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/* -*- 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 "mozilla/MathAlgorithms.h"
#include "jit/Lowering.h"
#include "jit/mips/Assembler-mips.h"
#include "jit/MIR.h"
#include "jit/shared/Lowering-shared-inl.h"
using namespace js;
using namespace js::jit;
bool
LIRGeneratorMIPS::useBox(LInstruction *lir, size_t n, MDefinition *mir,
LUse::Policy policy, bool useAtStart)
{
MOZ_ASSERT(mir->type() == MIRType_Value);
if (!ensureDefined(mir))
return false;
lir->setOperand(n, LUse(mir->virtualRegister(), policy, useAtStart));
lir->setOperand(n + 1, LUse(VirtualRegisterOfPayload(mir), policy, useAtStart));
return true;
}
bool
LIRGeneratorMIPS::useBoxFixed(LInstruction *lir, size_t n, MDefinition *mir, Register reg1,
Register reg2)
{
MOZ_ASSERT(mir->type() == MIRType_Value);
MOZ_ASSERT(reg1 != reg2);
if (!ensureDefined(mir))
return false;
lir->setOperand(n, LUse(reg1, mir->virtualRegister()));
lir->setOperand(n + 1, LUse(reg2, VirtualRegisterOfPayload(mir)));
return true;
}
LAllocation
LIRGeneratorMIPS::useByteOpRegister(MDefinition *mir)
{
return useRegister(mir);
}
LAllocation
LIRGeneratorMIPS::useByteOpRegisterOrNonDoubleConstant(MDefinition *mir)
{
return useRegisterOrNonDoubleConstant(mir);
}
bool
LIRGeneratorMIPS::lowerConstantDouble(double d, MInstruction *mir)
{
return define(new LDouble(d), mir);
}
bool
LIRGeneratorMIPS::visitConstant(MConstant *ins)
{
if (ins->type() == MIRType_Double)
return lowerConstantDouble(ins->value().toDouble(), ins);
// Emit non-double constants at their uses.
if (ins->canEmitAtUses())
return emitAtUses(ins);
return LIRGeneratorShared::visitConstant(ins);
}
bool
LIRGeneratorMIPS::visitBox(MBox *box)
{
MDefinition *inner = box->getOperand(0);
// If the box wrapped a double, it needs a new register.
if (inner->type() == MIRType_Double) {
return defineBox(new LBoxDouble(useRegisterAtStart(inner),
tempCopy(inner, 0), inner->type()), box);
}
if (box->canEmitAtUses())
return emitAtUses(box);
if (inner->isConstant())
return defineBox(new LValue(inner->toConstant()->value()), box);
LBox *lir = new LBox(use(inner), inner->type());
// Otherwise, we should not define a new register for the payload portion
// of the output, so bypass defineBox().
uint32_t vreg = getVirtualRegister();
if (vreg >= MAX_VIRTUAL_REGISTERS)
return false;
// Note that because we're using PASSTHROUGH, we do not change the type of
// the definition. We also do not define the first output as "TYPE",
// because it has no corresponding payload at (vreg + 1). Also note that
// although we copy the input's original type for the payload half of the
// definition, this is only for clarity. PASSTHROUGH definitions are
// ignored.
lir->setDef(0, LDefinition(vreg, LDefinition::GENERAL));
lir->setDef(1, LDefinition(inner->virtualRegister(), LDefinition::TypeFrom(inner->type()),
LDefinition::PASSTHROUGH));
box->setVirtualRegister(vreg);
return add(lir);
}
bool
LIRGeneratorMIPS::visitUnbox(MUnbox *unbox)
{
// An unbox on mips reads in a type tag (either in memory or a register) and
// a payload. Unlike most instructions consuming a box, we ask for the type
// second, so that the result can re-use the first input.
MDefinition *inner = unbox->getOperand(0);
if (!ensureDefined(inner))
return false;
if (unbox->type() == MIRType_Double) {
LUnboxDouble* lir = new LUnboxDouble();
if (unbox->fallible() && !assignSnapshot(lir, unbox->bailoutKind())) {
return false;
}
if (!useBox(lir, LUnboxDouble::Input, inner)) {
return false;
}
return define(lir, unbox);
}
// Swap the order we use the box pieces so we can re-use the payload
// register.
