#include "config.h"
#include "DFGOSREntry.h"
#if ENABLE(DFG_JIT)
#include "CallFrame.h"
#include "CodeBlock.h"
#include "DFGJITCode.h"
#include "DFGNode.h"
#include "JIT.h"
#include "JSCInlines.h"
#include "VMInlines.h"
#include <wtf/CommaPrinter.h>
namespace JSC { namespace DFG {
void OSREntryData::dumpInContext(PrintStream& out, DumpContext* context) const
{
out.print("bc#", m_bytecodeIndex, ", machine code offset = ", m_machineCodeOffset);
out.print(", stack rules = [");
auto printOperand = [&] (VirtualRegister reg) {
out.print(inContext(m_expectedValues.operand(reg), context), " (");
VirtualRegister toReg;
bool overwritten = false;
for (OSREntryReshuffling reshuffling : m_reshufflings) {
if (reg == VirtualRegister(reshuffling.fromOffset)) {
toReg = VirtualRegister(reshuffling.toOffset);
break;
}
if (reg == VirtualRegister(reshuffling.toOffset))
overwritten = true;
}
if (!overwritten && !toReg.isValid())
toReg = reg;
if (toReg.isValid()) {
if (toReg.isLocal() && !m_machineStackUsed.get(toReg.toLocal()))
out.print("ignored");
else
out.print("maps to ", toReg);
} else
out.print("overwritten");
if (reg.isLocal() && m_localsForcedDouble.get(reg.toLocal()))
out.print(", forced double");
if (reg.isLocal() && m_localsForcedAnyInt.get(reg.toLocal()))
out.print(", forced machine int");
out.print(")");
};
CommaPrinter comma;
for (size_t argumentIndex = m_expectedValues.numberOfArguments(); argumentIndex--;) {
out.print(comma, "arg", argumentIndex, ":");
printOperand(virtualRegisterForArgument(argumentIndex));
}
for (size_t localIndex = 0; localIndex < m_expectedValues.numberOfLocals(); ++localIndex) {
out.print(comma, "loc", localIndex, ":");
printOperand(virtualRegisterForLocal(localIndex));
}
out.print("], machine stack used = ", m_machineStackUsed);
}
void OSREntryData::dump(PrintStream& out) const
{
dumpInContext(out, nullptr);
}
SUPPRESS_ASAN
void* prepareOSREntry(ExecState* exec, CodeBlock* codeBlock, unsigned bytecodeIndex)
{
ASSERT(JITCode::isOptimizingJIT(codeBlock->jitType()));
ASSERT(codeBlock->alternative());
ASSERT(codeBlock->alternative()->jitType() == JITCode::BaselineJIT);
ASSERT(!codeBlock->jitCodeMap());
if (!Options::useOSREntryToDFG())
return 0;
if (Options::verboseOSR()) {
dataLog(
"DFG OSR in ", *codeBlock->alternative(), " -> ", *codeBlock,
" from bc#", bytecodeIndex, "\n");
}
VM* vm = &exec->vm();
sanitizeStackForVM(vm);
if (bytecodeIndex)
codeBlock->ownerScriptExecutable()->setDidTryToEnterInLoop(true);
if (codeBlock->jitType() != JITCode::DFGJIT) {
RELEASE_ASSERT(codeBlock->jitType() == JITCode::FTLJIT);
if (Options::verboseOSR())
dataLog(" OSR failed because the target code block is not DFG.\n");
return 0;
}
JITCode* jitCode = codeBlock->jitCode()->dfg();
OSREntryData* entry = jitCode->osrEntryDataForBytecodeIndex(bytecodeIndex);
if (!entry) {
if (Options::verboseOSR())
dataLogF(" OSR failed because the entrypoint was optimized out.\n");
return 0;
}
ASSERT(entry->m_bytecodeIndex == bytecodeIndex);
for (size_t argument = 0; argument < entry->m_expectedValues.numberOfArguments(); ++argument) {
if (argument >= exec->argumentCountIncludingThis()) {
if (Options::verboseOSR()) {
dataLogF(" OSR failed because argument %zu was not passed, expected ", argument);
entry->m_expectedValues.argument(argument).dump(WTF::dataFile());
dataLogF(".\n");
}
return 0;
}
JSValue value;
if (!argument)
value = exec->thisValue();
else
value = exec->argument(argument - 1);
if (!entry->m_expectedValues.argument(argument).validate(value)) {
if (Options::verboseOSR()) {
dataLog(
" OSR failed because argument ", argument, " is ", value,
", expected ", entry->m_expectedValues.argument(argument), ".\n");
}
return 0;
}
}
for (size_t local = 0; local < entry->m_expectedValues.numberOfLocals(); ++local) {
int localOffset = virtualRegisterForLocal(local).offset();
if (entry->m_localsForcedDouble.get(local)) {
if (!exec->registers()[localOffset].asanUnsafeJSValue().isNumber()) {
if (Options::verboseOSR()) {
dataLog(
