Changeset 164459 in webkit for trunk/Source/JavaScriptCore/dfg/DFGBasicBlock.h

Timestamp:

Feb 20, 2014, 5:20:48 PM (12 years ago)

Author:

[email protected]

Message:

DFG should do its own static estimates of execution frequency before it starts creating OSR entrypoints
​https://bugs.webkit.org/show_bug.cgi?id=129129

Reviewed by Geoffrey Garen.

We estimate execution counts based on loop depth, and then use those to estimate branch
weights. These weights then get carried all the way down to LLVM prof branch_weights
meta-data.

This is better than letting LLVM do its own static estimates, since by the time we
generate LLVM IR, we may have messed up the CFG due to OSR entrypoint creation. Of
course, it would be even better if we just slurped in some kind of execution counts
from profiling, but we don't do that, yet.

• CMakeLists.txt:
• GNUmakefile.list.am:
• JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
• JavaScriptCore.xcodeproj/project.pbxproj:
• dfg/DFGBasicBlock.cpp:

(JSC::DFG::BasicBlock::BasicBlock):

• dfg/DFGBasicBlock.h:
• dfg/DFGBlockInsertionSet.cpp:

(JSC::DFG::BlockInsertionSet::insert):
(JSC::DFG::BlockInsertionSet::insertBefore):

• dfg/DFGBlockInsertionSet.h:
• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::handleInlining):
(JSC::DFG::ByteCodeParser::parseCodeBlock):

• dfg/DFGCriticalEdgeBreakingPhase.cpp:

(JSC::DFG::CriticalEdgeBreakingPhase::breakCriticalEdge):

• dfg/DFGLoopPreHeaderCreationPhase.cpp:

(JSC::DFG::createPreHeader):

• dfg/DFGNaturalLoops.h:

(JSC::DFG::NaturalLoops::loopDepth):

• dfg/DFGOSREntrypointCreationPhase.cpp:

(JSC::DFG::OSREntrypointCreationPhase::run):

• dfg/DFGPlan.cpp:

(JSC::DFG::Plan::compileInThreadImpl):

• dfg/DFGStaticExecutionCountEstimationPhase.cpp: Added.

(JSC::DFG::StaticExecutionCountEstimationPhase::StaticExecutionCountEstimationPhase):
(JSC::DFG::StaticExecutionCountEstimationPhase::run):
(JSC::DFG::StaticExecutionCountEstimationPhase::applyCounts):
(JSC::DFG::performStaticExecutionCountEstimation):

• dfg/DFGStaticExecutionCountEstimationPhase.h: Added.

File:

• trunk/Source/JavaScriptCore/dfg/DFGBasicBlock.h (modified) (3 diffs)

trunk/Source/JavaScriptCore/dfg/DFGBasicBlock.h

@@ -1 +1 @@
 /*
- * Copyright (C) 2011, 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2011, 2013, 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -49 +49 @@
 
 struct BasicBlock : RefCounted<BasicBlock> {
-    BasicBlock(unsigned bytecodeBegin, unsigned numArguments, unsigned numLocals);
+    BasicBlock(
+        unsigned bytecodeBegin, unsigned numArguments, unsigned numLocals,
+        float executionCount);
     ~BasicBlock();
     
@@ -135 +137 @@
     Operands<AbstractValue> valuesAtTail;
     
+    float executionCount;
+    
     // These fields are reserved for NaturalLoops.
     static const unsigned numberOfInnerMostLoopIndices = 2;