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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
*
* Copyright 2016 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// This is an INTERNAL header for Wasm baseline compiler: definitions of
// registers and the register allocator.
#ifndef wasm_wasm_baseline_regdefs_h
#define wasm_wasm_baseline_regdefs_h
#include "wasm/WasmBCDefs.h"
namespace js {
namespace wasm {
struct BaseCompiler;
using namespace js::jit;
//////////////////////////////////////////////////////////////////////////////
//
// Scratch register configuration.
#if defined(JS_CODEGEN_NONE)
# define RABALDR_SCRATCH_I32
# define RABALDR_SCRATCH_F32
# define RABALDR_SCRATCH_F64
static constexpr Register RabaldrScratchI32 = Register::Invalid();
static constexpr FloatRegister RabaldrScratchF32 = InvalidFloatReg;
static constexpr FloatRegister RabaldrScratchF64 = InvalidFloatReg;
#endif
#ifdef JS_CODEGEN_ARM64
# define RABALDR_SCRATCH_I32
# define RABALDR_SCRATCH_F32
# define RABALDR_SCRATCH_F64
# define RABALDR_SCRATCH_V128
# define RABALDR_SCRATCH_F32_ALIASES_F64
static constexpr Register RabaldrScratchI32{Registers::x15};
// Note, the float scratch regs cannot be registers that are used for parameter
// passing in any ABI we use. Argregs tend to be low-numbered; register 30
// should be safe.
static constexpr FloatRegister RabaldrScratchF32{FloatRegisters::s30,
FloatRegisters::Single};
static constexpr FloatRegister RabaldrScratchF64{FloatRegisters::d30,
FloatRegisters::Double};
# ifdef ENABLE_WASM_SIMD
static constexpr FloatRegister RabaldrScratchV128{FloatRegisters::d30,
FloatRegisters::Simd128};
# endif
static_assert(RabaldrScratchF32 != ScratchFloat32Reg_, "Too busy");
static_assert(RabaldrScratchF64 != ScratchDoubleReg_, "Too busy");
# ifdef ENABLE_WASM_SIMD
static_assert(RabaldrScratchV128 != ScratchSimd128Reg, "Too busy");
# endif
#endif
#ifdef JS_CODEGEN_X86
// The selection of EBX here steps gingerly around: the need for EDX
// to be allocatable for multiply/divide; ECX to be allocatable for
// shift/rotate; EAX (= ReturnReg) to be allocatable as the result
// register; EBX not being one of the WasmTableCall registers; and
// needing a temp register for load/store that has a single-byte
// persona.
//
// The compiler assumes that RabaldrScratchI32 has a single-byte
// persona. Code for 8-byte atomic operations assumes that
// RabaldrScratchI32 is in fact ebx.
# define RABALDR_SCRATCH_I32
static constexpr Register RabaldrScratchI32 = ebx;
#endif
#ifdef JS_CODEGEN_ARM
// We use our own scratch register, because the macro assembler uses
// the regular scratch register(s) pretty liberally. We could
// work around that in several cases but the mess does not seem
// worth it yet. CallTempReg2 seems safe.
# define RABALDR_SCRATCH_I32
static constexpr Register RabaldrScratchI32 = CallTempReg2;
#endif
#ifdef JS_CODEGEN_MIPS64
# define RABALDR_SCRATCH_I32
static constexpr Register RabaldrScratchI32 = CallTempReg2;
#endif
#ifdef JS_CODEGEN_LOONG64
// We use our own scratch register, because the macro assembler uses
// the regular scratch register(s) pretty liberally. We could
// work around that in several cases but the mess does not seem
// worth it yet. CallTempReg2 seems safe.
