Plan::CompilationPath Plan::compileInThreadImpl(LongLivedState& longLivedState)
{
Graph dfg(vm, *this, longLivedState);
if (!parse(dfg)) {
finalizer = adoptPtr(new FailedFinalizer(*this));
return FailPath;
}
// By this point the DFG bytecode parser will have potentially mutated various tables
// in the CodeBlock. This is a good time to perform an early shrink, which is more
// powerful than a late one. It's safe to do so because we haven't generated any code
// that references any of the tables directly, yet.
codeBlock->shrinkToFit(CodeBlock::EarlyShrink);
if (validationEnabled())
validate(dfg);
performCPSRethreading(dfg);
performUnification(dfg);
performPredictionInjection(dfg);
if (validationEnabled())
validate(dfg);
performBackwardsPropagation(dfg);
performPredictionPropagation(dfg);
performFixup(dfg);
performTypeCheckHoisting(dfg);
unsigned count = 1;
dfg.m_fixpointState = FixpointNotConverged;
for (;; ++count) {
if (logCompilationChanges())
dataLogF("DFG beginning optimization fixpoint iteration #%u.\n", count);
bool changed = false;
if (validationEnabled())
validate(dfg);
performCFA(dfg);
changed |= performConstantFolding(dfg);
changed |= performArgumentsSimplification(dfg);
changed |= performCFGSimplification(dfg);
changed |= performCSE(dfg);
if (!changed)
break;
performCPSRethreading(dfg);
}
if (logCompilationChanges())
dataLogF("DFG optimization fixpoint converged in %u iterations.\n", count);
dfg.m_fixpointState = FixpointConverged;
performStoreElimination(dfg);
// If we're doing validation, then run some analyses, to give them an opportunity
// to self-validate. Now is as good a time as any to do this.
if (validationEnabled()) {
dfg.m_dominators.computeIfNecessary(dfg);
dfg.m_naturalLoops.computeIfNecessary(dfg);
}
#if ENABLE(FTL_JIT)
if (Options::useExperimentalFTL()
&& compileMode == CompileFunction
&& FTL::canCompile(dfg)) {
performCriticalEdgeBreaking(dfg);
performLoopPreHeaderCreation(dfg);
performCPSRethreading(dfg);
performSSAConversion(dfg);
performLivenessAnalysis(dfg);
performCFA(dfg);
performLICM(dfg);
performLivenessAnalysis(dfg);
performCFA(dfg);
performDCE(dfg); // We rely on this to convert dead SetLocals into the appropriate hint, and to kill dead code that won't be recognized as dead by LLVM.
performLivenessAnalysis(dfg);
performFlushLivenessAnalysis(dfg);
performOSRAvailabilityAnalysis(dfg);
dumpAndVerifyGraph(dfg, "Graph just before FTL lowering:");
// FIXME: Support OSR entry.
// https://bugs.webkit.org/show_bug.cgi?id=113625
FTL::State state(dfg);
FTL::lowerDFGToLLVM(state);
if (Options::reportCompileTimes())
beforeFTL = currentTimeMS();
if (Options::llvmAlwaysFails()) {
FTL::fail(state);
return FTLPath;
}
FTL::compile(state);
FTL::link(state);
return FTLPath;
}
#endif // ENABLE(FTL_JIT)
performCPSRethreading(dfg);
performDCE(dfg);
performVirtualRegisterAllocation(dfg);
dumpAndVerifyGraph(dfg, "Graph after optimization:");
JITCompiler dataFlowJIT(dfg);
if (compileMode == CompileFunction) {
dataFlowJIT.compileFunction();
dataFlowJIT.linkFunction();
} else {
ASSERT(compileMode == CompileOther);
dataFlowJIT.compile();
dataFlowJIT.link();
}
return DFGPath;
}
void Options::initialize()
{
static std::once_flag initializeOptionsOnceFlag;
std::call_once(
initializeOptionsOnceFlag,
[] {
// Initialize each of the options with their default values:
#define FOR_EACH_OPTION(type_, name_, defaultValue_, availability_, description_) \
name_() = defaultValue_; \
name_##Default() = defaultValue_;
JSC_OPTIONS(FOR_EACH_OPTION)
#undef FOR_EACH_OPTION
overrideDefaults();
// Allow environment vars to override options if applicable.
// The evn var should be the name of the option prefixed with
// "JSC_".
