() || def->isGuardRangeBailouts()) {
+ return true;
+ }
+
+ // Test if all uses have the same semantics for -0 and 0
+ for (MUseIterator use = def->usesBegin(); use != def->usesEnd(); use++) {
+ if (use->consumer()->isResumePoint()) {
+ return true;
+ }
+
+ MDefinition* use_def = use->consumer()->toDefinition();
+ switch (use_def->op()) {
+ case MDefinition::Opcode::Add: {
+ // If add is truncating -0 and 0 are observed as the same.
+ if (use_def->toAdd()->isTruncated()) {
+ break;
+ }
+
+ // x + y gives -0, when both x and y are -0
+
+ // Figure out the order in which the addition's operands will
+ // execute. EdgeCaseAnalysis::analyzeLate has renumbered the MIR
+ // definitions for us so that this just requires comparing ids.
+ MDefinition* first = use_def->toAdd()->lhs();
+ MDefinition* second = use_def->toAdd()->rhs();
+ if (first->id() > second->id()) {
+ std::swap(first, second);
+ }
+ // Negative zero checks can be removed on the first executed
+ // operand only if it is guaranteed the second executed operand
+ // will produce a value other than -0. While the second is
+ // typed as an int32, a bailout taken between execution of the
+ // operands may change that type and cause a -0 to flow to the
+ // second.
+ //
+ // There is no way to test whether there are any bailouts
+ // between execution of the operands, so remove negative
+ // zero checks from the first only if the second's type is
+ // independent from type changes that may occur after bailing.
+ if (def == first && CanProduceNegativeZero(second)) {
+ return true;
+ }
+
+ // The negative zero check can always be removed on the second
+ // executed operand; by the time this executes the first will have
+ // been evaluated as int32 and the addition's result cannot be -0.
+ break;
+ }
+ case MDefinition::Opcode::Sub: {
+ // If sub is truncating -0 and 0 are observed as the same
+ if (use_def->toSub()->isTruncated()) {
+ break;
+ }
+
+ // x + y gives -0, when x is -0 and y is 0
+
+ // We can remove the negative zero check on the rhs, only if we
+ // are sure the lhs isn't negative zero.
+
+ // The lhs is typed as integer (i.e. not -0.0), but it can bailout
+ // and change type. This should be fine if the lhs is executed
+ // first. However if the rhs is executed first, the lhs can bail,
+ // change type and become -0.0 while the rhs has already been
+ // optimized to not make a difference between zero and negative zero.
+ MDefinition* lhs = use_def->toSub()->lhs();
+ MDefinition* rhs = use_def->toSub()->rhs();
+ if (rhs->id() < lhs->id() && CanProduceNegativeZero(lhs)) {
+ return true;
+ }
+
+ [[fallthrough]];
+ }
+ case MDefinition::Opcode::StoreElement:
+ case MDefinition::Opcode::StoreHoleValueElement:
+ case MDefinition::Opcode::LoadElement:
+ case MDefinition::Opcode::LoadElementHole:
+ case MDefinition::Opcode::LoadUnboxedScalar:
+ case MDefinition::Opcode::LoadDataViewElement:
+ case MDefinition::Opcode::LoadTypedArrayElementHole:
+ case MDefinition::Opcode::CharCodeAt:
+ case MDefinition::Opcode::Mod:
+ case MDefinition::Opcode::InArray:
+ // Only allowed to remove check when definition is the second operand
+ if (use_def->getOperand(0) == def) {
+ return true;
+ }
+ for (size_t i = 2, e = use_def->numOperands(); i < e; i++) {
+ if (use_def->getOperand(i) == def) {
+ return true;
+ }
+ }
+ break;
+ case MDefinition::Opcode::BoundsCheck:
+ // Only allowed to remove check when definition is the first operand
+ if (use_def->toBoundsCheck()->getOperand(1) == def) {
+ return true;
+ }
+ break;
+ case MDefinition::Opcode::ToString:
+ case MDefinition::Opcode::FromCharCode:
+ case MDefinition::Opcode::FromCodePoint:
+ case MDefinition::Opcode::TableSwitch:
+ case MDefinition::Opcode::Compare:
+ case MDefinition::Opcode::BitAnd:
+ case MDefinition::Opcode::BitOr:
+ case MDefinition::Opcode::BitXor:
+ case MDefinition::Opcode::Abs:
+ case MDefinition::Opcode::TruncateToInt32:
+ // Always allowed to remove check. No matter which operand.
+ break;
+ case MDefinition::Opcode::StoreElementHole:
+ case MDefinition::Opcode::StoreTypedArrayElementHole:
+ case MDefinition::Opcode::PostWriteElementBarrier:
+ // Only allowed to remove check when definition is the third operand.
+ for (size_t i = 0, e = use_def->numOperands(); i < e; i++) {
+ if (i == 2) {
+ continue;
+ }
+ if (use_def->getOperand(i) == def) {
+ return true;
+ }
+ }
+ break;
+ default:
+ return true;
+ }
+ }
+ return false;
+}
+
+#ifdef JS_JITSPEW
+void MBinaryArithInstruction::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+
+ switch (type()) {
+ case MIRType::Int32:
+ if (isDiv()) {
+ out.printf(" [%s]", toDiv()->isUnsigned() ? "uint32" : "int32");
+ } else if (isMod()) {
+ out.printf(" [%s]", toMod()->isUnsigned() ? "uint32" : "int32");
+ } else {
+ out.printf(" [int32]");
+ }
+ break;
+ case MIRType::Int64:
+ if (isDiv()) {
+ out.printf(" [%s]", toDiv()->isUnsigned() ? "uint64" : "int64");
+ } else if (isMod()) {
+ out.printf(" [%s]", toMod()->isUnsigned() ? "uint64" : "int64");
+ } else {
+ out.printf(" [int64]");
+ }
+ break;
+ case MIRType::Float32:
+ out.printf(" [float]");
+ break;
+ case MIRType::Double:
+ out.printf(" [double]");
+ break;
+ default:
+ break;
+ }
+}
+#endif
+
+MDefinition* MRsh::foldsTo(TempAllocator& alloc) {
+ MDefinition* f = MBinaryBitwiseInstruction::foldsTo(alloc);
+
+ if (f != this) {
+ return f;
+ }
+
+ MDefinition* lhs = getOperand(0);
+ MDefinition* rhs = getOperand(1);
+
+ // It's probably OK to perform this optimization only for int32, as it will
+ // have the greatest effect for asm.js code that is compiled with the JS
+ // pipeline, and that code will not see int64 values.
+
+ if (!lhs->isLsh() || !rhs->isConstant() || rhs->type() != MIRType::Int32) {
+ return this;
+ }
+
+ if (!lhs->getOperand(1)->isConstant() ||
+ lhs->getOperand(1)->type() != MIRType::Int32) {
+ return this;
+ }
+
+ uint32_t shift = rhs->toConstant()->toInt32();
+ uint32_t shift_lhs = lhs->getOperand(1)->toConstant()->toInt32();
+ if (shift != shift_lhs) {
+ return this;
+ }
+
+ switch (shift) {
+ case 16:
+ return MSignExtendInt32::New(alloc, lhs->getOperand(0),
+ MSignExtendInt32::Half);
+ case 24:
+ return MSignExtendInt32::New(alloc, lhs->getOperand(0),
+ MSignExtendInt32::Byte);
+ }
+
+ return this;
+}
+
+MDefinition* MBinaryArithInstruction::foldsTo(TempAllocator& alloc) {
+ MOZ_ASSERT(IsNumberType(type()));
+
+ MDefinition* lhs = getOperand(0);
+ MDefinition* rhs = getOperand(1);
+
+ if (type() == MIRType::Int64) {
+ MOZ_ASSERT(!isTruncated());
+
+ if (MConstant* folded = EvaluateInt64ConstantOperands(alloc, this)) {
+ if (!folded->block()) {
+ block()->insertBefore(this, folded);
+ }
+ return folded;
+ }
+ if (isSub() || isDiv() || isMod()) {
+ return this;
+ }
+ if (rhs->isConstant() &&
+ rhs->toConstant()->toInt64() == int64_t(getIdentity())) {
+ return lhs;
+ }
+ if (lhs->isConstant() &&
+ lhs->toConstant()->toInt64() == int64_t(getIdentity())) {
+ return rhs;
+ }
+ return this;
+ }
+
+ if (MConstant* folded = EvaluateConstantOperands(alloc, this)) {
+ if (isTruncated()) {
+ if (!folded->block()) {
+ block()->insertBefore(this, folded);
+ }
+ if (folded->type() != MIRType::Int32) {
+ return MTruncateToInt32::New(alloc, folded);
+ }
+ }
+ return folded;
+ }
+
+ if (mustPreserveNaN_) {
+ return this;
+ }
+
+ // 0 + -0 = 0. So we can't remove addition
+ if (isAdd() && type() != MIRType::Int32) {
+ return this;
+ }
+
+ if (IsConstant(rhs, getIdentity())) {
+ if (isTruncated()) {
+ return MTruncateToInt32::New(alloc, lhs);
+ }
+ return lhs;
+ }
+
+ // subtraction isn't commutative. So we can't remove subtraction when lhs
+ // equals 0
+ if (isSub()) {
+ return this;
+ }
+
+ if (IsConstant(lhs, getIdentity())) {
+ if (isTruncated()) {
+ return MTruncateToInt32::New(alloc, rhs);
+ }
+ return rhs; // id op x => x
+ }
+
+ return this;
+}
+
+void MBinaryArithInstruction::trySpecializeFloat32(TempAllocator& alloc) {
+ MOZ_ASSERT(IsNumberType(type()));
+
+ // Do not use Float32 if we can use int32.
+ if (type() == MIRType::Int32) {
+ return;
+ }
+
+ if (EnsureFloatConsumersAndInputOrConvert(this, alloc)) {
+ setResultType(MIRType::Float32);
+ }
+}
+
+void MMinMax::trySpecializeFloat32(TempAllocator& alloc) {
+ if (type() == MIRType::Int32) {
+ return;
+ }
+
+ MDefinition* left = lhs();
+ MDefinition* right = rhs();
+
+ if ((left->canProduceFloat32() ||
+ (left->isMinMax() && left->type() == MIRType::Float32)) &&
+ (right->canProduceFloat32() ||
+ (right->isMinMax() && right->type() == MIRType::Float32))) {
+ setResultType(MIRType::Float32);
+ } else {
+ ConvertOperandsToDouble(this, alloc);
+ }
+}
+
+MDefinition* MMinMax::foldsTo(TempAllocator& alloc) {
+ MOZ_ASSERT(lhs()->type() == type());
+ MOZ_ASSERT(rhs()->type() == type());
+
+ if (lhs() == rhs()) {
+ return lhs();
+ }
+
+ // Fold min/max operations with same inputs.
+ if (lhs()->isMinMax() || rhs()->isMinMax()) {
+ auto* other = lhs()->isMinMax() ? lhs()->toMinMax() : rhs()->toMinMax();
+ auto* operand = lhs()->isMinMax() ? rhs() : lhs();
+
+ if (operand == other->lhs() || operand == other->rhs()) {
+ if (isMax() == other->isMax()) {
+ // min(x, min(x, y)) = min(x, y)
+ // max(x, max(x, y)) = max(x, y)
+ return other;
+ }
+ if (!IsFloatingPointType(type())) {
+ // When neither value is NaN:
+ // max(x, min(x, y)) = x
+ // min(x, max(x, y)) = x
+
+ // Ensure that any bailouts that we depend on to guarantee that |y| is
+ // Int32 are not removed.
+ auto* otherOp = operand == other->lhs() ? other->rhs() : other->lhs();
+ otherOp->setGuardRangeBailoutsUnchecked();
+
+ return operand;
+ }
+ }
+ }
+
+ if (!lhs()->isConstant() && !rhs()->isConstant()) {
+ return this;
+ }
+
+ auto foldConstants = [&alloc](MDefinition* lhs, MDefinition* rhs,
+ bool isMax) -> MConstant* {
+ MOZ_ASSERT(lhs->type() == rhs->type());
+ MOZ_ASSERT(lhs->toConstant()->isTypeRepresentableAsDouble());
+ MOZ_ASSERT(rhs->toConstant()->isTypeRepresentableAsDouble());
+
+ double lnum = lhs->toConstant()->numberToDouble();
+ double rnum = rhs->toConstant()->numberToDouble();
+
+ double result;
+ if (isMax) {
+ result = js::math_max_impl(lnum, rnum);
+ } else {
+ result = js::math_min_impl(lnum, rnum);
+ }
+
+ // The folded MConstant should maintain the same MIRType with the original
+ // inputs.
+ if (lhs->type() == MIRType::Int32) {
+ int32_t cast;
+ if (mozilla::NumberEqualsInt32(result, &cast)) {
+ return MConstant::New(alloc, Int32Value(cast));
+ }
+ return nullptr;
+ }
+ if (lhs->type() == MIRType::Float32) {
+ return MConstant::NewFloat32(alloc, result);
+ }
+ MOZ_ASSERT(lhs->type() == MIRType::Double);
+ return MConstant::New(alloc, DoubleValue(result));
+ };
+
+ // Directly apply math utility to compare the rhs() and lhs() when
+ // they are both constants.
+ if (lhs()->isConstant() && rhs()->isConstant()) {
+ if (!lhs()->toConstant()->isTypeRepresentableAsDouble() ||
+ !rhs()->toConstant()->isTypeRepresentableAsDouble()) {
+ return this;
+ }
+
+ if (auto* folded = foldConstants(lhs(), rhs(), isMax())) {
+ return folded;
+ }
+ }
+
+ MDefinition* operand = lhs()->isConstant() ? rhs() : lhs();
+ MConstant* constant =
+ lhs()->isConstant() ? lhs()->toConstant() : rhs()->toConstant();
+
+ if (operand->isToDouble() &&
+ operand->getOperand(0)->type() == MIRType::Int32) {
+ // min(int32, cte >= INT32_MAX) = int32
+ if (!isMax() && constant->isTypeRepresentableAsDouble() &&
+ constant->numberToDouble() >= INT32_MAX) {
+ MLimitedTruncate* limit = MLimitedTruncate::New(
+ alloc, operand->getOperand(0), TruncateKind::NoTruncate);
+ block()->insertBefore(this, limit);
+ MToDouble* toDouble = MToDouble::New(alloc, limit);
+ return toDouble;
+ }
+
+ // max(int32, cte <= INT32_MIN) = int32
+ if (isMax() && constant->isTypeRepresentableAsDouble() &&
+ constant->numberToDouble() <= INT32_MIN) {
+ MLimitedTruncate* limit = MLimitedTruncate::New(
+ alloc, operand->getOperand(0), TruncateKind::NoTruncate);
+ block()->insertBefore(this, limit);
+ MToDouble* toDouble = MToDouble::New(alloc, limit);
+ return toDouble;
+ }
+ }
+
+ auto foldLength = [](MDefinition* operand, MConstant* constant,
+ bool isMax) -> MDefinition* {
+ if ((operand->isArrayLength() || operand->isArrayBufferViewLength() ||
+ operand->isArgumentsLength() || operand->isStringLength()) &&
+ constant->type() == MIRType::Int32) {
+ // (Array|ArrayBufferView|Arguments|String)Length is always >= 0.
+ // max(array.length, cte <= 0) = array.length
+ // min(array.length, cte <= 0) = cte
+ if (constant->toInt32() <= 0) {
+ return isMax ? operand : constant;
+ }
+ }
+ return nullptr;
+ };
+
+ if (auto* folded = foldLength(operand, constant, isMax())) {
+ return folded;
+ }
+
+ // Attempt to fold nested min/max operations which are produced by
+ // self-hosted built-in functions.
+ if (operand->isMinMax()) {
+ auto* other = operand->toMinMax();
+ MOZ_ASSERT(other->lhs()->type() == type());
+ MOZ_ASSERT(other->rhs()->type() == type());
+
+ MConstant* otherConstant = nullptr;
+ MDefinition* otherOperand = nullptr;
+ if (other->lhs()->isConstant()) {
+ otherConstant = other->lhs()->toConstant();
+ otherOperand = other->rhs();
+ } else if (other->rhs()->isConstant()) {
+ otherConstant = other->rhs()->toConstant();
+ otherOperand = other->lhs();
+ }
+
+ if (otherConstant && constant->isTypeRepresentableAsDouble() &&
+ otherConstant->isTypeRepresentableAsDouble()) {
+ if (isMax() == other->isMax()) {
+ // Fold min(x, min(y, z)) to min(min(x, y), z) with constant min(x, y).
+ // Fold max(x, max(y, z)) to max(max(x, y), z) with constant max(x, y).
+ if (auto* left = foldConstants(constant, otherConstant, isMax())) {
+ block()->insertBefore(this, left);
+ return MMinMax::New(alloc, left, otherOperand, type(), isMax());
+ }
+ } else {
+ // Fold min(x, max(y, z)) to max(min(x, y), min(x, z)).
+ // Fold max(x, min(y, z)) to min(max(x, y), max(x, z)).
+ //
+ // But only do this when min(x, z) can also be simplified.
+ if (auto* right = foldLength(otherOperand, constant, isMax())) {
+ if (auto* left = foldConstants(constant, otherConstant, isMax())) {
+ block()->insertBefore(this, left);
+ return MMinMax::New(alloc, left, right, type(), !isMax());
+ }
+ }
+ }
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MPow::foldsConstant(TempAllocator& alloc) {
+ // Both `x` and `p` in `x^p` must be constants in order to precompute.
+ if (!input()->isConstant() || !power()->isConstant()) {
+ return nullptr;
+ }
+ if (!power()->toConstant()->isTypeRepresentableAsDouble()) {
+ return nullptr;
+ }
+ if (!input()->toConstant()->isTypeRepresentableAsDouble()) {
+ return nullptr;
+ }
+
+ double x = input()->toConstant()->numberToDouble();
+ double p = power()->toConstant()->numberToDouble();
+ double result = js::ecmaPow(x, p);
+ if (type() == MIRType::Int32) {
+ int32_t cast;
+ if (!mozilla::NumberIsInt32(result, &cast)) {
+ // Reject folding if the result isn't an int32, because we'll bail anyway.
+ return nullptr;
+ }
+ return MConstant::New(alloc, Int32Value(cast));
+ }
+ return MConstant::New(alloc, DoubleValue(result));
+}
+
+MDefinition* MPow::foldsConstantPower(TempAllocator& alloc) {
+ // If `p` in `x^p` isn't constant, we can't apply these folds.
+ if (!power()->isConstant()) {
+ return nullptr;
+ }
+ if (!power()->toConstant()->isTypeRepresentableAsDouble()) {
+ return nullptr;
+ }
+
+ MOZ_ASSERT(type() == MIRType::Double || type() == MIRType::Int32);
+
+ // NOTE: The optimizations must match the optimizations used in |js::ecmaPow|
+ // resp. |js::powi| to avoid differential testing issues.
+
+ double pow = power()->toConstant()->numberToDouble();
+
+ // Math.pow(x, 0.5) is a sqrt with edge-case detection.
+ if (pow == 0.5) {
+ MOZ_ASSERT(type() == MIRType::Double);
+ return MPowHalf::New(alloc, input());
+ }
+
+ // Math.pow(x, -0.5) == 1 / Math.pow(x, 0.5), even for edge cases.
+ if (pow == -0.5) {
+ MOZ_ASSERT(type() == MIRType::Double);
+ MPowHalf* half = MPowHalf::New(alloc, input());
+ block()->insertBefore(this, half);
+ MConstant* one = MConstant::New(alloc, DoubleValue(1.0));
+ block()->insertBefore(this, one);
+ return MDiv::New(alloc, one, half, MIRType::Double);
+ }
+
+ // Math.pow(x, 1) == x.
+ if (pow == 1.0) {
+ return input();
+ }
+
+ auto multiply = [this, &alloc](MDefinition* lhs, MDefinition* rhs) {
+ MMul* mul = MMul::New(alloc, lhs, rhs, type());
+ mul->setBailoutKind(bailoutKind());
+
+ // Multiplying the same number can't yield negative zero.
+ mul->setCanBeNegativeZero(lhs != rhs && canBeNegativeZero());
+ return mul;
+ };
+
+ // Math.pow(x, 2) == x*x.