# define RABALDR_SCRATCH_I32
static constexpr Register RabaldrScratchI32 = CallTempReg2;
#endif
#ifdef RABALDR_SCRATCH_F32_ALIASES_F64
# if !defined(RABALDR_SCRATCH_F32) || !defined(RABALDR_SCRATCH_F64)
# error "Bad configuration"
# endif
#endif
//////////////////////////////////////////////////////////////////////////////
//
// ...
template <MIRType t>
struct RegTypeOf {
#ifdef ENABLE_WASM_SIMD
static_assert(t == MIRType::Float32 || t == MIRType::Double ||
t == MIRType::Simd128,
"Float mask type");
#else
static_assert(t == MIRType::Float32 || t == MIRType::Double,
"Float mask type");
#endif
};
template <>
struct RegTypeOf<MIRType::Float32> {
static constexpr RegTypeName value = RegTypeName::Float32;
};
template <>
struct RegTypeOf<MIRType::Double> {
static constexpr RegTypeName value = RegTypeName::Float64;
};
#ifdef ENABLE_WASM_SIMD
template <>
struct RegTypeOf<MIRType::Simd128> {
static constexpr RegTypeName value = RegTypeName::Vector128;
};
#endif
//////////////////////////////////////////////////////////////////////////////
//
// Strongly typed register wrappers.
// The strongly typed register wrappers are especially useful to distinguish
// float registers from double registers, but they also clearly distinguish
// 32-bit registers from 64-bit register pairs on 32-bit systems.
struct RegI32 : public Register {
RegI32() : Register(Register::Invalid()) {}
explicit RegI32(Register reg) : Register(reg) {
MOZ_ASSERT(reg != Invalid());
}
bool isInvalid() const { return *this == Invalid(); }
bool isValid() const { return !isInvalid(); }
static RegI32 Invalid() { return RegI32(); }
};
struct RegI64 : public Register64 {
RegI64() : Register64(Register64::Invalid()) {}
explicit RegI64(Register64 reg) : Register64(reg) {
MOZ_ASSERT(reg != Invalid());
}
bool isInvalid() const { return *this == Invalid(); }
bool isValid() const { return !isInvalid(); }
static RegI64 Invalid() { return RegI64(); }
};
// RegRef is for GC-pointers, for non GC-pointers use RegPtr
struct RegRef : public Register {
RegRef() : Register(Register::Invalid()) {}
explicit RegRef(Register reg) : Register(reg) {
MOZ_ASSERT(reg != Invalid());
}
bool isInvalid() const { return *this == Invalid(); }
bool isValid() const { return !isInvalid(); }
static RegRef Invalid() { return RegRef(); }
};
// RegPtr is for non GC-pointers, for GC-pointers use RegRef
struct RegPtr : public Register {
RegPtr() : Register(Register::Invalid()) {}
explicit RegPtr(Register reg) : Register(reg) {
MOZ_ASSERT(reg != Invalid());
}
bool isInvalid() const { return *this == Invalid(); }
bool isValid() const { return !isInvalid(); }
static RegPtr Invalid() { return RegPtr(); }
};
struct RegF32 : public FloatRegister {
RegF32() : FloatRegister() {}
explicit RegF32(FloatRegister reg) : FloatRegister(reg) {
MOZ_ASSERT(isSingle());
}
bool isValid() const { return !isInvalid(); }
static RegF32 Invalid() { return RegF32(); }
};
struct RegF64 : public FloatRegister {
RegF64() : FloatRegister() {}
explicit RegF64(FloatRegister reg) : FloatRegister(reg) {
MOZ_ASSERT(isDouble());
}
bool isValid() const { return !isInvalid(); }
static RegF64 Invalid() { return RegF64(); }
};
#ifdef ENABLE_WASM_SIMD
struct RegV128 : public FloatRegister {
