DFGVariableEventStream.cpp [plain text]
#include "config.h"
#include "DFGVariableEventStream.h"
#if ENABLE(DFG_JIT)
#include "CodeBlock.h"
#include "DFGJITCode.h"
#include "DFGValueSource.h"
#include "InlineCallFrame.h"
#include "JSCInlines.h"
#include <wtf/DataLog.h>
#include <wtf/HashMap.h>
namespace JSC { namespace DFG {
void VariableEventStream::logEvent(const VariableEvent& event)
{
dataLogF("seq#%u:", static_cast<unsigned>(size()));
event.dump(WTF::dataFile());
dataLogF(" ");
}
namespace {
struct MinifiedGenerationInfo {
bool filled; bool alive;
VariableRepresentation u;
DataFormat format;
MinifiedGenerationInfo()
: filled(false)
, alive(false)
, format(DataFormatNone)
{
}
void update(const VariableEvent& event)
{
switch (event.kind()) {
case BirthToFill:
case Fill:
filled = true;
alive = true;
break;
case BirthToSpill:
case Spill:
filled = false;
alive = true;
break;
case Birth:
alive = true;
return;
case Death:
format = DataFormatNone;
alive = false;
return;
default:
return;
}
u = event.variableRepresentation();
format = event.dataFormat();
}
};
}
static bool tryToSetConstantRecovery(ValueRecovery& recovery, MinifiedNode* node)
{
if (!node)
return false;
if (node->hasConstant()) {
recovery = ValueRecovery::constant(node->constant());
return true;
}
if (node->op() == PhantomDirectArguments) {
recovery = ValueRecovery::directArgumentsThatWereNotCreated(node->id());
return true;
}
if (node->op() == PhantomClonedArguments) {
recovery = ValueRecovery::clonedArgumentsThatWereNotCreated(node->id());
return true;
}
return false;
}
template<VariableEventStream::ReconstructionStyle style>
unsigned VariableEventStream::reconstruct(
CodeBlock* codeBlock, CodeOrigin codeOrigin, MinifiedGraph& graph,
unsigned index, Operands<ValueRecovery>& valueRecoveries, Vector<UndefinedOperandSpan>* undefinedOperandSpans) const
{
ASSERT(codeBlock->jitType() == JITCode::DFGJIT);
CodeBlock* baselineCodeBlock = codeBlock->baselineVersion();
unsigned numVariables;
static const unsigned invalidIndex = std::numeric_limits<unsigned>::max();
unsigned firstUndefined = invalidIndex;
bool firstUndefinedIsArgument = false;
auto flushUndefinedOperandSpan = [&] (unsigned i) {
if (firstUndefined == invalidIndex)
return;
int firstOffset = valueRecoveries.virtualRegisterForIndex(firstUndefined).offset();
int lastOffset = valueRecoveries.virtualRegisterForIndex(i - 1).offset();
int minOffset = std::min(firstOffset, lastOffset);
undefinedOperandSpans->append({ firstUndefined, minOffset, i - firstUndefined });
firstUndefined = invalidIndex;
};
auto recordUndefinedOperand = [&] (unsigned i) {
if (firstUndefined != invalidIndex && firstUndefinedIsArgument != valueRecoveries.isArgument(i))
flushUndefinedOperandSpan(i);
if (firstUndefined == invalidIndex) {
firstUndefined = i;
firstUndefinedIsArgument = valueRecoveries.isArgument(i);
}
};
if (codeOrigin.inlineCallFrame)
numVariables = baselineCodeBlockForInlineCallFrame(codeOrigin.inlineCallFrame)->m_numCalleeLocals + VirtualRegister(codeOrigin.inlineCallFrame->stackOffset).toLocal() + 1;
else
numVariables = baselineCodeBlock->m_numCalleeLocals;
if (!index) {
valueRecoveries = Operands<ValueRecovery>(codeBlock->numParameters(), numVariables);
for (size_t i = 0; i < valueRecoveries.size(); ++i) {
valueRecoveries[i] = ValueRecovery::displacedInJSStack(
VirtualRegister(valueRecoveries.operandForIndex(i)), DataFormatJS);
}
return numVariables;
}
unsigned startIndex = index - 1;
while (at(startIndex).kind() != Reset)
startIndex--;
Operands<ValueSource> operandSources(codeBlock->numParameters(), numVariables);
