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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:
* 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_BaselineIC_h
#define jit_BaselineIC_h
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include <stddef.h>
#include <stdint.h>
#include "jit/ICState.h"
#include "jit/JitCode.h"
#include "jit/shared/Assembler-shared.h"
#include "jit/TypeData.h"
#include "js/TypeDecls.h"
class JS_PUBLIC_API JSTracer;
enum class JSOp : uint8_t;
namespace js {
MOZ_COLD void ReportOutOfMemory(JSContext* cx);
namespace jit {
class BaselineFrame;
class CacheIRStubInfo;
class ICScript;
enum class TailCallVMFunctionId;
enum class VMFunctionId;
// [SMDOC] JIT Inline Caches (ICs)
//
// Baseline Inline Caches are polymorphic caches that aggressively
// share their stub code.
//
// Every polymorphic site contains a linked list of stubs which are
// specific to that site. These stubs are composed of a |StubData|
// structure that stores parametrization information (e.g.
// the shape pointer for a shape-check-and-property-get stub), any
// dynamic information (e.g. warm-up counters), a pointer to the stub code,
// and a pointer to the next stub state in the linked list.
//
// Every BaselineScript keeps an table of |CacheDescriptor| data
// structures, which store the following:
// A pointer to the first StubData in the cache.
// The bytecode PC of the relevant IC.
// The machine-code PC where the call to the stubcode returns.
//
// A diagram:
//
// Control flow Pointers
// =======# ----. .---->
// # | |
// #======> \-----/
//
//
// .---------------------------------------.
// | .-------------------------. |
// | | .----. | |
// Baseline | | | | | |
// JIT Code 0 ^ 1 ^ 2 ^ | | |
// +--------------+ .-->+-----+ +-----+ +-----+ | | |
// | | #=|==>| |==>| |==>| FB | | | |
// | | # | +-----+ +-----+ +-----+ | | |
// | | # | # # # | | |
// |==============|==# | # # # | | |
// |=== IC =======| | # # # | | |
// .->|==============|<===|======#=========#=========# | | |
// | | | | | | |
// | | | | | | |
// | | | | | | |
// | | | | v | |
// | | | | +---------+ | |
// | | | | | Fallback| | |
// | | | | | Stub | | |
// | | | | | Code | | |
// | | | | +---------+ | |
// | +--------------+ | | |
// | |_______ | +---------+ | |
// | | | | Stub |<---/ |
// | IC | \--. | Code | |
// | Descriptor | | +---------+ |
// | Table v | |
// | +-----------------+ | +---------+ |
// \--| Ins | PC | Stub |----/ | Stub |<-------/
// +-----------------+ | Code |
// | ... | +---------+
// +-----------------+
// Shared
// Stub Code
//
class ICStub;
class ICCacheIRStub;
class ICFallbackStub;
#ifdef JS_JITSPEW
void FallbackICSpew(JSContext* cx, ICFallbackStub* stub, const char* fmt, ...)
MOZ_FORMAT_PRINTF(3, 4);
#else
# define FallbackICSpew(...)
#endif
// An entry in the ICScript IC table. There's one ICEntry per IC.
class ICEntry {
// A pointer to the first IC stub for this instruction.
ICStub* firstStub_;
public:
explicit ICEntry(ICStub* firstStub) : firstStub_(firstStub) {}
ICStub* firstStub() const {
MOZ_ASSERT(firstStub_);
return firstStub_;
}
void setFirstStub(ICStub* stub) { firstStub_ = stub; }
static constexpr size_t offsetOfFirstStub() {
return offsetof(ICEntry, firstStub_);
}
void trace(JSTracer* trc);
};
//
// Base class for all IC stubs.
//
class ICStub {
friend class ICFallbackStub;
protected:
// The raw jitcode to call for this stub.
uint8_t* stubCode_;
// Counts the number of times the stub was entered
//
// See Bug 1494473 comment 6 for a mechanism to handle overflow if overflow
// becomes a concern.
uint32_t enteredCount_ = 0;
// Tracks input types for some CacheIR stubs, to help optimize
// polymorphic cases. Stored in the base class to make use of
// padding bytes.
