path: root/js/src/jit/shared/CodeGenerator-shared-inl.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * 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/. */

#ifndef jit_shared_CodeGenerator_shared_inl_h
#define jit_shared_CodeGenerator_shared_inl_h

#include "jit/shared/CodeGenerator-shared.h"
#include "jit/Disassembler.h"

#include "jit/MacroAssembler-inl.h"

namespace js {
namespace jit {

static inline bool
IsConstant(const LInt64Allocation& a)
{
#if JS_BITS_PER_WORD == 32
    if (a.high().isConstantValue())
        return true;
    if (a.high().isConstantIndex())
        return true;
#else
    if (a.value().isConstantValue())
        return true;
    if (a.value().isConstantIndex())
        return true;
#endif
    return false;
}

static inline int32_t
ToInt32(const LAllocation* a)
{
    if (a->isConstantValue())
        return a->toConstant()->toInt32();
    if (a->isConstantIndex())
        return a->toConstantIndex()->index();
    MOZ_CRASH("this is not a constant!");
}

static inline int64_t
ToInt64(const LAllocation* a)
{
    if (a->isConstantValue())
        return a->toConstant()->toInt64();
    if (a->isConstantIndex())
        return a->toConstantIndex()->index();
    MOZ_CRASH("this is not a constant!");
}

static inline int64_t
ToInt64(const LInt64Allocation& a)
{
#if JS_BITS_PER_WORD == 32
    if (a.high().isConstantValue())
        return a.high().toConstant()->toInt64();
    if (a.high().isConstantIndex())
        return a.high().toConstantIndex()->index();
#else
    if (a.value().isConstantValue())
        return a.value().toConstant()->toInt64();
    if (a.value().isConstantIndex())
        return a.value().toConstantIndex()->index();
#endif
    MOZ_CRASH("this is not a constant!");
}

static inline double
ToDouble(const LAllocation* a)
{
    return a->toConstant()->numberToDouble();
}

static inline Register
ToRegister(const LAllocation& a)
{
    MOZ_ASSERT(a.isGeneralReg());
    return a.toGeneralReg()->reg();
}

static inline Register
ToRegister(const LAllocation* a)
{
    return ToRegister(*a);
}

static inline Register
ToRegister(const LDefinition* def)
{
    return ToRegister(*def->output());
}

static inline Register64
ToOutRegister64(LInstruction* ins)
{
#if JS_BITS_PER_WORD == 32
    Register loReg = ToRegister(ins->getDef(INT64LOW_INDEX));
    Register hiReg = ToRegister(ins->getDef(INT64HIGH_INDEX));
    return Register64(hiReg, loReg);
#else
    return Register64(ToRegister(ins->getDef(0)));
#endif
}

static inline Register64
ToRegister64(const LInt64Allocation& a)
{
#if JS_BITS_PER_WORD == 32
    return Register64(ToRegister(a.high()), ToRegister(a.low()));
#else
    return Register64(ToRegister(a.value()));
#endif
}

static inline Register
ToTempRegisterOrInvalid(const LDefinition* def)
{
    if (def->isBogusTemp())
        return InvalidReg;
    return ToRegister(def);
}

static inline Register
ToTempUnboxRegister(const LDefinition* def)
{
    return ToTempRegisterOrInvalid(def);
}

static inline Register
ToRegisterOrInvalid(const LDefinition* a)
{
    return a ? ToRegister(a) : InvalidReg;
}

static inline FloatRegister
ToFloatRegister(const LAllocation& a)
{
    MOZ_ASSERT(a.isFloatReg());
    return a.toFloatReg()->reg();
}

static inline FloatRegister
ToFloatRegister(const LAllocation* a)
{
    return ToFloatRegister(*a);
}

static inline FloatRegister
ToFloatRegister(const LDefinition* def)
{
    return ToFloatRegister(*def->output());
}

static inline FloatRegister
ToTempFloatRegisterOrInvalid(const LDefinition* def)
{
    if (def->isBogusTemp())
        return InvalidFloatReg;
    return ToFloatRegister(def);
}

static inline AnyRegister
ToAnyRegister(const LAllocation& a)
{
    MOZ_ASSERT(a.isGeneralReg() || a.isFloatReg());
    if (a.isGeneralReg())
        return AnyRegister(ToRegister(a));
    return AnyRegister(ToFloatRegister(a));
}

