Diff
Modified: branches/dfgFourthTier/Source/_javascript_Core/ChangeLog (152325 => 152326)
--- branches/dfgFourthTier/Source/_javascript_Core/ChangeLog 2013-07-02 22:18:37 UTC (rev 152325)
+++ branches/dfgFourthTier/Source/_javascript_Core/ChangeLog 2013-07-02 22:54:04 UTC (rev 152326)
@@ -1,5 +1,25 @@
2013-07-02 Filip Pizlo <[email protected]>
+ fourthTier: add option to disable OSR entry in loops
+ https://bugs.webkit.org/show_bug.cgi?id=118329
+
+ Reviewed by Mark Hahnenberg.
+
+ This adds that option, and also makes the OSR exit reoptimization trigger rely less on
+ OSR entry failing. Now even if we never attempt OSR entry but our execution counter gets
+ high after a small number of OSR exits, we will recompile.
+
+ * dfg/DFGOSRExitCompilerCommon.cpp:
+ (JSC::DFG::handleExitCounts):
+ * dfg/DFGOperations.cpp:
+ * jit/JITOpcodes.cpp:
+ (JSC::JIT::emit_op_loop_hint):
+ (JSC::JIT::emitSlow_op_loop_hint):
+ * runtime/Options.h:
+ (JSC):
+
+2013-07-02 Filip Pizlo <[email protected]>
+
fourthTier: since the FTL disassembly hacks cannot distinguish between code and data, the LLVM disassembler symbol table callback should be able to deal gracefully with arbitrary garbage
https://bugs.webkit.org/show_bug.cgi?id=118313
Modified: branches/dfgFourthTier/Source/_javascript_Core/dfg/DFGOSRExitCompilerCommon.cpp (152325 => 152326)
--- branches/dfgFourthTier/Source/_javascript_Core/dfg/DFGOSRExitCompilerCommon.cpp 2013-07-02 22:18:37 UTC (rev 152325)
+++ branches/dfgFourthTier/Source/_javascript_Core/dfg/DFGOSRExitCompilerCommon.cpp 2013-07-02 22:54:04 UTC (rev 152326)
@@ -44,9 +44,17 @@
jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfOSRExitCounter()), GPRInfo::regT2);
jit.add32(AssemblyHelpers::TrustedImm32(1), GPRInfo::regT2);
jit.store32(GPRInfo::regT2, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfOSRExitCounter()));
+
jit.move(AssemblyHelpers::TrustedImmPtr(jit.baselineCodeBlock()), GPRInfo::regT0);
+ AssemblyHelpers::Jump reoptimizeNow = jit.branch32(
+ AssemblyHelpers::GreaterThanOrEqual,
+ AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecuteCounter()),
+ AssemblyHelpers::TrustedImm32(0));
+
tooFewFails = jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, AssemblyHelpers::TrustedImm32(jit.codeBlock()->exitCountThresholdForReoptimization()));
+ reoptimizeNow.link(&jit);
+
// Reoptimize as soon as possible.
#if !NUMBER_OF_ARGUMENT_REGISTERS
jit.poke(GPRInfo::regT0);
Modified: branches/dfgFourthTier/Source/_javascript_Core/dfg/DFGOperations.cpp (152325 => 152326)
--- branches/dfgFourthTier/Source/_javascript_Core/dfg/DFGOperations.cpp 2013-07-02 22:18:37 UTC (rev 152325)
+++ branches/dfgFourthTier/Source/_javascript_Core/dfg/DFGOperations.cpp 2013-07-02 22:54:04 UTC (rev 152326)
@@ -1740,14 +1740,33 @@
// If I am my own replacement, then reoptimization has already been triggered.
// This can happen in recursive functions.
- if (codeBlock->replacement() == codeBlock)
+ if (codeBlock->replacement() == codeBlock) {
+ if (Options::verboseOSR())
+ dataLog(*codeBlock, ": Not reoptimizing because we've already been jettisoned.\n");
return;
-
+ }
+
// Otherwise, the replacement must be optimized code. Use this as an opportunity
// to check our logic.