RegV128() : FloatRegister() {}
explicit RegV128(FloatRegister reg) : FloatRegister(reg) {
MOZ_ASSERT(isSimd128());
}
bool isValid() const { return !isInvalid(); }
static RegV128 Invalid() { return RegV128(); }
};
#endif
struct AnyReg {
union {
RegI32 i32_;
RegI64 i64_;
RegRef ref_;
RegF32 f32_;
RegF64 f64_;
#ifdef ENABLE_WASM_SIMD
RegV128 v128_;
#endif
};
enum {
I32,
I64,
REF,
F32,
F64,
#ifdef ENABLE_WASM_SIMD
V128
#endif
} tag;
explicit AnyReg(RegI32 r) {
tag = I32;
i32_ = r;
}
explicit AnyReg(RegI64 r) {
tag = I64;
i64_ = r;
}
explicit AnyReg(RegF32 r) {
tag = F32;
f32_ = r;
}
explicit AnyReg(RegF64 r) {
tag = F64;
f64_ = r;
}
#ifdef ENABLE_WASM_SIMD
explicit AnyReg(RegV128 r) {
tag = V128;
v128_ = r;
}
#endif
explicit AnyReg(RegRef r) {
tag = REF;
ref_ = r;
}
RegI32 i32() const {
MOZ_ASSERT(tag == I32);
return i32_;
}
RegI64 i64() const {
MOZ_ASSERT(tag == I64);
return i64_;
}
RegF32 f32() const {
MOZ_ASSERT(tag == F32);
return f32_;
}
RegF64 f64() const {
MOZ_ASSERT(tag == F64);
return f64_;
}
#ifdef ENABLE_WASM_SIMD
RegV128 v128() const {
MOZ_ASSERT(tag == V128);
return v128_;
}
#endif
RegRef ref() const {
MOZ_ASSERT(tag == REF);
return ref_;
}
AnyRegister any() const {
switch (tag) {
case F32:
return AnyRegister(f32_);
case F64:
return AnyRegister(f64_);
#ifdef ENABLE_WASM_SIMD
case V128:
return AnyRegister(v128_);
#endif
case I32:
return AnyRegister(i32_);
case I64:
#ifdef JS_PUNBOX64
return AnyRegister(i64_.reg);
#else
// The compiler is written so that this is never needed: any() is
// called on arbitrary registers for asm.js but asm.js does not have
// 64-bit ints. For wasm, any() is called on arbitrary registers
// only on 64-bit platforms.
MOZ_CRASH("AnyReg::any() on 32-bit platform");
#endif
case REF:
MOZ_CRASH("AnyReg::any() not implemented for ref types");
default:
MOZ_CRASH();
}
// Work around GCC 5 analysis/warning bug.
MOZ_CRASH("AnyReg::any(): impossible case");
}
};
//////////////////////////////////////////////////////////////////////////////
//
// Platform-specific registers.
//
// All platforms must define struct SpecificRegs. All 32-bit platforms must
// have an abiReturnRegI64 member in that struct.
#if defined(JS_CODEGEN_X64)
struct SpecificRegs {
RegI32 eax, ecx, edx, edi, esi;
RegI64 rax, rcx, rdx;
SpecificRegs()
: eax(RegI32(js::jit::eax)),
ecx(RegI32(js::jit::ecx)),
edx(RegI32(js::jit::edx)),
edi(RegI32(js::jit::edi)),
esi(RegI32(js::jit::esi)),
rax(RegI64(Register64(js::jit::rax))),
rcx(RegI64(Register64(js::jit::rcx))),
rdx(RegI64(Register64(js::jit::rdx))) {}
};
#elif defined(JS_CODEGEN_X86)
struct SpecificRegs {
RegI32 eax, ecx, edx, edi, esi;
RegI64 ecx_ebx, edx_eax, abiReturnRegI64;
SpecificRegs()
: eax(RegI32(js::jit::eax)),
ecx(RegI32(js::jit::ecx)),
edx(RegI32(js::jit::edx)),
edi(RegI32(js::jit::edi)),
esi(RegI32(js::jit::esi)),
ecx_ebx(RegI64(Register64(js::jit::ecx, js::jit::ebx))),
edx_eax(RegI64(Register64(js::jit::edx, js::jit::eax))),
abiReturnRegI64(edx_eax) {}
};
#elif defined(JS_CODEGEN_ARM)
struct SpecificRegs {
RegI64 abiReturnRegI64;
SpecificRegs() : abiReturnRegI64(ReturnReg64) {}
};
#elif defined(JS_CODEGEN_ARM64) || defined(JS_CODEGEN_MIPS64) || \
defined(JS_CODEGEN_LOONG64)
struct SpecificRegs {
// Required by gcc.