TypeData typeData_;
// Whether this is an ICFallbackStub or an ICCacheIRStub.
bool isFallback_;
ICStub(uint8_t* stubCode, bool isFallback)
: stubCode_(stubCode), isFallback_(isFallback) {
MOZ_ASSERT(stubCode != nullptr);
}
public:
inline bool isFallback() const { return isFallback_; }
inline ICStub* maybeNext() const;
inline const ICFallbackStub* toFallbackStub() const {
MOZ_ASSERT(isFallback());
return reinterpret_cast<const ICFallbackStub*>(this);
}
inline ICFallbackStub* toFallbackStub() {
MOZ_ASSERT(isFallback());
return reinterpret_cast<ICFallbackStub*>(this);
}
ICCacheIRStub* toCacheIRStub() {
MOZ_ASSERT(!isFallback());
return reinterpret_cast<ICCacheIRStub*>(this);
}
const ICCacheIRStub* toCacheIRStub() const {
MOZ_ASSERT(!isFallback());
return reinterpret_cast<const ICCacheIRStub*>(this);
}
bool usesTrampolineCode() const {
// All fallback code is stored in a single JitCode instance, so we can't
// call JitCode::FromExecutable on the raw pointer.
return isFallback();
}
JitCode* jitCode() {
MOZ_ASSERT(!usesTrampolineCode());
return JitCode::FromExecutable(stubCode_);
}
uint32_t enteredCount() const { return enteredCount_; }
inline void incrementEnteredCount() { enteredCount_++; }
void resetEnteredCount() { enteredCount_ = 0; }
static constexpr size_t offsetOfStubCode() {
return offsetof(ICStub, stubCode_);
}
static constexpr size_t offsetOfEnteredCount() {
return offsetof(ICStub, enteredCount_);
}
};
class ICFallbackStub final : public ICStub {
friend class ICStubConstIterator;
protected:
// The PC offset of this IC's bytecode op within the JSScript.
uint32_t pcOffset_;
// The state of this IC.
ICState state_{};
public:
explicit ICFallbackStub(uint32_t pcOffset, TrampolinePtr stubCode)
: ICStub(stubCode.value, /* isFallback = */ true), pcOffset_(pcOffset) {}
inline size_t numOptimizedStubs() const { return state_.numOptimizedStubs(); }
bool newStubIsFirstStub() const { return state_.newStubIsFirstStub(); }
ICState& state() { return state_; }
uint32_t pcOffset() const { return pcOffset_; }
// Add a new stub to the IC chain terminated by this fallback stub.
inline void addNewStub(ICEntry* icEntry, ICCacheIRStub* stub);
void discardStubs(JSContext* cx, ICEntry* icEntry);
void clearUsedByTranspiler() { state_.clearUsedByTranspiler(); }
void setUsedByTranspiler() { state_.setUsedByTranspiler(); }
TrialInliningState trialInliningState() const {
return state_.trialInliningState();
}
void setTrialInliningState(TrialInliningState state) {
state_.setTrialInliningState(state);
}
void trackNotAttached();
void unlinkStub(Zone* zone, ICEntry* icEntry, ICCacheIRStub* prev,
ICCacheIRStub* stub);
};
class ICCacheIRStub final : public ICStub {
// Pointer to next IC stub.
ICStub* next_ = nullptr;
const CacheIRStubInfo* stubInfo_;
#ifndef JS_64BIT
// Ensure stub data is 8-byte aligned on 32-bit.
uintptr_t padding_ = 0;
#endif
public:
ICCacheIRStub(JitCode* stubCode, const CacheIRStubInfo* stubInfo)
: ICStub(stubCode->raw(), /* isFallback = */ false),
stubInfo_(stubInfo) {}
ICStub* next() const { return next_; }
void setNext(ICStub* stub) { next_ = stub; }
const CacheIRStubInfo* stubInfo() const { return stubInfo_; }
uint8_t* stubDataStart();
void trace(JSTracer* trc);
// Optimized stubs get purged on GC. But some stubs can be active on the
// stack during GC - specifically the ones that can make calls. To ensure
// that these do not get purged, all stubs that can make calls are allocated
// in the fallback stub space.
bool makesGCCalls() const;
bool allocatedInFallbackSpace() const { return makesGCCalls(); }
static constexpr size_t offsetOfNext() {
return offsetof(ICCacheIRStub, next_);
}
void setTypeData(TypeData data) { typeData_ = data; }
TypeData typeData() const { return typeData_; }
};
// Assert stub size is what we expect to catch regressions.