+ if (pow == 2.0) {
+ return multiply(input(), input());
+ }
+
+ // Math.pow(x, 3) == x*x*x.
+ if (pow == 3.0) {
+ MMul* mul1 = multiply(input(), input());
+ block()->insertBefore(this, mul1);
+ return multiply(input(), mul1);
+ }
+
+ // Math.pow(x, 4) == y*y, where y = x*x.
+ if (pow == 4.0) {
+ MMul* y = multiply(input(), input());
+ block()->insertBefore(this, y);
+ return multiply(y, y);
+ }
+
+ // No optimization
+ return nullptr;
+}
+
+MDefinition* MPow::foldsTo(TempAllocator& alloc) {
+ if (MDefinition* def = foldsConstant(alloc)) {
+ return def;
+ }
+ if (MDefinition* def = foldsConstantPower(alloc)) {
+ return def;
+ }
+ return this;
+}
+
+MDefinition* MInt32ToIntPtr::foldsTo(TempAllocator& alloc) {
+ MDefinition* def = input();
+ if (def->isConstant()) {
+ int32_t i = def->toConstant()->toInt32();
+ return MConstant::NewIntPtr(alloc, intptr_t(i));
+ }
+
+ if (def->isNonNegativeIntPtrToInt32()) {
+ return def->toNonNegativeIntPtrToInt32()->input();
+ }
+
+ return this;
+}
+
+bool MAbs::fallible() const {
+ return !implicitTruncate_ && (!range() || !range()->hasInt32Bounds());
+}
+
+void MAbs::trySpecializeFloat32(TempAllocator& alloc) {
+ // Do not use Float32 if we can use int32.
+ if (input()->type() == MIRType::Int32) {
+ return;
+ }
+
+ if (EnsureFloatConsumersAndInputOrConvert(this, alloc)) {
+ setResultType(MIRType::Float32);
+ }
+}
+
+MDefinition* MDiv::foldsTo(TempAllocator& alloc) {
+ MOZ_ASSERT(IsNumberType(type()));
+
+ if (type() == MIRType::Int64) {
+ if (MDefinition* folded = EvaluateInt64ConstantOperands(alloc, this)) {
+ return folded;
+ }
+ return this;
+ }
+
+ if (MDefinition* folded = EvaluateConstantOperands(alloc, this)) {
+ return folded;
+ }
+
+ if (MDefinition* folded = EvaluateExactReciprocal(alloc, this)) {
+ return folded;
+ }
+
+ return this;
+}
+
+void MDiv::analyzeEdgeCasesForward() {
+ // This is only meaningful when doing integer division.
+ if (type() != MIRType::Int32) {
+ return;
+ }
+
+ MOZ_ASSERT(lhs()->type() == MIRType::Int32);
+ MOZ_ASSERT(rhs()->type() == MIRType::Int32);
+
+ // Try removing divide by zero check
+ if (rhs()->isConstant() && !rhs()->toConstant()->isInt32(0)) {
+ canBeDivideByZero_ = false;
+ }
+
+ // If lhs is a constant int != INT32_MIN, then
+ // negative overflow check can be skipped.
+ if (lhs()->isConstant() && !lhs()->toConstant()->isInt32(INT32_MIN)) {
+ canBeNegativeOverflow_ = false;
+ }
+
+ // If rhs is a constant int != -1, likewise.
+ if (rhs()->isConstant() && !rhs()->toConstant()->isInt32(-1)) {
+ canBeNegativeOverflow_ = false;
+ }
+
+ // If lhs is != 0, then negative zero check can be skipped.
+ if (lhs()->isConstant() && !lhs()->toConstant()->isInt32(0)) {
+ setCanBeNegativeZero(false);
+ }
+
+ // If rhs is >= 0, likewise.
+ if (rhs()->isConstant() && rhs()->type() == MIRType::Int32) {
+ if (rhs()->toConstant()->toInt32() >= 0) {
+ setCanBeNegativeZero(false);
+ }
+ }
+}
+
+void MDiv::analyzeEdgeCasesBackward() {
+ if (canBeNegativeZero() && !NeedNegativeZeroCheck(this)) {
+ setCanBeNegativeZero(false);
+ }
+}
+
+bool MDiv::fallible() const { return !isTruncated(); }
+
+MDefinition* MMod::foldsTo(TempAllocator& alloc) {
+ MOZ_ASSERT(IsNumberType(type()));
+
+ if (type() == MIRType::Int64) {
+ if (MDefinition* folded = EvaluateInt64ConstantOperands(alloc, this)) {
+ return folded;
+ }
+ } else {
+ if (MDefinition* folded = EvaluateConstantOperands(alloc, this)) {
+ return folded;
+ }
+ }
+ return this;
+}
+
+void MMod::analyzeEdgeCasesForward() {
+ // These optimizations make sense only for integer division
+ if (type() != MIRType::Int32) {
+ return;
+ }
+
+ if (rhs()->isConstant() && !rhs()->toConstant()->isInt32(0)) {
+ canBeDivideByZero_ = false;
+ }
+
+ if (rhs()->isConstant()) {
+ int32_t n = rhs()->toConstant()->toInt32();
+ if (n > 0 && !IsPowerOfTwo(uint32_t(n))) {
+ canBePowerOfTwoDivisor_ = false;
+ }
+ }
+}
+
+bool MMod::fallible() const {
+ return !isTruncated() &&
+ (isUnsigned() || canBeDivideByZero() || canBeNegativeDividend());
+}
+
+void MMathFunction::trySpecializeFloat32(TempAllocator& alloc) {
+ if (EnsureFloatConsumersAndInputOrConvert(this, alloc)) {
+ setResultType(MIRType::Float32);
+ specialization_ = MIRType::Float32;
+ }
+}
+
+bool MMathFunction::isFloat32Commutative() const {
+ switch (function_) {
+ case UnaryMathFunction::Floor:
+ case UnaryMathFunction::Ceil:
+ case UnaryMathFunction::Round:
+ case UnaryMathFunction::Trunc:
+ return true;
+ default:
+ return false;
+ }
+}
+
+MHypot* MHypot::New(TempAllocator& alloc, const MDefinitionVector& vector) {
+ uint32_t length = vector.length();
+ MHypot* hypot = new (alloc) MHypot;
+ if (!hypot->init(alloc, length)) {
+ return nullptr;
+ }
+
+ for (uint32_t i = 0; i < length; ++i) {
+ hypot->initOperand(i, vector[i]);
+ }
+ return hypot;
+}
+
+bool MAdd::fallible() const {
+ // the add is fallible if range analysis does not say that it is finite, AND
+ // either the truncation analysis shows that there are non-truncated uses.
+ if (truncateKind() >= TruncateKind::IndirectTruncate) {
+ return false;
+ }
+ if (range() && range()->hasInt32Bounds()) {
+ return false;
+ }
+ return true;
+}
+
+bool MSub::fallible() const {
+ // see comment in MAdd::fallible()
+ if (truncateKind() >= TruncateKind::IndirectTruncate) {
+ return false;
+ }
+ if (range() && range()->hasInt32Bounds()) {
+ return false;
+ }
+ return true;
+}
+
+MDefinition* MSub::foldsTo(TempAllocator& alloc) {
+ MDefinition* out = MBinaryArithInstruction::foldsTo(alloc);
+ if (out != this) {
+ return out;
+ }
+
+ if (type() != MIRType::Int32) {
+ return this;
+ }
+
+ // Optimize X - X to 0. This optimization is only valid for Int32
+ // values. Subtracting a floating point value from itself returns
+ // NaN when the operand is either Infinity or NaN.
+ if (lhs() == rhs()) {
+ // Ensure that any bailouts that we depend on to guarantee that X
+ // is Int32 are not removed.
+ lhs()->setGuardRangeBailoutsUnchecked();
+ return MConstant::New(alloc, Int32Value(0));
+ }
+
+ return this;
+}
+
+MDefinition* MMul::foldsTo(TempAllocator& alloc) {
+ MDefinition* out = MBinaryArithInstruction::foldsTo(alloc);
+ if (out != this) {
+ return out;
+ }
+
+ if (type() != MIRType::Int32) {
+ return this;
+ }
+
+ if (lhs() == rhs()) {
+ setCanBeNegativeZero(false);
+ }
+
+ return this;
+}
+
+void MMul::analyzeEdgeCasesForward() {
+ // Try to remove the check for negative zero
+ // This only makes sense when using the integer multiplication
+ if (type() != MIRType::Int32) {
+ return;
+ }
+
+ // If lhs is > 0, no need for negative zero check.
+ if (lhs()->isConstant() && lhs()->type() == MIRType::Int32) {
+ if (lhs()->toConstant()->toInt32() > 0) {
+ setCanBeNegativeZero(false);
+ }
+ }
+
+ // If rhs is > 0, likewise.
+ if (rhs()->isConstant() && rhs()->type() == MIRType::Int32) {
+ if (rhs()->toConstant()->toInt32() > 0) {
+ setCanBeNegativeZero(false);
+ }
+ }
+}
+
+void MMul::analyzeEdgeCasesBackward() {
+ if (canBeNegativeZero() && !NeedNegativeZeroCheck(this)) {
+ setCanBeNegativeZero(false);
+ }
+}
+
+bool MMul::canOverflow() const {
+ if (isTruncated()) {
+ return false;
+ }
+ return !range() || !range()->hasInt32Bounds();
+}
+
+bool MUrsh::fallible() const {
+ if (bailoutsDisabled()) {
+ return false;
+ }
+ return !range() || !range()->hasInt32Bounds();
+}
+
+MIRType MCompare::inputType() {
+ switch (compareType_) {
+ case Compare_Undefined:
+ return MIRType::Undefined;
+ case Compare_Null:
+ return MIRType::Null;
+ case Compare_UInt32:
+ case Compare_Int32:
+ return MIRType::Int32;
+ case Compare_UIntPtr:
+ return MIRType::IntPtr;
+ case Compare_Double:
+ return MIRType::Double;
+ case Compare_Float32:
+ return MIRType::Float32;
+ case Compare_String:
+ return MIRType::String;
+ case Compare_Symbol:
+ return MIRType::Symbol;
+ case Compare_Object:
+ return MIRType::Object;
+ case Compare_BigInt:
+ case Compare_BigInt_Int32:
+ case Compare_BigInt_Double:
+ case Compare_BigInt_String:
+ return MIRType::BigInt;
+ default:
+ MOZ_CRASH("No known conversion");
+ }
+}
+
+static inline bool MustBeUInt32(MDefinition* def, MDefinition** pwrapped) {
+ if (def->isUrsh()) {
+ *pwrapped = def->toUrsh()->lhs();
+ MDefinition* rhs = def->toUrsh()->rhs();
+ return def->toUrsh()->bailoutsDisabled() && rhs->maybeConstantValue() &&
+ rhs->maybeConstantValue()->isInt32(0);
+ }
+
+ if (MConstant* defConst = def->maybeConstantValue()) {
+ *pwrapped = defConst;
+ return defConst->type() == MIRType::Int32 && defConst->toInt32() >= 0;
+ }
+
+ *pwrapped = nullptr; // silence GCC warning
+ return false;
+}
+
+/* static */
+bool MBinaryInstruction::unsignedOperands(MDefinition* left,
+ MDefinition* right) {
+ MDefinition* replace;
+ if (!MustBeUInt32(left, &replace)) {
+ return false;
+ }
+ if (replace->type() != MIRType::Int32) {
+ return false;
+ }
+ if (!MustBeUInt32(right, &replace)) {
+ return false;
+ }
+ if (replace->type() != MIRType::Int32) {
+ return false;
+ }
+ return true;
+}
+
+bool MBinaryInstruction::unsignedOperands() {
+ return unsignedOperands(getOperand(0), getOperand(1));
+}
+
+void MBinaryInstruction::replaceWithUnsignedOperands() {
+ MOZ_ASSERT(unsignedOperands());
+
+ for (size_t i = 0; i < numOperands(); i++) {
+ MDefinition* replace;
+ MustBeUInt32(getOperand(i), &replace);
+ if (replace == getOperand(i)) {
+ continue;
+ }
+
+ getOperand(i)->setImplicitlyUsedUnchecked();
+ replaceOperand(i, replace);
+ }
+}
+
+MDefinition* MBitNot::foldsTo(TempAllocator& alloc) {
+ if (type() == MIRType::Int64) {
+ return this;
+ }
+ MOZ_ASSERT(type() == MIRType::Int32);
+
+ MDefinition* input = getOperand(0);
+
+ if (input->isConstant()) {
+ js::Value v = Int32Value(~(input->toConstant()->toInt32()));
+ return MConstant::New(alloc, v);
+ }
+
+ if (input->isBitNot()) {
+ MOZ_ASSERT(input->toBitNot()->type() == MIRType::Int32);
+ MOZ_ASSERT(input->toBitNot()->getOperand(0)->type() == MIRType::Int32);
+ return MTruncateToInt32::New(alloc,
+ input->toBitNot()->input()); // ~~x => x | 0
+ }
+
+ return this;
+}
+
+static void AssertKnownClass(TempAllocator& alloc, MInstruction* ins,
+ MDefinition* obj) {
+#ifdef DEBUG
+ const JSClass* clasp = GetObjectKnownJSClass(obj);
+ MOZ_ASSERT(clasp);
+
+ auto* assert = MAssertClass::New(alloc, obj, clasp);
+ ins->block()->insertBefore(ins, assert);
+#endif
+}
+
+MDefinition* MBoxNonStrictThis::foldsTo(TempAllocator& alloc) {
+ MDefinition* in = input();
+ if (in->isBox()) {
+ in = in->toBox()->input();
+ }
+
+ if (in->type() == MIRType::Object) {
+ return in;
+ }
+
+ return this;
+}
+
+AliasSet MLoadArgumentsObjectArg::getAliasSet() const {
+ return AliasSet::Load(AliasSet::Any);
+}
+
+AliasSet MLoadArgumentsObjectArgHole::getAliasSet() const {
+ return AliasSet::Load(AliasSet::Any);
+}
+
+AliasSet MInArgumentsObjectArg::getAliasSet() const {
+ // Loads |arguments.length|, but not the actual element, so we can use the
+ // same alias-set as MArgumentsObjectLength.
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot);
+}
+
+AliasSet MArgumentsObjectLength::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot);
+}
+
+bool MGuardArgumentsObjectFlags::congruentTo(const MDefinition* ins) const {
+ if (!ins->isGuardArgumentsObjectFlags() ||
+ ins->toGuardArgumentsObjectFlags()->flags() != flags()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MGuardArgumentsObjectFlags::getAliasSet() const {
+ // The flags are packed with the length in a fixed private slot.
+ return AliasSet::Load(AliasSet::FixedSlot);
+}
+
+MDefinition* MReturnFromCtor::foldsTo(TempAllocator& alloc) {
+ MDefinition* rval = value();
+ if (rval->isBox()) {
+ rval = rval->toBox()->input();
+ }
+
+ if (rval->type() == MIRType::Object) {
+ return rval;
+ }
+
+ if (rval->type() != MIRType::Value) {
+ return object();
+ }
+
+ return this;
+}
+
+MDefinition* MTypeOf::foldsTo(TempAllocator& alloc) {
+ MDefinition* unboxed = input();
+ if (unboxed->isBox()) {
+ unboxed = unboxed->toBox()->input();
+ }
+
+ JSType type;
+ switch (unboxed->type()) {
+ case MIRType::Double:
+ case MIRType::Float32:
+ case MIRType::Int32:
+ type = JSTYPE_NUMBER;
+ break;
+ case MIRType::String:
+ type = JSTYPE_STRING;
+ break;
+ case MIRType::Symbol:
+ type = JSTYPE_SYMBOL;
+ break;
+ case MIRType::BigInt:
+ type = JSTYPE_BIGINT;
+ break;
+ case MIRType::Null:
+ type = JSTYPE_OBJECT;
+ break;
+ case MIRType::Undefined:
+ type = JSTYPE_UNDEFINED;
+ break;
+ case MIRType::Boolean:
+ type = JSTYPE_BOOLEAN;
+ break;
+ case MIRType::Object: {
+ KnownClass known = GetObjectKnownClass(unboxed);
+ if (known != KnownClass::None) {
+ if (known == KnownClass::Function) {
+ type = JSTYPE_FUNCTION;
+ } else {
+ type = JSTYPE_OBJECT;
+ }
+
+ AssertKnownClass(alloc, this, unboxed);
+ break;
+ }
+ [[fallthrough]];
+ }
+ default:
+ return this;
+ }
+
+ return MConstant::New(alloc, Int32Value(static_cast<int32_t>(type)));
+}
+
+MDefinition* MTypeOfName::foldsTo(TempAllocator& alloc) {
+ MOZ_ASSERT(input()->type() == MIRType::Int32);
+
+ if (!input()->isConstant()) {
+ return this;
+ }
+
+ static_assert(JSTYPE_UNDEFINED == 0);
+
+ int32_t type = input()->toConstant()->toInt32();
+ MOZ_ASSERT(JSTYPE_UNDEFINED <= type && type < JSTYPE_LIMIT);
+
+ JSString* name =
+ TypeName(static_cast<JSType>(type), GetJitContext()->runtime->names());
+ return MConstant::New(alloc, StringValue(name));
+}
+
+MUrsh* MUrsh::NewWasm(TempAllocator& alloc, MDefinition* left,
+ MDefinition* right, MIRType type) {
+ MUrsh* ins = new (alloc) MUrsh(left, right, type);
+
+ // Since Ion has no UInt32 type, we use Int32 and we have a special
+ // exception to the type rules: we can return values in
+ // (INT32_MIN,UINT32_MAX] and still claim that we have an Int32 type
+ // without bailing out. This is necessary because Ion has no UInt32
+ // type and we can't have bailouts in wasm code.
+ ins->bailoutsDisabled_ = true;
+
+ return ins;
+}
+
+MResumePoint* MResumePoint::New(TempAllocator& alloc, MBasicBlock* block,
+ jsbytecode* pc, ResumeMode mode) {
+ MResumePoint* resume = new (alloc) MResumePoint(block, pc, mode);
+ if (!resume->init(alloc)) {
+ block->discardPreAllocatedResumePoint(resume);
+ return nullptr;
+ }
+ resume->inherit(block);
+ return resume;
+}
+
+MResumePoint::MResumePoint(MBasicBlock* block, jsbytecode* pc, ResumeMode mode)
+ : MNode(block, Kind::ResumePoint),
+ pc_(pc),
+ instruction_(nullptr),
+ mode_(mode) {
+ block->addResumePoint(this);
+}
+
+bool MResumePoint::init(TempAllocator& alloc) {
+ return operands_.init(alloc, block()->stackDepth());
+}
+
+MResumePoint* MResumePoint::caller() const {
+ return block()->callerResumePoint();
+}
+
+void MResumePoint::inherit(MBasicBlock* block) {
+ // FixedList doesn't initialize its elements, so do unchecked inits.
+ for (size_t i = 0; i < stackDepth(); i++) {
+ initOperand(i, block->getSlot(i));
+ }
+}
+
+void MResumePoint::addStore(TempAllocator& alloc, MDefinition* store,
+ const MResumePoint* cache) {
+ MOZ_ASSERT(block()->outerResumePoint() != this);
+ MOZ_ASSERT_IF(cache, !cache->stores_.empty());
+
+ if (cache && cache->stores_.begin()->operand == store) {
+ // If the last resume point had the same side-effect stack, then we can
+ // reuse the current side effect without cloning it. This is a simple
+ // way to share common context by making a spaghetti stack.
+ if (++cache->stores_.begin() == stores_.begin()) {
+ stores_.copy(cache->stores_);
+ return;
+ }
+ }
+
+ // Ensure that the store would not be deleted by DCE.