static inline AnyRegister
ToAnyRegister(const LAllocation* a)
{
    return ToAnyRegister(*a);
}

static inline AnyRegister
ToAnyRegister(const LDefinition* def)
{
    return ToAnyRegister(def->output());
}

static inline RegisterOrInt32Constant
ToRegisterOrInt32Constant(const LAllocation* a)
{
    if (a->isConstant())
        return RegisterOrInt32Constant(ToInt32(a));
    return RegisterOrInt32Constant(ToRegister(a));
}

static inline ValueOperand
GetValueOutput(LInstruction* ins)
{
#if defined(JS_NUNBOX32)
    return ValueOperand(ToRegister(ins->getDef(TYPE_INDEX)),
                        ToRegister(ins->getDef(PAYLOAD_INDEX)));
#elif defined(JS_PUNBOX64)
    return ValueOperand(ToRegister(ins->getDef(0)));
#else
#error "Unknown"
#endif
}

static inline ValueOperand
GetTempValue(Register type, Register payload)
{
#if defined(JS_NUNBOX32)
    return ValueOperand(type, payload);
#elif defined(JS_PUNBOX64)
    (void)type;
    return ValueOperand(payload);
#else
#error "Unknown"
#endif
}

int32_t
CodeGeneratorShared::ArgToStackOffset(int32_t slot) const
{
    return masm.framePushed() +
           (gen->compilingWasm() ? sizeof(wasm::Frame) : sizeof(JitFrameLayout)) +
           slot;
}

int32_t
CodeGeneratorShared::CalleeStackOffset() const
{
    return masm.framePushed() + JitFrameLayout::offsetOfCalleeToken();
}

int32_t
CodeGeneratorShared::SlotToStackOffset(int32_t slot) const
{
    MOZ_ASSERT(slot > 0 && slot <= int32_t(graph.localSlotCount()));
    int32_t offset = masm.framePushed() - frameInitialAdjustment_ - slot;
    MOZ_ASSERT(offset >= 0);
    return offset;
}

int32_t
CodeGeneratorShared::StackOffsetToSlot(int32_t offset) const
{
    // See: SlotToStackOffset. This is used to convert pushed arguments
    // to a slot index that safepoints can use.
    //
    // offset = framePushed - frameInitialAdjustment - slot
    // offset + slot = framePushed - frameInitialAdjustment
    // slot = framePushed - frameInitialAdjustement - offset
    return masm.framePushed() - frameInitialAdjustment_ - offset;
}

// For argument construction for calls. Argslots are Value-sized.
int32_t
CodeGeneratorShared::StackOffsetOfPassedArg(int32_t slot) const
{
    // A slot of 0 is permitted only to calculate %esp offset for calls.
    MOZ_ASSERT(slot >= 0 && slot <= int32_t(graph.argumentSlotCount()));
    int32_t offset = masm.framePushed() -
                     graph.paddedLocalSlotsSize() -
                     (slot * sizeof(Value));

    // Passed arguments go below A function's local stack storage.
    // When arguments are being pushed, there is nothing important on the stack.
    // Therefore, It is safe to push the arguments down arbitrarily.  Pushing
    // by sizeof(Value) is desirable since everything on the stack is a Value.
    // Note that paddedLocalSlotCount() aligns to at least a Value boundary
    // specifically to support this.
    MOZ_ASSERT(offset >= 0);
    MOZ_ASSERT(offset % sizeof(Value) == 0);
    return offset;
}

int32_t
CodeGeneratorShared::ToStackOffset(LAllocation a) const
{
    if (a.isArgument())
        return ArgToStackOffset(a.toArgument()->index());
    return SlotToStackOffset(a.toStackSlot()->slot());
}

int32_t
CodeGeneratorShared::ToStackOffset(const LAllocation* a) const
{
    return ToStackOffset(*a);
}

Address
CodeGeneratorShared::ToAddress(const LAllocation& a)
{
    MOZ_ASSERT(a.isMemory());
    return Address(masm.getStackPointer(), ToStackOffset(&a));
}