SpecificRegs() {}
};
#else
struct SpecificRegs {
# ifndef JS_64BIT
RegI64 abiReturnRegI64;
# endif
SpecificRegs() { MOZ_CRASH("BaseCompiler porting interface: SpecificRegs"); }
};
#endif
//////////////////////////////////////////////////////////////////////////////
//
// Register allocator.
class BaseRegAlloc {
// Notes on float register allocation.
//
// The general rule in SpiderMonkey is that float registers can alias double
// registers, but there are predicates to handle exceptions to that rule:
// hasUnaliasedDouble() and hasMultiAlias(). The way aliasing actually
// works is platform dependent and exposed through the aliased(n, &r)
// predicate, etc.
//
// - hasUnaliasedDouble(): on ARM VFPv3-D32 there are double registers that
// cannot be treated as float.
// - hasMultiAlias(): on ARM and MIPS a double register aliases two float
// registers.
//
// On some platforms (x86, x64, ARM64) but not all (ARM)
// ScratchFloat32Register is the same as ScratchDoubleRegister.
//
// It's a basic invariant of the AllocatableRegisterSet that it deals
// properly with aliasing of registers: if s0 or s1 are allocated then d0 is
// not allocatable; if s0 and s1 are freed individually then d0 becomes
// allocatable.
BaseCompiler* bc;
AllocatableGeneralRegisterSet availGPR;
AllocatableFloatRegisterSet availFPU;
#ifdef DEBUG
// The registers available after removing ScratchReg, HeapReg, etc.
AllocatableGeneralRegisterSet allGPR;
AllocatableFloatRegisterSet allFPU;
uint32_t scratchTaken;
#endif
#ifdef JS_CODEGEN_X86
AllocatableGeneralRegisterSet singleByteRegs;
#endif
bool hasGPR() { return !availGPR.empty(); }
bool hasGPR64() {
#ifdef JS_PUNBOX64
return !availGPR.empty();
#else
if (availGPR.empty()) {
return false;
}
Register r = allocGPR();
bool available = !availGPR.empty();
freeGPR(r);
return available;
#endif
}
template <MIRType t>
bool hasFPU() {
return availFPU.hasAny<RegTypeOf<t>::value>();
}
bool isAvailableGPR(Register r) { return availGPR.has(r); }
bool isAvailableFPU(FloatRegister r) { return availFPU.has(r); }
void allocGPR(Register r) {
MOZ_ASSERT(isAvailableGPR(r));
availGPR.take(r);
}
Register allocGPR() {
MOZ_ASSERT(hasGPR());
return availGPR.takeAny();
}
void allocInt64(Register64 r) {
#ifdef JS_PUNBOX64
allocGPR(r.reg);
#else
allocGPR(r.low);
allocGPR(r.high);
#endif
}
Register64 allocInt64() {
MOZ_ASSERT(hasGPR64());
#ifdef JS_PUNBOX64
return Register64(availGPR.takeAny());
#else
Register high = availGPR.takeAny();
Register low = availGPR.takeAny();
return Register64(high, low);
#endif
}
#ifdef JS_CODEGEN_ARM
// r12 is normally the ScratchRegister and r13 is always the stack pointer,
// so the highest possible pair has r10 as the even-numbered register.