+ MOZ_ASSERT(store->isEffectful());
+
+ MStoreToRecover* top = new (alloc) MStoreToRecover(store);
+ stores_.push(top);
+}
+
+#ifdef JS_JITSPEW
+void MResumePoint::dump(GenericPrinter& out) const {
+ out.printf("resumepoint mode=");
+
+ switch (mode()) {
+ case ResumeMode::ResumeAt:
+ if (instruction_) {
+ out.printf("ResumeAt(%u)", instruction_->id());
+ } else {
+ out.printf("ResumeAt");
+ }
+ break;
+ default:
+ out.put(ResumeModeToString(mode()));
+ break;
+ }
+
+ if (MResumePoint* c = caller()) {
+ out.printf(" (caller in block%u)", c->block()->id());
+ }
+
+ for (size_t i = 0; i < numOperands(); i++) {
+ out.printf(" ");
+ if (operands_[i].hasProducer()) {
+ getOperand(i)->printName(out);
+ } else {
+ out.printf("(null)");
+ }
+ }
+ out.printf("\n");
+}
+
+void MResumePoint::dump() const {
+ Fprinter out(stderr);
+ dump(out);
+ out.finish();
+}
+#endif
+
+bool MResumePoint::isObservableOperand(MUse* u) const {
+ return isObservableOperand(indexOf(u));
+}
+
+bool MResumePoint::isObservableOperand(size_t index) const {
+ return block()->info().isObservableSlot(index);
+}
+
+bool MResumePoint::isRecoverableOperand(MUse* u) const {
+ return block()->info().isRecoverableOperand(indexOf(u));
+}
+
+MDefinition* MTruncateBigIntToInt64::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+
+ if (input->isBox()) {
+ input = input->getOperand(0);
+ }
+
+ // If the operand converts an I64 to BigInt, drop both conversions.
+ if (input->isInt64ToBigInt()) {
+ return input->getOperand(0);
+ }
+
+ // Fold this operation if the input operand is constant.
+ if (input->isConstant()) {
+ return MConstant::NewInt64(
+ alloc, BigInt::toInt64(input->toConstant()->toBigInt()));
+ }
+
+ return this;
+}
+
+MDefinition* MToInt64::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+
+ if (input->isBox()) {
+ input = input->getOperand(0);
+ }
+
+ // Unwrap MInt64ToBigInt: MToInt64(MInt64ToBigInt(int64)) = int64.
+ if (input->isInt64ToBigInt()) {
+ return input->getOperand(0);
+ }
+
+ // When the input is an Int64 already, just return it.
+ if (input->type() == MIRType::Int64) {
+ return input;
+ }
+
+ // Fold this operation if the input operand is constant.
+ if (input->isConstant()) {
+ switch (input->type()) {
+ case MIRType::Boolean:
+ return MConstant::NewInt64(alloc, input->toConstant()->toBoolean());
+ default:
+ break;
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MToNumberInt32::foldsTo(TempAllocator& alloc) {
+ // Fold this operation if the input operand is constant.
+ if (MConstant* cst = input()->maybeConstantValue()) {
+ switch (cst->type()) {
+ case MIRType::Null:
+ if (conversion() == IntConversionInputKind::Any) {
+ return MConstant::New(alloc, Int32Value(0));
+ }
+ break;
+ case MIRType::Boolean:
+ if (conversion() == IntConversionInputKind::Any ||
+ conversion() == IntConversionInputKind::NumbersOrBoolsOnly) {
+ return MConstant::New(alloc, Int32Value(cst->toBoolean()));
+ }
+ break;
+ case MIRType::Int32:
+ return MConstant::New(alloc, Int32Value(cst->toInt32()));
+ case MIRType::Float32:
+ case MIRType::Double:
+ int32_t ival;
+ // Only the value within the range of Int32 can be substituted as
+ // constant.
+ if (mozilla::NumberIsInt32(cst->numberToDouble(), &ival)) {
+ return MConstant::New(alloc, Int32Value(ival));
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ MDefinition* input = getOperand(0);
+ if (input->isBox()) {
+ input = input->toBox()->input();
+ }
+
+ // Do not fold the TruncateToInt32 node when the input is uint32 (e.g. ursh
+ // with a zero constant. Consider the test jit-test/tests/ion/bug1247880.js,
+ // where the relevant code is: |(imul(1, x >>> 0) % 2)|. The imul operator
+ // is folded to a MTruncateToInt32 node, which will result in this MIR:
+ // MMod(MTruncateToInt32(MUrsh(x, MConstant(0))), MConstant(2)). Note that
+ // the MUrsh node's type is int32 (since uint32 is not implemented), and
+ // that would fold the MTruncateToInt32 node. This will make the modulo
+ // unsigned, while is should have been signed.
+ if (input->type() == MIRType::Int32 && !IsUint32Type(input)) {
+ return input;
+ }
+
+ return this;
+}
+
+MDefinition* MBooleanToInt32::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+ MOZ_ASSERT(input->type() == MIRType::Boolean);
+
+ if (input->isConstant()) {
+ return MConstant::New(alloc, Int32Value(input->toConstant()->toBoolean()));
+ }
+
+ return this;
+}
+
+void MToNumberInt32::analyzeEdgeCasesBackward() {
+ if (!NeedNegativeZeroCheck(this)) {
+ setNeedsNegativeZeroCheck(false);
+ }
+}
+
+MDefinition* MTruncateToInt32::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+ if (input->isBox()) {
+ input = input->getOperand(0);
+ }
+
+ // Do not fold the TruncateToInt32 node when the input is uint32 (e.g. ursh
+ // with a zero constant. Consider the test jit-test/tests/ion/bug1247880.js,
+ // where the relevant code is: |(imul(1, x >>> 0) % 2)|. The imul operator
+ // is folded to a MTruncateToInt32 node, which will result in this MIR:
+ // MMod(MTruncateToInt32(MUrsh(x, MConstant(0))), MConstant(2)). Note that
+ // the MUrsh node's type is int32 (since uint32 is not implemented), and
+ // that would fold the MTruncateToInt32 node. This will make the modulo
+ // unsigned, while is should have been signed.
+ if (input->type() == MIRType::Int32 && !IsUint32Type(input)) {
+ return input;
+ }
+
+ if (input->type() == MIRType::Double && input->isConstant()) {
+ int32_t ret = ToInt32(input->toConstant()->toDouble());
+ return MConstant::New(alloc, Int32Value(ret));
+ }
+
+ return this;
+}
+
+MDefinition* MWasmTruncateToInt32::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+ if (input->type() == MIRType::Int32) {
+ return input;
+ }
+
+ if (input->type() == MIRType::Double && input->isConstant()) {
+ double d = input->toConstant()->toDouble();
+ if (std::isnan(d)) {
+ return this;
+ }
+
+ if (!isUnsigned() && d <= double(INT32_MAX) && d >= double(INT32_MIN)) {
+ return MConstant::New(alloc, Int32Value(ToInt32(d)));
+ }
+
+ if (isUnsigned() && d <= double(UINT32_MAX) && d >= 0) {
+ return MConstant::New(alloc, Int32Value(ToInt32(d)));
+ }
+ }
+
+ if (input->type() == MIRType::Float32 && input->isConstant()) {
+ double f = double(input->toConstant()->toFloat32());
+ if (std::isnan(f)) {
+ return this;
+ }
+
+ if (!isUnsigned() && f <= double(INT32_MAX) && f >= double(INT32_MIN)) {
+ return MConstant::New(alloc, Int32Value(ToInt32(f)));
+ }
+
+ if (isUnsigned() && f <= double(UINT32_MAX) && f >= 0) {
+ return MConstant::New(alloc, Int32Value(ToInt32(f)));
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MWrapInt64ToInt32::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = this->input();
+ if (input->isConstant()) {
+ uint64_t c = input->toConstant()->toInt64();
+ int32_t output = bottomHalf() ? int32_t(c) : int32_t(c >> 32);
+ return MConstant::New(alloc, Int32Value(output));
+ }
+
+ return this;
+}
+
+MDefinition* MExtendInt32ToInt64::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = this->input();
+ if (input->isConstant()) {
+ int32_t c = input->toConstant()->toInt32();
+ int64_t res = isUnsigned() ? int64_t(uint32_t(c)) : int64_t(c);
+ return MConstant::NewInt64(alloc, res);
+ }
+
+ return this;
+}
+
+MDefinition* MSignExtendInt32::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = this->input();
+ if (input->isConstant()) {
+ int32_t c = input->toConstant()->toInt32();
+ int32_t res;
+ switch (mode_) {
+ case Byte:
+ res = int32_t(int8_t(c & 0xFF));
+ break;
+ case Half:
+ res = int32_t(int16_t(c & 0xFFFF));
+ break;
+ }
+ return MConstant::New(alloc, Int32Value(res));
+ }
+
+ return this;
+}
+
+MDefinition* MSignExtendInt64::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = this->input();
+ if (input->isConstant()) {
+ int64_t c = input->toConstant()->toInt64();
+ int64_t res;
+ switch (mode_) {
+ case Byte:
+ res = int64_t(int8_t(c & 0xFF));
+ break;
+ case Half:
+ res = int64_t(int16_t(c & 0xFFFF));
+ break;
+ case Word:
+ res = int64_t(int32_t(c & 0xFFFFFFFFU));
+ break;
+ }
+ return MConstant::NewInt64(alloc, res);
+ }
+
+ return this;
+}
+
+MDefinition* MToDouble::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+ if (input->isBox()) {
+ input = input->getOperand(0);
+ }
+
+ if (input->type() == MIRType::Double) {
+ return input;
+ }
+
+ if (input->isConstant() &&
+ input->toConstant()->isTypeRepresentableAsDouble()) {
+ return MConstant::New(alloc,
+ DoubleValue(input->toConstant()->numberToDouble()));
+ }
+
+ return this;
+}
+
+MDefinition* MToFloat32::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = getOperand(0);
+ if (input->isBox()) {
+ input = input->getOperand(0);
+ }
+
+ if (input->type() == MIRType::Float32) {
+ return input;
+ }
+
+ // If x is a Float32, Float32(Double(x)) == x
+ if (!mustPreserveNaN_ && input->isToDouble() &&
+ input->toToDouble()->input()->type() == MIRType::Float32) {
+ return input->toToDouble()->input();
+ }
+
+ if (input->isConstant() &&
+ input->toConstant()->isTypeRepresentableAsDouble()) {
+ return MConstant::NewFloat32(alloc,
+ float(input->toConstant()->numberToDouble()));
+ }
+
+ // Fold ToFloat32(ToDouble(int32)) to ToFloat32(int32).
+ if (input->isToDouble() &&
+ input->toToDouble()->input()->type() == MIRType::Int32) {
+ return MToFloat32::New(alloc, input->toToDouble()->input());
+ }
+
+ return this;
+}
+
+MDefinition* MToString::foldsTo(TempAllocator& alloc) {
+ MDefinition* in = input();
+ if (in->isBox()) {
+ in = in->getOperand(0);
+ }
+
+ if (in->type() == MIRType::String) {
+ return in;
+ }
+ return this;
+}
+
+MDefinition* MClampToUint8::foldsTo(TempAllocator& alloc) {
+ if (MConstant* inputConst = input()->maybeConstantValue()) {
+ if (inputConst->isTypeRepresentableAsDouble()) {
+ int32_t clamped = ClampDoubleToUint8(inputConst->numberToDouble());
+ return MConstant::New(alloc, Int32Value(clamped));
+ }
+ }
+ return this;
+}
+
+bool MCompare::tryFoldEqualOperands(bool* result) {
+ if (lhs() != rhs()) {
+ return false;
+ }
+
+ // Intuitively somebody would think that if lhs === rhs,
+ // then we can just return true. (Or false for !==)
+ // However NaN !== NaN is true! So we spend some time trying
+ // to eliminate this case.
+
+ if (!IsStrictEqualityOp(jsop())) {
+ return false;
+ }
+
+ MOZ_ASSERT(
+ compareType_ == Compare_Undefined || compareType_ == Compare_Null ||
+ compareType_ == Compare_Int32 || compareType_ == Compare_UInt32 ||
+ compareType_ == Compare_UInt64 || compareType_ == Compare_Double ||
+ compareType_ == Compare_Float32 || compareType_ == Compare_UIntPtr ||
+ compareType_ == Compare_String || compareType_ == Compare_Object ||
+ compareType_ == Compare_Symbol || compareType_ == Compare_BigInt ||
+ compareType_ == Compare_BigInt_Int32 ||
+ compareType_ == Compare_BigInt_Double ||
+ compareType_ == Compare_BigInt_String);
+
+ if (isDoubleComparison() || isFloat32Comparison()) {
+ if (!operandsAreNeverNaN()) {
+ return false;
+ }
+ }
+
+ lhs()->setGuardRangeBailoutsUnchecked();
+
+ *result = (jsop() == JSOp::StrictEq);
+ return true;
+}
+
+static JSType TypeOfName(JSLinearString* str) {
+ static constexpr std::array types = {
+ JSTYPE_UNDEFINED, JSTYPE_OBJECT, JSTYPE_FUNCTION, JSTYPE_STRING,
+ JSTYPE_NUMBER, JSTYPE_BOOLEAN, JSTYPE_SYMBOL, JSTYPE_BIGINT,
+#ifdef ENABLE_RECORD_TUPLE
+ JSTYPE_RECORD, JSTYPE_TUPLE,
+#endif
+ };
+ static_assert(types.size() == JSTYPE_LIMIT);
+
+ const JSAtomState& names = GetJitContext()->runtime->names();
+ for (auto type : types) {
+ if (EqualStrings(str, TypeName(type, names))) {
+ return type;
+ }
+ }
+ return JSTYPE_LIMIT;
+}
+
+static mozilla::Maybe<std::pair<MTypeOfName*, JSType>> IsTypeOfCompare(
+ MCompare* ins) {
+ if (!IsEqualityOp(ins->jsop())) {
+ return mozilla::Nothing();
+ }
+ if (ins->compareType() != MCompare::Compare_String) {
+ return mozilla::Nothing();
+ }
+
+ auto* lhs = ins->lhs();
+ auto* rhs = ins->rhs();
+
+ MOZ_ASSERT(ins->type() == MIRType::Boolean);
+ MOZ_ASSERT(lhs->type() == MIRType::String);
+ MOZ_ASSERT(rhs->type() == MIRType::String);
+
+ if (!lhs->isTypeOfName() && !rhs->isTypeOfName()) {
+ return mozilla::Nothing();
+ }
+ if (!lhs->isConstant() && !rhs->isConstant()) {
+ return mozilla::Nothing();
+ }
+
+ auto* typeOfName =
+ lhs->isTypeOfName() ? lhs->toTypeOfName() : rhs->toTypeOfName();
+ MOZ_ASSERT(typeOfName->input()->isTypeOf());
+
+ auto* constant = lhs->isConstant() ? lhs->toConstant() : rhs->toConstant();
+
+ JSType type = TypeOfName(&constant->toString()->asLinear());
+ return mozilla::Some(std::pair(typeOfName, type));
+}
+
+bool MCompare::tryFoldTypeOf(bool* result) {
+ auto typeOfPair = IsTypeOfCompare(this);
+ if (!typeOfPair) {
+ return false;
+ }
+ auto [typeOfName, type] = *typeOfPair;
+ auto* typeOf = typeOfName->input()->toTypeOf();
+
+ switch (type) {
+ case JSTYPE_BOOLEAN:
+ if (!typeOf->input()->mightBeType(MIRType::Boolean)) {
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+ }
+ break;
+ case JSTYPE_NUMBER:
+ if (!typeOf->input()->mightBeType(MIRType::Int32) &&
+ !typeOf->input()->mightBeType(MIRType::Float32) &&
+ !typeOf->input()->mightBeType(MIRType::Double)) {
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+ }
+ break;
+ case JSTYPE_STRING:
+ if (!typeOf->input()->mightBeType(MIRType::String)) {
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+ }
+ break;
+ case JSTYPE_SYMBOL:
+ if (!typeOf->input()->mightBeType(MIRType::Symbol)) {
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+ }
+ break;
+ case JSTYPE_BIGINT:
+ if (!typeOf->input()->mightBeType(MIRType::BigInt)) {
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+ }
+ break;
+ case JSTYPE_OBJECT:
+ if (!typeOf->input()->mightBeType(MIRType::Object) &&
+ !typeOf->input()->mightBeType(MIRType::Null)) {
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+ }
+ break;
+ case JSTYPE_UNDEFINED:
+ if (!typeOf->input()->mightBeType(MIRType::Object) &&
+ !typeOf->input()->mightBeType(MIRType::Undefined)) {
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+ }
+ break;
+ case JSTYPE_FUNCTION:
+ if (!typeOf->input()->mightBeType(MIRType::Object)) {
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+ }
+ break;
+ case JSTYPE_LIMIT:
+ *result = (jsop() == JSOp::StrictNe || jsop() == JSOp::Ne);
+ return true;
+#ifdef ENABLE_RECORD_TUPLE
+ case JSTYPE_RECORD:
+ case JSTYPE_TUPLE:
+ MOZ_CRASH("Records and Tuples are not supported yet.");
+#endif
+ }
+
+ return false;
+}
+
+bool MCompare::tryFold(bool* result) {
+ JSOp op = jsop();
+
+ if (tryFoldEqualOperands(result)) {
+ return true;
+ }
+
+ if (tryFoldTypeOf(result)) {
+ return true;
+ }
+
+ if (compareType_ == Compare_Null || compareType_ == Compare_Undefined) {
+ // The LHS is the value we want to test against null or undefined.
+ if (IsStrictEqualityOp(op)) {
+ if (lhs()->type() == inputType()) {
+ *result = (op == JSOp::StrictEq);
+ return true;
+ }
+ if (!lhs()->mightBeType(inputType())) {
+ *result = (op == JSOp::StrictNe);
+ return true;
+ }
+ } else {
+ MOZ_ASSERT(IsLooseEqualityOp(op));
+ if (IsNullOrUndefined(lhs()->type())) {
+ *result = (op == JSOp::Eq);
+ return true;
+ }
+ if (!lhs()->mightBeType(MIRType::Null) &&
+ !lhs()->mightBeType(MIRType::Undefined) &&
+ !lhs()->mightBeType(MIRType::Object)) {
+ *result = (op == JSOp::Ne);
+ return true;
+ }
+ }
+ return false;
+ }
+
+ return false;
+}
+
+template <typename T>
+static bool FoldComparison(JSOp op, T left, T right) {
+ switch (op) {
+ case JSOp::Lt:
+ return left < right;
+ case JSOp::Le:
+ return left <= right;
+ case JSOp::Gt:
+ return left > right;
+ case JSOp::Ge:
+ return left >= right;
+ case JSOp::StrictEq:
+ case JSOp::Eq:
+ return left == right;
+ case JSOp::StrictNe:
+ case JSOp::Ne:
+ return left != right;
+ default:
+ MOZ_CRASH("Unexpected op.");
+ }
+}
+
+bool MCompare::evaluateConstantOperands(TempAllocator& alloc, bool* result) {
+ if (type() != MIRType::Boolean && type() != MIRType::Int32) {
+ return false;
+ }
+
+ MDefinition* left = getOperand(0);
+ MDefinition* right = getOperand(1);
+
+ if (compareType() == Compare_Double) {
+ // Optimize "MCompare MConstant (MToDouble SomethingInInt32Range).
+ // In most cases the MToDouble was added, because the constant is
+ // a double.
+ // e.g. v < 9007199254740991, where v is an int32 is always true.
+ if (!lhs()->isConstant() && !rhs()->isConstant()) {
+ return false;
+ }
+
+ MDefinition* operand = left->isConstant() ? right : left;
+ MConstant* constant =
+ left->isConstant() ? left->toConstant() : right->toConstant();
+ MOZ_ASSERT(constant->type() == MIRType::Double);
+ double cte = constant->toDouble();
+
+ if (operand->isToDouble() &&
+ operand->getOperand(0)->type() == MIRType::Int32) {
+ bool replaced = false;
+ switch (jsop_) {
+ case JSOp::Lt:
+ if (cte > INT32_MAX || cte < INT32_MIN) {
+ *result = !((constant == lhs()) ^ (cte < INT32_MIN));
+ replaced = true;
+ }
+ break;
+ case JSOp::Le:
+ if (constant == lhs()) {
+ if (cte > INT32_MAX || cte <= INT32_MIN) {
+ *result = (cte <= INT32_MIN);
+ replaced = true;
+ }
+ } else {
+ if (cte >= INT32_MAX || cte < INT32_MIN) {
+ *result = (cte >= INT32_MIN);
+ replaced = true;
+ }
+ }
+ break;
+ case JSOp::Gt:
+ if (cte > INT32_MAX || cte < INT32_MIN) {
+ *result = !((constant == rhs()) ^ (cte < INT32_MIN));
+ replaced = true;
+ }
+ break;
+ case JSOp::Ge:
+ if (constant == lhs()) {
+ if (cte >= INT32_MAX || cte < INT32_MIN) {
+ *result = (cte >= INT32_MAX);
+ replaced = true;
+ }
+ } else {
+ if (cte > INT32_MAX || cte <= INT32_MIN) {
+ *result = (cte <= INT32_MIN);
+ replaced = true;
+ }
+ }
+ break;
+ case JSOp::StrictEq: // Fall through.