" OSR failed because variable ", localOffset, " is ",
exec->registers()[localOffset].asanUnsafeJSValue(), ", expected number.\n");
}
return 0;
}
continue;
}
if (entry->m_localsForcedAnyInt.get(local)) {
if (!exec->registers()[localOffset].asanUnsafeJSValue().isAnyInt()) {
if (Options::verboseOSR()) {
dataLog(
" OSR failed because variable ", localOffset, " is ",
exec->registers()[localOffset].asanUnsafeJSValue(), ", expected ",
"machine int.\n");
}
return 0;
}
continue;
}
if (!entry->m_expectedValues.local(local).validate(exec->registers()[localOffset].asanUnsafeJSValue())) {
if (Options::verboseOSR()) {
dataLog(
" OSR failed because variable ", VirtualRegister(localOffset), " is ",
exec->registers()[localOffset].asanUnsafeJSValue(), ", expected ",
entry->m_expectedValues.local(local), ".\n");
}
return 0;
}
}
unsigned frameSizeForCheck = jitCode->common.requiredRegisterCountForExecutionAndExit();
if (UNLIKELY(!vm->ensureStackCapacityFor(&exec->registers()[virtualRegisterForLocal(frameSizeForCheck - 1).offset()]))) {
if (Options::verboseOSR())
dataLogF(" OSR failed because stack growth failed.\n");
return 0;
}
if (Options::verboseOSR())
dataLogF(" OSR should succeed.\n");
unsigned frameSize = jitCode->common.frameRegisterCount;
unsigned baselineFrameSize = entry->m_expectedValues.numberOfLocals();
unsigned maxFrameSize = std::max(frameSize, baselineFrameSize);
Register* scratch = bitwise_cast<Register*>(vm->scratchBufferForSize(sizeof(Register) * (2 + CallFrame::headerSizeInRegisters + maxFrameSize))->dataBuffer());
*bitwise_cast<size_t*>(scratch + 0) = frameSize;
void* targetPC = codeBlock->jitCode()->executableAddressAtOffset(entry->m_machineCodeOffset);
if (Options::verboseOSR())
dataLogF(" OSR using target PC %p.\n", targetPC);
RELEASE_ASSERT(targetPC);
*bitwise_cast<void**>(scratch + 1) = targetPC;
Register* pivot = scratch + 2 + CallFrame::headerSizeInRegisters;
for (int index = -CallFrame::headerSizeInRegisters; index < static_cast<int>(baselineFrameSize); ++index) {
VirtualRegister reg(-1 - index);
if (reg.isLocal()) {
if (entry->m_localsForcedDouble.get(reg.toLocal())) {
*bitwise_cast<double*>(pivot + index) = exec->registers()[reg.offset()].asanUnsafeJSValue().asNumber();
continue;
}
if (entry->m_localsForcedAnyInt.get(reg.toLocal())) {
*bitwise_cast<int64_t*>(pivot + index) = exec->registers()[reg.offset()].asanUnsafeJSValue().asAnyInt() << JSValue::int52ShiftAmount;
continue;
}
}
pivot[index] = exec->registers()[reg.offset()].asanUnsafeJSValue();
}
Vector<JSValue> temporaryLocals(entry->m_reshufflings.size());
for (unsigned i = entry->m_reshufflings.size(); i--;)
temporaryLocals[i] = pivot[VirtualRegister(entry->m_reshufflings[i].fromOffset).toLocal()].asanUnsafeJSValue();
for (unsigned i = entry->m_reshufflings.size(); i--;)
pivot[VirtualRegister(entry->m_reshufflings[i].toOffset).toLocal()] = temporaryLocals[i];
for (unsigned i = frameSize; i--;) {
if (entry->m_machineStackUsed.get(i))
continue;
pivot[i] = JSValue();
}
#if NUMBER_OF_CALLEE_SAVES_REGISTERS > 0
RegisterAtOffsetList* registerSaveLocations = codeBlock->calleeSaveRegisters();
RegisterAtOffsetList* allCalleeSaves = VM::getAllCalleeSaveRegisterOffsets();
RegisterSet dontSaveRegisters = RegisterSet(RegisterSet::stackRegisters(), RegisterSet::allFPRs());
unsigned registerCount = registerSaveLocations->size();
VMEntryRecord* record = vmEntryRecord(vm->topVMEntryFrame);
for (unsigned i = 0; i < registerCount; i++) {
RegisterAtOffset currentEntry = registerSaveLocations->at(i);
if (dontSaveRegisters.get(currentEntry.reg()))
continue;
RegisterAtOffset* calleeSavesEntry = allCalleeSaves->find(currentEntry.reg());
*(bitwise_cast<intptr_t*>(pivot - 1) - currentEntry.offsetAsIndex()) = record->calleeSaveRegistersBuffer[calleeSavesEntry->offsetAsIndex()];
}
#endif
*bitwise_cast<CodeBlock**>(pivot - 1 - CallFrameSlot::codeBlock) = codeBlock;
if (Options::verboseOSR())
dataLogF(" OSR returning data buffer %p.\n", scratch);
return scratch;
}
} }
#endif // ENABLE(DFG_JIT)