static constexpr uint32_t PAIR_LIMIT = 10;
bool hasGPRPair() {
for (uint32_t i = 0; i <= PAIR_LIMIT; i += 2) {
if (isAvailableGPR(Register::FromCode(i)) &&
isAvailableGPR(Register::FromCode(i + 1))) {
return true;
}
}
return false;
}
void allocGPRPair(Register* low, Register* high) {
MOZ_ASSERT(hasGPRPair());
for (uint32_t i = 0; i <= PAIR_LIMIT; i += 2) {
if (isAvailableGPR(Register::FromCode(i)) &&
isAvailableGPR(Register::FromCode(i + 1))) {
*low = Register::FromCode(i);
*high = Register::FromCode(i + 1);
allocGPR(*low);
allocGPR(*high);
return;
}
}
MOZ_CRASH("No pair");
}
#endif
void allocFPU(FloatRegister r) {
MOZ_ASSERT(isAvailableFPU(r));
availFPU.take(r);
}
template <MIRType t>
FloatRegister allocFPU() {
return availFPU.takeAny<RegTypeOf<t>::value>();
}
void freeGPR(Register r) { availGPR.add(r); }
void freeInt64(Register64 r) {
#ifdef JS_PUNBOX64
freeGPR(r.reg);
#else
freeGPR(r.low);
freeGPR(r.high);
#endif
}
void freeFPU(FloatRegister r) { availFPU.add(r); }
public:
explicit BaseRegAlloc()
: bc(nullptr),
availGPR(GeneralRegisterSet::All()),
availFPU(FloatRegisterSet::All())
#ifdef DEBUG
,
scratchTaken(0)
#endif
#ifdef JS_CODEGEN_X86
,
singleByteRegs(GeneralRegisterSet(Registers::SingleByteRegs))
#endif
{
RegisterAllocator::takeWasmRegisters(availGPR);
#ifdef RABALDR_PIN_INSTANCE
// If the InstanceReg is pinned then it is never available for
// allocation.
availGPR.take(InstanceReg);
#endif
// Allocate any private scratch registers.
#if defined(RABALDR_SCRATCH_I32)
if (RabaldrScratchI32 != RegI32::Invalid()) {
availGPR.take(RabaldrScratchI32);
}
#endif
#ifdef RABALDR_SCRATCH_F32_ALIASES_F64
static_assert(RabaldrScratchF32 != InvalidFloatReg, "Float reg definition");
static_assert(RabaldrScratchF64 != InvalidFloatReg, "Float reg definition");
#endif
#if defined(RABALDR_SCRATCH_F32) && !defined(RABALDR_SCRATCH_F32_ALIASES_F64)
if (RabaldrScratchF32 != RegF32::Invalid()) {
availFPU.take(RabaldrScratchF32);
}
#endif
#if defined(RABALDR_SCRATCH_F64)
# ifdef RABALDR_SCRATCH_F32_ALIASES_F64
MOZ_ASSERT(availFPU.has(RabaldrScratchF32));
# endif
if (RabaldrScratchF64 != RegF64::Invalid()) {
availFPU.take(RabaldrScratchF64);
}
# ifdef RABALDR_SCRATCH_F32_ALIASES_F64
MOZ_ASSERT(!availFPU.has(RabaldrScratchF32));
# endif
#endif
#ifdef DEBUG
allGPR = availGPR;
allFPU = availFPU;
#endif
}
void init(BaseCompiler* bc) { this->bc = bc; }
enum class ScratchKind { I32 = 1, F32 = 2, F64 = 4, V128 = 8 };
#ifdef DEBUG
bool isScratchRegisterTaken(ScratchKind s) const {
return (scratchTaken & uint32_t(s)) != 0;
}
void setScratchRegisterTaken(ScratchKind s, bool state) {
if (state) {
scratchTaken |= uint32_t(s);
} else {