+ case JSOp::Eq:
+ if (cte > INT32_MAX || cte < INT32_MIN) {
+ *result = false;
+ replaced = true;
+ }
+ break;
+ case JSOp::StrictNe: // Fall through.
+ case JSOp::Ne:
+ if (cte > INT32_MAX || cte < INT32_MIN) {
+ *result = true;
+ replaced = true;
+ }
+ break;
+ default:
+ MOZ_CRASH("Unexpected op.");
+ }
+ if (replaced) {
+ MLimitedTruncate* limit = MLimitedTruncate::New(
+ alloc, operand->getOperand(0), TruncateKind::NoTruncate);
+ limit->setGuardUnchecked();
+ block()->insertBefore(this, limit);
+ return true;
+ }
+ }
+
+ // Optimize comparison against NaN.
+ if (std::isnan(cte)) {
+ switch (jsop_) {
+ case JSOp::Lt:
+ case JSOp::Le:
+ case JSOp::Gt:
+ case JSOp::Ge:
+ case JSOp::Eq:
+ case JSOp::StrictEq:
+ *result = false;
+ break;
+ case JSOp::Ne:
+ case JSOp::StrictNe:
+ *result = true;
+ break;
+ default:
+ MOZ_CRASH("Unexpected op.");
+ }
+ return true;
+ }
+ }
+
+ if (!left->isConstant() || !right->isConstant()) {
+ return false;
+ }
+
+ MConstant* lhs = left->toConstant();
+ MConstant* rhs = right->toConstant();
+
+ // Fold away some String equality comparisons.
+ if (lhs->type() == MIRType::String && rhs->type() == MIRType::String) {
+ int32_t comp = 0; // Default to equal.
+ if (left != right) {
+ comp = CompareStrings(&lhs->toString()->asLinear(),
+ &rhs->toString()->asLinear());
+ }
+ *result = FoldComparison(jsop_, comp, 0);
+ return true;
+ }
+
+ if (compareType_ == Compare_UInt32) {
+ *result = FoldComparison(jsop_, uint32_t(lhs->toInt32()),
+ uint32_t(rhs->toInt32()));
+ return true;
+ }
+
+ if (compareType_ == Compare_Int64) {
+ *result = FoldComparison(jsop_, lhs->toInt64(), rhs->toInt64());
+ return true;
+ }
+
+ if (compareType_ == Compare_UInt64) {
+ *result = FoldComparison(jsop_, uint64_t(lhs->toInt64()),
+ uint64_t(rhs->toInt64()));
+ return true;
+ }
+
+ if (lhs->isTypeRepresentableAsDouble() &&
+ rhs->isTypeRepresentableAsDouble()) {
+ *result =
+ FoldComparison(jsop_, lhs->numberToDouble(), rhs->numberToDouble());
+ return true;
+ }
+
+ return false;
+}
+
+MDefinition* MCompare::tryFoldTypeOf(TempAllocator& alloc) {
+ auto typeOfPair = IsTypeOfCompare(this);
+ if (!typeOfPair) {
+ return this;
+ }
+ auto [typeOfName, type] = *typeOfPair;
+ auto* typeOf = typeOfName->input()->toTypeOf();
+
+ auto* input = typeOf->input();
+ MOZ_ASSERT(input->type() == MIRType::Value ||
+ input->type() == MIRType::Object);
+
+ // Constant typeof folding handles the other cases.
+ MOZ_ASSERT_IF(input->type() == MIRType::Object, type == JSTYPE_UNDEFINED ||
+ type == JSTYPE_OBJECT ||
+ type == JSTYPE_FUNCTION);
+
+ MOZ_ASSERT(type != JSTYPE_LIMIT, "unknown typeof strings folded earlier");
+
+ // If there's only a single use, assume this |typeof| is used in a simple
+ // comparison context.
+ //
+ // if (typeof thing === "number") { ... }
+ //
+ // It'll be compiled into something similar to:
+ //
+ // if (IsNumber(thing)) { ... }
+ //
+ // This heuristic can go wrong when repeated |typeof| are used in consecutive
+ // if-statements.
+ //
+ // if (typeof thing === "number") { ... }
+ // else if (typeof thing === "string") { ... }
+ // ... repeated for all possible types
+ //
+ // In that case it'd more efficient to emit MTypeOf compared to MTypeOfIs. We
+ // don't yet handle that case, because it'd require a separate optimization
+ // pass to correctly detect it.
+ if (typeOfName->hasOneUse()) {
+ return MTypeOfIs::New(alloc, input, jsop(), type);
+ }
+
+ MConstant* cst = MConstant::New(alloc, Int32Value(type));
+ block()->insertBefore(this, cst);
+
+ return MCompare::New(alloc, typeOf, cst, jsop(), MCompare::Compare_Int32);
+}
+
+MDefinition* MCompare::tryFoldCharCompare(TempAllocator& alloc) {
+ if (compareType() != Compare_String) {
+ return this;
+ }
+
+ MDefinition* left = lhs();
+ MOZ_ASSERT(left->type() == MIRType::String);
+
+ MDefinition* right = rhs();
+ MOZ_ASSERT(right->type() == MIRType::String);
+
+ // |str[i]| is compiled as |MFromCharCode(MCharCodeAt(str, i))|.
+ auto isCharAccess = [](MDefinition* ins) {
+ return ins->isFromCharCode() &&
+ ins->toFromCharCode()->input()->isCharCodeAt();
+ };
+
+ if (left->isConstant() || right->isConstant()) {
+ // Try to optimize |MConstant(string) <compare> (MFromCharCode MCharCodeAt)|
+ // as |MConstant(charcode) <compare> MCharCodeAt|.
+ MConstant* constant;
+ MDefinition* operand;
+ if (left->isConstant()) {
+ constant = left->toConstant();
+ operand = right;
+ } else {
+ constant = right->toConstant();
+ operand = left;
+ }
+
+ if (constant->toString()->length() != 1 || !isCharAccess(operand)) {
+ return this;
+ }
+
+ char16_t charCode = constant->toString()->asLinear().latin1OrTwoByteChar(0);
+ MConstant* charCodeConst = MConstant::New(alloc, Int32Value(charCode));
+ block()->insertBefore(this, charCodeConst);
+
+ MDefinition* charCodeAt = operand->toFromCharCode()->input();
+
+ if (left->isConstant()) {
+ left = charCodeConst;
+ right = charCodeAt;
+ } else {
+ left = charCodeAt;
+ right = charCodeConst;
+ }
+ } else if (isCharAccess(left) && isCharAccess(right)) {
+ // Try to optimize |(MFromCharCode MCharCodeAt) <compare> (MFromCharCode
+ // MCharCodeAt)| as |MCharCodeAt <compare> MCharCodeAt|.
+
+ left = left->toFromCharCode()->input();
+ right = right->toFromCharCode()->input();
+ } else {
+ return this;
+ }
+
+ return MCompare::New(alloc, left, right, jsop(), MCompare::Compare_Int32);
+}
+
+MDefinition* MCompare::tryFoldStringCompare(TempAllocator& alloc) {
+ if (compareType() != Compare_String) {
+ return this;
+ }
+
+ MDefinition* left = lhs();
+ MOZ_ASSERT(left->type() == MIRType::String);
+
+ MDefinition* right = rhs();
+ MOZ_ASSERT(right->type() == MIRType::String);
+
+ if (!left->isConstant() && !right->isConstant()) {
+ return this;
+ }
+
+ // Try to optimize |string <compare> MConstant("")| as |MStringLength(string)
+ // <compare> MConstant(0)|.
+
+ MConstant* constant =
+ left->isConstant() ? left->toConstant() : right->toConstant();
+ if (!constant->toString()->empty()) {
+ return this;
+ }
+
+ MDefinition* operand = left->isConstant() ? right : left;
+
+ auto* strLength = MStringLength::New(alloc, operand);
+ block()->insertBefore(this, strLength);
+
+ auto* zero = MConstant::New(alloc, Int32Value(0));
+ block()->insertBefore(this, zero);
+
+ if (left->isConstant()) {
+ left = zero;
+ right = strLength;
+ } else {
+ left = strLength;
+ right = zero;
+ }
+
+ return MCompare::New(alloc, left, right, jsop(), MCompare::Compare_Int32);
+}
+
+MDefinition* MCompare::tryFoldStringSubstring(TempAllocator& alloc) {
+ if (compareType() != Compare_String) {
+ return this;
+ }
+ if (!IsEqualityOp(jsop())) {
+ return this;
+ }
+
+ auto* left = lhs();
+ MOZ_ASSERT(left->type() == MIRType::String);
+
+ auto* right = rhs();
+ MOZ_ASSERT(right->type() == MIRType::String);
+
+ // One operand must be a constant string.
+ if (!left->isConstant() && !right->isConstant()) {
+ return this;
+ }
+
+ // The constant string must be non-empty.
+ auto* constant =
+ left->isConstant() ? left->toConstant() : right->toConstant();
+ if (constant->toString()->empty()) {
+ return this;
+ }
+
+ // The other operand must be a substring operation.
+ auto* operand = left->isConstant() ? right : left;
+ if (!operand->isSubstr()) {
+ return this;
+ }
+
+ // We want to match this pattern:
+ // Substr(string, Constant(0), Min(Constant(length), StringLength(string)))
+ auto* substr = operand->toSubstr();
+
+ auto isConstantZero = [](auto* def) {
+ return def->isConstant() && def->toConstant()->isInt32(0);
+ };
+
+ if (!isConstantZero(substr->begin())) {
+ return this;
+ }
+
+ auto* length = substr->length();
+ if (length->isBitOr()) {
+ // Unnecessary bit-ops haven't yet been removed.
+ auto* bitOr = length->toBitOr();
+ if (isConstantZero(bitOr->lhs())) {
+ length = bitOr->rhs();
+ } else if (isConstantZero(bitOr->rhs())) {
+ length = bitOr->lhs();
+ }
+ }
+ if (!length->isMinMax() || length->toMinMax()->isMax()) {
+ return this;
+ }
+
+ auto* min = length->toMinMax();
+ if (!min->lhs()->isConstant() && !min->rhs()->isConstant()) {
+ return this;
+ }
+
+ auto* minConstant = min->lhs()->isConstant() ? min->lhs()->toConstant()
+ : min->rhs()->toConstant();
+
+ auto* minOperand = min->lhs()->isConstant() ? min->rhs() : min->lhs();
+ if (!minOperand->isStringLength() ||
+ minOperand->toStringLength()->string() != substr->string()) {
+ return this;
+ }
+
+ static_assert(JSString::MAX_LENGTH < INT32_MAX,
+ "string length can be casted to int32_t");
+
+ // Ensure the string length matches the substring's length.
+ if (!minConstant->isInt32(int32_t(constant->toString()->length()))) {
+ return this;
+ }
+
+ // Now fold code like |str.substring(0, 2) == "aa"| to |str.startsWith("aa")|.
+
+ auto* startsWith = MStringStartsWith::New(alloc, substr->string(), constant);
+ if (jsop() == JSOp::Eq || jsop() == JSOp::StrictEq) {
+ return startsWith;
+ }
+
+ // Invert for inequality.
+ MOZ_ASSERT(jsop() == JSOp::Ne || jsop() == JSOp::StrictNe);
+
+ block()->insertBefore(this, startsWith);
+ return MNot::New(alloc, startsWith);
+}
+
+MDefinition* MCompare::tryFoldStringIndexOf(TempAllocator& alloc) {
+ if (compareType() != Compare_Int32) {
+ return this;
+ }
+ if (!IsEqualityOp(jsop())) {
+ return this;
+ }
+
+ auto* left = lhs();
+ MOZ_ASSERT(left->type() == MIRType::Int32);
+
+ auto* right = rhs();
+ MOZ_ASSERT(right->type() == MIRType::Int32);
+
+ // One operand must be a constant integer.
+ if (!left->isConstant() && !right->isConstant()) {
+ return this;
+ }
+
+ // The constant must be zero.
+ auto* constant =
+ left->isConstant() ? left->toConstant() : right->toConstant();
+ if (!constant->isInt32(0)) {
+ return this;
+ }
+
+ // The other operand must be an indexOf operation.
+ auto* operand = left->isConstant() ? right : left;
+ if (!operand->isStringIndexOf()) {
+ return this;
+ }
+
+ // Fold |str.indexOf(searchStr) == 0| to |str.startsWith(searchStr)|.
+
+ auto* indexOf = operand->toStringIndexOf();
+ auto* startsWith =
+ MStringStartsWith::New(alloc, indexOf->string(), indexOf->searchString());
+ if (jsop() == JSOp::Eq || jsop() == JSOp::StrictEq) {
+ return startsWith;
+ }
+
+ // Invert for inequality.
+ MOZ_ASSERT(jsop() == JSOp::Ne || jsop() == JSOp::StrictNe);
+
+ block()->insertBefore(this, startsWith);
+ return MNot::New(alloc, startsWith);
+}
+
+MDefinition* MCompare::foldsTo(TempAllocator& alloc) {
+ bool result;
+
+ if (tryFold(&result) || evaluateConstantOperands(alloc, &result)) {
+ if (type() == MIRType::Int32) {
+ return MConstant::New(alloc, Int32Value(result));
+ }
+
+ MOZ_ASSERT(type() == MIRType::Boolean);
+ return MConstant::New(alloc, BooleanValue(result));
+ }
+
+ if (MDefinition* folded = tryFoldTypeOf(alloc); folded != this) {
+ return folded;
+ }
+
+ if (MDefinition* folded = tryFoldCharCompare(alloc); folded != this) {
+ return folded;
+ }
+
+ if (MDefinition* folded = tryFoldStringCompare(alloc); folded != this) {
+ return folded;
+ }
+
+ if (MDefinition* folded = tryFoldStringSubstring(alloc); folded != this) {
+ return folded;
+ }
+
+ if (MDefinition* folded = tryFoldStringIndexOf(alloc); folded != this) {
+ return folded;
+ }
+
+ return this;
+}
+
+void MCompare::trySpecializeFloat32(TempAllocator& alloc) {
+ if (AllOperandsCanProduceFloat32(this) && compareType_ == Compare_Double) {
+ compareType_ = Compare_Float32;
+ } else {
+ ConvertOperandsToDouble(this, alloc);
+ }
+}
+
+MDefinition* MNot::foldsTo(TempAllocator& alloc) {
+ // Fold if the input is constant
+ if (MConstant* inputConst = input()->maybeConstantValue()) {
+ bool b;
+ if (inputConst->valueToBoolean(&b)) {
+ if (type() == MIRType::Int32 || type() == MIRType::Int64) {
+ return MConstant::New(alloc, Int32Value(!b));
+ }
+ return MConstant::New(alloc, BooleanValue(!b));
+ }
+ }
+
+ // If the operand of the Not is itself a Not, they cancel out. But we can't
+ // always convert Not(Not(x)) to x because that may loose the conversion to
+ // boolean. We can simplify Not(Not(Not(x))) to Not(x) though.
+ MDefinition* op = getOperand(0);
+ if (op->isNot()) {
+ MDefinition* opop = op->getOperand(0);
+ if (opop->isNot()) {
+ return opop;
+ }
+ }
+
+ // Not of an undefined or null value is always true
+ if (input()->type() == MIRType::Undefined ||
+ input()->type() == MIRType::Null) {
+ return MConstant::New(alloc, BooleanValue(true));
+ }
+
+ // Not of a symbol is always false.
+ if (input()->type() == MIRType::Symbol) {
+ return MConstant::New(alloc, BooleanValue(false));
+ }
+
+ return this;
+}
+
+void MNot::trySpecializeFloat32(TempAllocator& alloc) {
+ (void)EnsureFloatInputOrConvert(this, alloc);
+}
+
+#ifdef JS_JITSPEW
+void MBeta::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+
+ out.printf(" ");
+ comparison_->dump(out);
+}
+#endif
+
+AliasSet MCreateThis::getAliasSet() const {
+ return AliasSet::Load(AliasSet::Any);
+}
+
+bool MGetArgumentsObjectArg::congruentTo(const MDefinition* ins) const {
+ if (!ins->isGetArgumentsObjectArg()) {
+ return false;
+ }
+ if (ins->toGetArgumentsObjectArg()->argno() != argno()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MGetArgumentsObjectArg::getAliasSet() const {
+ return AliasSet::Load(AliasSet::Any);
+}
+
+AliasSet MSetArgumentsObjectArg::getAliasSet() const {
+ return AliasSet::Store(AliasSet::Any);
+}
+
+MObjectState::MObjectState(MObjectState* state)
+ : MVariadicInstruction(classOpcode),
+ numSlots_(state->numSlots_),
+ numFixedSlots_(state->numFixedSlots_) {
+ // This instruction is only used as a summary for bailout paths.
+ setResultType(MIRType::Object);
+ setRecoveredOnBailout();
+}
+
+MObjectState::MObjectState(JSObject* templateObject)
+ : MObjectState(templateObject->as<NativeObject>().shape()) {}
+
+MObjectState::MObjectState(const Shape* shape)
+ : MVariadicInstruction(classOpcode) {
+ // This instruction is only used as a summary for bailout paths.
+ setResultType(MIRType::Object);
+ setRecoveredOnBailout();
+
+ numSlots_ = shape->asShared().slotSpan();
+ numFixedSlots_ = shape->asShared().numFixedSlots();
+}
+
+/* static */
+JSObject* MObjectState::templateObjectOf(MDefinition* obj) {
+ // MNewPlainObject uses a shape constant, not an object.
+ MOZ_ASSERT(!obj->isNewPlainObject());
+
+ if (obj->isNewObject()) {
+ return obj->toNewObject()->templateObject();
+ } else if (obj->isNewCallObject()) {
+ return obj->toNewCallObject()->templateObject();
+ } else if (obj->isNewIterator()) {
+ return obj->toNewIterator()->templateObject();
+ }
+
+ MOZ_CRASH("unreachable");
+}
+
+bool MObjectState::init(TempAllocator& alloc, MDefinition* obj) {
+ if (!MVariadicInstruction::init(alloc, numSlots() + 1)) {
+ return false;
+ }
+ // +1, for the Object.
+ initOperand(0, obj);
+ return true;
+}
+
+void MObjectState::initFromTemplateObject(TempAllocator& alloc,
+ MDefinition* undefinedVal) {
+ if (object()->isNewPlainObject()) {
+ MOZ_ASSERT(object()->toNewPlainObject()->shape()->asShared().slotSpan() ==
+ numSlots());
+ for (size_t i = 0; i < numSlots(); i++) {
+ initSlot(i, undefinedVal);
+ }
+ return;
+ }
+
+ JSObject* templateObject = templateObjectOf(object());
+
+ // Initialize all the slots of the object state with the value contained in
+ // the template object. This is needed to account values which are baked in
+ // the template objects and not visible in IonMonkey, such as the
+ // uninitialized-lexical magic value of call objects.
