Changeset 44693 in webkit for trunk/JavaScriptCore/jit/JIT.cpp

Timestamp:

Jun 15, 2009, 1:17:50 PM (16 years ago)

Author:

[email protected]

Message:

2009-06-15 Gavin Barraclough <​[email protected]>

Reviewed by Geoff Hunt & Oliver Garen.

We are currently generating two copies of the slow path for op_call for no reason. Stop that.

Originally op_call used two slow paths since the first set up the pointer to the CallLinkInfo
for use when linking. However this is now looked up using the return address (as we do for
property accesses) so the two paths are now identical.

No performance impact, reduces memory footprint.

• bytecode/CodeBlock.h:
• jit/JIT.cpp: (JSC::JIT::privateCompile): (JSC::JIT::linkCall):
• jit/JIT.h:
• jit/JITCall.cpp: (JSC::JIT::compileOpCallSlowCase):
• jit/JITStubs.cpp: (JSC::JITStubs::DEFINE_STUB_FUNCTION):

File:

• trunk/JavaScriptCore/jit/JIT.cpp (modified) (3 diffs)

trunk/JavaScriptCore/jit/JIT.cpp

@@ -490 +490 @@
         info.hotPathBegin = patchBuffer.locationOf(m_callStructureStubCompilationInfo[i].hotPathBegin);
         info.hotPathOther = patchBuffer.locationOfNearCall(m_callStructureStubCompilationInfo[i].hotPathOther);
-        info.coldPathOther = patchBuffer.locationOf(m_callStructureStubCompilationInfo[i].coldPathOther);
     }
 #endif
@@ -907 +906 @@
 }
 
-void JIT::linkCall(JSFunction* callee, CodeBlock* calleeCodeBlock, JITCode& code, CallLinkInfo* callLinkInfo, int callerArgCount)
+void JIT::linkCall(JSFunction* callee, CodeBlock* calleeCodeBlock, JITCode& code, CallLinkInfo* callLinkInfo, int callerArgCount, JSGlobalData* globalData)
 {
     // Currently we only link calls with the exact number of arguments.
@@ -921 +920 @@
     }
 
-    // patch the instruction that jumps out to the cold path, so that we only try to link once.
-    callLinkInfo->hotPathBegin.jumpAtOffset(patchOffsetOpCallCompareToJump).relink(callLinkInfo->coldPathOther);
+    // patch the call so we do not continue to try to link.
+    callLinkInfo->callReturnLocation.relink(globalData->jitStubs.ctiVirtualCall());
 }