Google Git
Sign in
webkit / WebKit / 04824e630337b93a79d2ece4fdb0514ba4ab8bec / . / Source / JavaScriptCore / bytecode / CodeBlock.cpp
blob: cf6684ca829020388904ed8fc86ea5226138cdb9 [file] [log] [blame]
/*
* Copyright (C) 2008-2018 Apple Inc. All rights reserved.
* Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "CodeBlock.h"
#include "ArithProfile.h"
#include "BasicBlockLocation.h"
#include "BytecodeDumper.h"
#include "BytecodeGenerator.h"
#include "BytecodeLivenessAnalysis.h"
#include "BytecodeUseDef.h"
#include "CallLinkStatus.h"
#include "CodeBlockSet.h"
#include "DFGCapabilities.h"
#include "DFGCommon.h"
#include "DFGDriver.h"
#include "DFGJITCode.h"
#include "DFGWorklist.h"
#include "Debugger.h"
#include "EvalCodeBlock.h"
#include "FullCodeOrigin.h"
#include "FunctionCodeBlock.h"
#include "FunctionExecutableDump.h"
#include "GetPutInfo.h"
#include "InlineCallFrame.h"
#include "InterpreterInlines.h"
#include "IsoCellSetInlines.h"
#include "JIT.h"
#include "JITMathIC.h"
#include "JSBigInt.h"
#include "JSCInlines.h"
#include "JSCJSValue.h"
#include "JSFunction.h"
#include "JSLexicalEnvironment.h"
#include "JSModuleEnvironment.h"
#include "JSSet.h"
#include "JSString.h"
#include "JSTemplateObjectDescriptor.h"
#include "LLIntData.h"
#include "LLIntEntrypoint.h"
#include "LLIntPrototypeLoadAdaptiveStructureWatchpoint.h"
#include "LowLevelInterpreter.h"
#include "ModuleProgramCodeBlock.h"
#include "ObjectAllocationProfileInlines.h"
#include "PCToCodeOriginMap.h"
#include "PolymorphicAccess.h"
#include "ProfilerDatabase.h"
#include "ProgramCodeBlock.h"
#include "ReduceWhitespace.h"
#include "Repatch.h"
#include "SlotVisitorInlines.h"
#include "StackVisitor.h"
#include "StructureStubInfo.h"
#include "TypeLocationCache.h"
#include "TypeProfiler.h"
#include "UnlinkedInstructionStream.h"
#include "VMInlines.h"
#include <wtf/BagToHashMap.h>
#include <wtf/CommaPrinter.h>
#include <wtf/SimpleStats.h>
#include <wtf/StringPrintStream.h>
#include <wtf/text/UniquedStringImpl.h>
#if ENABLE(JIT)
#include "RegisterAtOffsetList.h"
#endif
#if ENABLE(DFG_JIT)
#include "DFGOperations.h"
#endif
#if ENABLE(FTL_JIT)
#include "FTLJITCode.h"
#endif
namespace JSC {
const ClassInfo CodeBlock::s_info = {
"CodeBlock", nullptr, nullptr, nullptr,
CREATE_METHOD_TABLE(CodeBlock)
};
CString CodeBlock::inferredName() const
{
switch (codeType()) {
case GlobalCode:
return "<global>";
case EvalCode:
return "<eval>";
case FunctionCode:
return jsCast<FunctionExecutable*>(ownerExecutable())->inferredName().utf8();
case ModuleCode:
return "<module>";
default:
CRASH();
return CString("", 0);
}
}
bool CodeBlock::hasHash() const
{
return !!m_hash;
}
bool CodeBlock::isSafeToComputeHash() const
{
return !isCompilationThread();
}
CodeBlockHash CodeBlock::hash() const
{
if (!m_hash) {
RELEASE_ASSERT(isSafeToComputeHash());
m_hash = CodeBlockHash(ownerScriptExecutable()->source(), specializationKind());
}
return m_hash;
}
CString CodeBlock::sourceCodeForTools() const
{
if (codeType() != FunctionCode)
return ownerScriptExecutable()->source().toUTF8();
SourceProvider* provider = source();
FunctionExecutable* executable = jsCast<FunctionExecutable*>(ownerExecutable());
UnlinkedFunctionExecutable* unlinked = executable->unlinkedExecutable();
unsigned unlinkedStartOffset = unlinked->startOffset();
unsigned linkedStartOffset = executable->source().startOffset();
int delta = linkedStartOffset - unlinkedStartOffset;
unsigned rangeStart = delta + unlinked->unlinkedFunctionNameStart();
unsigned rangeEnd = delta + unlinked->startOffset() + unlinked->sourceLength();
return toCString(
"function ",
provider->source().substring(rangeStart, rangeEnd - rangeStart).utf8());
}
CString CodeBlock::sourceCodeOnOneLine() const
{
return reduceWhitespace(sourceCodeForTools());
}
CString CodeBlock::hashAsStringIfPossible() const
{
if (hasHash() || isSafeToComputeHash())
return toCString(hash());
return "<no-hash>";
}
void CodeBlock::dumpAssumingJITType(PrintStream& out, JITCode::JITType jitType) const
{
out.print(inferredName(), "#", hashAsStringIfPossible());
out.print(":[", RawPointer(this), "->");
if (!!m_alternative)
out.print(RawPointer(alternative()), "->");
out.print(RawPointer(ownerExecutable()), ", ", jitType, codeType());
if (codeType() == FunctionCode)
out.print(specializationKind());
out.print(", ", instructionCount());
if (this->jitType() == JITCode::BaselineJIT && m_shouldAlwaysBeInlined)
out.print(" (ShouldAlwaysBeInlined)");
if (ownerScriptExecutable()->neverInline())
out.print(" (NeverInline)");
if (ownerScriptExecutable()->neverOptimize())
out.print(" (NeverOptimize)");
else if (ownerScriptExecutable()->neverFTLOptimize())
out.print(" (NeverFTLOptimize)");
if (ownerScriptExecutable()->didTryToEnterInLoop())
out.print(" (DidTryToEnterInLoop)");
if (ownerScriptExecutable()->isStrictMode())
out.print(" (StrictMode)");
if (m_didFailJITCompilation)
out.print(" (JITFail)");
if (this->jitType() == JITCode::BaselineJIT && m_didFailFTLCompilation)
out.print(" (FTLFail)");
if (this->jitType() == JITCode::BaselineJIT && m_hasBeenCompiledWithFTL)
out.print(" (HadFTLReplacement)");
out.print("]");
}
void CodeBlock::dump(PrintStream& out) const
{
dumpAssumingJITType(out, jitType());
}
void CodeBlock::dumpSource()
{
dumpSource(WTF::dataFile());
}
void CodeBlock::dumpSource(PrintStream& out)
{
ScriptExecutable* executable = ownerScriptExecutable();
if (executable->isFunctionExecutable()) {
FunctionExecutable* functionExecutable = reinterpret_cast<FunctionExecutable*>(executable);
StringView source = functionExecutable->source().provider()->getRange(
functionExecutable->parametersStartOffset(),
functionExecutable->typeProfilingEndOffset() + 1); // Type profiling end offset is the character before the '}'.
out.print("function ", inferredName(), source);
return;
}
out.print(executable->source().view());
}
void CodeBlock::dumpBytecode()
{
dumpBytecode(WTF::dataFile());
}
void CodeBlock::dumpBytecode(PrintStream& out)
{
StubInfoMap stubInfos;
CallLinkInfoMap callLinkInfos;
getStubInfoMap(stubInfos);
getCallLinkInfoMap(callLinkInfos);
BytecodeDumper<CodeBlock>::dumpBlock(this, instructions(), out, stubInfos, callLinkInfos);
}
void CodeBlock::dumpBytecode(PrintStream& out, const Instruction* begin, const Instruction*& it, const StubInfoMap& stubInfos, const CallLinkInfoMap& callLinkInfos)
{
BytecodeDumper<CodeBlock>::dumpBytecode(this, out, begin, it, stubInfos, callLinkInfos);
}
void CodeBlock::dumpBytecode(
PrintStream& out, unsigned bytecodeOffset,
const StubInfoMap& stubInfos, const CallLinkInfoMap& callLinkInfos)
{
const Instruction* it = &instructions()[bytecodeOffset];
dumpBytecode(out, instructions().begin(), it, stubInfos, callLinkInfos);
}
#define FOR_EACH_MEMBER_VECTOR(macro) \
macro(instructions) \
macro(callLinkInfos) \
macro(linkedCallerList) \
macro(identifiers) \
macro(functionExpressions) \
macro(constantRegisters)
template<typename T>
static size_t sizeInBytes(const Vector<T>& vector)
{
return vector.capacity() * sizeof(T);
}
namespace {
class PutToScopeFireDetail : public FireDetail {
public:
PutToScopeFireDetail(CodeBlock* codeBlock, const Identifier& ident)
: m_codeBlock(codeBlock)
, m_ident(ident)
{
}
void dump(PrintStream& out) const override
{
out.print("Linking put_to_scope in ", FunctionExecutableDump(jsCast<FunctionExecutable*>(m_codeBlock->ownerExecutable())), " for ", m_ident);
}
private:
CodeBlock* m_codeBlock;
const Identifier& m_ident;
};
} // anonymous namespace
CodeBlock::CodeBlock(VM* vm, Structure* structure, CopyParsedBlockTag, CodeBlock& other)
: JSCell(*vm, structure)
, m_globalObject(other.m_globalObject)
, m_numCalleeLocals(other.m_numCalleeLocals)
, m_numVars(other.m_numVars)
, m_shouldAlwaysBeInlined(true)
#if ENABLE(JIT)
, m_capabilityLevelState(DFG::CapabilityLevelNotSet)
#endif
, m_didFailJITCompilation(false)
, m_didFailFTLCompilation(false)
, m_hasBeenCompiledWithFTL(false)
, m_isConstructor(other.m_isConstructor)
, m_isStrictMode(other.m_isStrictMode)
, m_codeType(other.m_codeType)
, m_unlinkedCode(*other.vm(), this, other.m_unlinkedCode.get())
, m_numberOfArgumentsToSkip(other.m_numberOfArgumentsToSkip)
, m_hasDebuggerStatement(false)
, m_steppingMode(SteppingModeDisabled)
, m_numBreakpoints(0)
, m_ownerExecutable(*other.vm(), this, other.m_ownerExecutable.get())
, m_poisonedVM(other.m_poisonedVM)
, m_instructions(other.m_instructions)
, m_thisRegister(other.m_thisRegister)
, m_scopeRegister(other.m_scopeRegister)
, m_hash(other.m_hash)
, m_source(other.m_source)
, m_sourceOffset(other.m_sourceOffset)
, m_firstLineColumnOffset(other.m_firstLineColumnOffset)
, m_constantRegisters(other.m_constantRegisters)
, m_constantsSourceCodeRepresentation(other.m_constantsSourceCodeRepresentation)
, m_functionDecls(other.m_functionDecls)
, m_functionExprs(other.m_functionExprs)
, m_osrExitCounter(0)
, m_optimizationDelayCounter(0)
, m_reoptimizationRetryCounter(0)
, m_creationTime(MonotonicTime::now())
{
ASSERT(heap()->isDeferred());
ASSERT(m_scopeRegister.isLocal());
setNumParameters(other.numParameters());
vm->heap.codeBlockSet().add(this);
}
void CodeBlock::finishCreation(VM& vm, CopyParsedBlockTag, CodeBlock& other)
{
Base::finishCreation(vm);
finishCreationCommon(vm);
optimizeAfterWarmUp();
jitAfterWarmUp();
if (other.m_rareData) {
createRareDataIfNecessary();
m_rareData->m_exceptionHandlers = other.m_rareData->m_exceptionHandlers;
m_rareData->m_switchJumpTables = other.m_rareData->m_switchJumpTables;
m_rareData->m_stringSwitchJumpTables = other.m_rareData->m_stringSwitchJumpTables;
}
}
CodeBlock::CodeBlock(VM* vm, Structure* structure, ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock,
JSScope* scope, RefPtr<SourceProvider>&& sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
: JSCell(*vm, structure)
, m_globalObject(*vm, this, scope->globalObject())
, m_numCalleeLocals(unlinkedCodeBlock->m_numCalleeLocals)
, m_numVars(unlinkedCodeBlock->m_numVars)
, m_shouldAlwaysBeInlined(true)
#if ENABLE(JIT)
, m_capabilityLevelState(DFG::CapabilityLevelNotSet)
#endif
, m_didFailJITCompilation(false)
, m_didFailFTLCompilation(false)
, m_hasBeenCompiledWithFTL(false)
, m_isConstructor(unlinkedCodeBlock->isConstructor())
, m_isStrictMode(unlinkedCodeBlock->isStrictMode())
, m_codeType(unlinkedCodeBlock->codeType())
, m_unlinkedCode(*vm, this, unlinkedCodeBlock)
, m_hasDebuggerStatement(false)
, m_steppingMode(SteppingModeDisabled)
, m_numBreakpoints(0)
, m_ownerExecutable(*vm, this, ownerExecutable)
, m_poisonedVM(vm)
, m_thisRegister(unlinkedCodeBlock->thisRegister())
, m_scopeRegister(unlinkedCodeBlock->scopeRegister())
, m_source(WTFMove(sourceProvider))
, m_sourceOffset(sourceOffset)
, m_firstLineColumnOffset(firstLineColumnOffset)
, m_osrExitCounter(0)
, m_optimizationDelayCounter(0)
, m_reoptimizationRetryCounter(0)
, m_creationTime(MonotonicTime::now())
{
ASSERT(heap()->isDeferred());
ASSERT(m_scopeRegister.isLocal());
ASSERT(m_source);
setNumParameters(unlinkedCodeBlock->numParameters());
vm->heap.codeBlockSet().add(this);
}
// The main purpose of this function is to generate linked bytecode from unlinked bytecode. The process
// of linking is taking an abstract representation of bytecode and tying it to a GlobalObject and scope
// chain. For example, this process allows us to cache the depth of lexical environment reads that reach
// outside of this CodeBlock's compilation unit. It also allows us to generate particular constants that
// we can't generate during unlinked bytecode generation. This process is not allowed to generate control
// flow or introduce new locals. The reason for this is we rely on liveness analysis to be the same for
// all the CodeBlocks of an UnlinkedCodeBlock. We rely on this fact by caching the liveness analysis
// inside UnlinkedCodeBlock.
