summaryrefslogtreecommitdiffstats
path: root/js/src/jit/x64/Lowering-x64.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'js/src/jit/x64/Lowering-x64.cpp')
-rw-r--r--js/src/jit/x64/Lowering-x64.cpp495
1 files changed, 495 insertions, 0 deletions
diff --git a/js/src/jit/x64/Lowering-x64.cpp b/js/src/jit/x64/Lowering-x64.cpp
new file mode 100644
index 000000000..70801dc05
--- /dev/null
+++ b/js/src/jit/x64/Lowering-x64.cpp
@@ -0,0 +1,495 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/x64/Lowering-x64.h"
+
+#include "jit/MIR.h"
+#include "jit/x64/Assembler-x64.h"
+
+#include "jit/shared/Lowering-shared-inl.h"
+
+using namespace js;
+using namespace js::jit;
+
+LBoxAllocation
+LIRGeneratorX64::useBoxFixed(MDefinition* mir, Register reg1, Register, bool useAtStart)
+{
+ MOZ_ASSERT(mir->type() == MIRType::Value);
+
+ ensureDefined(mir);
+ return LBoxAllocation(LUse(reg1, mir->virtualRegister(), useAtStart));
+}
+
+LAllocation
+LIRGeneratorX64::useByteOpRegister(MDefinition* mir)
+{
+ return useRegister(mir);
+}
+
+LAllocation
+LIRGeneratorX64::useByteOpRegisterAtStart(MDefinition* mir)
+{
+ return useRegisterAtStart(mir);
+}
+
+LAllocation
+LIRGeneratorX64::useByteOpRegisterOrNonDoubleConstant(MDefinition* mir)
+{
+ return useRegisterOrNonDoubleConstant(mir);
+}
+
+LDefinition
+LIRGeneratorX64::tempByteOpRegister()
+{
+ return temp();
+}
+
+LDefinition
+LIRGeneratorX64::tempToUnbox()
+{
+ return temp();
+}
+
+void
+LIRGeneratorX64::lowerForALUInt64(LInstructionHelper<INT64_PIECES, 2 * INT64_PIECES, 0>* ins,
+ MDefinition* mir, MDefinition* lhs, MDefinition* rhs)
+{
+ ins->setInt64Operand(0, useInt64RegisterAtStart(lhs));
+ ins->setInt64Operand(INT64_PIECES,
+ lhs != rhs ? useInt64OrConstant(rhs) : useInt64OrConstantAtStart(rhs));
+ defineInt64ReuseInput(ins, mir, 0);
+}
+
+void
+LIRGeneratorX64::lowerForMulInt64(LMulI64* ins, MMul* mir, MDefinition* lhs, MDefinition* rhs)
+{
+ // X64 doesn't need a temp for 64bit multiplication.
+ ins->setInt64Operand(0, useInt64RegisterAtStart(lhs));
+ ins->setInt64Operand(INT64_PIECES,
+ lhs != rhs ? useInt64OrConstant(rhs) : useInt64OrConstantAtStart(rhs));
+ defineInt64ReuseInput(ins, mir, 0);
+}
+
+void
+LIRGeneratorX64::visitBox(MBox* box)
+{
+ MDefinition* opd = box->getOperand(0);
+
+ // If the operand is a constant, emit near its uses.