Address
CodeGeneratorShared::ToAddress(const LAllocation* a)
{
    return ToAddress(*a);
}

void
CodeGeneratorShared::saveLive(LInstruction* ins)
{
    MOZ_ASSERT(!ins->isCall());
    LSafepoint* safepoint = ins->safepoint();
    masm.PushRegsInMask(safepoint->liveRegs());
}

void
CodeGeneratorShared::restoreLive(LInstruction* ins)
{
    MOZ_ASSERT(!ins->isCall());
    LSafepoint* safepoint = ins->safepoint();
    masm.PopRegsInMask(safepoint->liveRegs());
}

void
CodeGeneratorShared::restoreLiveIgnore(LInstruction* ins, LiveRegisterSet ignore)
{
    MOZ_ASSERT(!ins->isCall());
    LSafepoint* safepoint = ins->safepoint();
    masm.PopRegsInMaskIgnore(safepoint->liveRegs(), ignore);
}

void
CodeGeneratorShared::saveLiveVolatile(LInstruction* ins)
{
    MOZ_ASSERT(!ins->isCall());
    LSafepoint* safepoint = ins->safepoint();
    LiveRegisterSet regs;
    regs.set() = RegisterSet::Intersect(safepoint->liveRegs().set(), RegisterSet::Volatile());
    masm.PushRegsInMask(regs);
}

void
CodeGeneratorShared::restoreLiveVolatile(LInstruction* ins)
{
    MOZ_ASSERT(!ins->isCall());
    LSafepoint* safepoint = ins->safepoint();
    LiveRegisterSet regs;
    regs.set() = RegisterSet::Intersect(safepoint->liveRegs().set(), RegisterSet::Volatile());
    masm.PopRegsInMask(regs);
}

void
CodeGeneratorShared::verifyHeapAccessDisassembly(uint32_t begin, uint32_t end, bool isLoad,
                                                 Scalar::Type type, Operand mem, LAllocation alloc)
{
#ifdef DEBUG
    using namespace Disassembler;

    Disassembler::HeapAccess::Kind kind = isLoad ? HeapAccess::Load : HeapAccess::Store;
    switch (type) {
      case Scalar::Int8:
      case Scalar::Int16:
        if (kind == HeapAccess::Load)
            kind = HeapAccess::LoadSext32;
        break;
      default:
        break;
    }

    OtherOperand op;
    switch (type) {
      case Scalar::Int8:
      case Scalar::Uint8:
      case Scalar::Int16:
      case Scalar::Uint16:
      case Scalar::Int32:
      case Scalar::Uint32:
        if (!alloc.isConstant()) {
            op = OtherOperand(ToRegister(alloc).encoding());
        } else {
            // x86 doesn't allow encoding an imm64 to memory move; the value
            // is wrapped anyways.
            int32_t i = ToInt32(&alloc);

            // Sign-extend the immediate value out to 32 bits. We do this even
            // for unsigned element types so that we match what the disassembly
            // code does, as it doesn't know about signedness of stores.
            unsigned shift = 32 - TypedArrayElemSize(type) * 8;
            i = i << shift >> shift;
            op = OtherOperand(i);
        }
        break;
      case Scalar::Int64:
        // Can't encode an imm64-to-memory move.
        op = OtherOperand(ToRegister(alloc).encoding());
        break;
      case Scalar::Float32:
      case Scalar::Float64:
      case Scalar::Float32x4:
      case Scalar::Int8x16:
      case Scalar::Int16x8:
      case Scalar::Int32x4:
        op = OtherOperand(ToFloatRegister(alloc).encoding());
        break;
      case Scalar::Uint8Clamped:
      case Scalar::MaxTypedArrayViewType:
        MOZ_CRASH("Unexpected array type");
    }

    HeapAccess access(kind, TypedArrayElemSize(type), ComplexAddress(mem), op);
    masm.verifyHeapAccessDisassembly(begin, end, access);
#endif
}

void
CodeGeneratorShared::verifyLoadDisassembly(uint32_t begin, uint32_t end, Scalar::Type type,
                                           Operand mem, LAllocation alloc)
{
    verifyHeapAccessDisassembly(begin, end, true, type, mem, alloc);
}

void
CodeGeneratorShared::verifyStoreDisassembly(uint32_t begin, uint32_t end, Scalar::Type type,
                                            Operand mem, LAllocation alloc)
{
    verifyHeapAccessDisassembly(begin, end, false, type, mem, alloc);
}

inline bool
CodeGeneratorShared::isGlobalObject(JSObject* object)
{
    // Calling object->is<GlobalObject>() is racy because this relies on
    // checking the group and this can be changed while we are compiling off the
    // main thread.
    return object == gen->compartment->maybeGlobal();
}

} // namespace jit
} // namespace js

#endif /* jit_shared_CodeGenerator_shared_inl_h */