+
+ MOZ_ASSERT(templateObject->is<NativeObject>());
+ NativeObject& nativeObject = templateObject->as<NativeObject>();
+ MOZ_ASSERT(nativeObject.slotSpan() == numSlots());
+
+ for (size_t i = 0; i < numSlots(); i++) {
+ Value val = nativeObject.getSlot(i);
+ MDefinition* def = undefinedVal;
+ if (!val.isUndefined()) {
+ MConstant* ins = MConstant::New(alloc, val);
+ block()->insertBefore(this, ins);
+ def = ins;
+ }
+ initSlot(i, def);
+ }
+}
+
+MObjectState* MObjectState::New(TempAllocator& alloc, MDefinition* obj) {
+ MObjectState* res;
+ if (obj->isNewPlainObject()) {
+ const Shape* shape = obj->toNewPlainObject()->shape();
+ res = new (alloc) MObjectState(shape);
+ } else {
+ JSObject* templateObject = templateObjectOf(obj);
+ MOZ_ASSERT(templateObject, "Unexpected object creation.");
+ res = new (alloc) MObjectState(templateObject);
+ }
+
+ if (!res || !res->init(alloc, obj)) {
+ return nullptr;
+ }
+ return res;
+}
+
+MObjectState* MObjectState::Copy(TempAllocator& alloc, MObjectState* state) {
+ MObjectState* res = new (alloc) MObjectState(state);
+ if (!res || !res->init(alloc, state->object())) {
+ return nullptr;
+ }
+ for (size_t i = 0; i < res->numSlots(); i++) {
+ res->initSlot(i, state->getSlot(i));
+ }
+ return res;
+}
+
+MArrayState::MArrayState(MDefinition* arr) : MVariadicInstruction(classOpcode) {
+ // This instruction is only used as a summary for bailout paths.
+ setResultType(MIRType::Object);
+ setRecoveredOnBailout();
+ if (arr->isNewArrayObject()) {
+ numElements_ = arr->toNewArrayObject()->length();
+ } else {
+ numElements_ = arr->toNewArray()->length();
+ }
+}
+
+bool MArrayState::init(TempAllocator& alloc, MDefinition* obj,
+ MDefinition* len) {
+ if (!MVariadicInstruction::init(alloc, numElements() + 2)) {
+ return false;
+ }
+ // +1, for the Array object.
+ initOperand(0, obj);
+ // +1, for the length value of the array.
+ initOperand(1, len);
+ return true;
+}
+
+void MArrayState::initFromTemplateObject(TempAllocator& alloc,
+ MDefinition* undefinedVal) {
+ for (size_t i = 0; i < numElements(); i++) {
+ initElement(i, undefinedVal);
+ }
+}
+
+MArrayState* MArrayState::New(TempAllocator& alloc, MDefinition* arr,
+ MDefinition* initLength) {
+ MArrayState* res = new (alloc) MArrayState(arr);
+ if (!res || !res->init(alloc, arr, initLength)) {
+ return nullptr;
+ }
+ return res;
+}
+
+MArrayState* MArrayState::Copy(TempAllocator& alloc, MArrayState* state) {
+ MDefinition* arr = state->array();
+ MDefinition* len = state->initializedLength();
+ MArrayState* res = new (alloc) MArrayState(arr);
+ if (!res || !res->init(alloc, arr, len)) {
+ return nullptr;
+ }
+ for (size_t i = 0; i < res->numElements(); i++) {
+ res->initElement(i, state->getElement(i));
+ }
+ return res;
+}
+
+MNewArray::MNewArray(uint32_t length, MConstant* templateConst,
+ gc::Heap initialHeap, bool vmCall)
+ : MUnaryInstruction(classOpcode, templateConst),
+ length_(length),
+ initialHeap_(initialHeap),
+ vmCall_(vmCall) {
+ setResultType(MIRType::Object);
+}
+
+MDefinition::AliasType MLoadFixedSlot::mightAlias(
+ const MDefinition* def) const {
+ if (def->isStoreFixedSlot()) {
+ const MStoreFixedSlot* store = def->toStoreFixedSlot();
+ if (store->slot() != slot()) {
+ return AliasType::NoAlias;
+ }
+ if (store->object() != object()) {
+ return AliasType::MayAlias;
+ }
+ return AliasType::MustAlias;
+ }
+ return AliasType::MayAlias;
+}
+
+MDefinition* MLoadFixedSlot::foldsTo(TempAllocator& alloc) {
+ if (MDefinition* def = foldsToStore(alloc)) {
+ return def;
+ }
+
+ return this;
+}
+
+MDefinition::AliasType MLoadFixedSlotAndUnbox::mightAlias(
+ const MDefinition* def) const {
+ if (def->isStoreFixedSlot()) {
+ const MStoreFixedSlot* store = def->toStoreFixedSlot();
+ if (store->slot() != slot()) {
+ return AliasType::NoAlias;
+ }
+ if (store->object() != object()) {
+ return AliasType::MayAlias;
+ }
+ return AliasType::MustAlias;
+ }
+ return AliasType::MayAlias;
+}
+
+MDefinition* MLoadFixedSlotAndUnbox::foldsTo(TempAllocator& alloc) {
+ if (MDefinition* def = foldsToStore(alloc)) {
+ return def;
+ }
+
+ return this;
+}
+
+MDefinition* MWasmExtendU32Index::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = this->input();
+ if (input->isConstant()) {
+ return MConstant::NewInt64(
+ alloc, int64_t(uint32_t(input->toConstant()->toInt32())));
+ }
+
+ return this;
+}
+
+MDefinition* MWasmWrapU32Index::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = this->input();
+ if (input->isConstant()) {
+ return MConstant::New(
+ alloc, Int32Value(int32_t(uint32_t(input->toConstant()->toInt64()))));
+ }
+
+ return this;
+}
+
+// Some helpers for folding wasm and/or/xor on int32/64 values. Rather than
+// duplicating these for 32 and 64-bit values, all folding is done on 64-bit
+// values and masked for the 32-bit case.
+
+const uint64_t Low32Mask = uint64_t(0xFFFFFFFFULL);
+
+// Routines to check and disassemble values.
+
+static bool IsIntegralConstant(const MDefinition* def) {
+ return def->isConstant() &&
+ (def->type() == MIRType::Int32 || def->type() == MIRType::Int64);
+}
+
+static uint64_t GetIntegralConstant(const MDefinition* def) {
+ if (def->type() == MIRType::Int32) {
+ return uint64_t(def->toConstant()->toInt32()) & Low32Mask;
+ }
+ return uint64_t(def->toConstant()->toInt64());
+}
+
+static bool IsIntegralConstantZero(const MDefinition* def) {
+ return IsIntegralConstant(def) && GetIntegralConstant(def) == 0;
+}
+
+static bool IsIntegralConstantOnes(const MDefinition* def) {
+ uint64_t ones = def->type() == MIRType::Int32 ? Low32Mask : ~uint64_t(0);
+ return IsIntegralConstant(def) && GetIntegralConstant(def) == ones;
+}
+
+// Routines to create values.
+static MDefinition* ToIntegralConstant(TempAllocator& alloc, MIRType ty,
+ uint64_t val) {
+ switch (ty) {
+ case MIRType::Int32:
+ return MConstant::New(alloc,
+ Int32Value(int32_t(uint32_t(val & Low32Mask))));
+ case MIRType::Int64:
+ return MConstant::NewInt64(alloc, int64_t(val));
+ default:
+ MOZ_CRASH();
+ }
+}
+
+static MDefinition* ZeroOfType(TempAllocator& alloc, MIRType ty) {
+ return ToIntegralConstant(alloc, ty, 0);
+}
+
+static MDefinition* OnesOfType(TempAllocator& alloc, MIRType ty) {
+ return ToIntegralConstant(alloc, ty, ~uint64_t(0));
+}
+
+MDefinition* MWasmBinaryBitwise::foldsTo(TempAllocator& alloc) {
+ MOZ_ASSERT(op() == Opcode::WasmBinaryBitwise);
+ MOZ_ASSERT(type() == MIRType::Int32 || type() == MIRType::Int64);
+
+ MDefinition* argL = getOperand(0);
+ MDefinition* argR = getOperand(1);
+ MOZ_ASSERT(argL->type() == type() && argR->type() == type());
+
+ // The args are the same (SSA name)
+ if (argL == argR) {
+ switch (subOpcode()) {
+ case SubOpcode::And:
+ case SubOpcode::Or:
+ return argL;
+ case SubOpcode::Xor:
+ return ZeroOfType(alloc, type());
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ // Both args constant
+ if (IsIntegralConstant(argL) && IsIntegralConstant(argR)) {
+ uint64_t valL = GetIntegralConstant(argL);
+ uint64_t valR = GetIntegralConstant(argR);
+ uint64_t val = valL;
+ switch (subOpcode()) {
+ case SubOpcode::And:
+ val &= valR;
+ break;
+ case SubOpcode::Or:
+ val |= valR;
+ break;
+ case SubOpcode::Xor:
+ val ^= valR;
+ break;
+ default:
+ MOZ_CRASH();
+ }
+ return ToIntegralConstant(alloc, type(), val);
+ }
+
+ // Left arg is zero
+ if (IsIntegralConstantZero(argL)) {
+ switch (subOpcode()) {
+ case SubOpcode::And:
+ return ZeroOfType(alloc, type());
+ case SubOpcode::Or:
+ case SubOpcode::Xor:
+ return argR;
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ // Right arg is zero
+ if (IsIntegralConstantZero(argR)) {
+ switch (subOpcode()) {
+ case SubOpcode::And:
+ return ZeroOfType(alloc, type());
+ case SubOpcode::Or:
+ case SubOpcode::Xor:
+ return argL;
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ // Left arg is ones
+ if (IsIntegralConstantOnes(argL)) {
+ switch (subOpcode()) {
+ case SubOpcode::And:
+ return argR;
+ case SubOpcode::Or:
+ return OnesOfType(alloc, type());
+ case SubOpcode::Xor:
+ return MBitNot::New(alloc, argR);
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ // Right arg is ones
+ if (IsIntegralConstantOnes(argR)) {
+ switch (subOpcode()) {
+ case SubOpcode::And:
+ return argL;
+ case SubOpcode::Or:
+ return OnesOfType(alloc, type());
+ case SubOpcode::Xor:
+ return MBitNot::New(alloc, argL);
+ default:
+ MOZ_CRASH();
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MWasmAddOffset::foldsTo(TempAllocator& alloc) {
+ MDefinition* baseArg = base();
+ if (!baseArg->isConstant()) {
+ return this;
+ }
+
+ if (baseArg->type() == MIRType::Int32) {
+ CheckedInt<uint32_t> ptr = baseArg->toConstant()->toInt32();
+ ptr += offset();
+ if (!ptr.isValid()) {
+ return this;
+ }
+ return MConstant::New(alloc, Int32Value(ptr.value()));
+ }
+
+ MOZ_ASSERT(baseArg->type() == MIRType::Int64);
+ CheckedInt<uint64_t> ptr = baseArg->toConstant()->toInt64();
+ ptr += offset();
+ if (!ptr.isValid()) {
+ return this;
+ }
+ return MConstant::NewInt64(alloc, ptr.value());
+}
+
+bool MWasmAlignmentCheck::congruentTo(const MDefinition* ins) const {
+ if (!ins->isWasmAlignmentCheck()) {
+ return false;
+ }
+ const MWasmAlignmentCheck* check = ins->toWasmAlignmentCheck();
+ return byteSize_ == check->byteSize() && congruentIfOperandsEqual(check);
+}
+
+MDefinition::AliasType MAsmJSLoadHeap::mightAlias(
+ const MDefinition* def) const {
+ if (def->isAsmJSStoreHeap()) {
+ const MAsmJSStoreHeap* store = def->toAsmJSStoreHeap();
+ if (store->accessType() != accessType()) {
+ return AliasType::MayAlias;
+ }
+ if (!base()->isConstant() || !store->base()->isConstant()) {
+ return AliasType::MayAlias;
+ }
+ const MConstant* otherBase = store->base()->toConstant();
+ if (base()->toConstant()->equals(otherBase)) {
+ return AliasType::MayAlias;
+ }
+ return AliasType::NoAlias;
+ }
+ return AliasType::MayAlias;
+}
+
+bool MAsmJSLoadHeap::congruentTo(const MDefinition* ins) const {
+ if (!ins->isAsmJSLoadHeap()) {
+ return false;
+ }
+ const MAsmJSLoadHeap* load = ins->toAsmJSLoadHeap();
+ return load->accessType() == accessType() && congruentIfOperandsEqual(load);
+}
+
+MDefinition::AliasType MWasmLoadInstanceDataField::mightAlias(
+ const MDefinition* def) const {
+ if (def->isWasmStoreInstanceDataField()) {
+ const MWasmStoreInstanceDataField* store =
+ def->toWasmStoreInstanceDataField();
+ return store->instanceDataOffset() == instanceDataOffset_
+ ? AliasType::MayAlias
+ : AliasType::NoAlias;
+ }
+
+ return AliasType::MayAlias;
+}
+
+MDefinition::AliasType MWasmLoadGlobalCell::mightAlias(
+ const MDefinition* def) const {
+ if (def->isWasmStoreGlobalCell()) {
+ // No globals of different type can alias. See bug 1467415 comment 3.
+ if (type() != def->toWasmStoreGlobalCell()->value()->type()) {
+ return AliasType::NoAlias;
+ }
+
+ // We could do better here. We're dealing with two indirect globals.
+ // If at at least one of them is created in this module, then they
+ // can't alias -- in other words they can only alias if they are both
+ // imported. That would require having a flag on globals to indicate
+ // which are imported. See bug 1467415 comment 3, 4th rule.
+ }
+
+ return AliasType::MayAlias;
+}
+
+HashNumber MWasmLoadInstanceDataField::valueHash() const {
+ // Same comment as in MWasmLoadInstanceDataField::congruentTo() applies here.
+ HashNumber hash = MDefinition::valueHash();
+ hash = addU32ToHash(hash, instanceDataOffset_);
+ return hash;
+}
+
+bool MWasmLoadInstanceDataField::congruentTo(const MDefinition* ins) const {
+ if (!ins->isWasmLoadInstanceDataField()) {
+ return false;
+ }
+
+ const MWasmLoadInstanceDataField* other = ins->toWasmLoadInstanceDataField();
+
+ // We don't need to consider the isConstant_ markings here, because
+ // equivalence of offsets implies equivalence of constness.
+ bool sameOffsets = instanceDataOffset_ == other->instanceDataOffset_;
+ MOZ_ASSERT_IF(sameOffsets, isConstant_ == other->isConstant_);
+
+ // We omit checking congruence of the operands. There is only one
+ // operand, the instance pointer, and it only ever has one value within the
+ // domain of optimization. If that should ever change then operand
+ // congruence checking should be reinstated.
+ return sameOffsets /* && congruentIfOperandsEqual(other) */;
+}
+
+MDefinition* MWasmLoadInstanceDataField::foldsTo(TempAllocator& alloc) {
+ if (!dependency() || !dependency()->isWasmStoreInstanceDataField()) {
+ return this;
+ }
+
+ MWasmStoreInstanceDataField* store =
+ dependency()->toWasmStoreInstanceDataField();
+ if (!store->block()->dominates(block())) {
+ return this;
+ }
+
+ if (store->instanceDataOffset() != instanceDataOffset()) {
+ return this;
+ }
+
+ if (store->value()->type() != type()) {
+ return this;
+ }
+
+ return store->value();
+}
+
+bool MWasmLoadGlobalCell::congruentTo(const MDefinition* ins) const {
+ if (!ins->isWasmLoadGlobalCell()) {
+ return false;
+ }
+ const MWasmLoadGlobalCell* other = ins->toWasmLoadGlobalCell();
+ return congruentIfOperandsEqual(other);
+}
+
+#ifdef ENABLE_WASM_SIMD
+MDefinition* MWasmTernarySimd128::foldsTo(TempAllocator& alloc) {
+ if (simdOp() == wasm::SimdOp::V128Bitselect) {
+ if (v2()->op() == MDefinition::Opcode::WasmFloatConstant) {
+ int8_t shuffle[16];
+ if (specializeBitselectConstantMaskAsShuffle(shuffle)) {
+ return BuildWasmShuffleSimd128(alloc, shuffle, v0(), v1());
+ }
+ } else if (canRelaxBitselect()) {
+ return MWasmTernarySimd128::New(alloc, v0(), v1(), v2(),
+ wasm::SimdOp::I8x16RelaxedLaneSelect);
+ }
+ }
+ return this;
+}
+
+inline static bool MatchSpecificShift(MDefinition* instr,
+ wasm::SimdOp simdShiftOp,
+ int shiftValue) {
+ return instr->isWasmShiftSimd128() &&
+ instr->toWasmShiftSimd128()->simdOp() == simdShiftOp &&
+ instr->toWasmShiftSimd128()->rhs()->isConstant() &&
+ instr->toWasmShiftSimd128()->rhs()->toConstant()->toInt32() ==
+ shiftValue;
+}
+
+// Matches MIR subtree that represents PMADDUBSW instruction generated by
+// emscripten. The a and b parameters return subtrees that correspond
+// operands of the instruction, if match is found.
+static bool MatchPmaddubswSequence(MWasmBinarySimd128* lhs,
+ MWasmBinarySimd128* rhs, MDefinition** a,
+ MDefinition** b) {
+ MOZ_ASSERT(lhs->simdOp() == wasm::SimdOp::I16x8Mul &&
+ rhs->simdOp() == wasm::SimdOp::I16x8Mul);
+ // The emscripten/LLVM produced the following sequence for _mm_maddubs_epi16:
+ //
+ // return _mm_adds_epi16(
+ // _mm_mullo_epi16(
+ // _mm_and_si128(__a, _mm_set1_epi16(0x00FF)),
+ // _mm_srai_epi16(_mm_slli_epi16(__b, 8), 8)),
+ // _mm_mullo_epi16(_mm_srli_epi16(__a, 8), _mm_srai_epi16(__b, 8)));
+ //
+ // This will roughly correspond the following MIR:
+ // MWasmBinarySimd128[I16x8AddSatS]
+ // |-- lhs: MWasmBinarySimd128[I16x8Mul] (lhs)
+ // | |-- lhs: MWasmBinarySimd128WithConstant[V128And] (op0)
+ // | | |-- lhs: a
+ // | | -- rhs: SimdConstant::SplatX8(0x00FF)
+ // | -- rhs: MWasmShiftSimd128[I16x8ShrS] (op1)
+ // | |-- lhs: MWasmShiftSimd128[I16x8Shl]
+ // | | |-- lhs: b
+ // | | -- rhs: MConstant[8]
+ // | -- rhs: MConstant[8]
+ // -- rhs: MWasmBinarySimd128[I16x8Mul] (rhs)
+ // |-- lhs: MWasmShiftSimd128[I16x8ShrU] (op2)
+ // | |-- lhs: a
+ // | |-- rhs: MConstant[8]
+ // -- rhs: MWasmShiftSimd128[I16x8ShrS] (op3)
+ // |-- lhs: b
+ // -- rhs: MConstant[8]
+
+ // The I16x8AddSatS and I16x8Mul are commutative, so their operands
+ // may be swapped. Rearrange op0, op1, op2, op3 to be in the order
+ // noted above.
+ MDefinition *op0 = lhs->lhs(), *op1 = lhs->rhs(), *op2 = rhs->lhs(),
+ *op3 = rhs->rhs();
+ if (op1->isWasmBinarySimd128WithConstant()) {
+ // Move MWasmBinarySimd128WithConstant[V128And] as first operand in lhs.
+ std::swap(op0, op1);
+ } else if (op3->isWasmBinarySimd128WithConstant()) {
+ // Move MWasmBinarySimd128WithConstant[V128And] as first operand in rhs.
+ std::swap(op2, op3);
+ }
+ if (op2->isWasmBinarySimd128WithConstant()) {
+ // The lhs and rhs are swapped.
+ // Make MWasmBinarySimd128WithConstant[V128And] to be op0.
+ std::swap(op0, op2);
+ std::swap(op1, op3);
+ }
+ if (op2->isWasmShiftSimd128() &&
+ op2->toWasmShiftSimd128()->simdOp() == wasm::SimdOp::I16x8ShrS) {
+ // The op2 and op3 appears to be in wrong order, swap.
+ std::swap(op2, op3);
+ }
+
+ // Check all instructions SIMD code and constant values for assigned
+ // names op0, op1, op2, op3 (see diagram above).