+ if (opd->isConstant() && box->canEmitAtUses()) {
+ emitAtUses(box);
+ return;
+ }
+
+ if (opd->isConstant()) {
+ define(new(alloc()) LValue(opd->toConstant()->toJSValue()), box, LDefinition(LDefinition::BOX));
+ } else {
+ LBox* ins = new(alloc()) LBox(useRegister(opd), opd->type());
+ define(ins, box, LDefinition(LDefinition::BOX));
+ }
+}
+
+void
+LIRGeneratorX64::visitUnbox(MUnbox* unbox)
+{
+ MDefinition* box = unbox->getOperand(0);
+
+ if (box->type() == MIRType::ObjectOrNull) {
+ LUnboxObjectOrNull* lir = new(alloc()) LUnboxObjectOrNull(useRegisterAtStart(box));
+ if (unbox->fallible())
+ assignSnapshot(lir, unbox->bailoutKind());
+ defineReuseInput(lir, unbox, 0);
+ return;
+ }
+
+ MOZ_ASSERT(box->type() == MIRType::Value);
+
+ LUnboxBase* lir;
+ if (IsFloatingPointType(unbox->type())) {
+ lir = new(alloc()) LUnboxFloatingPoint(useRegisterAtStart(box), unbox->type());
+ } else if (unbox->fallible()) {
+ // If the unbox is fallible, load the Value in a register first to
+ // avoid multiple loads.
+ lir = new(alloc()) LUnbox(useRegisterAtStart(box));
+ } else {
+ lir = new(alloc()) LUnbox(useAtStart(box));
+ }
+
+ if (unbox->fallible())
+ assignSnapshot(lir, unbox->bailoutKind());
+
+ define(lir, unbox);
+}
+
+void
+LIRGeneratorX64::visitReturn(MReturn* ret)
+{
+ MDefinition* opd = ret->getOperand(0);
+ MOZ_ASSERT(opd->type() == MIRType::Value);
+
+ LReturn* ins = new(alloc()) LReturn;
+ ins->setOperand(0, useFixed(opd, JSReturnReg));
+ add(ins);
+}
+
+void
+LIRGeneratorX64::defineUntypedPhi(MPhi* phi, size_t lirIndex)
+{
+ defineTypedPhi(phi, lirIndex);
+}
+
+void
+LIRGeneratorX64::lowerUntypedPhiInput(MPhi* phi, uint32_t inputPosition, LBlock* block, size_t lirIndex)
+{
+ lowerTypedPhiInput(phi, inputPosition, block, lirIndex);
+}
+
+void
+LIRGeneratorX64::defineInt64Phi(MPhi* phi, size_t lirIndex)
+{
+ defineTypedPhi(phi, lirIndex);
+}
+
+void
+LIRGeneratorX64::lowerInt64PhiInput(MPhi* phi, uint32_t inputPosition, LBlock* block, size_t lirIndex)
+{
+ lowerTypedPhiInput(phi, inputPosition, block, lirIndex);
+}
+
+void
+LIRGeneratorX64::visitCompareExchangeTypedArrayElement(MCompareExchangeTypedArrayElement* ins)
+{
+ lowerCompareExchangeTypedArrayElement(ins, /* useI386ByteRegisters = */ false);
+}
+
+void
+LIRGeneratorX64::visitAtomicExchangeTypedArrayElement(MAtomicExchangeTypedArrayElement* ins)
+{
+ lowerAtomicExchangeTypedArrayElement(ins, /* useI386ByteRegisters = */ false);
+}
+
+void
+LIRGeneratorX64::visitAtomicTypedArrayElementBinop(MAtomicTypedArrayElementBinop* ins)
+{
+ lowerAtomicTypedArrayElementBinop(ins, /* useI386ByteRegisters = */ false);
+}
+
+void
+LIRGeneratorX64::visitWasmUnsignedToDouble(MWasmUnsignedToDouble* ins)
+{
+ MOZ_ASSERT(ins->input()->type() == MIRType::Int32);
+ LWasmUint32ToDouble* lir = new(alloc()) LWasmUint32ToDouble(useRegisterAtStart(ins->input()));
+ define(lir, ins);
+}
+
+void
+LIRGeneratorX64::visitWasmUnsignedToFloat32(MWasmUnsignedToFloat32* ins)
+{
+ MOZ_ASSERT(ins->input()->type() == MIRType::Int32);