bool CodeBlock::finishCreation(VM& vm, ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock,
JSScope* scope)
{
Base::finishCreation(vm);
finishCreationCommon(vm);
auto throwScope = DECLARE_THROW_SCOPE(vm);
if (vm.typeProfiler() || vm.controlFlowProfiler())
vm.functionHasExecutedCache()->removeUnexecutedRange(ownerExecutable->sourceID(), ownerExecutable->typeProfilingStartOffset(), ownerExecutable->typeProfilingEndOffset());
setConstantRegisters(unlinkedCodeBlock->constantRegisters(), unlinkedCodeBlock->constantsSourceCodeRepresentation());
RETURN_IF_EXCEPTION(throwScope, false);
setConstantIdentifierSetRegisters(vm, unlinkedCodeBlock->constantIdentifierSets());
RETURN_IF_EXCEPTION(throwScope, false);
if (unlinkedCodeBlock->usesGlobalObject())
m_constantRegisters[unlinkedCodeBlock->globalObjectRegister().toConstantIndex()].set(vm, this, m_globalObject.get());
for (unsigned i = 0; i < LinkTimeConstantCount; i++) {
LinkTimeConstant type = static_cast<LinkTimeConstant>(i);
if (unsigned registerIndex = unlinkedCodeBlock->registerIndexForLinkTimeConstant(type))
m_constantRegisters[registerIndex].set(vm, this, m_globalObject->jsCellForLinkTimeConstant(type));
}
// We already have the cloned symbol table for the module environment since we need to instantiate
// the module environments before linking the code block. We replace the stored symbol table with the already cloned one.
if (UnlinkedModuleProgramCodeBlock* unlinkedModuleProgramCodeBlock = jsDynamicCast<UnlinkedModuleProgramCodeBlock*>(vm, unlinkedCodeBlock)) {
SymbolTable* clonedSymbolTable = jsCast<ModuleProgramExecutable*>(ownerExecutable)->moduleEnvironmentSymbolTable();
if (vm.typeProfiler()) {
ConcurrentJSLocker locker(clonedSymbolTable->m_lock);
clonedSymbolTable->prepareForTypeProfiling(locker);
}
replaceConstant(unlinkedModuleProgramCodeBlock->moduleEnvironmentSymbolTableConstantRegisterOffset(), clonedSymbolTable);
}
bool shouldUpdateFunctionHasExecutedCache = vm.typeProfiler() || vm.controlFlowProfiler();
m_functionDecls = RefCountedArray<WriteBarrier<FunctionExecutable>>(unlinkedCodeBlock->numberOfFunctionDecls());
for (size_t count = unlinkedCodeBlock->numberOfFunctionDecls(), i = 0; i < count; ++i) {
UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionDecl(i);
if (shouldUpdateFunctionHasExecutedCache)
vm.functionHasExecutedCache()->insertUnexecutedRange(ownerExecutable->sourceID(), unlinkedExecutable->typeProfilingStartOffset(), unlinkedExecutable->typeProfilingEndOffset());
m_functionDecls[i].set(vm, this, unlinkedExecutable->link(vm, ownerExecutable->source()));
}
m_functionExprs = RefCountedArray<WriteBarrier<FunctionExecutable>>(unlinkedCodeBlock->numberOfFunctionExprs());
for (size_t count = unlinkedCodeBlock->numberOfFunctionExprs(), i = 0; i < count; ++i) {
UnlinkedFunctionExecutable* unlinkedExecutable = unlinkedCodeBlock->functionExpr(i);
if (shouldUpdateFunctionHasExecutedCache)
vm.functionHasExecutedCache()->insertUnexecutedRange(ownerExecutable->sourceID(), unlinkedExecutable->typeProfilingStartOffset(), unlinkedExecutable->typeProfilingEndOffset());
m_functionExprs[i].set(vm, this, unlinkedExecutable->link(vm, ownerExecutable->source()));
}
if (unlinkedCodeBlock->hasRareData()) {
createRareDataIfNecessary();
if (size_t count = unlinkedCodeBlock->numberOfExceptionHandlers()) {
m_rareData->m_exceptionHandlers.resizeToFit(count);
for (size_t i = 0; i < count; i++) {
const UnlinkedHandlerInfo& unlinkedHandler = unlinkedCodeBlock->exceptionHandler(i);
HandlerInfo& handler = m_rareData->m_exceptionHandlers[i];
#if ENABLE(JIT)
handler.initialize(unlinkedHandler, CodeLocationLabel<ExceptionHandlerPtrTag>(LLInt::getCodePtr<BytecodePtrTag>(op_catch).retagged<ExceptionHandlerPtrTag>()));
#else
handler.initialize(unlinkedHandler);
#endif
}
}
if (size_t count = unlinkedCodeBlock->numberOfStringSwitchJumpTables()) {
m_rareData->m_stringSwitchJumpTables.grow(count);
for (size_t i = 0; i < count; i++) {
UnlinkedStringJumpTable::StringOffsetTable::iterator ptr = unlinkedCodeBlock->stringSwitchJumpTable(i).offsetTable.begin();
UnlinkedStringJumpTable::StringOffsetTable::iterator end = unlinkedCodeBlock->stringSwitchJumpTable(i).offsetTable.end();
for (; ptr != end; ++ptr) {
OffsetLocation offset;
offset.branchOffset = ptr->value.branchOffset;
m_rareData->m_stringSwitchJumpTables[i].offsetTable.add(ptr->key, offset);
}
}
}
if (size_t count = unlinkedCodeBlock->numberOfSwitchJumpTables()) {
m_rareData->m_switchJumpTables.grow(count);
for (size_t i = 0; i < count; i++) {
UnlinkedSimpleJumpTable& sourceTable = unlinkedCodeBlock->switchJumpTable(i);
SimpleJumpTable& destTable = m_rareData->m_switchJumpTables[i];
destTable.branchOffsets = sourceTable.branchOffsets;
destTable.min = sourceTable.min;
}
}
}
// Allocate metadata buffers for the bytecode
if (size_t size = unlinkedCodeBlock->numberOfLLintCallLinkInfos())
m_llintCallLinkInfos = RefCountedArray<LLIntCallLinkInfo>(size);
if (size_t size = unlinkedCodeBlock->numberOfArrayProfiles())
m_arrayProfiles.grow(size);
if (size_t size = unlinkedCodeBlock->numberOfArrayAllocationProfiles())
m_arrayAllocationProfiles = RefCountedArray<ArrayAllocationProfile>(size);
if (size_t size = unlinkedCodeBlock->numberOfValueProfiles())
m_valueProfiles = RefCountedArray<ValueProfile>(size);
if (size_t size = unlinkedCodeBlock->numberOfObjectAllocationProfiles())
m_objectAllocationProfiles = RefCountedArray<ObjectAllocationProfile>(size);
#if ENABLE(JIT)
setCalleeSaveRegisters(RegisterSet::llintBaselineCalleeSaveRegisters());
#endif
// Copy and translate the UnlinkedInstructions
unsigned instructionCount = unlinkedCodeBlock->instructions().count();
UnlinkedInstructionStream::Reader instructionReader(unlinkedCodeBlock->instructions());
// Bookkeep the strongly referenced module environments.
HashSet<JSModuleEnvironment*> stronglyReferencedModuleEnvironments;
RefCountedArray<Instruction> instructions(instructionCount);
unsigned valueProfileCount = 0;
auto linkValueProfile = [&](unsigned bytecodeOffset, unsigned opLength) {
unsigned valueProfileIndex = valueProfileCount++;
ValueProfile* profile = &m_valueProfiles[valueProfileIndex];
ASSERT(profile->m_bytecodeOffset == -1);
profile->m_bytecodeOffset = bytecodeOffset;
instructions[bytecodeOffset + opLength - 1] = profile;
};
for (unsigned i = 0; !instructionReader.atEnd(); ) {
const UnlinkedInstruction* pc = instructionReader.next();
unsigned opLength = opcodeLength(pc[0].u.opcode);
instructions[i] = Interpreter::getOpcode(pc[0].u.opcode);
for (size_t j = 1; j < opLength; ++j) {
if (sizeof(int32_t) != sizeof(intptr_t))
instructions[i + j].u.pointer = 0;
instructions[i + j].u.operand = pc[j].u.operand;
}
switch (pc[0].u.opcode) {
case op_has_indexed_property: {
int arrayProfileIndex = pc[opLength - 1].u.operand;
m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
break;
}
case op_call_varargs:
case op_tail_call_varargs:
case op_tail_call_forward_arguments:
case op_construct_varargs:
case op_get_by_val: {
int arrayProfileIndex = pc[opLength - 2].u.operand;
m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
FALLTHROUGH;
}
case op_get_direct_pname:
case op_get_by_id:
case op_get_by_id_with_this:
case op_try_get_by_id:
case op_get_by_id_direct:
case op_get_by_val_with_this:
case op_get_from_arguments:
case op_to_number:
case op_to_object:
case op_get_argument: {
linkValueProfile(i, opLength);
break;
}
case op_to_this: {
linkValueProfile(i, opLength);
break;
}
case op_in:
case op_put_by_val:
case op_put_by_val_direct: {
int arrayProfileIndex = pc[opLength - 1].u.operand;
m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
instructions[i + opLength - 1] = &m_arrayProfiles[arrayProfileIndex];
break;
}
case op_new_array:
case op_new_array_buffer:
case op_new_array_with_size: {
int arrayAllocationProfileIndex = pc[opLength - 1].u.operand;
instructions[i + opLength - 1] = &m_arrayAllocationProfiles[arrayAllocationProfileIndex];
break;
}
case op_new_object: {
int objectAllocationProfileIndex = pc[opLength - 1].u.operand;
ObjectAllocationProfile* objectAllocationProfile = &m_objectAllocationProfiles[objectAllocationProfileIndex];
int inferredInlineCapacity = pc[opLength - 2].u.operand;
instructions[i + opLength - 1] = objectAllocationProfile;
objectAllocationProfile->initializeProfile(vm,
m_globalObject.get(), this, m_globalObject->objectPrototype(), inferredInlineCapacity);
break;
}
case op_call:
case op_tail_call:
case op_call_eval: {
linkValueProfile(i, opLength);
int arrayProfileIndex = pc[opLength - 2].u.operand;
m_arrayProfiles[arrayProfileIndex] = ArrayProfile(i);
instructions[i + opLength - 2] = &m_arrayProfiles[arrayProfileIndex];
instructions[i + 5] = &m_llintCallLinkInfos[pc[5].u.operand];
break;
}
case op_construct: {
instructions[i + 5] = &m_llintCallLinkInfos[pc[5].u.operand];
linkValueProfile(i, opLength);
break;
}
case op_get_array_length:
CRASH();
case op_resolve_scope: {
const Identifier& ident = identifier(pc[3].u.operand);
ResolveType type = static_cast<ResolveType>(pc[4].u.operand);
RELEASE_ASSERT(type != LocalClosureVar);
int localScopeDepth = pc[5].u.operand;
ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, type, InitializationMode::NotInitialization);
RETURN_IF_EXCEPTION(throwScope, false);
instructions[i + 4].u.operand = op.type;
instructions[i + 5].u.operand = op.depth;
if (op.lexicalEnvironment) {
if (op.type == ModuleVar) {
// Keep the linked module environment strongly referenced.
if (stronglyReferencedModuleEnvironments.add(jsCast<JSModuleEnvironment*>(op.lexicalEnvironment)).isNewEntry)
addConstant(op.lexicalEnvironment);
instructions[i + 6].u.jsCell.set(vm, this, op.lexicalEnvironment);
} else
instructions[i + 6].u.symbolTable.set(vm, this, op.lexicalEnvironment->symbolTable());
} else if (JSScope* constantScope = JSScope::constantScopeForCodeBlock(op.type, this))
instructions[i + 6].u.jsCell.set(vm, this, constantScope);
else
instructions[i + 6].u.pointer = nullptr;
break;
}
case op_get_from_scope: {
linkValueProfile(i, opLength);
// get_from_scope dst, scope, id, GetPutInfo, Structure, Operand
int localScopeDepth = pc[5].u.operand;
instructions[i + 5].u.pointer = nullptr;
GetPutInfo getPutInfo = GetPutInfo(pc[4].u.operand);
ASSERT(!isInitialization(getPutInfo.initializationMode()));
if (getPutInfo.resolveType() == LocalClosureVar) {
instructions[i + 4] = GetPutInfo(getPutInfo.resolveMode(), ClosureVar, getPutInfo.initializationMode()).operand();
break;
}
const Identifier& ident = identifier(pc[3].u.operand);
ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, getPutInfo.resolveType(), InitializationMode::NotInitialization);
RETURN_IF_EXCEPTION(throwScope, false);
instructions[i + 4].u.operand = GetPutInfo(getPutInfo.resolveMode(), op.type, getPutInfo.initializationMode()).operand();
if (op.type == ModuleVar)
instructions[i + 4].u.operand = GetPutInfo(getPutInfo.resolveMode(), ClosureVar, getPutInfo.initializationMode()).operand();
if (op.type == GlobalVar || op.type == GlobalVarWithVarInjectionChecks || op.type == GlobalLexicalVar || op.type == GlobalLexicalVarWithVarInjectionChecks)
instructions[i + 5].u.watchpointSet = op.watchpointSet;
else if (op.structure)
instructions[i + 5].u.structure.set(vm, this, op.structure);
instructions[i + 6].u.pointer = reinterpret_cast<void*>(op.operand);
break;
}
case op_put_to_scope: {
// put_to_scope scope, id, value, GetPutInfo, Structure, Operand
GetPutInfo getPutInfo = GetPutInfo(pc[4].u.operand);
if (getPutInfo.resolveType() == LocalClosureVar) {
// Only do watching if the property we're putting to is not anonymous.
if (static_cast<unsigned>(pc[2].u.operand) != UINT_MAX) {
int symbolTableIndex = pc[5].u.operand;
SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
const Identifier& ident = identifier(pc[2].u.operand);
ConcurrentJSLocker locker(symbolTable->m_lock);
auto iter = symbolTable->find(locker, ident.impl());
ASSERT(iter != symbolTable->end(locker));
iter->value.prepareToWatch();
instructions[i + 5].u.watchpointSet = iter->value.watchpointSet();
} else
instructions[i + 5].u.watchpointSet = nullptr;
break;
}
const Identifier& ident = identifier(pc[2].u.operand);
int localScopeDepth = pc[5].u.operand;
instructions[i + 5].u.pointer = nullptr;
ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Put, getPutInfo.resolveType(), getPutInfo.initializationMode());
RETURN_IF_EXCEPTION(throwScope, false);
instructions[i + 4].u.operand = GetPutInfo(getPutInfo.resolveMode(), op.type, getPutInfo.initializationMode()).operand();
if (op.type == GlobalVar || op.type == GlobalVarWithVarInjectionChecks || op.type == GlobalLexicalVar || op.type == GlobalLexicalVarWithVarInjectionChecks)
instructions[i + 5].u.watchpointSet = op.watchpointSet;
else if (op.type == ClosureVar || op.type == ClosureVarWithVarInjectionChecks) {
if (op.watchpointSet)
op.watchpointSet->invalidate(vm, PutToScopeFireDetail(this, ident));
} else if (op.structure)
instructions[i + 5].u.structure.set(vm, this, op.structure);
instructions[i + 6].u.pointer = reinterpret_cast<void*>(op.operand);
break;
}
case op_profile_type: {
RELEASE_ASSERT(vm.typeProfiler());
// The format of this instruction is: op_profile_type regToProfile, TypeLocation*, flag, identifier?, resolveType?
size_t instructionOffset = i + opLength - 1;
unsigned divotStart, divotEnd;
GlobalVariableID globalVariableID = 0;
RefPtr<TypeSet> globalTypeSet;
bool shouldAnalyze = m_unlinkedCode->typeProfilerExpressionInfoForBytecodeOffset(instructionOffset, divotStart, divotEnd);
VirtualRegister profileRegister(pc[1].u.operand);
ProfileTypeBytecodeFlag flag = static_cast<ProfileTypeBytecodeFlag>(pc[3].u.operand);
SymbolTable* symbolTable = nullptr;
switch (flag) {
case ProfileTypeBytecodeClosureVar: {
const Identifier& ident = identifier(pc[4].u.operand);
int localScopeDepth = pc[2].u.operand;
ResolveType type = static_cast<ResolveType>(pc[5].u.operand);
// Even though type profiling may be profiling either a Get or a Put, we can always claim a Get because
// we're abstractly "read"ing from a JSScope.
