Changeset 113552 in webkit for trunk/Source/JavaScriptCore/bytecode

Timestamp:

Apr 8, 2012, 1:46:12 PM (13 years ago)

Author:

[email protected]

Message:

Forced OSR exits should lead to recompilation based on count, not rate
​https://bugs.webkit.org/show_bug.cgi?id=83247
<rdar://problem/10720925>

Reviewed by Geoff Garen.

Track which OSR exits happen because of inadequate coverage. Count them
separately. If the count reaches a threshold, immediately trigger
reoptimization.

This is in contrast to the recompilation trigger for all other OSR exits.
Normally recomp is triggered when the exit rate exceeds a certain ratio.

Looks like a slight V8 speedup (sub 1%).

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::CodeBlock):

• bytecode/CodeBlock.h:

(JSC::CodeBlock::forcedOSRExitCounter):
(JSC::CodeBlock::addressOfForcedOSRExitCounter):
(JSC::CodeBlock::offsetOfForcedOSRExitCounter):
(JSC::CodeBlock::shouldReoptimizeNow):
(JSC::CodeBlock::shouldReoptimizeFromLoopNow):
(CodeBlock):

• bytecode/DFGExitProfile.h:

(JSC::DFG::exitKindToString):

• dfg/DFGOSRExitCompiler.cpp:

(JSC::DFG::OSRExitCompiler::handleExitCounts):
(DFG):

• dfg/DFGOSRExitCompiler.h:

(OSRExitCompiler):

• dfg/DFGOSRExitCompiler32_64.cpp:

(JSC::DFG::OSRExitCompiler::compileExit):

• dfg/DFGOSRExitCompiler64.cpp:

(JSC::DFG::OSRExitCompiler::compileExit):

• dfg/DFGOperations.cpp:
• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compileGetIndexedPropertyStorage):

• dfg/DFGSpeculativeJIT32_64.cpp:

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

• dfg/DFGSpeculativeJIT64.cpp:

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

• runtime/Options.cpp:

(Options):
(JSC::Options::initializeOptions):

• runtime/Options.h:

(Options):

Location:

trunk/Source/JavaScriptCore/bytecode

Files:

• CodeBlock.cpp (modified) (1 diff)
• CodeBlock.h (modified) (3 diffs)
• DFGExitProfile.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -1433 +1433 @@
     , m_speculativeSuccessCounter(0)
     , m_speculativeFailCounter(0)
+    , m_forcedOSRExitCounter(0)
     , m_optimizationDelayCounter(0)
     , m_reoptimizationRetryCounter(0)

trunk/Source/JavaScriptCore/bytecode/CodeBlock.h

@@ -1007 +1007 @@
         uint32_t speculativeSuccessCounter() const { return m_speculativeSuccessCounter; }
         uint32_t speculativeFailCounter() const { return m_speculativeFailCounter; }
+        uint32_t forcedOSRExitCounter() const { return m_forcedOSRExitCounter; }
         
         uint32_t* addressOfSpeculativeSuccessCounter() { return &m_speculativeSuccessCounter; }
         uint32_t* addressOfSpeculativeFailCounter() { return &m_speculativeFailCounter; }
+        uint32_t* addressOfForcedOSRExitCounter() { return &m_forcedOSRExitCounter; }
         
         static ptrdiff_t offsetOfSpeculativeSuccessCounter() { return OBJECT_OFFSETOF(CodeBlock, m_speculativeSuccessCounter); }
         static ptrdiff_t offsetOfSpeculativeFailCounter() { return OBJECT_OFFSETOF(CodeBlock, m_speculativeFailCounter); }
+        static ptrdiff_t offsetOfForcedOSRExitCounter() { return OBJECT_OFFSETOF(CodeBlock, m_forcedOSRExitCounter); }
 
 #if ENABLE(JIT)
@@ -1021 +1024 @@
         bool shouldReoptimizeNow()
         {
-            return Options::desiredSpeculativeSuccessFailRatio * speculativeFailCounter() >= speculativeSuccessCounter() && speculativeFailCounter() >= largeFailCountThreshold();
+            return (Options::desiredSpeculativeSuccessFailRatio *
+                        speculativeFailCounter() >= speculativeSuccessCounter()
+                    && speculativeFailCounter() >= largeFailCountThreshold())
+                || forcedOSRExitCounter() >=
+                       Options::forcedOSRExitCountForReoptimization;
         }
 
         bool shouldReoptimizeFromLoopNow()
         {
-            return Options::desiredSpeculativeSuccessFailRatio * speculativeFailCounter() >= speculativeSuccessCounter() && speculativeFailCounter() >= largeFailCountThresholdForLoop();
+            return (Options::desiredSpeculativeSuccessFailRatio *
+                        speculativeFailCounter() >= speculativeSuccessCounter()
+                    && speculativeFailCounter() >= largeFailCountThresholdForLoop())
+                || forcedOSRExitCounter() >=
+                       Options::forcedOSRExitCountForReoptimization;
         }
 #endif
@@ -1229 +1240 @@
         uint32_t m_speculativeSuccessCounter;
         uint32_t m_speculativeFailCounter;
+        uint32_t m_forcedOSRExitCounter;
         uint16_t m_optimizationDelayCounter;
         uint16_t m_reoptimizationRetryCounter;

trunk/Source/JavaScriptCore/bytecode/DFGExitProfile.h

@@ -39 +39 @@
     Overflow, // We exited because of overflow.
     NegativeZero, // We exited because we encountered negative zero.
+    InadequateCoverage, // We exited because we ended up in code that didn't have profiling coverage.
     Uncountable, // We exited for none of the above reasons, and we should not count it. Most uses of this should be viewed as a FIXME.
 };
@@ -55 +56 @@
     case NegativeZero:
         return "NegativeZero";
+    case InadequateCoverage:
+        return "InadequateCoverage";
     default:
         return "Unknown";