for (unsigned i = operandSources.size(); i--;)
operandSources[i] = ValueSource(SourceIsDead);
HashMap<MinifiedID, MinifiedGenerationInfo> generationInfos;
for (unsigned i = startIndex; i < index; ++i) {
const VariableEvent& event = at(i);
switch (event.kind()) {
case Reset:
break;
case BirthToFill:
case BirthToSpill:
case Birth: {
MinifiedGenerationInfo info;
info.update(event);
generationInfos.add(event.id(), info);
break;
}
case Fill:
case Spill:
case Death: {
HashMap<MinifiedID, MinifiedGenerationInfo>::iterator iter = generationInfos.find(event.id());
ASSERT(iter != generationInfos.end());
iter->value.update(event);
break;
}
case MovHintEvent:
if (operandSources.hasOperand(event.bytecodeRegister()))
operandSources.setOperand(event.bytecodeRegister(), ValueSource(event.id()));
break;
case SetLocalEvent:
if (operandSources.hasOperand(event.bytecodeRegister()))
operandSources.setOperand(event.bytecodeRegister(), ValueSource::forDataFormat(event.machineRegister(), event.dataFormat()));
break;
default:
RELEASE_ASSERT_NOT_REACHED();
break;
}
}
valueRecoveries = Operands<ValueRecovery>(codeBlock->numParameters(), numVariables);
for (unsigned i = 0; i < operandSources.size(); ++i) {
ValueSource& source = operandSources[i];
if (source.isTriviallyRecoverable()) {
valueRecoveries[i] = source.valueRecovery();
if (style == ReconstructionStyle::Separated) {
if (valueRecoveries[i].isConstant() && valueRecoveries[i].constant() == jsUndefined())
recordUndefinedOperand(i);
else
flushUndefinedOperandSpan(i);
}
continue;
}
ASSERT(source.kind() == HaveNode);
MinifiedNode* node = graph.at(source.id());
MinifiedGenerationInfo info = generationInfos.get(source.id());
if (!info.alive) {
valueRecoveries[i] = ValueRecovery::constant(jsUndefined());
if (style == ReconstructionStyle::Separated)
recordUndefinedOperand(i);
continue;
}
if (tryToSetConstantRecovery(valueRecoveries[i], node)) {
if (style == ReconstructionStyle::Separated) {
if (node->hasConstant() && node->constant() == jsUndefined())
recordUndefinedOperand(i);
else
flushUndefinedOperandSpan(i);
}
continue;
}
ASSERT(info.format != DataFormatNone);
if (style == ReconstructionStyle::Separated)
flushUndefinedOperandSpan(i);
if (info.filled) {
if (info.format == DataFormatDouble) {
valueRecoveries[i] = ValueRecovery::inFPR(info.u.fpr, DataFormatDouble);
continue;
}
#if USE(JSVALUE32_64)
if (info.format & DataFormatJS) {
valueRecoveries[i] = ValueRecovery::inPair(info.u.pair.tagGPR, info.u.pair.payloadGPR);
continue;
}
#endif
valueRecoveries[i] = ValueRecovery::inGPR(info.u.gpr, info.format);
continue;
}
valueRecoveries[i] =
ValueRecovery::displacedInJSStack(static_cast<VirtualRegister>(info.u.virtualReg), info.format);
}
if (style == ReconstructionStyle::Separated)
flushUndefinedOperandSpan(operandSources.size());
return numVariables;
}
unsigned VariableEventStream::reconstruct(
CodeBlock* codeBlock, CodeOrigin codeOrigin, MinifiedGraph& graph,
unsigned index, Operands<ValueRecovery>& valueRecoveries) const
{
return reconstruct<ReconstructionStyle::Combined>(codeBlock, codeOrigin, graph, index, valueRecoveries, nullptr);
}
unsigned VariableEventStream::reconstruct(
CodeBlock* codeBlock, CodeOrigin codeOrigin, MinifiedGraph& graph,
unsigned index, Operands<ValueRecovery>& valueRecoveries, Vector<UndefinedOperandSpan>* undefinedOperandSpans) const
{
return reconstruct<ReconstructionStyle::Separated>(codeBlock, codeOrigin, graph, index, valueRecoveries, undefinedOperandSpans);
}
} }
#endif // ENABLE(DFG_JIT)