ResolveOp op = JSScope::abstractResolve(m_globalObject->globalExec(), localScopeDepth, scope, ident, Get, type, InitializationMode::NotInitialization);
RETURN_IF_EXCEPTION(throwScope, false);
if (op.type == ClosureVar || op.type == ModuleVar)
symbolTable = op.lexicalEnvironment->symbolTable();
else if (op.type == GlobalVar)
symbolTable = m_globalObject.get()->symbolTable();
UniquedStringImpl* impl = (op.type == ModuleVar) ? op.importedName.get() : ident.impl();
if (symbolTable) {
ConcurrentJSLocker locker(symbolTable->m_lock);
// If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
symbolTable->prepareForTypeProfiling(locker);
globalVariableID = symbolTable->uniqueIDForVariable(locker, impl, vm);
globalTypeSet = symbolTable->globalTypeSetForVariable(locker, impl, vm);
} else
globalVariableID = TypeProfilerNoGlobalIDExists;
break;
}
case ProfileTypeBytecodeLocallyResolved: {
int symbolTableIndex = pc[2].u.operand;
SymbolTable* symbolTable = jsCast<SymbolTable*>(getConstant(symbolTableIndex));
const Identifier& ident = identifier(pc[4].u.operand);
ConcurrentJSLocker locker(symbolTable->m_lock);
// If our parent scope was created while profiling was disabled, it will not have prepared for profiling yet.
globalVariableID = symbolTable->uniqueIDForVariable(locker, ident.impl(), vm);
globalTypeSet = symbolTable->globalTypeSetForVariable(locker, ident.impl(), vm);
break;
}
case ProfileTypeBytecodeDoesNotHaveGlobalID:
case ProfileTypeBytecodeFunctionArgument: {
globalVariableID = TypeProfilerNoGlobalIDExists;
break;
}
case ProfileTypeBytecodeFunctionReturnStatement: {
RELEASE_ASSERT(ownerExecutable->isFunctionExecutable());
globalTypeSet = jsCast<FunctionExecutable*>(ownerExecutable)->returnStatementTypeSet();
globalVariableID = TypeProfilerReturnStatement;
if (!shouldAnalyze) {
// Because a return statement can be added implicitly to return undefined at the end of a function,
// and these nodes don't emit expression ranges because they aren't in the actual source text of
// the user's program, give the type profiler some range to identify these return statements.
// Currently, the text offset that is used as identification is "f" in the function keyword
// and is stored on TypeLocation's m_divotForFunctionOffsetIfReturnStatement member variable.
divotStart = divotEnd = ownerExecutable->typeProfilingStartOffset();
shouldAnalyze = true;
}
break;
}
}
std::pair<TypeLocation*, bool> locationPair = vm.typeProfiler()->typeLocationCache()->getTypeLocation(globalVariableID,
ownerExecutable->sourceID(), divotStart, divotEnd, WTFMove(globalTypeSet), &vm);
TypeLocation* location = locationPair.first;
bool isNewLocation = locationPair.second;
if (flag == ProfileTypeBytecodeFunctionReturnStatement)
location->m_divotForFunctionOffsetIfReturnStatement = ownerExecutable->typeProfilingStartOffset();
if (shouldAnalyze && isNewLocation)
vm.typeProfiler()->insertNewLocation(location);
instructions[i + 2].u.location = location;
break;
}
case op_debug: {
if (pc[1].u.unsignedValue == DidReachBreakpoint)
m_hasDebuggerStatement = true;
break;
}
case op_create_rest: {
int numberOfArgumentsToSkip = instructions[i + 3].u.operand;
ASSERT_UNUSED(numberOfArgumentsToSkip, numberOfArgumentsToSkip >= 0);
// This is used when rematerializing the rest parameter during OSR exit in the FTL JIT.");
m_numberOfArgumentsToSkip = numberOfArgumentsToSkip;
break;
}
default:
break;
}
i += opLength;
}
if (vm.controlFlowProfiler())
insertBasicBlockBoundariesForControlFlowProfiler(instructions);
m_instructions = WTFMove(instructions);
// Set optimization thresholds only after m_instructions is initialized, since these
// rely on the instruction count (and are in theory permitted to also inspect the
// instruction stream to more accurate assess the cost of tier-up).
optimizeAfterWarmUp();
jitAfterWarmUp();
// If the concurrent thread will want the code block's hash, then compute it here
// synchronously.
if (Options::alwaysComputeHash())
hash();
if (Options::dumpGeneratedBytecodes())
dumpBytecode();
heap()->reportExtraMemoryAllocated(m_instructions.size() * sizeof(Instruction));
return true;
}
void CodeBlock::finishCreationCommon(VM& vm)
{
m_ownerEdge.set(vm, this, ExecutableToCodeBlockEdge::create(vm, this));
}
CodeBlock::~CodeBlock()
{
VM& vm = *m_poisonedVM;
vm.heap.codeBlockSet().remove(this);
if (UNLIKELY(vm.m_perBytecodeProfiler))
vm.m_perBytecodeProfiler->notifyDestruction(this);
if (!vm.heap.isShuttingDown() && unlinkedCodeBlock()->didOptimize() == MixedTriState)
unlinkedCodeBlock()->setDidOptimize(FalseTriState);
#if ENABLE(VERBOSE_VALUE_PROFILE)
dumpValueProfiles();
#endif
// We may be destroyed before any CodeBlocks that refer to us are destroyed.
// Consider that two CodeBlocks become unreachable at the same time. There
// is no guarantee about the order in which the CodeBlocks are destroyed.
// So, if we don't remove incoming calls, and get destroyed before the
// CodeBlock(s) that have calls into us, then the CallLinkInfo vector's
// destructor will try to remove nodes from our (no longer valid) linked list.
unlinkIncomingCalls();
// Note that our outgoing calls will be removed from other CodeBlocks'
// m_incomingCalls linked lists through the execution of the ~CallLinkInfo
// destructors.
#if ENABLE(JIT)
for (auto iter = m_stubInfos.begin(); !!iter; ++iter) {
StructureStubInfo* stub = *iter;
stub->aboutToDie();
stub->deref();
}
#endif // ENABLE(JIT)
}
void CodeBlock::setConstantIdentifierSetRegisters(VM& vm, const Vector<ConstantIndentifierSetEntry>& constants)
{
auto scope = DECLARE_THROW_SCOPE(vm);
JSGlobalObject* globalObject = m_globalObject.get();
ExecState* exec = globalObject->globalExec();
for (const auto& entry : constants) {
const IdentifierSet& set = entry.first;
Structure* setStructure = globalObject->setStructure();
RETURN_IF_EXCEPTION(scope, void());
JSSet* jsSet = JSSet::create(exec, vm, setStructure, set.size());
RETURN_IF_EXCEPTION(scope, void());
for (auto setEntry : set) {
JSString* jsString = jsOwnedString(&vm, setEntry.get());
jsSet->add(exec, jsString);
RETURN_IF_EXCEPTION(scope, void());
}
m_constantRegisters[entry.second].set(vm, this, jsSet);
}
}
void CodeBlock::setConstantRegisters(const Vector<WriteBarrier<Unknown>>& constants, const Vector<SourceCodeRepresentation>& constantsSourceCodeRepresentation)
{
VM& vm = *m_poisonedVM;
auto scope = DECLARE_THROW_SCOPE(vm);
JSGlobalObject* globalObject = m_globalObject.get();
ExecState* exec = globalObject->globalExec();
ASSERT(constants.size() == constantsSourceCodeRepresentation.size());
size_t count = constants.size();
m_constantRegisters.resizeToFit(count);
bool hasTypeProfiler = !!vm.typeProfiler();
for (size_t i = 0; i < count; i++) {
JSValue constant = constants[i].get();
if (!constant.isEmpty()) {
if (constant.isCell()) {
JSCell* cell = constant.asCell();
if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(vm, cell)) {
if (hasTypeProfiler) {
ConcurrentJSLocker locker(symbolTable->m_lock);
symbolTable->prepareForTypeProfiling(locker);
}
SymbolTable* clone = symbolTable->cloneScopePart(vm);
if (wasCompiledWithDebuggingOpcodes())
clone->setRareDataCodeBlock(this);
constant = clone;
} else if (auto* descriptor = jsDynamicCast<JSTemplateObjectDescriptor*>(vm, cell)) {
auto* templateObject = descriptor->createTemplateObject(exec);
RETURN_IF_EXCEPTION(scope, void());
constant = templateObject;
}
}
}
m_constantRegisters[i].set(vm, this, constant);
}
m_constantsSourceCodeRepresentation = constantsSourceCodeRepresentation;
}
void CodeBlock::setAlternative(VM& vm, CodeBlock* alternative)
{
m_alternative.set(vm, this, alternative);
}
void CodeBlock::setNumParameters(int newValue)
{
m_numParameters = newValue;
m_argumentValueProfiles = RefCountedArray<ValueProfile>(newValue);
}
CodeBlock* CodeBlock::specialOSREntryBlockOrNull()
{
#if ENABLE(FTL_JIT)
if (jitType() != JITCode::DFGJIT)
return 0;
DFG::JITCode* jitCode = m_jitCode->dfg();
return jitCode->osrEntryBlock();
#else // ENABLE(FTL_JIT)
return 0;
#endif // ENABLE(FTL_JIT)
}
size_t CodeBlock::estimatedSize(JSCell* cell)
{
CodeBlock* thisObject = jsCast<CodeBlock*>(cell);
size_t extraMemoryAllocated = thisObject->m_instructions.size() * sizeof(Instruction);
if (thisObject->m_jitCode)
extraMemoryAllocated += thisObject->m_jitCode->size();
return Base::estimatedSize(cell) + extraMemoryAllocated;
}
void CodeBlock::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
CodeBlock* thisObject = jsCast<CodeBlock*>(cell);
ASSERT_GC_OBJECT_INHERITS(thisObject, info());
JSCell::visitChildren(thisObject, visitor);
visitor.append(thisObject->m_ownerEdge);
thisObject->visitChildren(visitor);
}
void CodeBlock::visitChildren(SlotVisitor& visitor)
{
ConcurrentJSLocker locker(m_lock);
if (CodeBlock* otherBlock = specialOSREntryBlockOrNull())
visitor.appendUnbarriered(otherBlock);
if (m_jitCode)
visitor.reportExtraMemoryVisited(m_jitCode->size());
if (m_instructions.size()) {
unsigned refCount = m_instructions.refCount();
if (!refCount) {
dataLog("CodeBlock: ", RawPointer(this), "\n");
dataLog("m_instructions.data(): ", RawPointer(m_instructions.data()), "\n");
dataLog("refCount: ", refCount, "\n");
RELEASE_ASSERT_NOT_REACHED();
}
visitor.reportExtraMemoryVisited(m_instructions.size() * sizeof(Instruction) / refCount);
}
stronglyVisitStrongReferences(locker, visitor);
stronglyVisitWeakReferences(locker, visitor);
VM::SpaceAndFinalizerSet::finalizerSetFor(*subspace()).add(this);
}
bool CodeBlock::shouldVisitStrongly(const ConcurrentJSLocker& locker)
{
if (Options::forceCodeBlockLiveness())
return true;
if (shouldJettisonDueToOldAge(locker))
return false;
// Interpreter and Baseline JIT CodeBlocks don't need to be jettisoned when
// their weak references go stale. So if a basline JIT CodeBlock gets
// scanned, we can assume that this means that it's live.
if (!JITCode::isOptimizingJIT(jitType()))
return true;
return false;
}
bool CodeBlock::shouldJettisonDueToWeakReference()
{
if (!JITCode::isOptimizingJIT(jitType()))
return false;
return !Heap::isMarked(this);
}
static Seconds timeToLive(JITCode::JITType jitType)
{
if (UNLIKELY(Options::useEagerCodeBlockJettisonTiming())) {
switch (jitType) {
case JITCode::InterpreterThunk:
return 10_ms;
case JITCode::BaselineJIT:
return 30_ms;
case JITCode::DFGJIT:
return 40_ms;
case JITCode::FTLJIT:
return 120_ms;
default:
return Seconds::infinity();
}
}
switch (jitType) {
case JITCode::InterpreterThunk:
return 5_s;
case JITCode::BaselineJIT:
// Effectively 10 additional seconds, since BaselineJIT and
// InterpreterThunk share a CodeBlock.
return 15_s;
case JITCode::DFGJIT:
return 20_s;
case JITCode::FTLJIT:
return 60_s;
default:
return Seconds::infinity();
}
}
bool CodeBlock::shouldJettisonDueToOldAge(const ConcurrentJSLocker&)
{
if (Heap::isMarked(this))
return false;
if (UNLIKELY(Options::forceCodeBlockToJettisonDueToOldAge()))
return true;
if (timeSinceCreation() < timeToLive(jitType()))
return false;
return true;
}
#if ENABLE(DFG_JIT)
static bool shouldMarkTransition(DFG::WeakReferenceTransition& transition)
{
if (transition.m_codeOrigin && !Heap::isMarked(transition.m_codeOrigin.get()))
return false;
if (!Heap::isMarked(transition.m_from.get()))
return false;
return true;
}
#endif // ENABLE(DFG_JIT)
void CodeBlock::propagateTransitions(const ConcurrentJSLocker&, SlotVisitor& visitor)
{
UNUSED_PARAM(visitor);
VM& vm = *m_poisonedVM;
if (jitType() == JITCode::InterpreterThunk) {
const Vector<unsigned>& propertyAccessInstructions = m_unlinkedCode->propertyAccessInstructions();
for (size_t i = 0; i < propertyAccessInstructions.size(); ++i) {
Instruction* instruction = &instructions()[propertyAccessInstructions[i]];
switch (Interpreter::getOpcodeID(instruction[0])) {
case op_put_by_id: {
StructureID oldStructureID = instruction[4].u.structureID;
StructureID newStructureID = instruction[6].u.structureID;
if (!oldStructureID || !newStructureID)
break;
Structure* oldStructure =
vm.heap.structureIDTable().get(oldStructureID);
Structure* newStructure =
vm.heap.structureIDTable().get(newStructureID);
if (Heap::isMarked(oldStructure))
visitor.appendUnbarriered(newStructure);
break;
}
default:
break;
}
}
}
#if ENABLE(JIT)
if (JITCode::isJIT(jitType())) {
for (auto iter = m_stubInfos.begin(); !!iter; ++iter)
(*iter)->propagateTransitions(visitor);
}
#endif // ENABLE(JIT)
#if ENABLE(DFG_JIT)
if (JITCode::isOptimizingJIT(jitType())) {
DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
for (auto& weakReference : dfgCommon->weakStructureReferences)
weakReference->markIfCheap(visitor);
for (auto& transition : dfgCommon->transitions) {
if (shouldMarkTransition(transition)) {
// If the following three things are live, then the target of the
// transition is also live:
//
// - This code block. We know it's live already because otherwise
// we wouldn't be scanning ourselves.