+ LWasmUint32ToFloat32* lir = new(alloc()) LWasmUint32ToFloat32(useRegisterAtStart(ins->input()));
+ define(lir, ins);
+}
+
+void
+LIRGeneratorX64::visitWasmLoad(MWasmLoad* ins)
+{
+ if (ins->type() != MIRType::Int64) {
+ lowerWasmLoad(ins);
+ return;
+ }
+
+ MDefinition* base = ins->base();
+ MOZ_ASSERT(base->type() == MIRType::Int32);
+
+ auto* lir = new(alloc()) LWasmLoadI64(useRegisterOrZeroAtStart(base));
+ defineInt64(lir, ins);
+}
+
+void
+LIRGeneratorX64::visitWasmStore(MWasmStore* ins)
+{
+ MDefinition* base = ins->base();
+ MOZ_ASSERT(base->type() == MIRType::Int32);
+
+ MDefinition* value = ins->value();
+ LAllocation valueAlloc;
+ switch (ins->access().type()) {
+ case Scalar::Int8:
+ case Scalar::Uint8:
+ case Scalar::Int16:
+ case Scalar::Uint16:
+ case Scalar::Int32:
+ case Scalar::Uint32:
+ valueAlloc = useRegisterOrConstantAtStart(value);
+ break;
+ case Scalar::Int64:
+ // No way to encode an int64-to-memory move on x64.
+ if (value->isConstant() && value->type() != MIRType::Int64)
+ valueAlloc = useOrConstantAtStart(value);
+ else
+ valueAlloc = useRegisterAtStart(value);
+ break;
+ case Scalar::Float32:
+ case Scalar::Float64:
+ case Scalar::Float32x4:
+ case Scalar::Int8x16:
+ case Scalar::Int16x8:
+ case Scalar::Int32x4:
+ valueAlloc = useRegisterAtStart(value);
+ break;
+ case Scalar::Uint8Clamped:
+ case Scalar::MaxTypedArrayViewType:
+ MOZ_CRASH("unexpected array type");
+ }
+
+ LAllocation baseAlloc = useRegisterOrZeroAtStart(base);
+ auto* lir = new(alloc()) LWasmStore(baseAlloc, valueAlloc);
+ add(lir, ins);
+}
+
+void
+LIRGeneratorX64::visitAsmJSLoadHeap(MAsmJSLoadHeap* ins)
+{
+ MDefinition* base = ins->base();
+ MOZ_ASSERT(base->type() == MIRType::Int32);
+
+ define(new(alloc()) LAsmJSLoadHeap(useRegisterOrZeroAtStart(base)), ins);
+}
+
+void
+LIRGeneratorX64::visitAsmJSStoreHeap(MAsmJSStoreHeap* ins)
+{
+ MDefinition* base = ins->base();
+ MOZ_ASSERT(base->type() == MIRType::Int32);
+
+ LAsmJSStoreHeap* lir = nullptr; // initialize to silence GCC warning
+ switch (ins->access().type()) {
+ case Scalar::Int8:
+ case Scalar::Uint8:
+ case Scalar::Int16:
+ case Scalar::Uint16:
+ case Scalar::Int32:
+ case Scalar::Uint32:
+ lir = new(alloc()) LAsmJSStoreHeap(useRegisterOrZeroAtStart(base),
+ useRegisterOrConstantAtStart(ins->value()));
+ break;
+ case Scalar::Float32:
+ case Scalar::Float64:
+ case Scalar::Float32x4:
+ case Scalar::Int8x16:
+ case Scalar::Int16x8:
+ case Scalar::Int32x4:
+ lir = new(alloc()) LAsmJSStoreHeap(useRegisterOrZeroAtStart(base),
+ useRegisterAtStart(ins->value()));
+ break;
+ case Scalar::Int64:
+ case Scalar::Uint8Clamped:
+ case Scalar::MaxTypedArrayViewType:
+ MOZ_CRASH("unexpected array type");
+ }
+ add(lir, ins);
+}
+
+void
+LIRGeneratorX64::visitAsmJSCompareExchangeHeap(MAsmJSCompareExchangeHeap* ins)
+{
+ MDefinition* base = ins->base();
+ MOZ_ASSERT(base->type() == MIRType::Int32);
+
+ // The output may not be used but will be clobbered regardless, so
+ // pin the output to eax.