LUnbox *lir = new LUnbox();
lir->setOperand(0, usePayloadInRegisterAtStart(inner));
lir->setOperand(1, useType(inner, LUse::REGISTER));
if (unbox->fallible() && !assignSnapshot(lir, unbox->bailoutKind()))
return false;
// Note that PASSTHROUGH here is illegal, since types and payloads form two
// separate intervals. If the type becomes dead before the payload, it
// could be used as a Value without the type being recoverable. Unbox's
// purpose is to eagerly kill the definition of a type tag, so keeping both
// alive (for the purpose of gcmaps) is unappealing. Instead, we create a
// new virtual register.
return defineReuseInput(lir, unbox, 0);
}
bool
LIRGeneratorMIPS::visitReturn(MReturn *ret)
{
MDefinition *opd = ret->getOperand(0);
MOZ_ASSERT(opd->type() == MIRType_Value);
LReturn *ins = new LReturn();
ins->setOperand(0, LUse(JSReturnReg_Type));
ins->setOperand(1, LUse(JSReturnReg_Data));
return fillBoxUses(ins, 0, opd) && add(ins);
}
// x = !y
bool
LIRGeneratorMIPS::lowerForALU(LInstructionHelper<1, 1, 0> *ins,
MDefinition *mir, MDefinition *input)
{
ins->setOperand(0, useRegister(input));
return define(ins, mir,
LDefinition(LDefinition::TypeFrom(mir->type()), LDefinition::DEFAULT));
}
// z = x+y
bool
LIRGeneratorMIPS::lowerForALU(LInstructionHelper<1, 2, 0> *ins, MDefinition *mir,
MDefinition *lhs, MDefinition *rhs)
{
ins->setOperand(0, useRegister(lhs));
ins->setOperand(1, useRegisterOrConstant(rhs));
return define(ins, mir,
LDefinition(LDefinition::TypeFrom(mir->type()), LDefinition::DEFAULT));
}
bool
LIRGeneratorMIPS::lowerForFPU(LInstructionHelper<1, 1, 0> *ins, MDefinition *mir,
MDefinition *input)
{
ins->setOperand(0, useRegister(input));
return define(ins, mir,
LDefinition(LDefinition::TypeFrom(mir->type()), LDefinition::DEFAULT));
}
bool
LIRGeneratorMIPS::lowerForFPU(LInstructionHelper<1, 2, 0> *ins, MDefinition *mir,
MDefinition *lhs, MDefinition *rhs)
{
ins->setOperand(0, useRegister(lhs));
ins->setOperand(1, useRegister(rhs));
return define(ins, mir,
LDefinition(LDefinition::TypeFrom(mir->type()), LDefinition::DEFAULT));
}
bool
LIRGeneratorMIPS::defineUntypedPhi(MPhi *phi, size_t lirIndex)
{
LPhi *type = current->getPhi(lirIndex + VREG_TYPE_OFFSET);
LPhi *payload = current->getPhi(lirIndex + VREG_DATA_OFFSET);
uint32_t typeVreg = getVirtualRegister();
if (typeVreg >= MAX_VIRTUAL_REGISTERS)
return false;
phi->setVirtualRegister(typeVreg);
uint32_t payloadVreg = getVirtualRegister();
if (payloadVreg >= MAX_VIRTUAL_REGISTERS)
return false;
MOZ_ASSERT(typeVreg + 1 == payloadVreg);
type->setDef(0, LDefinition(typeVreg, LDefinition::TYPE));
payload->setDef(0, LDefinition(payloadVreg, LDefinition::PAYLOAD));
annotate(type);
annotate(payload);
return true;
}
void
LIRGeneratorMIPS::lowerUntypedPhiInput(MPhi *phi, uint32_t inputPosition,
LBlock *block, size_t lirIndex)
{
MDefinition *operand = phi->getOperand(inputPosition);
LPhi *type = block->getPhi(lirIndex + VREG_TYPE_OFFSET);
LPhi *payload = block->getPhi(lirIndex + VREG_DATA_OFFSET);
type->setOperand(inputPosition, LUse(operand->virtualRegister() + VREG_TYPE_OFFSET,
LUse::ANY));
payload->setOperand(inputPosition, LUse(VirtualRegisterOfPayload(operand), LUse::ANY));
}
bool
LIRGeneratorMIPS::lowerForShift(LInstructionHelper<1, 2, 0> *ins, MDefinition *mir,
MDefinition *lhs, MDefinition *rhs)
{
ins->setOperand(0, useRegister(lhs));
ins->setOperand(1, useRegisterOrConstant(rhs));
return define(ins, mir);
}
bool
LIRGeneratorMIPS::lowerDivI(MDiv *div)
{
// Division instructions are slow. Division by constant denominators can be
// rewritten to use other instructions.