//
// - The code origin of the transition. Transitions may arise from
// code that was inlined. They are not relevant if the user's
// object that is required for the inlinee to run is no longer
// live.
//
// - The source of the transition. The transition checks if some
// heap location holds the source, and if so, stores the target.
// Hence the source must be live for the transition to be live.
//
// We also short-circuit the liveness if the structure is harmless
// to mark (i.e. its global object and prototype are both already
// live).
visitor.append(transition.m_to);
}
}
}
#endif // ENABLE(DFG_JIT)
}
void CodeBlock::determineLiveness(const ConcurrentJSLocker&, SlotVisitor& visitor)
{
UNUSED_PARAM(visitor);
#if ENABLE(DFG_JIT)
if (Heap::isMarked(this))
return;
// In rare and weird cases, this could be called on a baseline CodeBlock. One that I found was
// that we might decide that the CodeBlock should be jettisoned due to old age, so the
// isMarked check doesn't protect us.
if (!JITCode::isOptimizingJIT(jitType()))
return;
DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
// Now check all of our weak references. If all of them are live, then we
// have proved liveness and so we scan our strong references. If at end of
// GC we still have not proved liveness, then this code block is toast.
bool allAreLiveSoFar = true;
for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i) {
JSCell* reference = dfgCommon->weakReferences[i].get();
ASSERT(!jsDynamicCast<CodeBlock*>(*reference->vm(), reference));
if (!Heap::isMarked(reference)) {
allAreLiveSoFar = false;
break;
}
}
if (allAreLiveSoFar) {
for (unsigned i = 0; i < dfgCommon->weakStructureReferences.size(); ++i) {
if (!Heap::isMarked(dfgCommon->weakStructureReferences[i].get())) {
allAreLiveSoFar = false;
break;
}
}
}
// If some weak references are dead, then this fixpoint iteration was
// unsuccessful.
if (!allAreLiveSoFar)
return;
// All weak references are live. Record this information so we don't
// come back here again, and scan the strong references.
visitor.appendUnbarriered(this);
#endif // ENABLE(DFG_JIT)
}
void CodeBlock::clearLLIntGetByIdCache(Instruction* instruction)
{
instruction[0].u.opcode = LLInt::getOpcode(op_get_by_id);
instruction[4].u.pointer = nullptr;
instruction[5].u.pointer = nullptr;
instruction[6].u.pointer = nullptr;
}
void CodeBlock::finalizeLLIntInlineCaches()
{
VM& vm = *m_poisonedVM;
const Vector<unsigned>& propertyAccessInstructions = m_unlinkedCode->propertyAccessInstructions();
for (size_t size = propertyAccessInstructions.size(), i = 0; i < size; ++i) {
Instruction* curInstruction = &instructions()[propertyAccessInstructions[i]];
switch (Interpreter::getOpcodeID(curInstruction[0])) {
case op_get_by_id:
case op_get_by_id_proto_load:
case op_get_by_id_unset: {
StructureID oldStructureID = curInstruction[4].u.structureID;
if (!oldStructureID || Heap::isMarked(vm.heap.structureIDTable().get(oldStructureID)))
break;
if (Options::verboseOSR())
dataLogF("Clearing LLInt property access.\n");
clearLLIntGetByIdCache(curInstruction);
break;
}
case op_get_by_id_direct: {
StructureID oldStructureID = curInstruction[4].u.structureID;
if (!oldStructureID || Heap::isMarked(vm.heap.structureIDTable().get(oldStructureID)))
break;
if (Options::verboseOSR())
dataLogF("Clearing LLInt property access.\n");
curInstruction[4].u.pointer = nullptr;
curInstruction[5].u.pointer = nullptr;
break;
}
case op_put_by_id: {
StructureID oldStructureID = curInstruction[4].u.structureID;
StructureID newStructureID = curInstruction[6].u.structureID;
StructureChain* chain = curInstruction[7].u.structureChain.get();
if ((!oldStructureID || Heap::isMarked(vm.heap.structureIDTable().get(oldStructureID)))
&& (!newStructureID || Heap::isMarked(vm.heap.structureIDTable().get(newStructureID)))
&& (!chain || Heap::isMarked(chain)))
break;
if (Options::verboseOSR())
dataLogF("Clearing LLInt put transition.\n");
curInstruction[4].u.structureID = 0;
curInstruction[5].u.operand = 0;
curInstruction[6].u.structureID = 0;
curInstruction[7].u.structureChain.clear();
break;
}
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=166418
// We need to add optimizations for op_resolve_scope_for_hoisting_func_decl_in_eval to do link time scope resolution.
case op_resolve_scope_for_hoisting_func_decl_in_eval:
break;
case op_get_array_length:
break;
case op_to_this:
if (!curInstruction[2].u.structure || Heap::isMarked(curInstruction[2].u.structure.get()))
break;
if (Options::verboseOSR())
dataLogF("Clearing LLInt to_this with structure %p.\n", curInstruction[2].u.structure.get());
curInstruction[2].u.structure.clear();
curInstruction[3].u.toThisStatus = merge(
curInstruction[3].u.toThisStatus, ToThisClearedByGC);
break;
case op_create_this: {
auto& cacheWriteBarrier = curInstruction[4].u.jsCell;
if (!cacheWriteBarrier || cacheWriteBarrier.unvalidatedGet() == JSCell::seenMultipleCalleeObjects())
break;
JSCell* cachedFunction = cacheWriteBarrier.get();
if (Heap::isMarked(cachedFunction))
break;
if (Options::verboseOSR())
dataLogF("Clearing LLInt create_this with cached callee %p.\n", cachedFunction);
cacheWriteBarrier.clear();
break;
}
case op_resolve_scope: {
// Right now this isn't strictly necessary. Any symbol tables that this will refer to
// are for outer functions, and we refer to those functions strongly, and they refer
// to the symbol table strongly. But it's nice to be on the safe side.
WriteBarrierBase<SymbolTable>& symbolTable = curInstruction[6].u.symbolTable;
if (!symbolTable || Heap::isMarked(symbolTable.get()))
break;
if (Options::verboseOSR())
dataLogF("Clearing dead symbolTable %p.\n", symbolTable.get());
symbolTable.clear();
break;
}
case op_get_from_scope:
case op_put_to_scope: {
GetPutInfo getPutInfo = GetPutInfo(curInstruction[4].u.operand);
if (getPutInfo.resolveType() == GlobalVar || getPutInfo.resolveType() == GlobalVarWithVarInjectionChecks
|| getPutInfo.resolveType() == LocalClosureVar || getPutInfo.resolveType() == GlobalLexicalVar || getPutInfo.resolveType() == GlobalLexicalVarWithVarInjectionChecks)
continue;
WriteBarrierBase<Structure>& structure = curInstruction[5].u.structure;
if (!structure || Heap::isMarked(structure.get()))
break;
if (Options::verboseOSR())
dataLogF("Clearing scope access with structure %p.\n", structure.get());
structure.clear();
break;
}
default:
OpcodeID opcodeID = Interpreter::getOpcodeID(curInstruction[0]);
ASSERT_WITH_MESSAGE_UNUSED(opcodeID, false, "Unhandled opcode in CodeBlock::finalizeUnconditionally, %s(%d) at bc %u", opcodeNames[opcodeID], opcodeID, propertyAccessInstructions[i]);
}
}
// We can't just remove all the sets when we clear the caches since we might have created a watchpoint set
// then cleared the cache without GCing in between.
m_llintGetByIdWatchpointMap.removeIf([](const StructureWatchpointMap::KeyValuePairType& pair) -> bool {
return !Heap::isMarked(pair.key);
});
for (unsigned i = 0; i < m_llintCallLinkInfos.size(); ++i) {
if (m_llintCallLinkInfos[i].isLinked() && !Heap::isMarked(m_llintCallLinkInfos[i].callee.get())) {
if (Options::verboseOSR())
dataLog("Clearing LLInt call from ", *this, "\n");
m_llintCallLinkInfos[i].unlink();
}
if (!!m_llintCallLinkInfos[i].lastSeenCallee && !Heap::isMarked(m_llintCallLinkInfos[i].lastSeenCallee.get()))
m_llintCallLinkInfos[i].lastSeenCallee.clear();
}
}
void CodeBlock::finalizeBaselineJITInlineCaches()
{
#if ENABLE(JIT)
for (auto iter = callLinkInfosBegin(); !!iter; ++iter)
(*iter)->visitWeak(*vm());
for (auto iter = m_stubInfos.begin(); !!iter; ++iter) {
StructureStubInfo& stubInfo = **iter;
stubInfo.visitWeakReferences(this);
}
#endif
}
void CodeBlock::finalizeUnconditionally(VM&)
{
updateAllPredictions();
if (JITCode::couldBeInterpreted(jitType()))
finalizeLLIntInlineCaches();
#if ENABLE(JIT)
if (!!jitCode())
finalizeBaselineJITInlineCaches();
#endif
VM::SpaceAndFinalizerSet::finalizerSetFor(*subspace()).remove(this);
}
void CodeBlock::getStubInfoMap(const ConcurrentJSLocker&, StubInfoMap& result)
{
#if ENABLE(JIT)
if (JITCode::isJIT(jitType()))
toHashMap(m_stubInfos, getStructureStubInfoCodeOrigin, result);
#else
UNUSED_PARAM(result);
#endif
}
void CodeBlock::getStubInfoMap(StubInfoMap& result)
{
ConcurrentJSLocker locker(m_lock);
getStubInfoMap(locker, result);
}
void CodeBlock::getCallLinkInfoMap(const ConcurrentJSLocker&, CallLinkInfoMap& result)
{
#if ENABLE(JIT)
if (JITCode::isJIT(jitType()))
toHashMap(m_callLinkInfos, getCallLinkInfoCodeOrigin, result);
#else
UNUSED_PARAM(result);
#endif
}
void CodeBlock::getCallLinkInfoMap(CallLinkInfoMap& result)
{
ConcurrentJSLocker locker(m_lock);
getCallLinkInfoMap(locker, result);
}
void CodeBlock::getByValInfoMap(const ConcurrentJSLocker&, ByValInfoMap& result)
{
#if ENABLE(JIT)
if (JITCode::isJIT(jitType())) {
for (auto* byValInfo : m_byValInfos)
result.add(CodeOrigin(byValInfo->bytecodeIndex), byValInfo);
}
#else
UNUSED_PARAM(result);
#endif
}
void CodeBlock::getByValInfoMap(ByValInfoMap& result)
{
ConcurrentJSLocker locker(m_lock);
getByValInfoMap(locker, result);
}
#if ENABLE(JIT)
StructureStubInfo* CodeBlock::addStubInfo(AccessType accessType)
{
ConcurrentJSLocker locker(m_lock);
return m_stubInfos.add(accessType);
}
JITAddIC* CodeBlock::addJITAddIC(ArithProfile* arithProfile, Instruction* instruction)
{
return m_addICs.add(arithProfile, instruction);
}
JITMulIC* CodeBlock::addJITMulIC(ArithProfile* arithProfile, Instruction* instruction)
{
return m_mulICs.add(arithProfile, instruction);
}
JITSubIC* CodeBlock::addJITSubIC(ArithProfile* arithProfile, Instruction* instruction)
{
return m_subICs.add(arithProfile, instruction);
}
JITNegIC* CodeBlock::addJITNegIC(ArithProfile* arithProfile, Instruction* instruction)
{
return m_negICs.add(arithProfile, instruction);
}
StructureStubInfo* CodeBlock::findStubInfo(CodeOrigin codeOrigin)
{
for (StructureStubInfo* stubInfo : m_stubInfos) {
if (stubInfo->codeOrigin == codeOrigin)
return stubInfo;
}
return nullptr;
}
ByValInfo* CodeBlock::addByValInfo()
{
ConcurrentJSLocker locker(m_lock);
return m_byValInfos.add();
}
CallLinkInfo* CodeBlock::addCallLinkInfo()
{
ConcurrentJSLocker locker(m_lock);
return m_callLinkInfos.add();
}
CallLinkInfo* CodeBlock::getCallLinkInfoForBytecodeIndex(unsigned index)
{
for (auto iter = m_callLinkInfos.begin(); !!iter; ++iter) {
if ((*iter)->codeOrigin() == CodeOrigin(index))
return *iter;
}
return nullptr;
}
void CodeBlock::resetJITData()
{
RELEASE_ASSERT(!JITCode::isJIT(jitType()));
ConcurrentJSLocker locker(m_lock);
// We can clear these because no other thread will have references to any stub infos, call
// link infos, or by val infos if we don't have JIT code. Attempts to query these data
// structures using the concurrent API (getStubInfoMap and friends) will return nothing if we
// don't have JIT code.
m_stubInfos.clear();
m_callLinkInfos.clear();
m_byValInfos.clear();
// We can clear this because the DFG's queries to these data structures are guarded by whether
// there is JIT code.
m_rareCaseProfiles.clear();
}
#endif
void CodeBlock::visitOSRExitTargets(const ConcurrentJSLocker&, SlotVisitor& visitor)
{
// We strongly visit OSR exits targets because we don't want to deal with
// the complexity of generating an exit target CodeBlock on demand and
// guaranteeing that it matches the details of the CodeBlock we compiled
// the OSR exit against.
visitor.append(m_alternative);
#if ENABLE(DFG_JIT)
DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
if (dfgCommon->inlineCallFrames) {
for (auto* inlineCallFrame : *dfgCommon->inlineCallFrames) {
ASSERT(inlineCallFrame->baselineCodeBlock);
visitor.append(inlineCallFrame->baselineCodeBlock);
}
}
#endif
}
void CodeBlock::stronglyVisitStrongReferences(const ConcurrentJSLocker& locker, SlotVisitor& visitor)
{
UNUSED_PARAM(locker);
visitor.append(m_globalObject);
visitor.append(m_ownerExecutable); // This is extra important since it causes the ExecutableToCodeBlockEdge to be marked.
visitor.append(m_unlinkedCode);
if (m_rareData)
m_rareData->m_directEvalCodeCache.visitAggregate(visitor);
visitor.appendValues(m_constantRegisters.data(), m_constantRegisters.size());
for (auto& functionExpr : m_functionExprs)
visitor.append(functionExpr);
for (auto& functionDecl : m_functionDecls)
visitor.append(functionDecl);
for (auto& objectAllocationProfile : m_objectAllocationProfiles)
objectAllocationProfile.visitAggregate(visitor);
#if ENABLE(JIT)
for (ByValInfo* byValInfo : m_byValInfos)
visitor.append(byValInfo->cachedSymbol);
#endif
#if ENABLE(DFG_JIT)
if (JITCode::isOptimizingJIT(jitType()))
visitOSRExitTargets(locker, visitor);
#endif
}
void CodeBlock::stronglyVisitWeakReferences(const ConcurrentJSLocker&, SlotVisitor& visitor)
{
UNUSED_PARAM(visitor);
#if ENABLE(DFG_JIT)
if (!JITCode::isOptimizingJIT(jitType()))
return;
DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
for (auto& transition : dfgCommon->transitions) {
if (!!transition.m_codeOrigin)
visitor.append(transition.m_codeOrigin); // Almost certainly not necessary, since the code origin should also be a weak reference. Better to be safe, though.
visitor.append(transition.m_from);
visitor.append(transition.m_to);
}
for (auto& weakReference : dfgCommon->weakReferences)
visitor.append(weakReference);
for (auto& weakStructureReference : dfgCommon->weakStructureReferences)
visitor.append(weakStructureReference);
dfgCommon->livenessHasBeenProved = true;
#endif
}
CodeBlock* CodeBlock::baselineAlternative()
{
#if ENABLE(JIT)
CodeBlock* result = this;
while (result->alternative())
result = result->alternative();
RELEASE_ASSERT(result);
RELEASE_ASSERT(JITCode::isBaselineCode(result->jitType()) || result->jitType() == JITCode::None);
return result;
#else
return this;
#endif
}
CodeBlock* CodeBlock::baselineVersion()
{
#if ENABLE(JIT)
if (JITCode::isBaselineCode(jitType()))
return this;
CodeBlock* result = replacement();
if (!result) {
// This can happen if we're creating the original CodeBlock for an executable.