+ //
+ // The input values must both be in registers.
+
+ const LAllocation oldval = useRegister(ins->oldValue());
+ const LAllocation newval = useRegister(ins->newValue());
+
+ LAsmJSCompareExchangeHeap* lir =
+ new(alloc()) LAsmJSCompareExchangeHeap(useRegister(base), oldval, newval);
+
+ defineFixed(lir, ins, LAllocation(AnyRegister(eax)));
+}
+
+void
+LIRGeneratorX64::visitAsmJSAtomicExchangeHeap(MAsmJSAtomicExchangeHeap* ins)
+{
+ MOZ_ASSERT(ins->base()->type() == MIRType::Int32);
+
+ const LAllocation base = useRegister(ins->base());
+ const LAllocation value = useRegister(ins->value());
+
+ // The output may not be used but will be clobbered regardless,
+ // so ignore the case where we're not using the value and just
+ // use the output register as a temp.
+
+ LAsmJSAtomicExchangeHeap* lir =
+ new(alloc()) LAsmJSAtomicExchangeHeap(base, value);
+ define(lir, ins);
+}
+
+void
+LIRGeneratorX64::visitAsmJSAtomicBinopHeap(MAsmJSAtomicBinopHeap* ins)
+{
+ MDefinition* base = ins->base();
+ MOZ_ASSERT(base->type() == MIRType::Int32);
+
+ // Case 1: the result of the operation is not used.
+ //
+ // We'll emit a single instruction: LOCK ADD, LOCK SUB, LOCK AND,
+ // LOCK OR, or LOCK XOR.
+
+ if (!ins->hasUses()) {
+ LAsmJSAtomicBinopHeapForEffect* lir =
+ new(alloc()) LAsmJSAtomicBinopHeapForEffect(useRegister(base),
+ useRegisterOrConstant(ins->value()));
+ add(lir, ins);
+ return;
+ }
+
+ // Case 2: the result of the operation is used.
+ //
+ // For ADD and SUB we'll use XADD with word and byte ops as
+ // appropriate. Any output register can be used and if value is a
+ // register it's best if it's the same as output:
+ //
+ // movl value, output ; if value != output
+ // lock xaddl output, mem
+ //
+ // For AND/OR/XOR we need to use a CMPXCHG loop, and the output is
+ // always in rax:
+ //
+ // movl *mem, rax
+ // L: mov rax, temp
+ // andl value, temp
+ // lock cmpxchg temp, mem ; reads rax also
+ // jnz L
+ // ; result in rax
+ //
+ // Note the placement of L, cmpxchg will update rax with *mem if
+ // *mem does not have the expected value, so reloading it at the
+ // top of the loop would be redundant.
