Changeset 95930 in webkit for trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

Timestamp:

Sep 25, 2011, 7:25:02 PM (14 years ago)

Author:

[email protected]

Message:

DFG static prediction code is no longer needed and should be removed
​https://bugs.webkit.org/show_bug.cgi?id=68784

Reviewed by Oliver Hunt.

This gets rid of static prediction code, and ensures that we do not
try to compile code where dynamic predictions are not available.
This is accomplished by immediately performing an OSR exit wherever
a value is retrieved for which no predictions exist.

This also adds value profiling for this on functions used for calls.

The heuristics for deciding when to optimize code are also tweaked,
since it is now profitable to optimize sooner. This may need to be
tweaked further, but this patch only makes minimal changes.

This results in a 16% speed-up on Kraken/ai-astar, leading to a 3%
overall win on Kraken. It's neutral elsewhere.

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::shouldOptimizeNow):
(JSC::CodeBlock::dumpValueProfiles):

• bytecode/CodeBlock.h:
• bytecode/PredictedType.cpp:

(JSC::predictionToString):

• bytecode/PredictedType.h:

(JSC::isCellPrediction):
(JSC::isObjectPrediction):
(JSC::isFinalObjectPrediction):
(JSC::isStringPrediction):
(JSC::isArrayPrediction):
(JSC::isInt32Prediction):
(JSC::isDoublePrediction):
(JSC::isNumberPrediction):
(JSC::isBooleanPrediction):
(JSC::mergePredictions):

• bytecode/PredictionTracker.h:

(JSC::PredictionTracker::predictArgument):
(JSC::PredictionTracker::predict):
(JSC::PredictionTracker::predictGlobalVar):

• bytecode/ValueProfile.cpp:

(JSC::ValueProfile::computeUpdatedPrediction):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::set):
(JSC::DFG::ByteCodeParser::addCall):
(JSC::DFG::ByteCodeParser::getPrediction):
(JSC::DFG::ByteCodeParser::parseBlock):

• dfg/DFGGraph.cpp:

(JSC::DFG::Graph::predictArgumentTypes):

• dfg/DFGGraph.h:

(JSC::DFG::Graph::predict):
(JSC::DFG::Graph::predictGlobalVar):
(JSC::DFG::Graph::getMethodCheckPrediction):
(JSC::DFG::Graph::getJSConstantPrediction):
(JSC::DFG::Graph::getPrediction):

• dfg/DFGJITCodeGenerator.cpp:

(JSC::DFG::JITCodeGenerator::writeBarrier):
(JSC::DFG::JITCodeGenerator::emitBranch):

• dfg/DFGJITCompiler.h:

(JSC::DFG::JITCompiler::getPrediction):

• dfg/DFGNode.h:

(JSC::DFG::Node::valueOfJSConstantNode):
(JSC::DFG::Node::isInt32Constant):
(JSC::DFG::Node::isDoubleConstant):
(JSC::DFG::Node::isNumberConstant):
(JSC::DFG::Node::isBooleanConstant):
(JSC::DFG::Node::predict):

• dfg/DFGPropagator.cpp:

(JSC::DFG::Propagator::Propagator):
(JSC::DFG::Propagator::propagateNodePredictions):
(JSC::DFG::Propagator::fixupNode):
(JSC::DFG::Propagator::isPredictedNumerical):
(JSC::DFG::Propagator::logicalNotIsPure):

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGSpeculativeJIT.h:

(JSC::DFG::SpeculativeJIT::shouldSpeculateInteger):
(JSC::DFG::SpeculativeJIT::shouldSpeculateDouble):
(JSC::DFG::SpeculativeJIT::shouldSpeculateNumber):
(JSC::DFG::SpeculativeJIT::shouldNotSpeculateInteger):
(JSC::DFG::SpeculativeJIT::shouldSpeculateFinalObject):
(JSC::DFG::SpeculativeJIT::shouldSpeculateArray):
(JSC::DFG::SpeculativeJIT::shouldSpeculateObject):
(JSC::DFG::SpeculativeJIT::shouldSpeculateCell):

• jit/JIT.cpp:

(JSC::JIT::privateCompile):

File:

• trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -2000 +2000 @@
 
     if ((!numberOfNonArgumentValueProfiles || (double)numberOfLiveNonArgumentValueProfiles / numberOfNonArgumentValueProfiles >= 0.75)
-        && (!numberOfValueProfiles() || (double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / numberOfValueProfiles() >= 0.5))
+        && (!numberOfValueProfiles() || (double)numberOfSamplesInProfiles / ValueProfile::numberOfBuckets / numberOfValueProfiles() >= 0.25))
         return true;
     
@@ -2027 +2027 @@
         if (profile->m_bytecodeOffset < 0) {
             ASSERT(profile->m_bytecodeOffset == -1);
-            fprintf(stderr, "   arg = %u: ", i + 1);
+            fprintf(stderr, "   arg = %u: ", i);
         } else
             fprintf(stderr, "   bc = %d: ", profile->m_bytecodeOffset);