// Assume that we're the baseline CodeBlock.
RELEASE_ASSERT(jitType() == JITCode::None);
return this;
}
result = result->baselineAlternative();
return result;
#else
return this;
#endif
}
#if ENABLE(JIT)
bool CodeBlock::hasOptimizedReplacement(JITCode::JITType typeToReplace)
{
return JITCode::isHigherTier(replacement()->jitType(), typeToReplace);
}
bool CodeBlock::hasOptimizedReplacement()
{
return hasOptimizedReplacement(jitType());
}
#endif
HandlerInfo* CodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset, RequiredHandler requiredHandler)
{
RELEASE_ASSERT(bytecodeOffset < instructions().size());
return handlerForIndex(bytecodeOffset, requiredHandler);
}
HandlerInfo* CodeBlock::handlerForIndex(unsigned index, RequiredHandler requiredHandler)
{
if (!m_rareData)
return 0;
return HandlerInfo::handlerForIndex(m_rareData->m_exceptionHandlers, index, requiredHandler);
}
CallSiteIndex CodeBlock::newExceptionHandlingCallSiteIndex(CallSiteIndex originalCallSite)
{
#if ENABLE(DFG_JIT)
RELEASE_ASSERT(JITCode::isOptimizingJIT(jitType()));
RELEASE_ASSERT(canGetCodeOrigin(originalCallSite));
ASSERT(!!handlerForIndex(originalCallSite.bits()));
CodeOrigin originalOrigin = codeOrigin(originalCallSite);
return m_jitCode->dfgCommon()->addUniqueCallSiteIndex(originalOrigin);
#else
// We never create new on-the-fly exception handling
// call sites outside the DFG/FTL inline caches.
UNUSED_PARAM(originalCallSite);
RELEASE_ASSERT_NOT_REACHED();
return CallSiteIndex(0u);
#endif
}
void CodeBlock::ensureCatchLivenessIsComputedForBytecodeOffsetSlow(unsigned bytecodeOffset)
{
ASSERT(Interpreter::getOpcodeID(m_instructions[bytecodeOffset]) == op_catch);
BytecodeLivenessAnalysis& bytecodeLiveness = livenessAnalysis();
// We get the live-out set of variables at op_catch, not the live-in. This
// is because the variables that the op_catch defines might be dead, and
// we can avoid profiling them and extracting them when doing OSR entry
// into the DFG.
FastBitVector liveLocals = bytecodeLiveness.getLivenessInfoAtBytecodeOffset(this, bytecodeOffset + OPCODE_LENGTH(op_catch));
Vector<VirtualRegister> liveOperands;
liveOperands.reserveInitialCapacity(liveLocals.bitCount());
liveLocals.forEachSetBit([&] (unsigned liveLocal) {
liveOperands.append(virtualRegisterForLocal(liveLocal));
});
for (int i = 0; i < numParameters(); ++i)
liveOperands.append(virtualRegisterForArgument(i));
auto profiles = std::make_unique<ValueProfileAndOperandBuffer>(liveOperands.size());
RELEASE_ASSERT(profiles->m_size == liveOperands.size());
for (unsigned i = 0; i < profiles->m_size; ++i)
profiles->m_buffer.get()[i].m_operand = liveOperands[i].offset();
// The compiler thread will read this pointer value and then proceed to dereference it
// if it is not null. We need to make sure all above stores happen before this store so
// the compiler thread reads fully initialized data.
WTF::storeStoreFence();
m_instructions[bytecodeOffset + 3].u.pointer = profiles.get();
{
ConcurrentJSLocker locker(m_lock);
m_catchProfiles.append(WTFMove(profiles));
}
}
void CodeBlock::removeExceptionHandlerForCallSite(CallSiteIndex callSiteIndex)
{
RELEASE_ASSERT(m_rareData);
Vector<HandlerInfo>& exceptionHandlers = m_rareData->m_exceptionHandlers;
unsigned index = callSiteIndex.bits();
for (size_t i = 0; i < exceptionHandlers.size(); ++i) {
HandlerInfo& handler = exceptionHandlers[i];
if (handler.start <= index && handler.end > index) {
exceptionHandlers.remove(i);
return;
}
}
RELEASE_ASSERT_NOT_REACHED();
}
unsigned CodeBlock::lineNumberForBytecodeOffset(unsigned bytecodeOffset)
{
RELEASE_ASSERT(bytecodeOffset < instructions().size());
return ownerScriptExecutable()->firstLine() + m_unlinkedCode->lineNumberForBytecodeOffset(bytecodeOffset);
}
unsigned CodeBlock::columnNumberForBytecodeOffset(unsigned bytecodeOffset)
{
int divot;
int startOffset;
int endOffset;
unsigned line;
unsigned column;
expressionRangeForBytecodeOffset(bytecodeOffset, divot, startOffset, endOffset, line, column);
return column;
}
void CodeBlock::expressionRangeForBytecodeOffset(unsigned bytecodeOffset, int& divot, int& startOffset, int& endOffset, unsigned& line, unsigned& column) const
{
m_unlinkedCode->expressionRangeForBytecodeOffset(bytecodeOffset, divot, startOffset, endOffset, line, column);
divot += m_sourceOffset;
column += line ? 1 : firstLineColumnOffset();
line += ownerScriptExecutable()->firstLine();
}
bool CodeBlock::hasOpDebugForLineAndColumn(unsigned line, unsigned column)
{
const Instruction* begin = instructions().begin();
const Instruction* end = instructions().end();
for (const Instruction* it = begin; it != end;) {
OpcodeID opcodeID = Interpreter::getOpcodeID(*it);
if (opcodeID == op_debug) {
unsigned bytecodeOffset = it - begin;
int unused;
unsigned opDebugLine;
unsigned opDebugColumn;
expressionRangeForBytecodeOffset(bytecodeOffset, unused, unused, unused, opDebugLine, opDebugColumn);
if (line == opDebugLine && (column == Breakpoint::unspecifiedColumn || column == opDebugColumn))
return true;
}
it += opcodeLengths[opcodeID];
}
return false;
}
void CodeBlock::shrinkToFit(ShrinkMode shrinkMode)
{
ConcurrentJSLocker locker(m_lock);
m_rareCaseProfiles.shrinkToFit();
if (shrinkMode == EarlyShrink) {
m_constantRegisters.shrinkToFit();
m_constantsSourceCodeRepresentation.shrinkToFit();
if (m_rareData) {
m_rareData->m_switchJumpTables.shrinkToFit();
m_rareData->m_stringSwitchJumpTables.shrinkToFit();
}
} // else don't shrink these, because we would have already pointed pointers into these tables.
}
#if ENABLE(JIT)
void CodeBlock::linkIncomingCall(ExecState* callerFrame, CallLinkInfo* incoming)
{
noticeIncomingCall(callerFrame);
m_incomingCalls.push(incoming);
}
void CodeBlock::linkIncomingPolymorphicCall(ExecState* callerFrame, PolymorphicCallNode* incoming)
{
noticeIncomingCall(callerFrame);
m_incomingPolymorphicCalls.push(incoming);
}
#endif // ENABLE(JIT)
void CodeBlock::unlinkIncomingCalls()
{
while (m_incomingLLIntCalls.begin() != m_incomingLLIntCalls.end())
m_incomingLLIntCalls.begin()->unlink();
#if ENABLE(JIT)
while (m_incomingCalls.begin() != m_incomingCalls.end())
m_incomingCalls.begin()->unlink(*vm());
while (m_incomingPolymorphicCalls.begin() != m_incomingPolymorphicCalls.end())
m_incomingPolymorphicCalls.begin()->unlink(*vm());
#endif // ENABLE(JIT)
}
void CodeBlock::linkIncomingCall(ExecState* callerFrame, LLIntCallLinkInfo* incoming)
{
noticeIncomingCall(callerFrame);
m_incomingLLIntCalls.push(incoming);
}
CodeBlock* CodeBlock::newReplacement()
{
return ownerScriptExecutable()->newReplacementCodeBlockFor(specializationKind());
}
#if ENABLE(JIT)
CodeBlock* CodeBlock::replacement()
{
const ClassInfo* classInfo = this->classInfo(*vm());
if (classInfo == FunctionCodeBlock::info())
return jsCast<FunctionExecutable*>(ownerExecutable())->codeBlockFor(m_isConstructor ? CodeForConstruct : CodeForCall);
if (classInfo == EvalCodeBlock::info())
return jsCast<EvalExecutable*>(ownerExecutable())->codeBlock();
if (classInfo == ProgramCodeBlock::info())
return jsCast<ProgramExecutable*>(ownerExecutable())->codeBlock();
if (classInfo == ModuleProgramCodeBlock::info())
return jsCast<ModuleProgramExecutable*>(ownerExecutable())->codeBlock();
RELEASE_ASSERT_NOT_REACHED();
return nullptr;
}
DFG::CapabilityLevel CodeBlock::computeCapabilityLevel()
{
const ClassInfo* classInfo = this->classInfo(*vm());
if (classInfo == FunctionCodeBlock::info()) {
if (m_isConstructor)
return DFG::functionForConstructCapabilityLevel(this);
return DFG::functionForCallCapabilityLevel(this);
}
if (classInfo == EvalCodeBlock::info())
return DFG::evalCapabilityLevel(this);
if (classInfo == ProgramCodeBlock::info())
return DFG::programCapabilityLevel(this);
if (classInfo == ModuleProgramCodeBlock::info())
return DFG::programCapabilityLevel(this);
RELEASE_ASSERT_NOT_REACHED();
return DFG::CannotCompile;
}
#endif // ENABLE(JIT)
void CodeBlock::jettison(Profiler::JettisonReason reason, ReoptimizationMode mode, const FireDetail* detail)
{
#if !ENABLE(DFG_JIT)
UNUSED_PARAM(mode);
UNUSED_PARAM(detail);
#endif
CODEBLOCK_LOG_EVENT(this, "jettison", ("due to ", reason, ", counting = ", mode == CountReoptimization, ", detail = ", pointerDump(detail)));
RELEASE_ASSERT(reason != Profiler::NotJettisoned);
#if ENABLE(DFG_JIT)
if (DFG::shouldDumpDisassembly()) {
dataLog("Jettisoning ", *this);
if (mode == CountReoptimization)
dataLog(" and counting reoptimization");
dataLog(" due to ", reason);
if (detail)
dataLog(", ", *detail);
dataLog(".\n");
}
if (reason == Profiler::JettisonDueToWeakReference) {
if (DFG::shouldDumpDisassembly()) {
dataLog(*this, " will be jettisoned because of the following dead references:\n");
DFG::CommonData* dfgCommon = m_jitCode->dfgCommon();
for (auto& transition : dfgCommon->transitions) {
JSCell* origin = transition.m_codeOrigin.get();
JSCell* from = transition.m_from.get();
JSCell* to = transition.m_to.get();
if ((!origin || Heap::isMarked(origin)) && Heap::isMarked(from))
continue;
dataLog(" Transition under ", RawPointer(origin), ", ", RawPointer(from), " -> ", RawPointer(to), ".\n");
}
for (unsigned i = 0; i < dfgCommon->weakReferences.size(); ++i) {
JSCell* weak = dfgCommon->weakReferences[i].get();
if (Heap::isMarked(weak))
continue;
dataLog(" Weak reference ", RawPointer(weak), ".\n");
}
}
}
#endif // ENABLE(DFG_JIT)
VM& vm = *m_poisonedVM;
DeferGCForAWhile deferGC(*heap());
// We want to accomplish two things here:
// 1) Make sure that if this CodeBlock is on the stack right now, then if we return to it
// we should OSR exit at the top of the next bytecode instruction after the return.
// 2) Make sure that if we call the owner executable, then we shouldn't call this CodeBlock.
#if ENABLE(DFG_JIT)
if (reason != Profiler::JettisonDueToOldAge) {
Profiler::Compilation* compilation = jitCode()->dfgCommon()->compilation.get();
if (UNLIKELY(compilation))
compilation->setJettisonReason(reason, detail);
// This accomplishes (1), and does its own book-keeping about whether it has already happened.
if (!jitCode()->dfgCommon()->invalidate()) {
// We've already been invalidated.
RELEASE_ASSERT(this != replacement() || (vm.heap.isCurrentThreadBusy() && !Heap::isMarked(ownerScriptExecutable())));
return;
}
}
if (DFG::shouldDumpDisassembly())
dataLog(" Did invalidate ", *this, "\n");
// Count the reoptimization if that's what the user wanted.
if (mode == CountReoptimization) {
// FIXME: Maybe this should call alternative().