scratchTaken &= ~uint32_t(s);
}
}
#endif
#ifdef JS_CODEGEN_X86
bool isSingleByteI32(Register r) { return singleByteRegs.has(r); }
#endif
bool isAvailableI32(RegI32 r) { return isAvailableGPR(r); }
bool isAvailableI64(RegI64 r) {
#ifdef JS_PUNBOX64
return isAvailableGPR(r.reg);
#else
return isAvailableGPR(r.low) && isAvailableGPR(r.high);
#endif
}
bool isAvailableRef(RegRef r) { return isAvailableGPR(r); }
bool isAvailablePtr(RegPtr r) { return isAvailableGPR(r); }
bool isAvailableF32(RegF32 r) { return isAvailableFPU(r); }
bool isAvailableF64(RegF64 r) { return isAvailableFPU(r); }
#ifdef ENABLE_WASM_SIMD
bool isAvailableV128(RegV128 r) { return isAvailableFPU(r); }
#endif
[[nodiscard]] inline RegI32 needI32();
inline void needI32(RegI32 specific);
[[nodiscard]] inline RegI64 needI64();
inline void needI64(RegI64 specific);
[[nodiscard]] inline RegRef needRef();
inline void needRef(RegRef specific);
[[nodiscard]] inline RegPtr needPtr();
inline void needPtr(RegPtr specific);
[[nodiscard]] inline RegF32 needF32();
inline void needF32(RegF32 specific);
[[nodiscard]] inline RegF64 needF64();
inline void needF64(RegF64 specific);
#ifdef ENABLE_WASM_SIMD
[[nodiscard]] inline RegV128 needV128();
inline void needV128(RegV128 specific);
#endif
inline void freeI32(RegI32 r);
inline void freeI64(RegI64 r);
inline void freeRef(RegRef r);
inline void freePtr(RegPtr r);
inline void freeF64(RegF64 r);
inline void freeF32(RegF32 r);
#ifdef ENABLE_WASM_SIMD
inline void freeV128(RegV128 r);
#endif
// Use when you need a register for a short time but explicitly want to avoid
// a full sync().
[[nodiscard]] inline RegPtr needTempPtr(RegPtr fallback, bool* saved);
inline void freeTempPtr(RegPtr r, bool saved);
#ifdef JS_CODEGEN_ARM
[[nodiscard]] inline RegI64 needI64Pair();
#endif
#ifdef DEBUG
friend class LeakCheck;
class MOZ_RAII LeakCheck {
private:
const BaseRegAlloc& ra;
AllocatableGeneralRegisterSet knownGPR_;
AllocatableFloatRegisterSet knownFPU_;
public:
explicit LeakCheck(const BaseRegAlloc& ra) : ra(ra) {
knownGPR_ = ra.availGPR;
knownFPU_ = ra.availFPU;
}
~LeakCheck() {
MOZ_ASSERT(knownGPR_.bits() == ra.allGPR.bits());
MOZ_ASSERT(knownFPU_.bits() == ra.allFPU.bits());
}
void addKnownI32(RegI32 r) { knownGPR_.add(r); }
void addKnownI64(RegI64 r) {
# ifdef JS_PUNBOX64
knownGPR_.add(r.reg);
# else
knownGPR_.add(r.high);
knownGPR_.add(r.low);
# endif
}
void addKnownF32(RegF32 r) { knownFPU_.add(r); }
void addKnownF64(RegF64 r) { knownFPU_.add(r); }
# ifdef ENABLE_WASM_SIMD
void addKnownV128(RegV128 r) { knownFPU_.add(r); }
# endif
void addKnownRef(RegRef r) { knownGPR_.add(r); }
};
#endif
};
// Scratch register abstractions.