#if PLATFORM(COCOA)
bool hasBadOptions = false;
for (char** envp = *_NSGetEnviron(); *envp; envp++) {
const char* env = *envp;
if (!strncmp("JSC_", env, 4)) {
if (!Options::setOption(&env[4])) {
dataLog("ERROR: invalid option: ", *envp, "\n");
hasBadOptions = true;
}
}
}
if (hasBadOptions && Options::validateOptions())
CRASH();
#else // PLATFORM(COCOA)
#define FOR_EACH_OPTION(type_, name_, defaultValue_, availability_, description_) \
overrideOptionWithHeuristic(name_(), name_##ID, "JSC_" #name_, Availability::availability_);
JSC_OPTIONS(FOR_EACH_OPTION)
#undef FOR_EACH_OPTION
#endif // PLATFORM(COCOA)
#define FOR_EACH_OPTION(aliasedName_, unaliasedName_, equivalence_) \
overrideAliasedOptionWithHeuristic("JSC_" #aliasedName_);
JSC_ALIASED_OPTIONS(FOR_EACH_OPTION)
#undef FOR_EACH_OPTION
#if 0
; // Deconfuse editors that do auto indentation
#endif
#if USE(OPTIONS_FILE)
{
const char* filename = OPTIONS_FILENAME;
FILE* optionsFile = fopen(filename, "r");
if (!optionsFile) {
dataLogF("Failed to open file %s. Did you add the file-read-data entitlement to WebProcess.sb?\n", filename);
return;
}
StringBuilder builder;
char* line;
char buffer[BUFSIZ];
while ((line = fgets(buffer, sizeof(buffer), optionsFile)))
builder.append(buffer);
const char* optionsStr = builder.toString().utf8().data();
dataLogF("Setting options: %s\n", optionsStr);
setOptions(optionsStr);
int result = fclose(optionsFile);
if (result)
dataLogF("Failed to close file %s: %s\n", filename, strerror(errno));
}
#endif
recomputeDependentOptions();
// Do range checks where needed and make corrections to the options:
ASSERT(Options::thresholdForOptimizeAfterLongWarmUp() >= Options::thresholdForOptimizeAfterWarmUp());
ASSERT(Options::thresholdForOptimizeAfterWarmUp() >= Options::thresholdForOptimizeSoon());
ASSERT(Options::thresholdForOptimizeAfterWarmUp() >= 0);
dumpOptionsIfNeeded();
ensureOptionsAreCoherent();
});
}
inline bool compile(CompileMode compileMode, ExecState* exec, CodeBlock* codeBlock, JITCode& jitCode, MacroAssemblerCodePtr* jitCodeWithArityCheck, unsigned osrEntryBytecodeIndex)
{
SamplingRegion samplingRegion("DFG Compilation (Driver)");
numCompilations++;
ASSERT(codeBlock);
ASSERT(codeBlock->alternative());
ASSERT(codeBlock->alternative()->getJITType() == JITCode::BaselineJIT);
ASSERT(osrEntryBytecodeIndex != UINT_MAX);
if (!Options::useDFGJIT())
return false;
#if DFG_ENABLE(DEBUG_VERBOSE)
dataLog("DFG compiling ", *codeBlock, ", number of instructions = ", codeBlock->instructionCount(), "\n");
#endif
// Derive our set of must-handle values. The compilation must be at least conservative
// enough to allow for OSR entry with these values.
unsigned numVarsWithValues;
if (osrEntryBytecodeIndex)
numVarsWithValues = codeBlock->m_numVars;
else
numVarsWithValues = 0;
Operands<JSValue> mustHandleValues(codeBlock->numParameters(), numVarsWithValues);
for (size_t i = 0; i < mustHandleValues.size(); ++i) {
int operand = mustHandleValues.operandForIndex(i);
if (operandIsArgument(operand)
&& !operandToArgument(operand)
&& compileMode == CompileFunction
&& codeBlock->specializationKind() == CodeForConstruct) {
// Ugh. If we're in a constructor, the 'this' argument may hold garbage. It will
// also never be used. It doesn't matter what we put into the value for this,
// but it has to be an actual value that can be grokked by subsequent DFG passes,
// so we sanitize it here by turning it into Undefined.
mustHandleValues[i] = jsUndefined();
} else
mustHandleValues[i] = exec->uncheckedR(operand).jsValue();
}
Graph dfg(exec->globalData(), codeBlock, osrEntryBytecodeIndex, mustHandleValues);
if (!parse(exec, dfg))
return false;
if (compileMode == CompileFunction)
dfg.predictArgumentTypes();
// By this point the DFG bytecode parser will have potentially mutated various tables
// in the CodeBlock. This is a good time to perform an early shrink, which is more
// powerful than a late one. It's safe to do so because we haven't generated any code
// that references any of the tables directly, yet.
codeBlock->shrinkToFit(CodeBlock::EarlyShrink);
validate(dfg);
performPredictionPropagation(dfg);
performFixup(dfg);
performStructureCheckHoisting(dfg);
unsigned cnt = 1;
dfg.m_fixpointState = FixpointNotConverged;
for (;; ++cnt) {
#if DFG_ENABLE(DEBUG_VERBOSE)
dataLogF("DFG beginning optimization fixpoint iteration #%u.\n", cnt);
#endif
bool changed = false;
performCFA(dfg);
changed |= performConstantFolding(dfg);
changed |= performArgumentsSimplification(dfg);
changed |= performCFGSimplification(dfg);
changed |= performCSE(dfg);
if (!changed)
break;
dfg.resetExitStates();
performFixup(dfg);
}
dfg.m_fixpointState = FixpointConverged;
performCSE(dfg);
#if DFG_ENABLE(DEBUG_VERBOSE)
dataLogF("DFG optimization fixpoint converged in %u iterations.\n", cnt);
#endif
performVirtualRegisterAllocation(dfg);
GraphDumpMode modeForFinalValidate = DumpGraph;
#if DFG_ENABLE(DEBUG_VERBOSE)
dataLogF("Graph after optimization:\n");
dfg.dump();
modeForFinalValidate = DontDumpGraph;
#endif
validate(dfg, modeForFinalValidate);
JITCompiler dataFlowJIT(dfg);
bool result;
if (compileMode == CompileFunction) {
ASSERT(jitCodeWithArityCheck);
result = dataFlowJIT.compileFunction(jitCode, *jitCodeWithArityCheck);
} else {
ASSERT(compileMode == CompileOther);
ASSERT(!jitCodeWithArityCheck);
result = dataFlowJIT.compile(jitCode);
}
return result;
}