// https://bugs.webkit.org/show_bug.cgi?id=123677
baselineAlternative()->countReoptimization();
if (DFG::shouldDumpDisassembly())
dataLog(" Did count reoptimization for ", *this, "\n");
}
if (this != replacement()) {
// This means that we were never the entrypoint. This can happen for OSR entry code
// blocks.
return;
}
if (alternative())
alternative()->optimizeAfterWarmUp();
if (reason != Profiler::JettisonDueToOldAge && reason != Profiler::JettisonDueToVMTraps)
tallyFrequentExitSites();
#endif // ENABLE(DFG_JIT)
// Jettison can happen during GC. We don't want to install code to a dead executable
// because that would add a dead object to the remembered set.
if (vm.heap.isCurrentThreadBusy() && !Heap::isMarked(ownerScriptExecutable()))
return;
// This accomplishes (2).
ownerScriptExecutable()->installCode(vm, alternative(), codeType(), specializationKind());
#if ENABLE(DFG_JIT)
if (DFG::shouldDumpDisassembly())
dataLog(" Did install baseline version of ", *this, "\n");
#endif // ENABLE(DFG_JIT)
}
JSGlobalObject* CodeBlock::globalObjectFor(CodeOrigin codeOrigin)
{
if (!codeOrigin.inlineCallFrame)
return globalObject();
return codeOrigin.inlineCallFrame->baselineCodeBlock->globalObject();
}
class RecursionCheckFunctor {
public:
RecursionCheckFunctor(CallFrame* startCallFrame, CodeBlock* codeBlock, unsigned depthToCheck)
: m_startCallFrame(startCallFrame)
, m_codeBlock(codeBlock)
, m_depthToCheck(depthToCheck)
, m_foundStartCallFrame(false)
, m_didRecurse(false)
{ }
StackVisitor::Status operator()(StackVisitor& visitor) const
{
CallFrame* currentCallFrame = visitor->callFrame();
if (currentCallFrame == m_startCallFrame)
m_foundStartCallFrame = true;
if (m_foundStartCallFrame) {
if (visitor->callFrame()->codeBlock() == m_codeBlock) {
m_didRecurse = true;
return StackVisitor::Done;
}
if (!m_depthToCheck--)
return StackVisitor::Done;
}
return StackVisitor::Continue;
}
bool didRecurse() const { return m_didRecurse; }
private:
CallFrame* m_startCallFrame;
CodeBlock* m_codeBlock;
mutable unsigned m_depthToCheck;
mutable bool m_foundStartCallFrame;
mutable bool m_didRecurse;
};
void CodeBlock::noticeIncomingCall(ExecState* callerFrame)
{
CodeBlock* callerCodeBlock = callerFrame->codeBlock();
if (Options::verboseCallLink())
dataLog("Noticing call link from ", pointerDump(callerCodeBlock), " to ", *this, "\n");
#if ENABLE(DFG_JIT)
if (!m_shouldAlwaysBeInlined)
return;
if (!callerCodeBlock) {
m_shouldAlwaysBeInlined = false;
if (Options::verboseCallLink())
dataLog(" Clearing SABI because caller is native.\n");
return;
}
if (!hasBaselineJITProfiling())
return;
if (!DFG::mightInlineFunction(this))
return;
if (!canInline(capabilityLevelState()))
return;
if (!DFG::isSmallEnoughToInlineCodeInto(callerCodeBlock)) {
m_shouldAlwaysBeInlined = false;
if (Options::verboseCallLink())
dataLog(" Clearing SABI because caller is too large.\n");
return;
}
if (callerCodeBlock->jitType() == JITCode::InterpreterThunk) {
// If the caller is still in the interpreter, then we can't expect inlining to
// happen anytime soon. Assume it's profitable to optimize it separately. This
// ensures that a function is SABI only if it is called no more frequently than
// any of its callers.
m_shouldAlwaysBeInlined = false;
if (Options::verboseCallLink())
dataLog(" Clearing SABI because caller is in LLInt.\n");
return;
}
if (JITCode::isOptimizingJIT(callerCodeBlock->jitType())) {
m_shouldAlwaysBeInlined = false;
if (Options::verboseCallLink())
dataLog(" Clearing SABI bcause caller was already optimized.\n");
return;
}
if (callerCodeBlock->codeType() != FunctionCode) {
// If the caller is either eval or global code, assume that that won't be
// optimized anytime soon. For eval code this is particularly true since we
// delay eval optimization by a *lot*.
m_shouldAlwaysBeInlined = false;
if (Options::verboseCallLink())
dataLog(" Clearing SABI because caller is not a function.\n");
return;
}
// Recursive calls won't be inlined.
RecursionCheckFunctor functor(callerFrame, this, Options::maximumInliningDepth());
vm()->topCallFrame->iterate(functor);
if (functor.didRecurse()) {
if (Options::verboseCallLink())
dataLog(" Clearing SABI because recursion was detected.\n");
m_shouldAlwaysBeInlined = false;
return;
}
if (callerCodeBlock->capabilityLevelState() == DFG::CapabilityLevelNotSet) {
dataLog("In call from ", FullCodeOrigin(callerCodeBlock, callerFrame->codeOrigin()), " to ", *this, ": caller's DFG capability level is not set.\n");
CRASH();
}
if (canCompile(callerCodeBlock->capabilityLevelState()))
return;
if (Options::verboseCallLink())
dataLog(" Clearing SABI because the caller is not a DFG candidate.\n");
m_shouldAlwaysBeInlined = false;
#endif
}
unsigned CodeBlock::reoptimizationRetryCounter() const
{
#if ENABLE(JIT)
ASSERT(m_reoptimizationRetryCounter <= Options::reoptimizationRetryCounterMax());
return m_reoptimizationRetryCounter;
#else
return 0;
#endif // ENABLE(JIT)
}
#if ENABLE(JIT)
void CodeBlock::setCalleeSaveRegisters(RegisterSet calleeSaveRegisters)
{
m_calleeSaveRegisters = std::make_unique<RegisterAtOffsetList>(calleeSaveRegisters);
}
void CodeBlock::setCalleeSaveRegisters(std::unique_ptr<RegisterAtOffsetList> registerAtOffsetList)
{
m_calleeSaveRegisters = WTFMove(registerAtOffsetList);
}
static size_t roundCalleeSaveSpaceAsVirtualRegisters(size_t calleeSaveRegisters)
{
static const unsigned cpuRegisterSize = sizeof(void*);
return (WTF::roundUpToMultipleOf(sizeof(Register), calleeSaveRegisters * cpuRegisterSize) / sizeof(Register));
}
size_t CodeBlock::llintBaselineCalleeSaveSpaceAsVirtualRegisters()
{
return roundCalleeSaveSpaceAsVirtualRegisters(numberOfLLIntBaselineCalleeSaveRegisters());
}
size_t CodeBlock::calleeSaveSpaceAsVirtualRegisters()
{
return roundCalleeSaveSpaceAsVirtualRegisters(m_calleeSaveRegisters->size());
}
void CodeBlock::countReoptimization()
{
m_reoptimizationRetryCounter++;
if (m_reoptimizationRetryCounter > Options::reoptimizationRetryCounterMax())
m_reoptimizationRetryCounter = Options::reoptimizationRetryCounterMax();
}
unsigned CodeBlock::numberOfDFGCompiles()
{
ASSERT(JITCode::isBaselineCode(jitType()));
if (Options::testTheFTL()) {
if (m_didFailFTLCompilation)
return 1000000;
return (m_hasBeenCompiledWithFTL ? 1 : 0) + m_reoptimizationRetryCounter;
}
return (JITCode::isOptimizingJIT(replacement()->jitType()) ? 1 : 0) + m_reoptimizationRetryCounter;
}
int32_t CodeBlock::codeTypeThresholdMultiplier() const
{
if (codeType() == EvalCode)
return Options::evalThresholdMultiplier();
return 1;
}
double CodeBlock::optimizationThresholdScalingFactor()
{
// This expression arises from doing a least-squares fit of
//
// F[x_] =: a * Sqrt[x + b] + Abs[c * x] + d
//
// against the data points:
//
// x F[x_]
// 10 0.9 (smallest reasonable code block)
// 200 1.0 (typical small-ish code block)
// 320 1.2 (something I saw in 3d-cube that I wanted to optimize)
// 1268 5.0 (something I saw in 3d-cube that I didn't want to optimize)
// 4000 5.5 (random large size, used to cause the function to converge to a shallow curve of some sort)
// 10000 6.0 (similar to above)
//
// I achieve the minimization using the following Mathematica code:
//
// MyFunctionTemplate[x_, a_, b_, c_, d_] := a*Sqrt[x + b] + Abs[c*x] + d
//
// samples = {{10, 0.9}, {200, 1}, {320, 1.2}, {1268, 5}, {4000, 5.5}, {10000, 6}}
//
// solution =
// Minimize[Plus @@ ((MyFunctionTemplate[#[[1]], a, b, c, d] - #[[2]])^2 & /@ samples),
// {a, b, c, d}][[2]]
//
// And the code below (to initialize a, b, c, d) is generated by:
//
// Print["const double " <> ToString[#[[1]]] <> " = " <>
// If[#[[2]] < 0.00001, "0.0", ToString[#[[2]]]] <> ";"] & /@ solution
//
// We've long known the following to be true:
// - Small code blocks are cheap to optimize and so we should do it sooner rather
// than later.
// - Large code blocks are expensive to optimize and so we should postpone doing so,
// and sometimes have a large enough threshold that we never optimize them.
// - The difference in cost is not totally linear because (a) just invoking the
// DFG incurs some base cost and (b) for large code blocks there is enough slop
// in the correlation between instruction count and the actual compilation cost
// that for those large blocks, the instruction count should not have a strong
// influence on our threshold.
//
// I knew the goals but I didn't know how to achieve them; so I picked an interesting
// example where the heuristics were right (code block in 3d-cube with instruction
// count 320, which got compiled early as it should have been) and one where they were
// totally wrong (code block in 3d-cube with instruction count 1268, which was expensive
// to compile and didn't run often enough to warrant compilation in my opinion), and
// then threw in additional data points that represented my own guess of what our
// heuristics should do for some round-numbered examples.
//
// The expression to which I decided to fit the data arose because I started with an
// affine function, and then did two things: put the linear part in an Abs to ensure
// that the fit didn't end up choosing a negative value of c (which would result in
// the function turning over and going negative for large x) and I threw in a Sqrt
// term because Sqrt represents my intution that the function should be more sensitive
// to small changes in small values of x, but less sensitive when x gets large.
// Note that the current fit essentially eliminates the linear portion of the
// expression (c == 0.0).
const double a = 0.061504;
const double b = 1.02406;
const double c = 0.0;
const double d = 0.825914;
double instructionCount = this->instructionCount();
ASSERT(instructionCount); // Make sure this is called only after we have an instruction stream; otherwise it'll just return the value of d, which makes no sense.
double result = d + a * sqrt(instructionCount + b) + c * instructionCount;
result *= codeTypeThresholdMultiplier();
if (Options::verboseOSR()) {
dataLog(
*this, ": instruction count is ", instructionCount,
", scaling execution counter by ", result, " * ", codeTypeThresholdMultiplier(),
"\n");
}
return result;
}
static int32_t clipThreshold(double threshold)
{
if (threshold < 1.0)
return 1;
if (threshold > static_cast<double>(std::numeric_limits<int32_t>::max()))
return std::numeric_limits<int32_t>::max();
return static_cast<int32_t>(threshold);
}
int32_t CodeBlock::adjustedCounterValue(int32_t desiredThreshold)
{
return clipThreshold(
static_cast<double>(desiredThreshold) *
optimizationThresholdScalingFactor() *
(1 << reoptimizationRetryCounter()));
}
bool CodeBlock::checkIfOptimizationThresholdReached()
{
#if ENABLE(DFG_JIT)
if (DFG::Worklist* worklist = DFG::existingGlobalDFGWorklistOrNull()) {
if (worklist->compilationState(DFG::CompilationKey(this, DFG::DFGMode))
== DFG::Worklist::Compiled) {
optimizeNextInvocation();
return true;
}
}
#endif
return m_jitExecuteCounter.checkIfThresholdCrossedAndSet(this);
}
#if ENABLE(DFG_JIT)
auto CodeBlock::updateOSRExitCounterAndCheckIfNeedToReoptimize(DFG::OSRExitState& exitState) -> OptimizeAction
{
DFG::OSRExitBase& exit = exitState.exit;
if (!exitKindMayJettison(exit.m_kind)) {
// FIXME: We may want to notice that we're frequently exiting
// at an op_catch that we didn't compile an entrypoint for, and
// then trigger a reoptimization of this CodeBlock:
// https://bugs.webkit.org/show_bug.cgi?id=175842
return OptimizeAction::None;
}
exit.m_count++;
m_osrExitCounter++;
CodeBlock* baselineCodeBlock = exitState.baselineCodeBlock;
ASSERT(baselineCodeBlock == baselineAlternative());
if (UNLIKELY(baselineCodeBlock->jitExecuteCounter().hasCrossedThreshold()))
return OptimizeAction::ReoptimizeNow;
// We want to figure out if there's a possibility that we're in a loop. For the outermost
// code block in the inline stack, we handle this appropriately by having the loop OSR trigger
// check the exit count of the replacement of the CodeBlock from which we are OSRing. The
// problem is the inlined functions, which might also have loops, but whose baseline versions
// don't know where to look for the exit count. Figure out if those loops are severe enough
// that we had tried to OSR enter. If so, then we should use the loop reoptimization trigger.
// Otherwise, we should use the normal reoptimization trigger.
bool didTryToEnterInLoop = false;
for (InlineCallFrame* inlineCallFrame = exit.m_codeOrigin.inlineCallFrame; inlineCallFrame; inlineCallFrame = inlineCallFrame->directCaller.inlineCallFrame) {
if (inlineCallFrame->baselineCodeBlock->ownerScriptExecutable()->didTryToEnterInLoop()) {
didTryToEnterInLoop = true;
break;
}
}
uint32_t exitCountThreshold = didTryToEnterInLoop
? exitCountThresholdForReoptimizationFromLoop()
: exitCountThresholdForReoptimization();
if (m_osrExitCounter > exitCountThreshold)
return OptimizeAction::ReoptimizeNow;
// Too few fails. Adjust the execution counter such that the target is to only optimize after a while.
baselineCodeBlock->m_jitExecuteCounter.setNewThresholdForOSRExit(exitState.activeThreshold, exitState.memoryUsageAdjustedThreshold);
return OptimizeAction::None;
}
#endif
void CodeBlock::optimizeNextInvocation()
{
if (Options::verboseOSR())
dataLog(*this, ": Optimizing next invocation.\n");
m_jitExecuteCounter.setNewThreshold(0, this);
}
void CodeBlock::dontOptimizeAnytimeSoon()
{
if (Options::verboseOSR())
dataLog(*this, ": Not optimizing anytime soon.\n");
m_jitExecuteCounter.deferIndefinitely();
}
void CodeBlock::optimizeAfterWarmUp()
{
if (Options::verboseOSR())
dataLog(*this, ": Optimizing after warm-up.\n");
#if ENABLE(DFG_JIT)
m_jitExecuteCounter.setNewThreshold(
adjustedCounterValue(Options::thresholdForOptimizeAfterWarmUp()), this);
#endif
}
void CodeBlock::optimizeAfterLongWarmUp()
{
if (Options::verboseOSR())
dataLog(*this, ": Optimizing after long warm-up.\n");
#if ENABLE(DFG_JIT)
m_jitExecuteCounter.setNewThreshold(
adjustedCounterValue(Options::thresholdForOptimizeAfterLongWarmUp()), this);
#endif
}
void CodeBlock::optimizeSoon()
{
if (Options::verboseOSR())
dataLog(*this, ": Optimizing soon.\n");
#if ENABLE(DFG_JIT)
m_jitExecuteCounter.setNewThreshold(
adjustedCounterValue(Options::thresholdForOptimizeSoon()), this);
#endif
}
void CodeBlock::forceOptimizationSlowPathConcurrently()
{
if (Options::verboseOSR())
dataLog(*this, ": Forcing slow path concurrently.\n");
m_jitExecuteCounter.forceSlowPathConcurrently();
}
#if ENABLE(DFG_JIT)
void CodeBlock::setOptimizationThresholdBasedOnCompilationResult(CompilationResult result)
{
JITCode::JITType type = jitType();
if (type != JITCode::BaselineJIT) {
dataLog(*this, ": expected to have baseline code but have ", type, "\n");
RELEASE_ASSERT_NOT_REACHED();
}
CodeBlock* theReplacement = replacement();
if ((result == CompilationSuccessful) != (theReplacement != this)) {
dataLog(*this, ": we have result = ", result, " but ");
if (theReplacement == this)
dataLog("we are our own replacement.\n");
else
dataLog("our replacement is ", pointerDump(theReplacement), "\n");
RELEASE_ASSERT_NOT_REACHED();
}
switch (result) {
case CompilationSuccessful:
RELEASE_ASSERT(JITCode::isOptimizingJIT(replacement()->jitType()));
optimizeNextInvocation();
return;
case CompilationFailed:
dontOptimizeAnytimeSoon();
return;
case CompilationDeferred:
// We'd like to do dontOptimizeAnytimeSoon() but we cannot because
// forceOptimizationSlowPathConcurrently() is inherently racy. It won't
// necessarily guarantee anything. So, we make sure that even if that
// function ends up being a no-op, we still eventually retry and realize
// that we have optimized code ready.