+ const uint16_t const00FF[8] = {255, 255, 255, 255, 255, 255, 255, 255};
+ if (!op0->isWasmBinarySimd128WithConstant() ||
+ op0->toWasmBinarySimd128WithConstant()->simdOp() !=
+ wasm::SimdOp::V128And ||
+ memcmp(op0->toWasmBinarySimd128WithConstant()->rhs().bytes(), const00FF,
+ 16) != 0 ||
+ !MatchSpecificShift(op1, wasm::SimdOp::I16x8ShrS, 8) ||
+ !MatchSpecificShift(op2, wasm::SimdOp::I16x8ShrU, 8) ||
+ !MatchSpecificShift(op3, wasm::SimdOp::I16x8ShrS, 8) ||
+ !MatchSpecificShift(op1->toWasmShiftSimd128()->lhs(),
+ wasm::SimdOp::I16x8Shl, 8)) {
+ return false;
+ }
+
+ // Check if the instructions arguments that are subtrees match the
+ // a and b assignments. May depend on GVN behavior.
+ MDefinition* maybeA = op0->toWasmBinarySimd128WithConstant()->lhs();
+ MDefinition* maybeB = op3->toWasmShiftSimd128()->lhs();
+ if (maybeA != op2->toWasmShiftSimd128()->lhs() ||
+ maybeB != op1->toWasmShiftSimd128()->lhs()->toWasmShiftSimd128()->lhs()) {
+ return false;
+ }
+
+ *a = maybeA;
+ *b = maybeB;
+ return true;
+}
+
+MDefinition* MWasmBinarySimd128::foldsTo(TempAllocator& alloc) {
+ if (simdOp() == wasm::SimdOp::I8x16Swizzle && rhs()->isWasmFloatConstant()) {
+ // Specialize swizzle(v, constant) as shuffle(mask, v, zero) to trigger all
+ // our shuffle optimizations. We don't report this rewriting as the report
+ // will be overwritten by the subsequent shuffle analysis.
+ int8_t shuffleMask[16];
+ memcpy(shuffleMask, rhs()->toWasmFloatConstant()->toSimd128().bytes(), 16);
+ for (int i = 0; i < 16; i++) {
+ // Out-of-bounds lanes reference the zero vector; in many cases, the zero
+ // vector is removed by subsequent optimizations.
+ if (shuffleMask[i] < 0 || shuffleMask[i] > 15) {
+ shuffleMask[i] = 16;
+ }
+ }
+ MWasmFloatConstant* zero =
+ MWasmFloatConstant::NewSimd128(alloc, SimdConstant::SplatX4(0));
+ if (!zero) {
+ return nullptr;
+ }
+ block()->insertBefore(this, zero);
+ return BuildWasmShuffleSimd128(alloc, shuffleMask, lhs(), zero);
+ }
+
+ // Specialize var OP const / const OP var when possible.
+ //
+ // As the LIR layer can't directly handle v128 constants as part of its normal
+ // machinery we specialize some nodes here if they have single-use v128
+ // constant arguments. The purpose is to generate code that inlines the
+ // constant in the instruction stream, using either a rip-relative load+op or
+ // quickly-synthesized constant in a scratch on x64. There is a general
+ // assumption here that that is better than generating the constant into an
+ // allocatable register, since that register value could not be reused. (This
+ // ignores the possibility that the constant load could be hoisted).
+
+ if (lhs()->isWasmFloatConstant() != rhs()->isWasmFloatConstant() &&
+ specializeForConstantRhs()) {
+ if (isCommutative() && lhs()->isWasmFloatConstant() && lhs()->hasOneUse()) {
+ return MWasmBinarySimd128WithConstant::New(
+ alloc, rhs(), lhs()->toWasmFloatConstant()->toSimd128(), simdOp());
+ }
+
+ if (rhs()->isWasmFloatConstant() && rhs()->hasOneUse()) {
+ return MWasmBinarySimd128WithConstant::New(
+ alloc, lhs(), rhs()->toWasmFloatConstant()->toSimd128(), simdOp());
+ }
+ }
+
+ // Check special encoding for PMADDUBSW.
+ if (canPmaddubsw() && simdOp() == wasm::SimdOp::I16x8AddSatS &&
+ lhs()->isWasmBinarySimd128() && rhs()->isWasmBinarySimd128() &&
+ lhs()->toWasmBinarySimd128()->simdOp() == wasm::SimdOp::I16x8Mul &&
+ rhs()->toWasmBinarySimd128()->simdOp() == wasm::SimdOp::I16x8Mul) {
+ MDefinition *a, *b;
+ if (MatchPmaddubswSequence(lhs()->toWasmBinarySimd128(),
+ rhs()->toWasmBinarySimd128(), &a, &b)) {
+ return MWasmBinarySimd128::New(alloc, a, b, /* commutative = */ false,
+ wasm::SimdOp::MozPMADDUBSW);
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MWasmScalarToSimd128::foldsTo(TempAllocator& alloc) {
+# ifdef DEBUG
+ auto logging = mozilla::MakeScopeExit([&] {
+ js::wasm::ReportSimdAnalysis("scalar-to-simd128 -> constant folded");
+ });
+# endif
+ if (input()->isConstant()) {
+ MConstant* c = input()->toConstant();
+ switch (simdOp()) {
+ case wasm::SimdOp::I8x16Splat:
+ return MWasmFloatConstant::NewSimd128(
+ alloc, SimdConstant::SplatX16(c->toInt32()));
+ case wasm::SimdOp::I16x8Splat:
+ return MWasmFloatConstant::NewSimd128(
+ alloc, SimdConstant::SplatX8(c->toInt32()));
+ case wasm::SimdOp::I32x4Splat:
+ return MWasmFloatConstant::NewSimd128(
+ alloc, SimdConstant::SplatX4(c->toInt32()));
+ case wasm::SimdOp::I64x2Splat:
+ return MWasmFloatConstant::NewSimd128(
+ alloc, SimdConstant::SplatX2(c->toInt64()));
+ default:
+# ifdef DEBUG
+ logging.release();
+# endif
+ return this;
+ }
+ }
+ if (input()->isWasmFloatConstant()) {
+ MWasmFloatConstant* c = input()->toWasmFloatConstant();
+ switch (simdOp()) {
+ case wasm::SimdOp::F32x4Splat:
+ return MWasmFloatConstant::NewSimd128(
+ alloc, SimdConstant::SplatX4(c->toFloat32()));
+ case wasm::SimdOp::F64x2Splat:
+ return MWasmFloatConstant::NewSimd128(
+ alloc, SimdConstant::SplatX2(c->toDouble()));
+ default:
+# ifdef DEBUG
+ logging.release();
+# endif
+ return this;
+ }
+ }
+# ifdef DEBUG
+ logging.release();
+# endif
+ return this;
+}
+
+template <typename T>
+static bool AllTrue(const T& v) {
+ constexpr size_t count = sizeof(T) / sizeof(*v);
+ static_assert(count == 16 || count == 8 || count == 4 || count == 2);
+ bool result = true;
+ for (unsigned i = 0; i < count; i++) {
+ result = result && v[i] != 0;
+ }
+ return result;
+}
+
+template <typename T>
+static int32_t Bitmask(const T& v) {
+ constexpr size_t count = sizeof(T) / sizeof(*v);
+ constexpr size_t shift = 8 * sizeof(*v) - 1;
+ static_assert(shift == 7 || shift == 15 || shift == 31 || shift == 63);
+ int32_t result = 0;
+ for (unsigned i = 0; i < count; i++) {
+ result = result | int32_t(((v[i] >> shift) & 1) << i);
+ }
+ return result;
+}
+
+MDefinition* MWasmReduceSimd128::foldsTo(TempAllocator& alloc) {
+# ifdef DEBUG
+ auto logging = mozilla::MakeScopeExit([&] {
+ js::wasm::ReportSimdAnalysis("simd128-to-scalar -> constant folded");
+ });
+# endif
+ if (input()->isWasmFloatConstant()) {
+ SimdConstant c = input()->toWasmFloatConstant()->toSimd128();
+ int32_t i32Result = 0;
+ switch (simdOp()) {
+ case wasm::SimdOp::V128AnyTrue:
+ i32Result = !c.isZeroBits();
+ break;
+ case wasm::SimdOp::I8x16AllTrue:
+ i32Result = AllTrue(
+ SimdConstant::CreateSimd128((int8_t*)c.bytes()).asInt8x16());
+ break;
+ case wasm::SimdOp::I8x16Bitmask:
+ i32Result = Bitmask(
+ SimdConstant::CreateSimd128((int8_t*)c.bytes()).asInt8x16());
+ break;
+ case wasm::SimdOp::I16x8AllTrue:
+ i32Result = AllTrue(
+ SimdConstant::CreateSimd128((int16_t*)c.bytes()).asInt16x8());
+ break;
+ case wasm::SimdOp::I16x8Bitmask:
+ i32Result = Bitmask(
+ SimdConstant::CreateSimd128((int16_t*)c.bytes()).asInt16x8());
+ break;
+ case wasm::SimdOp::I32x4AllTrue:
+ i32Result = AllTrue(
+ SimdConstant::CreateSimd128((int32_t*)c.bytes()).asInt32x4());
+ break;
+ case wasm::SimdOp::I32x4Bitmask:
+ i32Result = Bitmask(
+ SimdConstant::CreateSimd128((int32_t*)c.bytes()).asInt32x4());
+ break;
+ case wasm::SimdOp::I64x2AllTrue:
+ i32Result = AllTrue(
+ SimdConstant::CreateSimd128((int64_t*)c.bytes()).asInt64x2());
+ break;
+ case wasm::SimdOp::I64x2Bitmask:
+ i32Result = Bitmask(
+ SimdConstant::CreateSimd128((int64_t*)c.bytes()).asInt64x2());
+ break;
+ case wasm::SimdOp::I8x16ExtractLaneS:
+ i32Result =
+ SimdConstant::CreateSimd128((int8_t*)c.bytes()).asInt8x16()[imm()];
+ break;
+ case wasm::SimdOp::I8x16ExtractLaneU:
+ i32Result = int32_t(SimdConstant::CreateSimd128((int8_t*)c.bytes())
+ .asInt8x16()[imm()]) &
+ 0xFF;
+ break;
+ case wasm::SimdOp::I16x8ExtractLaneS:
+ i32Result =
+ SimdConstant::CreateSimd128((int16_t*)c.bytes()).asInt16x8()[imm()];
+ break;
+ case wasm::SimdOp::I16x8ExtractLaneU:
+ i32Result = int32_t(SimdConstant::CreateSimd128((int16_t*)c.bytes())
+ .asInt16x8()[imm()]) &
+ 0xFFFF;
+ break;
+ case wasm::SimdOp::I32x4ExtractLane:
+ i32Result =
+ SimdConstant::CreateSimd128((int32_t*)c.bytes()).asInt32x4()[imm()];
+ break;
+ case wasm::SimdOp::I64x2ExtractLane:
+ return MConstant::NewInt64(
+ alloc, SimdConstant::CreateSimd128((int64_t*)c.bytes())
+ .asInt64x2()[imm()]);
+ case wasm::SimdOp::F32x4ExtractLane:
+ return MWasmFloatConstant::NewFloat32(
+ alloc, SimdConstant::CreateSimd128((float*)c.bytes())
+ .asFloat32x4()[imm()]);
+ case wasm::SimdOp::F64x2ExtractLane:
+ return MWasmFloatConstant::NewDouble(
+ alloc, SimdConstant::CreateSimd128((double*)c.bytes())
+ .asFloat64x2()[imm()]);
+ default:
+# ifdef DEBUG
+ logging.release();
+# endif
+ return this;
+ }
+ return MConstant::New(alloc, Int32Value(i32Result), MIRType::Int32);
+ }
+# ifdef DEBUG
+ logging.release();
+# endif
+ return this;
+}
+#endif // ENABLE_WASM_SIMD
+
+MDefinition::AliasType MLoadDynamicSlot::mightAlias(
+ const MDefinition* def) const {
+ if (def->isStoreDynamicSlot()) {
+ const MStoreDynamicSlot* store = def->toStoreDynamicSlot();
+ if (store->slot() != slot()) {
+ return AliasType::NoAlias;
+ }
+
+ if (store->slots() != slots()) {
+ return AliasType::MayAlias;
+ }
+
+ return AliasType::MustAlias;
+ }
+ return AliasType::MayAlias;
+}
+
+HashNumber MLoadDynamicSlot::valueHash() const {
+ HashNumber hash = MDefinition::valueHash();
+ hash = addU32ToHash(hash, slot_);
+ return hash;
+}
+
+MDefinition* MLoadDynamicSlot::foldsTo(TempAllocator& alloc) {
+ if (MDefinition* def = foldsToStore(alloc)) {
+ return def;
+ }
+
+ return this;
+}
+
+#ifdef JS_JITSPEW
+void MLoadDynamicSlot::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" (slot %u)", slot());
+}
+
+void MLoadDynamicSlotAndUnbox::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" (slot %zu)", slot());
+}
+
+void MStoreDynamicSlot::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" (slot %u)", slot());
+}
+
+void MLoadFixedSlot::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" (slot %zu)", slot());
+}
+
+void MLoadFixedSlotAndUnbox::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" (slot %zu)", slot());
+}
+
+void MStoreFixedSlot::printOpcode(GenericPrinter& out) const {
+ MDefinition::printOpcode(out);
+ out.printf(" (slot %zu)", slot());
+}
+#endif
+
+MDefinition* MGuardFunctionScript::foldsTo(TempAllocator& alloc) {
+ MDefinition* in = input();
+ if (in->isLambda() &&
+ in->toLambda()->templateFunction()->baseScript() == expected()) {
+ return in;
+ }
+ return this;
+}
+
+MDefinition* MFunctionEnvironment::foldsTo(TempAllocator& alloc) {
+ if (input()->isLambda()) {
+ return input()->toLambda()->environmentChain();
+ }
+ if (input()->isFunctionWithProto()) {
+ return input()->toFunctionWithProto()->environmentChain();
+ }
+ return this;
+}
+
+static bool AddIsANonZeroAdditionOf(MAdd* add, MDefinition* ins) {
+ if (add->lhs() != ins && add->rhs() != ins) {
+ return false;
+ }
+ MDefinition* other = (add->lhs() == ins) ? add->rhs() : add->lhs();
+ if (!IsNumberType(other->type())) {
+ return false;
+ }
+ if (!other->isConstant()) {
+ return false;
+ }
+ if (other->toConstant()->numberToDouble() == 0) {
+ return false;
+ }
+ return true;
+}
+
+// Skip over instructions that usually appear between the actual index
+// value being used and the MLoadElement.
+// They don't modify the index value in a meaningful way.
+static MDefinition* SkipUninterestingInstructions(MDefinition* ins) {
+ // Drop the MToNumberInt32 added by the TypePolicy for double and float
+ // values.
+ if (ins->isToNumberInt32()) {
+ return SkipUninterestingInstructions(ins->toToNumberInt32()->input());
+ }
+
+ // Ignore the bounds check, which don't modify the index.
+ if (ins->isBoundsCheck()) {
+ return SkipUninterestingInstructions(ins->toBoundsCheck()->index());
+ }
+
+ // Masking the index for Spectre-mitigation is not observable.
+ if (ins->isSpectreMaskIndex()) {
+ return SkipUninterestingInstructions(ins->toSpectreMaskIndex()->index());
+ }
+
+ return ins;
+}
+
+static bool DefinitelyDifferentValue(MDefinition* ins1, MDefinition* ins2) {
+ ins1 = SkipUninterestingInstructions(ins1);
+ ins2 = SkipUninterestingInstructions(ins2);
+
+ if (ins1 == ins2) {
+ return false;
+ }
+
+ // For constants check they are not equal.
+ if (ins1->isConstant() && ins2->isConstant()) {
+ MConstant* cst1 = ins1->toConstant();
+ MConstant* cst2 = ins2->toConstant();
+
+ if (!cst1->isTypeRepresentableAsDouble() ||
+ !cst2->isTypeRepresentableAsDouble()) {
+ return false;
+ }
+
+ // Be conservative and only allow values that fit into int32.
+ int32_t n1, n2;
+ if (!mozilla::NumberIsInt32(cst1->numberToDouble(), &n1) ||
+ !mozilla::NumberIsInt32(cst2->numberToDouble(), &n2)) {
+ return false;
+ }
+
+ return n1 != n2;
+ }
+
+ // Check if "ins1 = ins2 + cte", which would make both instructions
+ // have different values.
+ if (ins1->isAdd()) {
+ if (AddIsANonZeroAdditionOf(ins1->toAdd(), ins2)) {
+ return true;
+ }
+ }
+ if (ins2->isAdd()) {
+ if (AddIsANonZeroAdditionOf(ins2->toAdd(), ins1)) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+MDefinition::AliasType MLoadElement::mightAlias(const MDefinition* def) const {
+ if (def->isStoreElement()) {
+ const MStoreElement* store = def->toStoreElement();
+ if (store->index() != index()) {
+ if (DefinitelyDifferentValue(store->index(), index())) {
+ return AliasType::NoAlias;
+ }
+ return AliasType::MayAlias;
+ }
+
+ if (store->elements() != elements()) {
+ return AliasType::MayAlias;
+ }
+
+ return AliasType::MustAlias;
+ }
+ return AliasType::MayAlias;
+}
+
+MDefinition* MLoadElement::foldsTo(TempAllocator& alloc) {
+ if (MDefinition* def = foldsToStore(alloc)) {
+ return def;
+ }
+
+ return this;
+}
+
+MDefinition* MWasmUnsignedToDouble::foldsTo(TempAllocator& alloc) {
+ if (input()->isConstant()) {
+ return MConstant::New(
+ alloc, DoubleValue(uint32_t(input()->toConstant()->toInt32())));
+ }
+
+ return this;
+}
+
+MDefinition* MWasmUnsignedToFloat32::foldsTo(TempAllocator& alloc) {
+ if (input()->isConstant()) {
+ double dval = double(uint32_t(input()->toConstant()->toInt32()));
+ if (IsFloat32Representable(dval)) {
+ return MConstant::NewFloat32(alloc, float(dval));
+ }
+ }
+
+ return this;
+}
+
+MWasmCallCatchable* MWasmCallCatchable::New(TempAllocator& alloc,
+ const wasm::CallSiteDesc& desc,
+ const wasm::CalleeDesc& callee,
+ const Args& args,
+ uint32_t stackArgAreaSizeUnaligned,
+ const MWasmCallTryDesc& tryDesc,
+ MDefinition* tableIndexOrRef) {
+ MOZ_ASSERT(tryDesc.inTry);
+
+ MWasmCallCatchable* call = new (alloc) MWasmCallCatchable(
+ desc, callee, stackArgAreaSizeUnaligned, tryDesc.tryNoteIndex);
+
+ call->setSuccessor(FallthroughBranchIndex, tryDesc.fallthroughBlock);
+ call->setSuccessor(PrePadBranchIndex, tryDesc.prePadBlock);
+
+ MOZ_ASSERT_IF(callee.isTable() || callee.isFuncRef(), tableIndexOrRef);
+ if (!call->initWithArgs(alloc, call, args, tableIndexOrRef)) {
+ return nullptr;
+ }
+
+ return call;
+}
+
+MWasmCallUncatchable* MWasmCallUncatchable::New(
+ TempAllocator& alloc, const wasm::CallSiteDesc& desc,
+ const wasm::CalleeDesc& callee, const Args& args,
+ uint32_t stackArgAreaSizeUnaligned, MDefinition* tableIndexOrRef) {
+ MWasmCallUncatchable* call =
+ new (alloc) MWasmCallUncatchable(desc, callee, stackArgAreaSizeUnaligned);
+
+ MOZ_ASSERT_IF(callee.isTable() || callee.isFuncRef(), tableIndexOrRef);
+ if (!call->initWithArgs(alloc, call, args, tableIndexOrRef)) {
+ return nullptr;
+ }
+
+ return call;
+}
+
+MWasmCallUncatchable* MWasmCallUncatchable::NewBuiltinInstanceMethodCall(
+ TempAllocator& alloc, const wasm::CallSiteDesc& desc,
+ const wasm::SymbolicAddress builtin, wasm::FailureMode failureMode,
+ const ABIArg& instanceArg, const Args& args,
+ uint32_t stackArgAreaSizeUnaligned) {
+ auto callee = wasm::CalleeDesc::builtinInstanceMethod(builtin);
+ MWasmCallUncatchable* call = MWasmCallUncatchable::New(
+ alloc, desc, callee, args, stackArgAreaSizeUnaligned, nullptr);
+ if (!call) {
+ return nullptr;
+ }
+
+ MOZ_ASSERT(instanceArg != ABIArg());
+ call->instanceArg_ = instanceArg;
+ call->builtinMethodFailureMode_ = failureMode;
+ return call;
+}
+
+void MSqrt::trySpecializeFloat32(TempAllocator& alloc) {
+ if (EnsureFloatConsumersAndInputOrConvert(this, alloc)) {
+ setResultType(MIRType::Float32);
+ specialization_ = MIRType::Float32;
+ }
+}
+
+MDefinition* MClz::foldsTo(TempAllocator& alloc) {
+ if (num()->isConstant()) {
+ MConstant* c = num()->toConstant();
+ if (type() == MIRType::Int32) {
+ int32_t n = c->toInt32();
+ if (n == 0) {
+ return MConstant::New(alloc, Int32Value(32));
+ }
+ return MConstant::New(alloc,
+ Int32Value(mozilla::CountLeadingZeroes32(n)));
+ }
+ int64_t n = c->toInt64();
+ if (n == 0) {
+ return MConstant::NewInt64(alloc, int64_t(64));
+ }
+ return MConstant::NewInt64(alloc,
+ int64_t(mozilla::CountLeadingZeroes64(n)));
+ }
+
+ return this;
+}
+
+MDefinition* MCtz::foldsTo(TempAllocator& alloc) {
+ if (num()->isConstant()) {
+ MConstant* c = num()->toConstant();
+ if (type() == MIRType::Int32) {
+ int32_t n = num()->toConstant()->toInt32();
+ if (n == 0) {
+ return MConstant::New(alloc, Int32Value(32));
+ }
+ return MConstant::New(alloc,
+ Int32Value(mozilla::CountTrailingZeroes32(n)));
+ }
+ int64_t n = c->toInt64();
+ if (n == 0) {
+ return MConstant::NewInt64(alloc, int64_t(64));
+ }
+ return MConstant::NewInt64(alloc,
+ int64_t(mozilla::CountTrailingZeroes64(n)));
+ }
+
+ return this;
+}
+
+MDefinition* MPopcnt::foldsTo(TempAllocator& alloc) {
+ if (num()->isConstant()) {
+ MConstant* c = num()->toConstant();
+ if (type() == MIRType::Int32) {
+ int32_t n = num()->toConstant()->toInt32();
+ return MConstant::New(alloc, Int32Value(mozilla::CountPopulation32(n)));
+ }
+ int64_t n = c->toInt64();
+ return MConstant::NewInt64(alloc, int64_t(mozilla::CountPopulation64(n)));
+ }
+
+ return this;
+}
+
+MDefinition* MBoundsCheck::foldsTo(TempAllocator& alloc) {
+ if (type() == MIRType::Int32 && index()->isConstant() &&
+ length()->isConstant()) {
+ uint32_t len = length()->toConstant()->toInt32();
+ uint32_t idx = index()->toConstant()->toInt32();
+ if (idx + uint32_t(minimum()) < len && idx + uint32_t(maximum()) < len) {
+ return index();
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MTableSwitch::foldsTo(TempAllocator& alloc) {
+ MDefinition* op = getOperand(0);
+
+ // If we only have one successor, convert to a plain goto to the only
+ // successor. TableSwitch indices are numeric; other types will always go to
+ // the only successor.