//
// We define our own scratch registers when the platform doesn't provide what we
// need. A notable use case is that we will need a private scratch register
// when the platform masm uses its scratch register very frequently (eg, ARM).
class BaseScratchRegister {
#ifdef DEBUG
BaseRegAlloc& ra;
BaseRegAlloc::ScratchKind kind_;
public:
explicit BaseScratchRegister(BaseRegAlloc& ra, BaseRegAlloc::ScratchKind kind)
: ra(ra), kind_(kind) {
MOZ_ASSERT(!ra.isScratchRegisterTaken(kind_));
ra.setScratchRegisterTaken(kind_, true);
}
~BaseScratchRegister() {
MOZ_ASSERT(ra.isScratchRegisterTaken(kind_));
ra.setScratchRegisterTaken(kind_, false);
}
#else
public:
explicit BaseScratchRegister(BaseRegAlloc& ra,
BaseRegAlloc::ScratchKind kind) {}
#endif
};
#ifdef ENABLE_WASM_SIMD
# ifdef RABALDR_SCRATCH_V128
class ScratchV128 : public BaseScratchRegister {
public:
explicit ScratchV128(BaseRegAlloc& ra)
: BaseScratchRegister(ra, BaseRegAlloc::ScratchKind::V128) {}
operator RegV128() const { return RegV128(RabaldrScratchV128); }
};
# else
class ScratchV128 : public ScratchSimd128Scope {
public:
explicit ScratchV128(MacroAssembler& m) : ScratchSimd128Scope(m) {}
operator RegV128() const { return RegV128(FloatRegister(*this)); }
};
# endif
#endif
#ifdef RABALDR_SCRATCH_F64
class ScratchF64 : public BaseScratchRegister {
public:
explicit ScratchF64(BaseRegAlloc& ra)
: BaseScratchRegister(ra, BaseRegAlloc::ScratchKind::F64) {}
operator RegF64() const { return RegF64(RabaldrScratchF64); }
};
#else
class ScratchF64 : public ScratchDoubleScope {
public:
explicit ScratchF64(MacroAssembler& m) : ScratchDoubleScope(m) {}
operator RegF64() const { return RegF64(FloatRegister(*this)); }
};
#endif
#ifdef RABALDR_SCRATCH_F32
class ScratchF32 : public BaseScratchRegister {
public:
explicit ScratchF32(BaseRegAlloc& ra)
: BaseScratchRegister(ra, BaseRegAlloc::ScratchKind::F32) {}
operator RegF32() const { return RegF32(RabaldrScratchF32); }
};
#else
class ScratchF32 : public ScratchFloat32Scope {
public:
explicit ScratchF32(MacroAssembler& m) : ScratchFloat32Scope(m) {}
operator RegF32() const { return RegF32(FloatRegister(*this)); }
};
#endif
#ifdef RABALDR_SCRATCH_I32
template <class RegType>
class ScratchGPR : public BaseScratchRegister {
public:
explicit ScratchGPR(BaseRegAlloc& ra)
: BaseScratchRegister(ra, BaseRegAlloc::ScratchKind::I32) {}
operator RegType() const { return RegType(RabaldrScratchI32); }
};
#else
template <class RegType>
class ScratchGPR : public ScratchRegisterScope {
public:
explicit ScratchGPR(MacroAssembler& m) : ScratchRegisterScope(m) {}
operator RegType() const { return RegType(Register(*this)); }
};
#endif
using ScratchI32 = ScratchGPR<RegI32>;
using ScratchPtr = ScratchGPR<RegPtr>;
using ScratchRef = ScratchGPR<RegRef>;
#if defined(JS_CODEGEN_X86)
// ScratchEBX is a mnemonic device: For some atomic ops we really need EBX,
// no other register will do. And we would normally have to allocate that
// register using ScratchI32 since normally the scratch register is EBX.
// But the whole point of ScratchI32 is to hide that relationship. By using
// the ScratchEBX alias, we document that at that point we require the
// scratch register to be EBX.
using ScratchEBX = ScratchI32;
// ScratchI8 is a mnemonic device: For some ops we need a register with a
// byte subregister.
using ScratchI8 = ScratchI32;
#endif
} // namespace wasm
} // namespace js
#endif // wasm_wasm_baseline_regdefs_h