+
+ bool bitOp = !(ins->operation() == AtomicFetchAddOp || ins->operation() == AtomicFetchSubOp);
+ bool reuseInput = false;
+ LAllocation value;
+
+ if (bitOp || ins->value()->isConstant()) {
+ value = useRegisterOrConstant(ins->value());
+ } else {
+ reuseInput = true;
+ value = useRegisterAtStart(ins->value());
+ }
+
+ LAsmJSAtomicBinopHeap* lir =
+ new(alloc()) LAsmJSAtomicBinopHeap(useRegister(base),
+ value,
+ bitOp ? temp() : LDefinition::BogusTemp());
+
+ if (reuseInput)
+ defineReuseInput(lir, ins, LAsmJSAtomicBinopHeap::valueOp);
+ else if (bitOp)
+ defineFixed(lir, ins, LAllocation(AnyRegister(rax)));
+ else
+ define(lir, ins);
+}
+
+void
+LIRGeneratorX64::visitSubstr(MSubstr* ins)
+{
+ LSubstr* lir = new (alloc()) LSubstr(useRegister(ins->string()),
+ useRegister(ins->begin()),
+ useRegister(ins->length()),
+ temp(),
+ temp(),
+ tempByteOpRegister());
+ define(lir, ins);
+ assignSafepoint(lir, ins);
+}
+
+void
+LIRGeneratorX64::visitStoreTypedArrayElementStatic(MStoreTypedArrayElementStatic* ins)
+{
+ MOZ_CRASH("NYI");
+}
+
+void
+LIRGeneratorX64::visitRandom(MRandom* ins)
+{
+ LRandom *lir = new(alloc()) LRandom(temp(),
+ temp(),
+ temp());
+ defineFixed(lir, ins, LFloatReg(ReturnDoubleReg));
+}
+
+void
+LIRGeneratorX64::lowerDivI64(MDiv* div)
+{
+ if (div->isUnsigned()) {
+ lowerUDivI64(div);
+ return;
+ }
+
+ LDivOrModI64* lir = new(alloc()) LDivOrModI64(useRegister(div->lhs()), useRegister(div->rhs()),
+ tempFixed(rdx));
+ defineInt64Fixed(lir, div, LInt64Allocation(LAllocation(AnyRegister(rax))));
+}
+
+void
+LIRGeneratorX64::lowerModI64(MMod* mod)
+{
+ if (mod->isUnsigned()) {
+ lowerUModI64(mod);
+ return;
+ }
+
+ LDivOrModI64* lir = new(alloc()) LDivOrModI64(useRegister(mod->lhs()), useRegister(mod->rhs()),
+ tempFixed(rax));
+ defineInt64Fixed(lir, mod, LInt64Allocation(LAllocation(AnyRegister(rdx))));
+}
+
+void
+LIRGeneratorX64::lowerUDivI64(MDiv* div)
+{
+ LUDivOrModI64* lir = new(alloc()) LUDivOrModI64(useRegister(div->lhs()),
+ useRegister(div->rhs()),
+ tempFixed(rdx));
+ defineInt64Fixed(lir, div, LInt64Allocation(LAllocation(AnyRegister(rax))));
+}
+
+void
+LIRGeneratorX64::lowerUModI64(MMod* mod)
+{
+ LUDivOrModI64* lir = new(alloc()) LUDivOrModI64(useRegister(mod->lhs()),
+ useRegister(mod->rhs()),
+ tempFixed(rax));
+ defineInt64Fixed(lir, mod, LInt64Allocation(LAllocation(AnyRegister(rdx))));
+}
+
+void
+LIRGeneratorX64::visitWasmTruncateToInt64(MWasmTruncateToInt64* ins)
+{
+ MDefinition* opd = ins->input();
+ MOZ_ASSERT(opd->type() == MIRType::Double || opd->type() == MIRType::Float32);
+
+ LDefinition maybeTemp = ins->isUnsigned() ? tempDouble() : LDefinition::BogusTemp();
+ defineInt64(new(alloc()) LWasmTruncateToInt64(useRegister(opd), maybeTemp), ins);
+}
+
+void
+LIRGeneratorX64::visitInt64ToFloatingPoint(MInt64ToFloatingPoint* ins)
+{
+ MDefinition* opd = ins->input();
+ MOZ_ASSERT(opd->type() == MIRType::Int64);
+ MOZ_ASSERT(IsFloatingPointType(ins->type()));
+
+ define(new(alloc()) LInt64ToFloatingPoint(useInt64Register(opd), LDefinition::BogusTemp()), ins);
+}
+
+void
+LIRGeneratorX64::visitExtendInt32ToInt64(MExtendInt32ToInt64* ins)
+{
+ defineInt64(new(alloc()) LExtendInt32ToInt64(useAtStart(ins->input())), ins);
+}