optimizeAfterWarmUp();
return;
case CompilationInvalidated:
// Retry with exponential backoff.
countReoptimization();
optimizeAfterWarmUp();
return;
}
dataLog("Unrecognized result: ", static_cast<int>(result), "\n");
RELEASE_ASSERT_NOT_REACHED();
}
#endif
uint32_t CodeBlock::adjustedExitCountThreshold(uint32_t desiredThreshold)
{
ASSERT(JITCode::isOptimizingJIT(jitType()));
// Compute this the lame way so we don't saturate. This is called infrequently
// enough that this loop won't hurt us.
unsigned result = desiredThreshold;
for (unsigned n = baselineVersion()->reoptimizationRetryCounter(); n--;) {
unsigned newResult = result << 1;
if (newResult < result)
return std::numeric_limits<uint32_t>::max();
result = newResult;
}
return result;
}
uint32_t CodeBlock::exitCountThresholdForReoptimization()
{
return adjustedExitCountThreshold(Options::osrExitCountForReoptimization() * codeTypeThresholdMultiplier());
}
uint32_t CodeBlock::exitCountThresholdForReoptimizationFromLoop()
{
return adjustedExitCountThreshold(Options::osrExitCountForReoptimizationFromLoop() * codeTypeThresholdMultiplier());
}
bool CodeBlock::shouldReoptimizeNow()
{
return osrExitCounter() >= exitCountThresholdForReoptimization();
}
bool CodeBlock::shouldReoptimizeFromLoopNow()
{
return osrExitCounter() >= exitCountThresholdForReoptimizationFromLoop();
}
#endif
ArrayProfile* CodeBlock::getArrayProfile(const ConcurrentJSLocker&, unsigned bytecodeOffset)
{
for (auto& m_arrayProfile : m_arrayProfiles) {
if (m_arrayProfile.bytecodeOffset() == bytecodeOffset)
return &m_arrayProfile;
}
return 0;
}
ArrayProfile* CodeBlock::getArrayProfile(unsigned bytecodeOffset)
{
ConcurrentJSLocker locker(m_lock);
return getArrayProfile(locker, bytecodeOffset);
}
ArrayProfile* CodeBlock::addArrayProfile(const ConcurrentJSLocker&, unsigned bytecodeOffset)
{
m_arrayProfiles.append(ArrayProfile(bytecodeOffset));
return &m_arrayProfiles.last();
}
ArrayProfile* CodeBlock::addArrayProfile(unsigned bytecodeOffset)
{
ConcurrentJSLocker locker(m_lock);
return addArrayProfile(locker, bytecodeOffset);
}
ArrayProfile* CodeBlock::getOrAddArrayProfile(const ConcurrentJSLocker& locker, unsigned bytecodeOffset)
{
ArrayProfile* result = getArrayProfile(locker, bytecodeOffset);
if (result)
return result;
return addArrayProfile(locker, bytecodeOffset);
}
ArrayProfile* CodeBlock::getOrAddArrayProfile(unsigned bytecodeOffset)
{
ConcurrentJSLocker locker(m_lock);
return getOrAddArrayProfile(locker, bytecodeOffset);
}
#if ENABLE(DFG_JIT)
Vector<CodeOrigin, 0, UnsafeVectorOverflow>& CodeBlock::codeOrigins()
{
return m_jitCode->dfgCommon()->codeOrigins;
}
size_t CodeBlock::numberOfDFGIdentifiers() const
{
if (!JITCode::isOptimizingJIT(jitType()))
return 0;
return m_jitCode->dfgCommon()->dfgIdentifiers.size();
}
const Identifier& CodeBlock::identifier(int index) const
{
size_t unlinkedIdentifiers = m_unlinkedCode->numberOfIdentifiers();
if (static_cast<unsigned>(index) < unlinkedIdentifiers)
return m_unlinkedCode->identifier(index);
ASSERT(JITCode::isOptimizingJIT(jitType()));
return m_jitCode->dfgCommon()->dfgIdentifiers[index - unlinkedIdentifiers];
}
#endif // ENABLE(DFG_JIT)
void CodeBlock::updateAllPredictionsAndCountLiveness(unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles)
{
ConcurrentJSLocker locker(m_lock);
numberOfLiveNonArgumentValueProfiles = 0;
numberOfSamplesInProfiles = 0; // If this divided by ValueProfile::numberOfBuckets equals numberOfValueProfiles() then value profiles are full.
for (unsigned i = 0; i < totalNumberOfValueProfiles(); ++i) {
ValueProfile& profile = getFromAllValueProfiles(i);
unsigned numSamples = profile.totalNumberOfSamples();
if (numSamples > ValueProfile::numberOfBuckets)
numSamples = ValueProfile::numberOfBuckets; // We don't want profiles that are extremely hot to be given more weight.
numberOfSamplesInProfiles += numSamples;
if (profile.m_bytecodeOffset < 0) {
profile.computeUpdatedPrediction(locker);
continue;
}
if (profile.numberOfSamples() || profile.m_prediction != SpecNone)
numberOfLiveNonArgumentValueProfiles++;
profile.computeUpdatedPrediction(locker);
}
for (auto& profileBucket : m_catchProfiles) {
profileBucket->forEach([&] (ValueProfileAndOperand& profile) {
profile.m_profile.computeUpdatedPrediction(locker);
});
}
#if ENABLE(DFG_JIT)
m_lazyOperandValueProfiles.computeUpdatedPredictions(locker);
#endif
}
void CodeBlock::updateAllValueProfilePredictions()
{
unsigned ignoredValue1, ignoredValue2;
updateAllPredictionsAndCountLiveness(ignoredValue1, ignoredValue2);
}
void CodeBlock::updateAllArrayPredictions()
{
ConcurrentJSLocker locker(m_lock);
for (unsigned i = m_arrayProfiles.size(); i--;)
m_arrayProfiles[i].computeUpdatedPrediction(locker, this);
// Don't count these either, for similar reasons.
for (unsigned i = m_arrayAllocationProfiles.size(); i--;)
m_arrayAllocationProfiles[i].updateProfile();
}
void CodeBlock::updateAllPredictions()
{
updateAllValueProfilePredictions();
updateAllArrayPredictions();
}
bool CodeBlock::shouldOptimizeNow()
{
if (Options::verboseOSR())
dataLog("Considering optimizing ", *this, "...\n");
if (m_optimizationDelayCounter >= Options::maximumOptimizationDelay())
return true;
updateAllArrayPredictions();
unsigned numberOfLiveNonArgumentValueProfiles;
unsigned numberOfSamplesInProfiles;
updateAllPredictionsAndCountLiveness(numberOfLiveNonArgumentValueProfiles, numberOfSamplesInProfiles);
if (Options::verboseOSR()) {
dataLogF(
"Profile hotness: %lf (%u / %u), %lf (%u / %u)\n",
(double)numberOfLiveNonArgumentValueProfiles / numberOfValueProfiles(),
numberOfLiveNonArgumentValueProfiles, numberOfValueProfiles(),
(double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / numberOfValueProfiles(),
numberOfSamplesInProfiles, ValueProfile::numberOfBuckets * numberOfValueProfiles());
}
if ((!numberOfValueProfiles() || (double)numberOfLiveNonArgumentValueProfiles / numberOfValueProfiles() >= Options::desiredProfileLivenessRate())
&& (!totalNumberOfValueProfiles() || (double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / totalNumberOfValueProfiles() >= Options::desiredProfileFullnessRate())
&& static_cast<unsigned>(m_optimizationDelayCounter) + 1 >= Options::minimumOptimizationDelay())
return true;
ASSERT(m_optimizationDelayCounter < std::numeric_limits<uint8_t>::max());
m_optimizationDelayCounter++;
optimizeAfterWarmUp();
return false;
}
#if ENABLE(DFG_JIT)
void CodeBlock::tallyFrequentExitSites()
{
ASSERT(JITCode::isOptimizingJIT(jitType()));
ASSERT(alternative()->jitType() == JITCode::BaselineJIT);
CodeBlock* profiledBlock = alternative();
switch (jitType()) {
case JITCode::DFGJIT: {
DFG::JITCode* jitCode = m_jitCode->dfg();
for (auto& exit : jitCode->osrExit)
exit.considerAddingAsFrequentExitSite(profiledBlock);
break;
}
#if ENABLE(FTL_JIT)
case JITCode::FTLJIT: {
// There is no easy way to avoid duplicating this code since the FTL::JITCode::osrExit
// vector contains a totally different type, that just so happens to behave like
// DFG::JITCode::osrExit.
FTL::JITCode* jitCode = m_jitCode->ftl();
for (unsigned i = 0; i < jitCode->osrExit.size(); ++i) {
FTL::OSRExit& exit = jitCode->osrExit[i];
exit.considerAddingAsFrequentExitSite(profiledBlock);
}
break;
}
#endif
default:
RELEASE_ASSERT_NOT_REACHED();
break;
}
}
#endif // ENABLE(DFG_JIT)
#if ENABLE(VERBOSE_VALUE_PROFILE)
void CodeBlock::dumpValueProfiles()
{
dataLog("ValueProfile for ", *this, ":\n");
for (unsigned i = 0; i < totalNumberOfValueProfiles(); ++i) {
ValueProfile& profile = getFromAllValueProfiles(i);
if (profile.m_bytecodeOffset < 0) {
ASSERT(profile.m_bytecodeOffset == -1);
dataLogF(" arg = %u: ", i);
} else
dataLogF(" bc = %d: ", profile.m_bytecodeOffset);
if (!profile.numberOfSamples() && profile.m_prediction == SpecNone) {
dataLogF("<empty>\n");
continue;
}
profile.dump(WTF::dataFile());
dataLogF("\n");
}
dataLog("RareCaseProfile for ", *this, ":\n");
for (unsigned i = 0; i < numberOfRareCaseProfiles(); ++i) {
RareCaseProfile* profile = rareCaseProfile(i);
dataLogF(" bc = %d: %u\n", profile->m_bytecodeOffset, profile->m_counter);
}
}
#endif // ENABLE(VERBOSE_VALUE_PROFILE)
unsigned CodeBlock::frameRegisterCount()
{
switch (jitType()) {
case JITCode::InterpreterThunk:
return LLInt::frameRegisterCountFor(this);
#if ENABLE(JIT)
case JITCode::BaselineJIT:
return JIT::frameRegisterCountFor(this);
#endif // ENABLE(JIT)
#if ENABLE(DFG_JIT)
case JITCode::DFGJIT:
case JITCode::FTLJIT:
return jitCode()->dfgCommon()->frameRegisterCount;
#endif // ENABLE(DFG_JIT)
default:
RELEASE_ASSERT_NOT_REACHED();
return 0;
}
}
int CodeBlock::stackPointerOffset()
{
return virtualRegisterForLocal(frameRegisterCount() - 1).offset();
}
size_t CodeBlock::predictedMachineCodeSize()
{
VM* vm = m_poisonedVM.unpoisoned();
// This will be called from CodeBlock::CodeBlock before either m_poisonedVM or the
// instructions have been initialized. It's OK to return 0 because what will really
// matter is the recomputation of this value when the slow path is triggered.
if (!vm)
return 0;
if (!*vm->machineCodeBytesPerBytecodeWordForBaselineJIT)
return 0; // It's as good of a prediction as we'll get.
// Be conservative: return a size that will be an overestimation 84% of the time.
double multiplier = vm->machineCodeBytesPerBytecodeWordForBaselineJIT->mean() +
vm->machineCodeBytesPerBytecodeWordForBaselineJIT->standardDeviation();
// Be paranoid: silently reject bogus multipiers. Silently doing the "wrong" thing
// here is OK, since this whole method is just a heuristic.
if (multiplier < 0 || multiplier > 1000)
return 0;
double doubleResult = multiplier * m_instructions.size();
// Be even more paranoid: silently reject values that won't fit into a size_t. If
// the function is so huge that we can't even fit it into virtual memory then we
// should probably have some other guards in place to prevent us from even getting
// to this point.
if (doubleResult > std::numeric_limits<size_t>::max())
return 0;
return static_cast<size_t>(doubleResult);
}
String CodeBlock::nameForRegister(VirtualRegister virtualRegister)
{
for (auto& constantRegister : m_constantRegisters) {
if (constantRegister.get().isEmpty())
continue;
if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(*vm(), constantRegister.get())) {
ConcurrentJSLocker locker(symbolTable->m_lock);
auto end = symbolTable->end(locker);
for (auto ptr = symbolTable->begin(locker); ptr != end; ++ptr) {
if (ptr->value.varOffset() == VarOffset(virtualRegister)) {
// FIXME: This won't work from the compilation thread.
// https://bugs.webkit.org/show_bug.cgi?id=115300
return ptr->key.get();
}
}
}
}
if (virtualRegister == thisRegister())
return ASCIILiteral("this");
if (virtualRegister.isArgument())
return String::format("arguments[%3d]", virtualRegister.toArgument());
return "";
}
ValueProfile* CodeBlock::tryGetValueProfileForBytecodeOffset(int bytecodeOffset)
{
return tryBinarySearch<ValueProfile, int>(
m_valueProfiles, m_valueProfiles.size(), bytecodeOffset,
getValueProfileBytecodeOffset<ValueProfile>);
}
ValueProfile& CodeBlock::valueProfileForBytecodeOffset(int bytecodeOffset)
{
OpcodeID opcodeID = Interpreter::getOpcodeID(instructions()[bytecodeOffset]);
unsigned length = opcodeLength(opcodeID);
ASSERT(!!tryGetValueProfileForBytecodeOffset(bytecodeOffset));
return *instructions()[bytecodeOffset + length - 1].u.profile;
}
void CodeBlock::validate()
{
BytecodeLivenessAnalysis liveness(this); // Compute directly from scratch so it doesn't effect CodeBlock footprint.
