[webkit-changes] [165797] trunk/Source/JavaScriptCore

Mon, 17 Mar 2014 20:46:24 -0700

Title: [165797] trunk/Source/_javascript_Core
Revision
165797
Author
[email protected]
Date
2014-03-17 20:46:10 -0700 (Mon, 17 Mar 2014)

Log Message

V8 regexp spends most of its time in operationGetById
https://bugs.webkit.org/show_bug.cgi?id=130380

Reviewed by Filip Pizlo.

Added String.length case to tryCacheGetByID that will only help the BaseLine JIT.
When V8 regexp is run from the command line, this nets a 2% performance improvement.
When the test is run for a longer amount of time, there is much less benefit as the
DFG will emit the appropriate code for String.length.  This does remove
operationGetById as the hottest function whne run from the command line.

* jit/Repatch.cpp:
(JSC::tryCacheGetByID):

Modified Paths

Diff

Modified: trunk/Source/_javascript_Core/ChangeLog (165796 => 165797)


--- trunk/Source/_javascript_Core/ChangeLog	2014-03-18 03:28:19 UTC (rev 165796)
+++ trunk/Source/_javascript_Core/ChangeLog	2014-03-18 03:46:10 UTC (rev 165797)
@@ -1,3 +1,19 @@
+2014-03-17  Michael Saboff  <[email protected]>
+
+        V8 regexp spends most of its time in operationGetById
+        https://bugs.webkit.org/show_bug.cgi?id=130380
+
+        Reviewed by Filip Pizlo.
+
+        Added String.length case to tryCacheGetByID that will only help the BaseLine JIT.
+        When V8 regexp is run from the command line, this nets a 2% performance improvement.
+        When the test is run for a longer amount of time, there is much less benefit as the
+        DFG will emit the appropriate code for String.length.  This does remove
+        operationGetById as the hottest function whne run from the command line.
+
+        * jit/Repatch.cpp:
+        (JSC::tryCacheGetByID):
+
 2014-03-17  Andreas Kling  <[email protected]>
 
         Add one-deep cache to opaque roots hashset.

Modified: trunk/Source/_javascript_Core/jit/Repatch.cpp (165796 => 165797)


--- trunk/Source/_javascript_Core/jit/Repatch.cpp	2014-03-18 03:28:19 UTC (rev 165796)
+++ trunk/Source/_javascript_Core/jit/Repatch.cpp	2014-03-18 03:46:10 UTC (rev 165797)
@@ -374,66 +374,97 @@
     CodeBlock* codeBlock = exec->codeBlock();
     VM* vm = &exec->vm();
     