#ifdef JS_64BIT
static_assert(sizeof(ICFallbackStub) == 3 * sizeof(uintptr_t));
static_assert(sizeof(ICCacheIRStub) == 4 * sizeof(uintptr_t));
#else
static_assert(sizeof(ICFallbackStub) == 5 * sizeof(uintptr_t));
static_assert(sizeof(ICCacheIRStub) == 6 * sizeof(uintptr_t));
#endif
inline ICStub* ICStub::maybeNext() const {
return isFallback() ? nullptr : toCacheIRStub()->next();
}
inline void ICFallbackStub::addNewStub(ICEntry* icEntry, ICCacheIRStub* stub) {
MOZ_ASSERT(stub->next() == nullptr);
stub->setNext(icEntry->firstStub());
icEntry->setFirstStub(stub);
state_.trackAttached();
}
AllocatableGeneralRegisterSet BaselineICAvailableGeneralRegs(size_t numInputs);
bool ICSupportsPolymorphicTypeData(JSOp op);
struct IonOsrTempData;
extern bool DoCallFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, uint32_t argc, Value* vp,
MutableHandleValue res);
extern bool DoSpreadCallFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, Value* vp,
MutableHandleValue res);
extern bool DoToBoolFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue arg,
MutableHandleValue ret);
extern bool DoGetElemSuperFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue lhs,
HandleValue rhs, HandleValue receiver,
MutableHandleValue res);
extern bool DoGetElemFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue lhs,
HandleValue rhs, MutableHandleValue res);
extern bool DoSetElemFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, Value* stack,
HandleValue objv, HandleValue index,
HandleValue rhs);
extern bool DoInFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue key,
HandleValue objValue, MutableHandleValue res);
extern bool DoHasOwnFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue keyValue,
HandleValue objValue, MutableHandleValue res);
extern bool DoCheckPrivateFieldFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub,
HandleValue objValue,
HandleValue keyValue,
MutableHandleValue res);
extern bool DoGetNameFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleObject envChain,
MutableHandleValue res);
extern bool DoBindNameFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleObject envChain,
MutableHandleValue res);
extern bool DoGetIntrinsicFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub,
MutableHandleValue res);
extern bool DoGetPropFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, MutableHandleValue val,
MutableHandleValue res);
extern bool DoGetPropSuperFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue receiver,
MutableHandleValue val,
MutableHandleValue res);
extern bool DoSetPropFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, Value* stack,
HandleValue lhs, HandleValue rhs);
extern bool DoGetIteratorFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue value,
MutableHandleValue res);
extern bool DoOptimizeSpreadCallFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub,
HandleValue value,
MutableHandleValue res);
extern bool DoInstanceOfFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue lhs,
HandleValue rhs, MutableHandleValue res);
extern bool DoTypeOfFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue val,
MutableHandleValue res);
extern bool DoToPropertyKeyFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue val,
MutableHandleValue res);
extern bool DoRestFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, MutableHandleValue res);
extern bool DoUnaryArithFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue val,
MutableHandleValue res);
extern bool DoBinaryArithFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue lhs,
HandleValue rhs, MutableHandleValue ret);
extern bool DoNewArrayFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, MutableHandleValue res);
extern bool DoNewObjectFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, MutableHandleValue res);
extern bool DoCompareFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleValue lhs,
HandleValue rhs, MutableHandleValue ret);
extern bool DoCloseIterFallback(JSContext* cx, BaselineFrame* frame,
ICFallbackStub* stub, HandleObject iter);
} // namespace jit
} // namespace js
#endif /* jit_BaselineIC_h */