if (div->rhs()->isConstant()) {
int32_t rhs = div->rhs()->toConstant()->value().toInt32();
// Check for division by a positive power of two, which is an easy and
// important case to optimize. Note that other optimizations are also
// possible; division by negative powers of two can be optimized in a
// similar manner as positive powers of two, and division by other
// constants can be optimized by a reciprocal multiplication technique.
int32_t shift;
JS_FLOOR_LOG2(shift, rhs);
if (rhs > 0 && 1 << shift == rhs) {
LDivPowTwoI *lir = new LDivPowTwoI(useRegister(div->lhs()), shift, temp());
if (div->fallible() && !assignSnapshot(lir))
return false;
return define(lir, div);
}
}
LDivI *lir = new LDivI(useRegister(div->lhs()), useRegister(div->rhs()), temp());
if (div->fallible() && !assignSnapshot(lir))
return false;
return define(lir, div);
}
bool
LIRGeneratorMIPS::lowerMulI(MMul *mul, MDefinition *lhs, MDefinition *rhs)
{
LMulI *lir = new LMulI;
if (mul->fallible() && !assignSnapshot(lir))
return false;
return lowerForALU(lir, mul, lhs, rhs);
}
bool
LIRGeneratorMIPS::lowerModI(MMod *mod)
{
if (mod->isUnsigned())
return lowerUMod(mod);
if (mod->rhs()->isConstant()) {
int32_t rhs = mod->rhs()->toConstant()->value().toInt32();
int32_t shift;
JS_FLOOR_LOG2(shift, rhs);
if (rhs > 0 && 1 << shift == rhs) {
LModPowTwoI *lir = new LModPowTwoI(useRegister(mod->lhs()), shift);
if (mod->fallible() && !assignSnapshot(lir))
return false;
return define(lir, mod);
} else if (shift < 31 && (1 << (shift + 1)) - 1 == rhs) {
LModMaskI *lir = new LModMaskI(
useRegister(mod->lhs()),
temp(LDefinition::GENERAL),
shift + 1
);
if (mod->fallible() && !assignSnapshot(lir))
return false;
return define(lir, mod);
}
}
LModI *lir = new LModI(useRegister(mod->lhs()), useRegister(mod->rhs()),
temp(LDefinition::GENERAL));
if (mod->fallible() && !assignSnapshot(lir))
return false;
return define(lir, mod);
}
bool
LIRGeneratorMIPS::visitPowHalf(MPowHalf *ins)
{
MDefinition *input = ins->input();
MOZ_ASSERT(input->type() == MIRType_Double);
LPowHalfD *lir = new LPowHalfD(useRegisterAtStart(input));
return defineReuseInput(lir, ins, 0);
}
LTableSwitch *
LIRGeneratorMIPS::newLTableSwitch(const LAllocation &in, const LDefinition &inputCopy,
MTableSwitch *tableswitch)
{
return new LTableSwitch(in, inputCopy, temp(), tableswitch);
}
LTableSwitchV *
LIRGeneratorMIPS::newLTableSwitchV(MTableSwitch *tableswitch)
{
return new LTableSwitchV(temp(), tempFloat(), temp(), tableswitch);
}
bool
LIRGeneratorMIPS::visitGuardShape(MGuardShape *ins)
{
MOZ_ASSERT(ins->obj()->type() == MIRType_Object);
LDefinition tempObj = temp(LDefinition::OBJECT);
LGuardShape *guard = new LGuardShape(useRegister(ins->obj()), tempObj);
if (!assignSnapshot(guard, ins->bailoutKind()))
return false;
if (!add(guard, ins))
return false;
return redefine(ins, ins->obj());
}
bool
LIRGeneratorMIPS::visitGuardObjectType(MGuardObjectType *ins)
{
MOZ_ASSERT(ins->obj()->type() == MIRType_Object);
LDefinition tempObj = temp(LDefinition::OBJECT);
LGuardObjectType *guard = new LGuardObjectType(useRegister(ins->obj()), tempObj);
if (!assignSnapshot(guard))
return false;
if (!add(guard, ins))
return false;
return redefine(ins, ins->obj());
}
bool
LIRGeneratorMIPS::lowerUrshD(MUrsh *mir)
{
MDefinition *lhs = mir->lhs();
MDefinition *rhs = mir->rhs();
MOZ_ASSERT(lhs->type() == MIRType_Int32);
MOZ_ASSERT(rhs->type() == MIRType_Int32);