+ if (numSuccessors() == 1 ||
+ (op->type() != MIRType::Value && !IsNumberType(op->type()))) {
+ return MGoto::New(alloc, getDefault());
+ }
+
+ if (MConstant* opConst = op->maybeConstantValue()) {
+ if (op->type() == MIRType::Int32) {
+ int32_t i = opConst->toInt32() - low_;
+ MBasicBlock* target;
+ if (size_t(i) < numCases()) {
+ target = getCase(size_t(i));
+ } else {
+ target = getDefault();
+ }
+ MOZ_ASSERT(target);
+ return MGoto::New(alloc, target);
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MArrayJoin::foldsTo(TempAllocator& alloc) {
+ MDefinition* arr = array();
+
+ if (!arr->isStringSplit()) {
+ return this;
+ }
+
+ setRecoveredOnBailout();
+ if (arr->hasLiveDefUses()) {
+ setNotRecoveredOnBailout();
+ return this;
+ }
+
+ // The MStringSplit won't generate any code.
+ arr->setRecoveredOnBailout();
+
+ // We're replacing foo.split(bar).join(baz) by
+ // foo.replace(bar, baz). MStringSplit could be recovered by
+ // a bailout. As we are removing its last use, and its result
+ // could be captured by a resume point, this MStringSplit will
+ // be executed on the bailout path.
+ MDefinition* string = arr->toStringSplit()->string();
+ MDefinition* pattern = arr->toStringSplit()->separator();
+ MDefinition* replacement = sep();
+
+ MStringReplace* substr =
+ MStringReplace::New(alloc, string, pattern, replacement);
+ substr->setFlatReplacement();
+ return substr;
+}
+
+MDefinition* MGetFirstDollarIndex::foldsTo(TempAllocator& alloc) {
+ MDefinition* strArg = str();
+ if (!strArg->isConstant()) {
+ return this;
+ }
+
+ JSLinearString* str = &strArg->toConstant()->toString()->asLinear();
+ int32_t index = GetFirstDollarIndexRawFlat(str);
+ return MConstant::New(alloc, Int32Value(index));
+}
+
+AliasSet MThrowRuntimeLexicalError::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ExceptionState);
+}
+
+AliasSet MSlots::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+MDefinition::AliasType MSlots::mightAlias(const MDefinition* store) const {
+ // ArrayPush only modifies object elements, but not object slots.
+ if (store->isArrayPush()) {
+ return AliasType::NoAlias;
+ }
+ return MInstruction::mightAlias(store);
+}
+
+AliasSet MElements::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MInitializedLength::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MSetInitializedLength::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ObjectFields);
+}
+
+AliasSet MArrayLength::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MSetArrayLength::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ObjectFields);
+}
+
+AliasSet MFunctionLength::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot);
+}
+
+AliasSet MFunctionName::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot);
+}
+
+AliasSet MArrayBufferByteLength::getAliasSet() const {
+ return AliasSet::Load(AliasSet::FixedSlot);
+}
+
+AliasSet MArrayBufferViewLength::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ArrayBufferViewLengthOrOffset);
+}
+
+AliasSet MArrayBufferViewByteOffset::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ArrayBufferViewLengthOrOffset);
+}
+
+AliasSet MArrayBufferViewElements::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MGuardHasAttachedArrayBuffer::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot);
+}
+
+AliasSet MArrayPush::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ObjectFields | AliasSet::Element);
+}
+
+MDefinition* MGuardNumberToIntPtrIndex::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = this->input();
+
+ if (input->isToDouble() && input->getOperand(0)->type() == MIRType::Int32) {
+ return MInt32ToIntPtr::New(alloc, input->getOperand(0));
+ }
+
+ if (!input->isConstant()) {
+ return this;
+ }
+
+ // Fold constant double representable as intptr to intptr.
+ int64_t ival;
+ if (!mozilla::NumberEqualsInt64(input->toConstant()->toDouble(), &ival)) {
+ // If not representable as an int64, this access is equal to an OOB access.
+ // So replace it with a known int64/intptr value which also produces an OOB
+ // access. If we don't support OOB accesses we have to bail out.
+ if (!supportOOB()) {
+ return this;
+ }
+ ival = -1;
+ }
+
+ if (ival < INTPTR_MIN || ival > INTPTR_MAX) {
+ return this;
+ }
+
+ return MConstant::NewIntPtr(alloc, intptr_t(ival));
+}
+
+MDefinition* MIsObject::foldsTo(TempAllocator& alloc) {
+ if (!object()->isBox()) {
+ return this;
+ }
+
+ MDefinition* unboxed = object()->getOperand(0);
+ if (unboxed->type() == MIRType::Object) {
+ return MConstant::New(alloc, BooleanValue(true));
+ }
+
+ return this;
+}
+
+MDefinition* MIsNullOrUndefined::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = value();
+ if (input->isBox()) {
+ input = input->toBox()->input();
+ }
+
+ if (input->definitelyType({MIRType::Null, MIRType::Undefined})) {
+ return MConstant::New(alloc, BooleanValue(true));
+ }
+
+ if (!input->mightBeType(MIRType::Null) &&
+ !input->mightBeType(MIRType::Undefined)) {
+ return MConstant::New(alloc, BooleanValue(false));
+ }
+
+ return this;
+}
+
+AliasSet MHomeObjectSuperBase::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+MDefinition* MGuardValue::foldsTo(TempAllocator& alloc) {
+ if (MConstant* cst = value()->maybeConstantValue()) {
+ if (cst->toJSValue() == expected()) {
+ return value();
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MGuardNullOrUndefined::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = value();
+ if (input->isBox()) {
+ input = input->toBox()->input();
+ }
+
+ if (input->definitelyType({MIRType::Null, MIRType::Undefined})) {
+ return value();
+ }
+
+ return this;
+}
+
+MDefinition* MGuardIsNotObject::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = value();
+ if (input->isBox()) {
+ input = input->toBox()->input();
+ }
+
+ if (!input->mightBeType(MIRType::Object)) {
+ return value();
+ }
+
+ return this;
+}
+
+MDefinition* MGuardObjectIdentity::foldsTo(TempAllocator& alloc) {
+ if (object()->isConstant() && expected()->isConstant()) {
+ JSObject* obj = &object()->toConstant()->toObject();
+ JSObject* other = &expected()->toConstant()->toObject();
+ if (!bailOnEquality()) {
+ if (obj == other) {
+ return object();
+ }
+ } else {
+ if (obj != other) {
+ return object();
+ }
+ }
+ }
+
+ if (!bailOnEquality() && object()->isNurseryObject() &&
+ expected()->isNurseryObject()) {
+ uint32_t objIndex = object()->toNurseryObject()->nurseryIndex();
+ uint32_t otherIndex = expected()->toNurseryObject()->nurseryIndex();
+ if (objIndex == otherIndex) {
+ return object();
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MGuardSpecificFunction::foldsTo(TempAllocator& alloc) {
+ if (function()->isConstant() && expected()->isConstant()) {
+ JSObject* fun = &function()->toConstant()->toObject();
+ JSObject* other = &expected()->toConstant()->toObject();
+ if (fun == other) {
+ return function();
+ }
+ }
+
+ if (function()->isNurseryObject() && expected()->isNurseryObject()) {
+ uint32_t funIndex = function()->toNurseryObject()->nurseryIndex();
+ uint32_t otherIndex = expected()->toNurseryObject()->nurseryIndex();
+ if (funIndex == otherIndex) {
+ return function();
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MGuardSpecificAtom::foldsTo(TempAllocator& alloc) {
+ if (str()->isConstant()) {
+ JSString* s = str()->toConstant()->toString();
+ if (s->isAtom()) {
+ JSAtom* cstAtom = &s->asAtom();
+ if (cstAtom == atom()) {
+ return str();
+ }
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MGuardSpecificSymbol::foldsTo(TempAllocator& alloc) {
+ if (symbol()->isConstant()) {
+ if (symbol()->toConstant()->toSymbol() == expected()) {
+ return symbol();
+ }
+ }
+
+ return this;
+}
+
+MDefinition* MGuardSpecificInt32::foldsTo(TempAllocator& alloc) {
+ if (num()->isConstant() && num()->toConstant()->isInt32(expected())) {
+ return num();
+ }
+ return this;
+}
+
+bool MCallBindVar::congruentTo(const MDefinition* ins) const {
+ if (!ins->isCallBindVar()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+bool MGuardShape::congruentTo(const MDefinition* ins) const {
+ if (!ins->isGuardShape()) {
+ return false;
+ }
+ if (shape() != ins->toGuardShape()->shape()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MGuardShape::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+MDefinition::AliasType MGuardShape::mightAlias(const MDefinition* store) const {
+ // These instructions only modify object elements, but not the shape.
+ if (store->isStoreElementHole() || store->isArrayPush()) {
+ return AliasType::NoAlias;
+ }
+ if (object()->isConstantProto()) {
+ const MDefinition* receiverObject =
+ object()->toConstantProto()->getReceiverObject();
+ switch (store->op()) {
+ case MDefinition::Opcode::StoreFixedSlot:
+ if (store->toStoreFixedSlot()->object()->skipObjectGuards() ==
+ receiverObject) {
+ return AliasType::NoAlias;
+ }
+ break;
+ case MDefinition::Opcode::StoreDynamicSlot:
+ if (store->toStoreDynamicSlot()
+ ->slots()
+ ->toSlots()
+ ->object()
+ ->skipObjectGuards() == receiverObject) {
+ return AliasType::NoAlias;
+ }
+ break;
+ case MDefinition::Opcode::AddAndStoreSlot:
+ if (store->toAddAndStoreSlot()->object()->skipObjectGuards() ==
+ receiverObject) {
+ return AliasType::NoAlias;
+ }
+ break;
+ case MDefinition::Opcode::AllocateAndStoreSlot:
+ if (store->toAllocateAndStoreSlot()->object()->skipObjectGuards() ==
+ receiverObject) {
+ return AliasType::NoAlias;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ return MInstruction::mightAlias(store);
+}
+
+AliasSet MGuardMultipleShapes::getAliasSet() const {
+ // Note: This instruction loads the elements of the ListObject used to
+ // store the list of shapes, but that object is internal and not exposed
+ // to script, so it doesn't have to be in the alias set.
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MGuardGlobalGeneration::getAliasSet() const {
+ return AliasSet::Load(AliasSet::GlobalGenerationCounter);
+}
+
+bool MGuardGlobalGeneration::congruentTo(const MDefinition* ins) const {
+ return ins->isGuardGlobalGeneration() &&
+ ins->toGuardGlobalGeneration()->expected() == expected() &&
+ ins->toGuardGlobalGeneration()->generationAddr() == generationAddr();
+}
+
+MDefinition* MGuardIsNotProxy::foldsTo(TempAllocator& alloc) {
+ KnownClass known = GetObjectKnownClass(object());
+ if (known == KnownClass::None) {
+ return this;
+ }
+
+ MOZ_ASSERT(!GetObjectKnownJSClass(object())->isProxyObject());
+ AssertKnownClass(alloc, this, object());
+ return object();
+}
+
+AliasSet MMegamorphicLoadSlotByValue::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot);
+}
+
+MDefinition* MMegamorphicLoadSlotByValue::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = idVal();
+ if (input->isBox()) {
+ input = input->toBox()->input();
+ }
+
+ MDefinition* result = this;
+
+ if (input->isConstant()) {
+ MConstant* constant = input->toConstant();
+ if (constant->type() == MIRType::Symbol) {
+ PropertyKey id = PropertyKey::Symbol(constant->toSymbol());
+ result = MMegamorphicLoadSlot::New(alloc, object(), id);
+ }
+
+ if (constant->type() == MIRType::String) {
+ JSString* str = constant->toString();
+ if (str->isAtom() && !str->asAtom().isIndex()) {
+ PropertyKey id = PropertyKey::NonIntAtom(str);
+ result = MMegamorphicLoadSlot::New(alloc, object(), id);
+ }
+ }
+ }
+
+ if (result != this) {
+ result->setDependency(dependency());
+ }
+
+ return result;
+}
+
+bool MMegamorphicLoadSlot::congruentTo(const MDefinition* ins) const {
+ if (!ins->isMegamorphicLoadSlot()) {
+ return false;
+ }
+ if (ins->toMegamorphicLoadSlot()->name() != name()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MMegamorphicLoadSlot::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot);
+}
+
+bool MMegamorphicHasProp::congruentTo(const MDefinition* ins) const {
+ if (!ins->isMegamorphicHasProp()) {
+ return false;
+ }
+ if (ins->toMegamorphicHasProp()->hasOwn() != hasOwn()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MMegamorphicHasProp::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot);
+}
+
+bool MNurseryObject::congruentTo(const MDefinition* ins) const {
+ if (!ins->isNurseryObject()) {
+ return false;
+ }
+ return nurseryIndex() == ins->toNurseryObject()->nurseryIndex();
+}
+
+AliasSet MGuardFunctionIsNonBuiltinCtor::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+bool MGuardFunctionKind::congruentTo(const MDefinition* ins) const {
+ if (!ins->isGuardFunctionKind()) {
+ return false;
+ }
+ if (expected() != ins->toGuardFunctionKind()->expected()) {
+ return false;
+ }
+ if (bailOnEquality() != ins->toGuardFunctionKind()->bailOnEquality()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MGuardFunctionKind::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+bool MGuardFunctionScript::congruentTo(const MDefinition* ins) const {
+ if (!ins->isGuardFunctionScript()) {
+ return false;
+ }
+ if (expected() != ins->toGuardFunctionScript()->expected()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MGuardFunctionScript::getAliasSet() const {
+ // A JSFunction's BaseScript pointer is immutable. Relazification of
+ // self-hosted functions is an exception to this, but we don't use this
+ // guard for self-hosted functions.
+ MOZ_ASSERT(!flags_.isSelfHostedOrIntrinsic());
+ return AliasSet::None();
+}
+
+bool MGuardSpecificAtom::congruentTo(const MDefinition* ins) const {
+ if (!ins->isGuardSpecificAtom()) {
+ return false;
+ }
+ if (atom() != ins->toGuardSpecificAtom()->atom()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+MDefinition* MGuardStringToIndex::foldsTo(TempAllocator& alloc) {
+ if (!string()->isConstant()) {
+ return this;
+ }
+
+ JSString* str = string()->toConstant()->toString();
+
+ int32_t index = GetIndexFromString(str);
+ if (index < 0) {
+ return this;
+ }
+
+ return MConstant::New(alloc, Int32Value(index));
+}
+
+MDefinition* MGuardStringToInt32::foldsTo(TempAllocator& alloc) {
+ if (!string()->isConstant()) {
+ return this;
+ }
+
+ JSLinearString* str = &string()->toConstant()->toString()->asLinear();
+ double number = LinearStringToNumber(str);
+
+ int32_t n;
+ if (!mozilla::NumberIsInt32(number, &n)) {
+ return this;
+ }
+
+ return MConstant::New(alloc, Int32Value(n));
+}
+
+MDefinition* MGuardStringToDouble::foldsTo(TempAllocator& alloc) {
+ if (!string()->isConstant()) {
+ return this;
+ }
+
+ JSLinearString* str = &string()->toConstant()->toString()->asLinear();
+ double number = LinearStringToNumber(str);
+ return MConstant::New(alloc, DoubleValue(number));
+}
+
+AliasSet MGuardNoDenseElements::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MIteratorHasIndices::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MAllocateAndStoreSlot::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ObjectFields | AliasSet::DynamicSlot);
+}
+
+AliasSet MLoadDOMExpandoValue::getAliasSet() const {
+ return AliasSet::Load(AliasSet::DOMProxyExpando);
+}
+
+AliasSet MLoadDOMExpandoValueIgnoreGeneration::getAliasSet() const {
+ return AliasSet::Load(AliasSet::DOMProxyExpando);
+}
+
+bool MGuardDOMExpandoMissingOrGuardShape::congruentTo(
+ const MDefinition* ins) const {
+ if (!ins->isGuardDOMExpandoMissingOrGuardShape()) {
+ return false;
+ }
+ if (shape() != ins->toGuardDOMExpandoMissingOrGuardShape()->shape()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MGuardDOMExpandoMissingOrGuardShape::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+MDefinition* MGuardToClass::foldsTo(TempAllocator& alloc) {
+ const JSClass* clasp = GetObjectKnownJSClass(object());
+ if (!clasp || getClass() != clasp) {
+ return this;
+ }
+
+ AssertKnownClass(alloc, this, object());
+ return object();
+}
+
+MDefinition* MGuardToFunction::foldsTo(TempAllocator& alloc) {
+ if (GetObjectKnownClass(object()) != KnownClass::Function) {
+ return this;
+ }
+
+ AssertKnownClass(alloc, this, object());
+ return object();
+}
+
+MDefinition* MHasClass::foldsTo(TempAllocator& alloc) {
+ const JSClass* clasp = GetObjectKnownJSClass(object());
+ if (!clasp) {
+ return this;
+ }
+
+ AssertKnownClass(alloc, this, object());
+ return MConstant::New(alloc, BooleanValue(getClass() == clasp));
+}
+
+MDefinition* MIsCallable::foldsTo(TempAllocator& alloc) {
+ if (input()->type() != MIRType::Object) {
+ return this;
+ }
+
+ KnownClass known = GetObjectKnownClass(input());
+ if (known == KnownClass::None) {
+ return this;
+ }
+
+ AssertKnownClass(alloc, this, input());
+ return MConstant::New(alloc, BooleanValue(known == KnownClass::Function));
+}
+
+MDefinition* MIsArray::foldsTo(TempAllocator& alloc) {
+ if (input()->type() != MIRType::Object) {
+ return this;
+ }
+
+ KnownClass known = GetObjectKnownClass(input());
+ if (known == KnownClass::None) {
+ return this;
+ }
+
+ AssertKnownClass(alloc, this, input());
+ return MConstant::New(alloc, BooleanValue(known == KnownClass::Array));
+}
+
+AliasSet MObjectClassToString::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot);
+}
+
+MDefinition* MGuardIsNotArrayBufferMaybeShared::foldsTo(TempAllocator& alloc) {
+ switch (GetObjectKnownClass(object())) {
+ case KnownClass::PlainObject:
+ case KnownClass::Array:
+ case KnownClass::Function:
+ case KnownClass::RegExp:
+ case KnownClass::ArrayIterator:
+ case KnownClass::StringIterator:
+ case KnownClass::RegExpStringIterator: {
+ AssertKnownClass(alloc, this, object());
+ return object();
+ }
+ case KnownClass::None:
+ break;
+ }
+
+ return this;
+}
+
+MDefinition* MCheckIsObj::foldsTo(TempAllocator& alloc) {
+ if (!input()->isBox()) {
+ return this;
+ }
+
+ MDefinition* unboxed = input()->getOperand(0);
+ if (unboxed->type() == MIRType::Object) {
+ return unboxed;
+ }
+
+ return this;
+}
+
+static bool IsBoxedObject(MDefinition* def) {
+ MOZ_ASSERT(def->type() == MIRType::Value);
+
+ if (def->isBox()) {
+ return def->toBox()->input()->type() == MIRType::Object;
+ }
+
+ // Construct calls are always returning a boxed object.