ASSERT(codeBlock->hasOptimizedReplacement());
- ASSERT(JITCode::isOptimizingJIT(codeBlock->replacement()->jitType()));
+ CodeBlock* optimizedCodeBlock = codeBlock->replacement();
+ ASSERT(JITCode::isOptimizingJIT(optimizedCodeBlock->jitType()));
+ // In order to trigger reoptimization, one of two things must have happened:
+ // 1) We exited more than some number of times.
+ // 2) We exited and got stuck in a loop, and now we're exiting again.
+ bool didExitABunch = optimizedCodeBlock->shouldReoptimizeNow();
+ bool didGetStuckInLoop =
+ codeBlock->checkIfOptimizationThresholdReached()
+ && optimizedCodeBlock->shouldReoptimizeFromLoopNow();
+
+ if (!didExitABunch && !didGetStuckInLoop) {
+ if (Options::verboseOSR())
+ dataLog(*codeBlock, ": Not reoptimizing ", *optimizedCodeBlock, " because it either didn't exit enough or didn't loop enough after exit.\n");
+ codeBlock->optimizeAfterLongWarmUp();
+ return;
+ }
+
codeBlock->reoptimize();
}
Modified: branches/dfgFourthTier/Source/_javascript_Core/jit/JITOpcodes.cpp (152325 => 152326)
--- branches/dfgFourthTier/Source/_javascript_Core/jit/JITOpcodes.cpp 2013-07-02 22:18:37 UTC (rev 152325)
+++ branches/dfgFourthTier/Source/_javascript_Core/jit/JITOpcodes.cpp 2013-07-02 22:54:04 UTC (rev 152326)
@@ -1154,9 +1154,22 @@
void JIT::emit_op_loop_hint(Instruction*)
{
// Emit the JIT optimization check:
- if (canBeOptimized())
- addSlowCase(branchAdd32(PositiveOrZero, TrustedImm32(Options::executionCounterIncrementForLoop()),
- AbsoluteAddress(m_codeBlock->addressOfJITExecuteCounter())));
+ if (canBeOptimized()) {
+ if (Options::enableOSREntryInLoops()) {
+ addSlowCase(branchAdd32(PositiveOrZero, TrustedImm32(Options::executionCounterIncrementForLoop()),
+ AbsoluteAddress(m_codeBlock->addressOfJITExecuteCounter())));
+ } else {
+ // Add with saturation.
+ move(TrustedImmPtr(m_codeBlock->addressOfJITExecuteCounter()), regT3);
+ load32(regT3, regT2);
+ Jump dontAdd = branch32(
+ GreaterThan, regT2,
+ TrustedImm32(std::numeric_limits<int32_t>::max() - Options::executionCounterIncrementForLoop()));
+ add32(TrustedImm32(Options::executionCounterIncrementForLoop()), regT2);
+ store32(regT2, regT3);
+ dontAdd.link(this);
+ }
+ }
// Emit the watchdog timer check:
if (m_vm->watchdog.isEnabled())
@@ -1167,13 +1180,13 @@
{
#if ENABLE(DFG_JIT)
// Emit the slow path for the JIT optimization check:
- if (canBeOptimized()) {
+ if (canBeOptimized() && Options::enableOSREntryInLoops()) {
linkSlowCase(iter);
-
+
JITStubCall stubCall(this, cti_optimize);
stubCall.addArgument(TrustedImm32(m_bytecodeOffset));
stubCall.call();
-
+
emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_loop_hint));
}
#endif
Modified: branches/dfgFourthTier/Source/_javascript_Core/runtime/Options.h (152325 => 152326)
--- branches/dfgFourthTier/Source/_javascript_Core/runtime/Options.h 2013-07-02 22:18:37 UTC (rev 152325)
+++ branches/dfgFourthTier/Source/_javascript_Core/runtime/Options.h 2013-07-02 22:54:04 UTC (rev 152326)
@@ -86,6 +86,8 @@
v(bool, verboseCompilationQueue, false) \
v(bool, reportCompileTimes, false) \
\
+ v(bool, enableOSREntryInLoops, true) \
+ \
v(bool, useExperimentalFTL, false) \
v(bool, useFTLTBAA, true) \
v(bool, enableLLVMFastISel, false) \