FastBitVector liveAtHead = liveness.getLivenessInfoAtBytecodeOffset(this, 0);
if (liveAtHead.numBits() != static_cast<size_t>(m_numCalleeLocals)) {
beginValidationDidFail();
dataLog(" Wrong number of bits in result!\n");
dataLog(" Result: ", liveAtHead, "\n");
dataLog(" Bit count: ", liveAtHead.numBits(), "\n");
endValidationDidFail();
}
for (unsigned i = m_numCalleeLocals; i--;) {
VirtualRegister reg = virtualRegisterForLocal(i);
if (liveAtHead[i]) {
beginValidationDidFail();
dataLog(" Variable ", reg, " is expected to be dead.\n");
dataLog(" Result: ", liveAtHead, "\n");
endValidationDidFail();
}
}
for (unsigned i = 0; i + 1 < numberOfValueProfiles(); ++i) {
if (valueProfile(i).m_bytecodeOffset > valueProfile(i + 1).m_bytecodeOffset) {
beginValidationDidFail();
dataLog(" Value profiles are not sorted.\n");
endValidationDidFail();
}
}
for (unsigned bytecodeOffset = 0; bytecodeOffset < m_instructions.size(); ) {
OpcodeID opcode = Interpreter::getOpcodeID(m_instructions[bytecodeOffset]);
if (!!baselineAlternative()->handlerForBytecodeOffset(bytecodeOffset)) {
if (opcode == op_catch || opcode == op_enter) {
// op_catch/op_enter logically represent an entrypoint. Entrypoints are not allowed to be
// inside of a try block because they are responsible for bootstrapping state. And they
// are never allowed throw an exception because of this. We rely on this when compiling
// in the DFG. Because an entrypoint never throws, the bytecode generator will never
// allow once inside a try block.
beginValidationDidFail();
dataLog(" entrypoint not allowed inside a try block.");
endValidationDidFail();
}
}
bytecodeOffset += opcodeLength(opcode);
}
}
void CodeBlock::beginValidationDidFail()
{
dataLog("Validation failure in ", *this, ":\n");
dataLog("\n");
}
void CodeBlock::endValidationDidFail()
{
dataLog("\n");
dumpBytecode();
dataLog("\n");
dataLog("Validation failure.\n");
RELEASE_ASSERT_NOT_REACHED();
}
void CodeBlock::addBreakpoint(unsigned numBreakpoints)
{
m_numBreakpoints += numBreakpoints;
ASSERT(m_numBreakpoints);
if (JITCode::isOptimizingJIT(jitType()))
jettison(Profiler::JettisonDueToDebuggerBreakpoint);
}
void CodeBlock::setSteppingMode(CodeBlock::SteppingMode mode)
{
m_steppingMode = mode;
if (mode == SteppingModeEnabled && JITCode::isOptimizingJIT(jitType()))
jettison(Profiler::JettisonDueToDebuggerStepping);
}
RareCaseProfile* CodeBlock::addRareCaseProfile(int bytecodeOffset)
{
m_rareCaseProfiles.append(RareCaseProfile(bytecodeOffset));
return &m_rareCaseProfiles.last();
}
RareCaseProfile* CodeBlock::rareCaseProfileForBytecodeOffset(int bytecodeOffset)
{
return tryBinarySearch<RareCaseProfile, int>(
m_rareCaseProfiles, m_rareCaseProfiles.size(), bytecodeOffset,
getRareCaseProfileBytecodeOffset);
}
unsigned CodeBlock::rareCaseProfileCountForBytecodeOffset(int bytecodeOffset)
{
RareCaseProfile* profile = rareCaseProfileForBytecodeOffset(bytecodeOffset);
if (profile)
return profile->m_counter;
return 0;
}
ArithProfile* CodeBlock::arithProfileForBytecodeOffset(int bytecodeOffset)
{
return arithProfileForPC(&instructions()[bytecodeOffset]);
}
ArithProfile* CodeBlock::arithProfileForPC(Instruction* pc)
{
auto opcodeID = Interpreter::getOpcodeID(pc[0]);
switch (opcodeID) {
case op_negate:
return bitwise_cast<ArithProfile*>(&pc[3].u.operand);
case op_bitor:
case op_bitand:
case op_bitxor:
case op_add:
case op_mul:
case op_sub:
case op_div:
return bitwise_cast<ArithProfile*>(&pc[4].u.operand);
default:
break;
}
return nullptr;
}
bool CodeBlock::couldTakeSpecialFastCase(int bytecodeOffset)
{
if (!hasBaselineJITProfiling())
return false;
ArithProfile* profile = arithProfileForBytecodeOffset(bytecodeOffset);
if (!profile)
return false;
return profile->tookSpecialFastPath();
}
#if ENABLE(JIT)
DFG::CapabilityLevel CodeBlock::capabilityLevel()
{
DFG::CapabilityLevel result = computeCapabilityLevel();
m_capabilityLevelState = result;
return result;
}
#endif
void CodeBlock::insertBasicBlockBoundariesForControlFlowProfiler(RefCountedArray<Instruction>& instructions)
{
if (!unlinkedCodeBlock()->hasOpProfileControlFlowBytecodeOffsets())
return;
const Vector<size_t>& bytecodeOffsets = unlinkedCodeBlock()->opProfileControlFlowBytecodeOffsets();
for (size_t i = 0, offsetsLength = bytecodeOffsets.size(); i < offsetsLength; i++) {
// Because op_profile_control_flow is emitted at the beginning of every basic block, finding
// the next op_profile_control_flow will give us the text range of a single basic block.
size_t startIdx = bytecodeOffsets[i];
RELEASE_ASSERT(Interpreter::getOpcodeID(instructions[startIdx]) == op_profile_control_flow);
int basicBlockStartOffset = instructions[startIdx + 1].u.operand;
int basicBlockEndOffset;
if (i + 1 < offsetsLength) {
size_t endIdx = bytecodeOffsets[i + 1];
RELEASE_ASSERT(Interpreter::getOpcodeID(instructions[endIdx]) == op_profile_control_flow);
basicBlockEndOffset = instructions[endIdx + 1].u.operand - 1;
} else {
basicBlockEndOffset = m_sourceOffset + ownerScriptExecutable()->source().length() - 1; // Offset before the closing brace.
basicBlockStartOffset = std::min(basicBlockStartOffset, basicBlockEndOffset); // Some start offsets may be at the closing brace, ensure it is the offset before.
}
// The following check allows for the same textual JavaScript basic block to have its bytecode emitted more
// than once and still play nice with the control flow profiler. When basicBlockStartOffset is larger than
// basicBlockEndOffset, it indicates that the bytecode generator has emitted code for the same AST node
// more than once (for example: ForInNode, Finally blocks in TryNode, etc). Though these are different
// basic blocks at the bytecode level, they are generated from the same textual basic block in the JavaScript
// program. The condition:
// (basicBlockEndOffset < basicBlockStartOffset)
// is encountered when op_profile_control_flow lies across the boundary of these duplicated bytecode basic
// blocks and the textual offset goes from the end of the duplicated block back to the beginning. These
// ranges are dummy ranges and are ignored. The duplicated bytecode basic blocks point to the same
// internal data structure, so if any of them execute, it will record the same textual basic block in the
// JavaScript program as executing.
// At the bytecode level, this situation looks like:
// j: op_profile_control_flow (from j->k, we have basicBlockEndOffset < basicBlockStartOffset)
// ...
// k: op_profile_control_flow (we want to skip over the j->k block and start fresh at offset k as the start of a new basic block k->m).
// ...
// m: op_profile_control_flow
if (basicBlockEndOffset < basicBlockStartOffset) {
RELEASE_ASSERT(i + 1 < offsetsLength); // We should never encounter dummy blocks at the end of a CodeBlock.
instructions[startIdx + 1].u.basicBlockLocation = vm()->controlFlowProfiler()->dummyBasicBlock();
continue;
}
BasicBlockLocation* basicBlockLocation = vm()->controlFlowProfiler()->getBasicBlockLocation(ownerScriptExecutable()->sourceID(), basicBlockStartOffset, basicBlockEndOffset);
// Find all functions that are enclosed within the range: [basicBlockStartOffset, basicBlockEndOffset]
// and insert these functions' start/end offsets as gaps in the current BasicBlockLocation.
// This is necessary because in the original source text of a JavaScript program,
// function literals form new basic blocks boundaries, but they aren't represented
// inside the CodeBlock's instruction stream.
auto insertFunctionGaps = [basicBlockLocation, basicBlockStartOffset, basicBlockEndOffset] (const WriteBarrier<FunctionExecutable>& functionExecutable) {
const UnlinkedFunctionExecutable* executable = functionExecutable->unlinkedExecutable();
int functionStart = executable->typeProfilingStartOffset();
int functionEnd = executable->typeProfilingEndOffset();
if (functionStart >= basicBlockStartOffset && functionEnd <= basicBlockEndOffset)
basicBlockLocation->insertGap(functionStart, functionEnd);
};
for (const WriteBarrier<FunctionExecutable>& executable : m_functionDecls)
insertFunctionGaps(executable);
for (const WriteBarrier<FunctionExecutable>& executable : m_functionExprs)
insertFunctionGaps(executable);
instructions[startIdx + 1].u.basicBlockLocation = basicBlockLocation;
}
}
#if ENABLE(JIT)
void CodeBlock::setPCToCodeOriginMap(std::unique_ptr<PCToCodeOriginMap>&& map)
{
m_pcToCodeOriginMap = WTFMove(map);
}
std::optional<CodeOrigin> CodeBlock::findPC(void* pc)
{
if (m_pcToCodeOriginMap) {
if (std::optional<CodeOrigin> codeOrigin = m_pcToCodeOriginMap->findPC(pc))
return codeOrigin;
}
for (auto iter = m_stubInfos.begin(); !!iter; ++iter) {
StructureStubInfo* stub = *iter;
if (stub->containsPC(pc))
return std::optional<CodeOrigin>(stub->codeOrigin);
}
if (std::optional<CodeOrigin> codeOrigin = m_jitCode->findPC(this, pc))
return codeOrigin;
return std::nullopt;
}
#endif // ENABLE(JIT)
std::optional<unsigned> CodeBlock::bytecodeOffsetFromCallSiteIndex(CallSiteIndex callSiteIndex)
{
std::optional<unsigned> bytecodeOffset;
JITCode::JITType jitType = this->jitType();
if (jitType == JITCode::InterpreterThunk || jitType == JITCode::BaselineJIT) {
#if USE(JSVALUE64)
bytecodeOffset = callSiteIndex.bits();
#else
Instruction* instruction = bitwise_cast<Instruction*>(callSiteIndex.bits());
bytecodeOffset = this->bytecodeOffset(instruction);
#endif
} else if (jitType == JITCode::DFGJIT || jitType == JITCode::FTLJIT) {
#if ENABLE(DFG_JIT)
RELEASE_ASSERT(canGetCodeOrigin(callSiteIndex));
CodeOrigin origin = codeOrigin(callSiteIndex);
bytecodeOffset = origin.bytecodeIndex;
#else
RELEASE_ASSERT_NOT_REACHED();
#endif
}
return bytecodeOffset;
}
int32_t CodeBlock::thresholdForJIT(int32_t threshold)
{
switch (unlinkedCodeBlock()->didOptimize()) {
case MixedTriState:
return threshold;
case FalseTriState:
return threshold * 4;
case TrueTriState:
return threshold / 2;
}
ASSERT_NOT_REACHED();
return threshold;
}
void CodeBlock::jitAfterWarmUp()
{
m_llintExecuteCounter.setNewThreshold(thresholdForJIT(Options::thresholdForJITAfterWarmUp()), this);
}
void CodeBlock::jitSoon()
{
m_llintExecuteCounter.setNewThreshold(thresholdForJIT(Options::thresholdForJITSoon()), this);
}
bool CodeBlock::hasInstalledVMTrapBreakpoints() const
{
#if ENABLE(SIGNAL_BASED_VM_TRAPS)
// This function may be called from a signal handler. We need to be
// careful to not call anything that is not signal handler safe, e.g.
// we should not perturb the refCount of m_jitCode.
if (!JITCode::isOptimizingJIT(jitType()))
return false;
return m_jitCode->dfgCommon()->hasInstalledVMTrapsBreakpoints();
#else
return false;
#endif
}
bool CodeBlock::installVMTrapBreakpoints()
{
#if ENABLE(SIGNAL_BASED_VM_TRAPS)
// This function may be called from a signal handler. We need to be
// careful to not call anything that is not signal handler safe, e.g.
// we should not perturb the refCount of m_jitCode.
if (!JITCode::isOptimizingJIT(jitType()))
return false;
auto& commonData = *m_jitCode->dfgCommon();
commonData.installVMTrapBreakpoints(this);
return true;
#else
UNREACHABLE_FOR_PLATFORM();
return false;
#endif
}
void CodeBlock::dumpMathICStats()
{
#if ENABLE(MATH_IC_STATS)
double numAdds = 0.0;
double totalAddSize = 0.0;
double numMuls = 0.0;
double totalMulSize = 0.0;
double numNegs = 0.0;
double totalNegSize = 0.0;
double numSubs = 0.0;
double totalSubSize = 0.0;
auto countICs = [&] (CodeBlock* codeBlock) {
for (JITAddIC* addIC : codeBlock->m_addICs) {
numAdds++;
totalAddSize += addIC->codeSize();
}
for (JITMulIC* mulIC : codeBlock->m_mulICs) {
numMuls++;
totalMulSize += mulIC->codeSize();
}
for (JITNegIC* negIC : codeBlock->m_negICs) {
numNegs++;
totalNegSize += negIC->codeSize();
}
for (JITSubIC* subIC : codeBlock->m_subICs) {
numSubs++;
totalSubSize += subIC->codeSize();
}
};
heap()->forEachCodeBlock(countICs);
dataLog("Num Adds: ", numAdds, "\n");
dataLog("Total Add size in bytes: ", totalAddSize, "\n");
dataLog("Average Add size: ", totalAddSize / numAdds, "\n");
dataLog("\n");
dataLog("Num Muls: ", numMuls, "\n");
dataLog("Total Mul size in bytes: ", totalMulSize, "\n");
dataLog("Average Mul size: ", totalMulSize / numMuls, "\n");
dataLog("\n");
dataLog("Num Negs: ", numNegs, "\n");
dataLog("Total Neg size in bytes: ", totalNegSize, "\n");
dataLog("Average Neg size: ", totalNegSize / numNegs, "\n");
dataLog("\n");
dataLog("Num Subs: ", numSubs, "\n");
dataLog("Total Sub size in bytes: ", totalSubSize, "\n");
dataLog("Average Sub size: ", totalSubSize / numSubs, "\n");
dataLog("-----------------------\n");
#endif
}
void setPrinter(Printer::PrintRecord& record, CodeBlock* codeBlock)
{
Printer::setPrinter(record, toCString(codeBlock));
}
} // namespace JSC
namespace WTF {
void printInternal(PrintStream& out, JSC::CodeBlock* codeBlock)
{
if (UNLIKELY(!codeBlock)) {
out.print("<null codeBlock>");
return;
}
out.print(*codeBlock);
}
} // namespace WTF