LUrshD *lir = new LUrshD(useRegister(lhs), useRegisterOrConstant(rhs), temp());
return define(lir, mir);
}
bool
LIRGeneratorMIPS::visitAsmJSNeg(MAsmJSNeg *ins)
{
if (ins->type() == MIRType_Int32)
return define(new LNegI(useRegisterAtStart(ins->input())), ins);
MOZ_ASSERT(ins->type() == MIRType_Double);
return define(new LNegD(useRegisterAtStart(ins->input())), ins);
}
bool
LIRGeneratorMIPS::lowerUDiv(MDiv *div)
{
MDefinition *lhs = div->getOperand(0);
MDefinition *rhs = div->getOperand(1);
LUDiv *lir = new LUDiv;
lir->setOperand(0, useRegister(lhs));
lir->setOperand(1, useRegister(rhs));
if (div->fallible() && !assignSnapshot(lir))
return false;
return define(lir, div);
}
bool
LIRGeneratorMIPS::lowerUMod(MMod *mod)
{
MDefinition *lhs = mod->getOperand(0);
MDefinition *rhs = mod->getOperand(1);
LUMod *lir = new LUMod;
lir->setOperand(0, useRegister(lhs));
lir->setOperand(1, useRegister(rhs));
if (mod->fallible() && !assignSnapshot(lir))
return false;
return define(lir, mod);
}
bool
LIRGeneratorMIPS::visitAsmJSUnsignedToDouble(MAsmJSUnsignedToDouble *ins)
{
MOZ_ASSERT(ins->input()->type() == MIRType_Int32);
LUInt32ToDouble *lir = new LUInt32ToDouble(useRegisterAtStart(ins->input()));
return define(lir, ins);
}
bool
LIRGeneratorMIPS::visitAsmJSStoreHeap(MAsmJSStoreHeap *ins)
{
LAsmJSStoreHeap *lir;
switch (ins->viewType()) {
case ArrayBufferView::TYPE_INT8: case ArrayBufferView::TYPE_UINT8:
case ArrayBufferView::TYPE_INT16: case ArrayBufferView::TYPE_UINT16:
case ArrayBufferView::TYPE_INT32: case ArrayBufferView::TYPE_UINT32:
lir = new LAsmJSStoreHeap(useRegisterAtStart(ins->ptr()),
useRegisterAtStart(ins->value()));
break;
case ArrayBufferView::TYPE_FLOAT32:
case ArrayBufferView::TYPE_FLOAT64:
lir = new LAsmJSStoreHeap(useRegisterAtStart(ins->ptr()),
useRegisterAtStart(ins->value()));
break;
default: JS_NOT_REACHED("unexpected array type");
}
return add(lir, ins);
}
bool
LIRGeneratorMIPS::visitAsmJSLoadFuncPtr(MAsmJSLoadFuncPtr *ins)
{
return define(new LAsmJSLoadFuncPtr(useRegister(ins->index()), temp()), ins);
}
bool
LIRGeneratorMIPS::lowerTruncateDToInt32(MTruncateToInt32 *ins)
{
MDefinition *opd = ins->input();
MOZ_ASSERT(opd->type() == MIRType_Double);
return define(new LTruncateDToInt32(useRegister(opd), LDefinition::BogusTemp()), ins);
}
bool
LIRGeneratorMIPS::visitStoreTypedArrayElementStatic(MStoreTypedArrayElementStatic *ins)
{
JS_NOT_REACHED("NYI");
}
bool LIRGeneratorMIPS::visitAsmJSUDiv(MAsmJSUDiv* ins) {
// LAsmJSDivOrMod doesn't exist in MIPS, not clear how to implement this.
// It doesn't look like it's called anywhere...
JS_NOT_REACHED("NYI_COBALT");
return false;
}
bool LIRGeneratorMIPS::visitInterruptCheck(MInterruptCheck *ins) {
LInterruptCheck *lir = new LInterruptCheck();
if (!add(lir))
return false;
if (!assignSafepoint(lir, ins))
return false;
return true;
}
bool
LIRGeneratorMIPS::visitAsmJSLoadHeap(MAsmJSLoadHeap *ins)
{
MDefinition *ptr = ins->ptr();
MOZ_ASSERT(ptr->type() == MIRType_Int32);
LAllocation ptrAlloc;
// For MIPS it is best to keep the 'ptr' in a register if a bounds check
// is needed.
// if (ptr->isConstant() && ins->skipBoundsCheck()) {
JS_NOT_REACHED("NYI_COBALT");
if (ptr->isConstant() && false) {
int32_t ptrValue = ptr->toConstant()->value().toInt32();
// A bounds check is only skipped for a positive index.
MOZ_ASSERT(ptrValue >= 0);
ptrAlloc = LAllocation(ptr->toConstant()->vp());
} else
ptrAlloc = useRegisterAtStart(ptr);
return define(new LAsmJSLoadHeap(ptrAlloc), ins);
}