+ //
+ // TODO: We should consider encoding this directly in the graph instead of
+ // having to special case it here.
+ if (def->isCall()) {
+ return def->toCall()->isConstructing();
+ }
+ if (def->isConstructArray()) {
+ return true;
+ }
+ if (def->isConstructArgs()) {
+ return true;
+ }
+
+ return false;
+}
+
+MDefinition* MCheckReturn::foldsTo(TempAllocator& alloc) {
+ auto* returnVal = returnValue();
+ if (!returnVal->isBox()) {
+ return this;
+ }
+
+ auto* unboxedReturnVal = returnVal->toBox()->input();
+ if (unboxedReturnVal->type() == MIRType::Object) {
+ return returnVal;
+ }
+
+ if (unboxedReturnVal->type() != MIRType::Undefined) {
+ return this;
+ }
+
+ auto* thisVal = thisValue();
+ if (IsBoxedObject(thisVal)) {
+ return thisVal;
+ }
+
+ return this;
+}
+
+MDefinition* MCheckThis::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = thisValue();
+ if (!input->isBox()) {
+ return this;
+ }
+
+ MDefinition* unboxed = input->getOperand(0);
+ if (unboxed->mightBeMagicType()) {
+ return this;
+ }
+
+ return input;
+}
+
+MDefinition* MCheckThisReinit::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = thisValue();
+ if (!input->isBox()) {
+ return this;
+ }
+
+ MDefinition* unboxed = input->getOperand(0);
+ if (unboxed->type() != MIRType::MagicUninitializedLexical) {
+ return this;
+ }
+
+ return input;
+}
+
+MDefinition* MCheckObjCoercible::foldsTo(TempAllocator& alloc) {
+ MDefinition* input = checkValue();
+ if (!input->isBox()) {
+ return this;
+ }
+
+ MDefinition* unboxed = input->getOperand(0);
+ if (unboxed->mightBeType(MIRType::Null) ||
+ unboxed->mightBeType(MIRType::Undefined)) {
+ return this;
+ }
+
+ return input;
+}
+
+AliasSet MCheckObjCoercible::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ExceptionState);
+}
+
+AliasSet MCheckReturn::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ExceptionState);
+}
+
+AliasSet MCheckThis::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ExceptionState);
+}
+
+AliasSet MCheckThisReinit::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ExceptionState);
+}
+
+AliasSet MIsPackedArray::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MGuardArrayIsPacked::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MSuperFunction::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MInitHomeObject::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ObjectFields);
+}
+
+AliasSet MLoadWrapperTarget::getAliasSet() const {
+ return AliasSet::Load(AliasSet::Any);
+}
+
+AliasSet MGuardHasGetterSetter::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+bool MGuardHasGetterSetter::congruentTo(const MDefinition* ins) const {
+ if (!ins->isGuardHasGetterSetter()) {
+ return false;
+ }
+ if (ins->toGuardHasGetterSetter()->propId() != propId()) {
+ return false;
+ }
+ if (ins->toGuardHasGetterSetter()->getterSetter() != getterSetter()) {
+ return false;
+ }
+ return congruentIfOperandsEqual(ins);
+}
+
+AliasSet MGuardIsExtensible::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MGuardIndexIsNotDenseElement::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::Element);
+}
+
+AliasSet MGuardIndexIsValidUpdateOrAdd::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields);
+}
+
+AliasSet MCallObjectHasSparseElement::getAliasSet() const {
+ return AliasSet::Load(AliasSet::Element | AliasSet::ObjectFields |
+ AliasSet::FixedSlot | AliasSet::DynamicSlot);
+}
+
+AliasSet MLoadSlotByIteratorIndex::getAliasSet() const {
+ return AliasSet::Load(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot | AliasSet::Element);
+}
+
+AliasSet MStoreSlotByIteratorIndex::getAliasSet() const {
+ return AliasSet::Store(AliasSet::ObjectFields | AliasSet::FixedSlot |
+ AliasSet::DynamicSlot | AliasSet::Element);
+}
+
+MDefinition* MGuardInt32IsNonNegative::foldsTo(TempAllocator& alloc) {
+ MOZ_ASSERT(index()->type() == MIRType::Int32);
+
+ MDefinition* input = index();
+ if (!input->isConstant() || input->toConstant()->toInt32() < 0) {
+ return this;
+ }
+ return input;
+}
+
+MDefinition* MGuardInt32Range::foldsTo(TempAllocator& alloc) {
+ MOZ_ASSERT(input()->type() == MIRType::Int32);
+ MOZ_ASSERT(minimum() <= maximum());
+
+ MDefinition* in = input();
+ if (!in->isConstant()) {
+ return this;
+ }
+ int32_t cst = in->toConstant()->toInt32();
+ if (cst < minimum() || cst > maximum()) {
+ return this;
+ }
+ return in;
+}
+
+MDefinition* MGuardNonGCThing::foldsTo(TempAllocator& alloc) {
+ if (!input()->isBox()) {
+ return this;
+ }
+
+ MDefinition* unboxed = input()->getOperand(0);
+ if (!IsNonGCThing(unboxed->type())) {
+ return this;
+ }
+ return input();
+}
+
+AliasSet MSetObjectHasNonBigInt::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MSetObjectHasBigInt::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MSetObjectHasValue::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MSetObjectHasValueVMCall::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MSetObjectSize::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectHasNonBigInt::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectHasBigInt::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectHasValue::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectHasValueVMCall::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectGetNonBigInt::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectGetBigInt::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectGetValue::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectGetValueVMCall::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+AliasSet MMapObjectSize::getAliasSet() const {
+ return AliasSet::Load(AliasSet::MapOrSetHashTable);
+}
+
+MIonToWasmCall* MIonToWasmCall::New(TempAllocator& alloc,
+ WasmInstanceObject* instanceObj,
+ const wasm::FuncExport& funcExport) {
+ const wasm::FuncType& funcType =
+ instanceObj->instance().metadata().getFuncExportType(funcExport);
+ const wasm::ValTypeVector& results = funcType.results();
+ MIRType resultType = MIRType::Value;
+ // At the JS boundary some wasm types must be represented as a Value, and in
+ // addition a void return requires an Undefined value.
+ if (results.length() > 0 && !results[0].isEncodedAsJSValueOnEscape()) {
+ MOZ_ASSERT(results.length() == 1,
+ "multiple returns not implemented for inlined Wasm calls");
+ resultType = results[0].toMIRType();
+ }
+
+ auto* ins = new (alloc) MIonToWasmCall(instanceObj, resultType, funcExport);
+ if (!ins->init(alloc, funcType.args().length())) {
+ return nullptr;
+ }
+ return ins;
+}
+
+MBindFunction* MBindFunction::New(TempAllocator& alloc, MDefinition* target,
+ uint32_t argc, JSObject* templateObj) {
+ auto* ins = new (alloc) MBindFunction(templateObj);
+ if (!ins->init(alloc, NumNonArgumentOperands + argc)) {
+ return nullptr;
+ }
+ ins->initOperand(0, target);
+ return ins;
+}
+
+#ifdef DEBUG
+bool MIonToWasmCall::isConsistentFloat32Use(MUse* use) const {
+ const wasm::FuncType& funcType =
+ instance()->metadata().getFuncExportType(funcExport_);
+ return funcType.args()[use->index()].kind() == wasm::ValType::F32;
+}
+#endif
+
+MCreateInlinedArgumentsObject* MCreateInlinedArgumentsObject::New(
+ TempAllocator& alloc, MDefinition* callObj, MDefinition* callee,
+ MDefinitionVector& args, ArgumentsObject* templateObj) {
+ MCreateInlinedArgumentsObject* ins =
+ new (alloc) MCreateInlinedArgumentsObject(templateObj);
+
+ uint32_t argc = args.length();
+ MOZ_ASSERT(argc <= ArgumentsObject::MaxInlinedArgs);
+
+ if (!ins->init(alloc, argc + NumNonArgumentOperands)) {
+ return nullptr;
+ }
+
+ ins->initOperand(0, callObj);
+ ins->initOperand(1, callee);
+ for (uint32_t i = 0; i < argc; i++) {
+ ins->initOperand(i + NumNonArgumentOperands, args[i]);
+ }
+
+ return ins;
+}
+
+MGetInlinedArgument* MGetInlinedArgument::New(
+ TempAllocator& alloc, MDefinition* index,
+ MCreateInlinedArgumentsObject* args) {
+ MGetInlinedArgument* ins = new (alloc) MGetInlinedArgument();
+
+ uint32_t argc = args->numActuals();
+ MOZ_ASSERT(argc <= ArgumentsObject::MaxInlinedArgs);
+
+ if (!ins->init(alloc, argc + NumNonArgumentOperands)) {
+ return nullptr;
+ }
+
+ ins->initOperand(0, index);
+ for (uint32_t i = 0; i < argc; i++) {
+ ins->initOperand(i + NumNonArgumentOperands, args->getArg(i));
+ }
+
+ return ins;
+}
+
+MGetInlinedArgument* MGetInlinedArgument::New(TempAllocator& alloc,
+ MDefinition* index,
+ const CallInfo& callInfo) {
+ MGetInlinedArgument* ins = new (alloc) MGetInlinedArgument();
+
+ uint32_t argc = callInfo.argc();
+ MOZ_ASSERT(argc <= ArgumentsObject::MaxInlinedArgs);
+
+ if (!ins->init(alloc, argc + NumNonArgumentOperands)) {
+ return nullptr;
+ }
+
+ ins->initOperand(0, index);
+ for (uint32_t i = 0; i < argc; i++) {
+ ins->initOperand(i + NumNonArgumentOperands, callInfo.getArg(i));
+ }
+
+ return ins;
+}
+
+MDefinition* MGetInlinedArgument::foldsTo(TempAllocator& alloc) {
+ MDefinition* indexDef = SkipUninterestingInstructions(index());
+ if (!indexDef->isConstant() || indexDef->type() != MIRType::Int32) {
+ return this;
+ }
+
+ int32_t indexConst = indexDef->toConstant()->toInt32();
+ if (indexConst < 0 || uint32_t(indexConst) >= numActuals()) {
+ return this;
+ }
+
+ MDefinition* arg = getArg(indexConst);
+ if (arg->type() != MIRType::Value) {
+ arg = MBox::New(alloc, arg);
+ }
+
+ return arg;
+}
+
+MGetInlinedArgumentHole* MGetInlinedArgumentHole::New(
+ TempAllocator& alloc, MDefinition* index,
+ MCreateInlinedArgumentsObject* args) {
+ auto* ins = new (alloc) MGetInlinedArgumentHole();
+
+ uint32_t argc = args->numActuals();
+ MOZ_ASSERT(argc <= ArgumentsObject::MaxInlinedArgs);
+
+ if (!ins->init(alloc, argc + NumNonArgumentOperands)) {
+ return nullptr;
+ }
+
+ ins->initOperand(0, index);
+ for (uint32_t i = 0; i < argc; i++) {
+ ins->initOperand(i + NumNonArgumentOperands, args->getArg(i));
+ }
+
+ return ins;
+}
+
+MDefinition* MGetInlinedArgumentHole::foldsTo(TempAllocator& alloc) {
+ MDefinition* indexDef = SkipUninterestingInstructions(index());
+ if (!indexDef->isConstant() || indexDef->type() != MIRType::Int32) {
+ return this;
+ }
+
+ int32_t indexConst = indexDef->toConstant()->toInt32();
+ if (indexConst < 0) {
+ return this;
+ }
+
+ MDefinition* arg;
+ if (uint32_t(indexConst) < numActuals()) {
+ arg = getArg(indexConst);
+
+ if (arg->type() != MIRType::Value) {
+ arg = MBox::New(alloc, arg);
+ }
+ } else {
+ auto* undefined = MConstant::New(alloc, UndefinedValue());
+ block()->insertBefore(this, undefined);
+
+ arg = MBox::New(alloc, undefined);
+ }
+
+ return arg;
+}
+
+MInlineArgumentsSlice* MInlineArgumentsSlice::New(
+ TempAllocator& alloc, MDefinition* begin, MDefinition* count,
+ MCreateInlinedArgumentsObject* args, JSObject* templateObj,
+ gc::Heap initialHeap) {
+ auto* ins = new (alloc) MInlineArgumentsSlice(templateObj, initialHeap);
+
+ uint32_t argc = args->numActuals();
+ MOZ_ASSERT(argc <= ArgumentsObject::MaxInlinedArgs);
+
+ if (!ins->init(alloc, argc + NumNonArgumentOperands)) {
+ return nullptr;
+ }
+
+ ins->initOperand(0, begin);
+ ins->initOperand(1, count);
+ for (uint32_t i = 0; i < argc; i++) {
+ ins->initOperand(i + NumNonArgumentOperands, args->getArg(i));
+ }
+
+ return ins;
+}
+
+MDefinition* MNormalizeSliceTerm::foldsTo(TempAllocator& alloc) {
+ auto* length = this->length();
+ if (!length->isConstant() && !length->isArgumentsLength()) {
+ return this;
+ }
+
+ if (length->isConstant()) {
+ int32_t lengthConst = length->toConstant()->toInt32();
+ MOZ_ASSERT(lengthConst >= 0);
+
+ // Result is always zero when |length| is zero.
+ if (lengthConst == 0) {
+ return length;
+ }
+
+ auto* value = this->value();
+ if (value->isConstant()) {
+ int32_t valueConst = value->toConstant()->toInt32();
+
+ int32_t normalized;
+ if (valueConst < 0) {
+ normalized = std::max(valueConst + lengthConst, 0);
+ } else {
+ normalized = std::min(valueConst, lengthConst);
+ }
+
+ if (normalized == valueConst) {
+ return value;
+ }
+ if (normalized == lengthConst) {
+ return length;
+ }
+ return MConstant::New(alloc, Int32Value(normalized));
+ }
+
+ return this;
+ }
+
+ auto* value = this->value();
+ if (value->isConstant()) {
+ int32_t valueConst = value->toConstant()->toInt32();
+
+ // Minimum of |value| and |length|.
+ if (valueConst > 0) {
+ bool isMax = false;
+ return MMinMax::New(alloc, value, length, MIRType::Int32, isMax);
+ }
+
+ // Maximum of |value + length| and zero.
+ if (valueConst < 0) {
+ // Safe to truncate because |length| is never negative.
+ auto* add = MAdd::New(alloc, value, length, TruncateKind::Truncate);
+ block()->insertBefore(this, add);
+
+ auto* zero = MConstant::New(alloc, Int32Value(0));
+ block()->insertBefore(this, zero);
+
+ bool isMax = true;
+ return MMinMax::New(alloc, add, zero, MIRType::Int32, isMax);
+ }
+
+ // Directly return the value when it's zero.
+ return value;
+ }
+
+ // Normalizing MArgumentsLength is a no-op.
+ if (value->isArgumentsLength()) {
+ return value;
+ }
+
+ return this;
+}
+
+bool MWasmShiftSimd128::congruentTo(const MDefinition* ins) const {
+ return ins->toWasmShiftSimd128()->simdOp() == simdOp_ &&
+ congruentIfOperandsEqual(ins);
+}
+
+bool MWasmShuffleSimd128::congruentTo(const MDefinition* ins) const {
+ return ins->toWasmShuffleSimd128()->shuffle().equals(&shuffle_) &&
+ congruentIfOperandsEqual(ins);
+}
+
+bool MWasmUnarySimd128::congruentTo(const MDefinition* ins) const {
+ return ins->toWasmUnarySimd128()->simdOp() == simdOp_ &&
+ congruentIfOperandsEqual(ins);
+}
+
+#ifdef ENABLE_WASM_SIMD
+MWasmShuffleSimd128* jit::BuildWasmShuffleSimd128(TempAllocator& alloc,
+ const int8_t* control,
+ MDefinition* lhs,
+ MDefinition* rhs) {
+ SimdShuffle s =
+ AnalyzeSimdShuffle(SimdConstant::CreateX16(control), lhs, rhs);
+ switch (s.opd) {
+ case SimdShuffle::Operand::LEFT:
+ // When SimdShuffle::Operand is LEFT the right operand is not used,
+ // lose reference to rhs.
+ rhs = lhs;
+ break;
+ case SimdShuffle::Operand::RIGHT:
+ // When SimdShuffle::Operand is RIGHT the left operand is not used,
+ // lose reference to lhs.
+ lhs = rhs;
+ break;
+ default:
+ break;
+ }
+ return MWasmShuffleSimd128::New(alloc, lhs, rhs, s);
+}
+#endif // ENABLE_WASM_SIMD
+
+static MDefinition* FoldTrivialWasmCasts(TempAllocator& alloc,
+ wasm::RefType sourceType,
+ wasm::RefType destType) {
+ // Upcasts are trivially valid.
+ if (wasm::RefType::isSubTypeOf(sourceType, destType)) {
+ return MConstant::New(alloc, Int32Value(1), MIRType::Int32);
+ }
+
+ // If two types are completely disjoint, then all casts between them are
+ // impossible.
+ if (!wasm::RefType::castPossible(destType, sourceType)) {
+ return MConstant::New(alloc, Int32Value(0), MIRType::Int32);
+ }
+
+ return nullptr;
+}
+
+MDefinition* MWasmGcObjectIsSubtypeOfAbstract::foldsTo(TempAllocator& alloc) {
+ MDefinition* folded = FoldTrivialWasmCasts(alloc, sourceType(), destType());
+ if (folded) {
+ return folded;
+ }
+ return this;
+}
+
+MDefinition* MWasmGcObjectIsSubtypeOfConcrete::foldsTo(TempAllocator& alloc) {
+ MDefinition* folded = FoldTrivialWasmCasts(alloc, sourceType(), destType());
+ if (folded) {
+ return folded;
+ }
+ return this;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-04 13:45:43 +0000