-    if (isJSArray(baseValue) && propertyName == exec->propertyNames().length) {
+    if ((isJSArray(baseValue) || isJSString(baseValue)) && propertyName == exec->propertyNames().length) {
         GPRReg baseGPR = static_cast<GPRReg>(stubInfo.patch.baseGPR);
 #if USE(JSVALUE32_64)
         GPRReg resultTagGPR = static_cast<GPRReg>(stubInfo.patch.valueTagGPR);
 #endif
         GPRReg resultGPR = static_cast<GPRReg>(stubInfo.patch.valueGPR);
-        GPRReg scratchGPR = TempRegisterSet(stubInfo.patch.usedRegisters).getFreeGPR();
-        bool needToRestoreScratch = false;
-        
+
         MacroAssembler stubJit;
-        
-        if (scratchGPR == InvalidGPRReg) {
+
+        if (isJSArray(baseValue)) {
+            GPRReg scratchGPR = TempRegisterSet(stubInfo.patch.usedRegisters).getFreeGPR();
+            bool needToRestoreScratch = false;
+
+            if (scratchGPR == InvalidGPRReg) {
 #if USE(JSVALUE64)
-            scratchGPR = AssemblyHelpers::selectScratchGPR(baseGPR, resultGPR);
+                scratchGPR = AssemblyHelpers::selectScratchGPR(baseGPR, resultGPR);
 #else
-            scratchGPR = AssemblyHelpers::selectScratchGPR(baseGPR, resultGPR, resultTagGPR);
+                scratchGPR = AssemblyHelpers::selectScratchGPR(baseGPR, resultGPR, resultTagGPR);
 #endif
-            stubJit.pushToSave(scratchGPR);
-            needToRestoreScratch = true;
+                stubJit.pushToSave(scratchGPR);
+                needToRestoreScratch = true;
+            }
+
+            MacroAssembler::JumpList failureCases;
+
+            stubJit.load8(MacroAssembler::Address(baseGPR, JSCell::indexingTypeOffset()), scratchGPR);
+            failureCases.append(stubJit.branchTest32(MacroAssembler::Zero, scratchGPR, MacroAssembler::TrustedImm32(IsArray)));
+            failureCases.append(stubJit.branchTest32(MacroAssembler::Zero, scratchGPR, MacroAssembler::TrustedImm32(IndexingShapeMask)));
+
+            stubJit.loadPtr(MacroAssembler::Address(baseGPR, JSObject::butterflyOffset()), scratchGPR);
+            stubJit.load32(MacroAssembler::Address(scratchGPR, ArrayStorage::lengthOffset()), scratchGPR);
+            failureCases.append(stubJit.branch32(MacroAssembler::LessThan, scratchGPR, MacroAssembler::TrustedImm32(0)));
+
+            stubJit.move(scratchGPR, resultGPR);
+#if USE(JSVALUE64)
+            stubJit.or64(AssemblyHelpers::TrustedImm64(TagTypeNumber), resultGPR);
+#elif USE(JSVALUE32_64)
+            stubJit.move(AssemblyHelpers::TrustedImm32(0xffffffff), resultTagGPR); // JSValue::Int32Tag
+#endif
+
+            MacroAssembler::Jump success, fail;
+
+            emitRestoreScratch(stubJit, needToRestoreScratch, scratchGPR, success, fail, failureCases);
+            
+            LinkBuffer patchBuffer(*vm, &stubJit, codeBlock);
+
+            linkRestoreScratch(patchBuffer, needToRestoreScratch, stubInfo, success, fail, failureCases);
+
+            stubInfo.stubRoutine = FINALIZE_CODE_FOR_STUB(
+                exec->codeBlock(), patchBuffer,
+                ("GetById array length stub for %s, return point %p",
+                    toCString(*exec->codeBlock()).data(), stubInfo.callReturnLocation.labelAtOffset(
+                        stubInfo.patch.deltaCallToDone).executableAddress()));
+
+            RepatchBuffer repatchBuffer(codeBlock);
+            replaceWithJump(repatchBuffer, stubInfo, stubInfo.stubRoutine->code().code());
+            repatchCall(repatchBuffer, stubInfo.callReturnLocation, operationGetById);
+
+            return true;
         }
-        
-        MacroAssembler::JumpList failureCases;
-       
-        stubJit.load8(MacroAssembler::Address(baseGPR, JSCell::indexingTypeOffset()), scratchGPR);
-        failureCases.append(stubJit.branchTest32(MacroAssembler::Zero, scratchGPR, MacroAssembler::TrustedImm32(IsArray)));
-        failureCases.append(stubJit.branchTest32(MacroAssembler::Zero, scratchGPR, MacroAssembler::TrustedImm32(IndexingShapeMask)));
-        
-        stubJit.loadPtr(MacroAssembler::Address(baseGPR, JSObject::butterflyOffset()), scratchGPR);
-        stubJit.load32(MacroAssembler::Address(scratchGPR, ArrayStorage::lengthOffset()), scratchGPR);
-        failureCases.append(stubJit.branch32(MacroAssembler::LessThan, scratchGPR, MacroAssembler::TrustedImm32(0)));
 
-        stubJit.move(scratchGPR, resultGPR);
+        // String.length case
+        MacroAssembler::Jump failure = stubJit.branch8(MacroAssembler::NotEqual, MacroAssembler::Address(baseGPR, JSCell::typeInfoTypeOffset()), MacroAssembler::TrustedImm32(StringType));
+
+        stubJit.load32(MacroAssembler::Address(baseGPR, JSString::offsetOfLength()), resultGPR);
+
 #if USE(JSVALUE64)
         stubJit.or64(AssemblyHelpers::TrustedImm64(TagTypeNumber), resultGPR);
 #elif USE(JSVALUE32_64)
         stubJit.move(AssemblyHelpers::TrustedImm32(0xffffffff), resultTagGPR); // JSValue::Int32Tag
 #endif
 
-        MacroAssembler::Jump success, fail;
-        
-        emitRestoreScratch(stubJit, needToRestoreScratch, scratchGPR, success, fail, failureCases);
-        
+        MacroAssembler::Jump success = stubJit.jump();
+
         LinkBuffer patchBuffer(*vm, &stubJit, codeBlock);
-        
-        linkRestoreScratch(patchBuffer, needToRestoreScratch, stubInfo, success, fail, failureCases);
-        
+
+        patchBuffer.link(success, stubInfo.callReturnLocation.labelAtOffset(stubInfo.patch.deltaCallToDone));
+        patchBuffer.link(failure, stubInfo.callReturnLocation.labelAtOffset(stubInfo.patch.deltaCallToSlowCase));
+
         stubInfo.stubRoutine = FINALIZE_CODE_FOR_STUB(
             exec->codeBlock(), patchBuffer,
-            ("GetById array length stub for %s, return point %p",
+            ("GetById string length stub for %s, return point %p",
                 toCString(*exec->codeBlock()).data(), stubInfo.callReturnLocation.labelAtOffset(
                     stubInfo.patch.deltaCallToDone).executableAddress()));
-        
+
         RepatchBuffer repatchBuffer(codeBlock);
         replaceWithJump(repatchBuffer, stubInfo, stubInfo.stubRoutine->code().code());
         repatchCall(repatchBuffer, stubInfo.callReturnLocation, operationGetById);
-        
+
         return true;
     }
-    
-    // FIXME: should support length access for String.
 
     // FIXME: Cache property access for immediates.
     if (!baseValue.isCell())

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