Changeset 39156 in webkit for trunk/JavaScriptCore/interpreter/Interpreter.cpp

Timestamp:

Dec 9, 2008, 4:26:13 PM (16 years ago)

Author:

[email protected]

Message:

2008-12-09 Sam Weinig <​[email protected]>

Reviewed by Geoffrey Garen.

Remove unnecessary extra lookup when throwing an exception.
We used to first lookup the target offset using getHandlerForVPC
and then we would lookup the native code stub using
nativeExceptionCodeForHandlerVPC. Instead, we can just pass around
the HandlerInfo.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::handlerForVPC): Return the HandlerInfo.
• bytecode/CodeBlock.h: Remove nativeExceptionCodeForHandlerVPC.

• interpreter/Interpreter.cpp: (JSC::Interpreter::throwException): Return a HandlerInfo instead of and Instruction offset. (JSC::Interpreter::privateExecute): Get the offset from HandlerInfo. (JSC::Interpreter::cti_op_throw): Get the native code from the HandleInfo. (JSC::Interpreter::cti_vm_throw): Ditto.
• interpreter/Interpreter.h:

File:

• trunk/JavaScriptCore/interpreter/Interpreter.cpp (modified) (11 diffs)

trunk/JavaScriptCore/interpreter/Interpreter.cpp

@@ -793 +793 @@
 }
 
-NEVER_INLINE Instruction* Interpreter::throwException(CallFrame*& callFrame, JSValue*& exceptionValue, const Instruction* vPC, bool explicitThrow)
+NEVER_INLINE HandlerInfo* Interpreter::throwException(CallFrame*& callFrame, JSValue*& exceptionValue, const Instruction* vPC, bool explicitThrow)
 {
     // Set up the exception object
@@ -853 +853 @@
     // Calculate an exception handler vPC, unwinding call frames as necessary.
 
-    int scopeDepth;
-    Instruction* handlerVPC;
-
-    while (!codeBlock->getHandlerForVPC(vPC, handlerVPC, scopeDepth)) {
+    HandlerInfo* handler = 0;
+    while (!(handler = codeBlock->handlerForVPC(vPC))) {
         if (!unwindCallFrame(callFrame, exceptionValue, vPC, codeBlock))
             return 0;
@@ -864 +862 @@
 
     ScopeChain sc(callFrame->scopeChain());
-    int scopeDelta = depth(codeBlock, sc) - scopeDepth;
+    int scopeDelta = depth(codeBlock, sc) - handler->scopeDepth;
     ASSERT(scopeDelta >= 0);
     while (scopeDelta--)
@@ -870 +868 @@
     callFrame->setScopeChain(sc.node());
 
-    return handlerVPC;
+    return handler;
 }
 
@@ -1481 +1479 @@
     JSGlobalData* globalData = &callFrame->globalData();
     JSValue* exceptionValue = noValue();
-    Instruction* handlerVPC = 0;
+    HandlerInfo* handler = 0;
 
     Instruction* vPC = callFrame->codeBlock()->instructions().begin();
@@ -3794 +3792 @@
         exceptionValue = callFrame[ex].jsValue(callFrame);
 
-        handlerVPC = throwException(callFrame, exceptionValue, vPC, true);
-        if (!handlerVPC) {
+        handler = throwException(callFrame, exceptionValue, vPC, true);
+        if (!handler) {
             *exception = exceptionValue;
             return jsNull();
         }
 
-        vPC = handlerVPC;
+        vPC = callFrame->codeBlock()->instructions().begin() + handler->target;
         NEXT_INSTRUCTION();
     }
@@ -3970 +3968 @@
             exceptionValue = createInterruptedExecutionException(globalData);
         }
-        handlerVPC = throwException(callFrame, exceptionValue, vPC, false);
-        if (!handlerVPC) {
+        handler = throwException(callFrame, exceptionValue, vPC, false);
+        if (!handler) {
             *exception = exceptionValue;
             return jsNull();
         }
-        vPC = handlerVPC;
+
+        vPC = callFrame->codeBlock()->instructions().begin() + handler->target;
         NEXT_INSTRUCTION();
     }
@@ -5754 +5753 @@
     ASSERT(exceptionValue);
 
-    Instruction* handlerVPC = ARG_globalData->interpreter->throwException(callFrame, exceptionValue, codeBlock->instructions().begin() + vPCIndex, true);
-
-    if (!handlerVPC) {
+    HandlerInfo* handler = ARG_globalData->interpreter->throwException(callFrame, exceptionValue, codeBlock->instructions().begin() + vPCIndex, true);
+
+    if (!handler) {
         *ARG_exception = exceptionValue;
         return JSImmediate::nullImmediate();
@@ -5762 +5761 @@
 
     ARG_setCallFrame(callFrame);
-    void* catchRoutine = callFrame->codeBlock()->nativeExceptionCodeForHandlerVPC(handlerVPC);
+    void* catchRoutine = handler->nativeCode;
     ASSERT(catchRoutine);
     CTI_SET_RETURN_ADDRESS(catchRoutine);
@@ -6100 +6099 @@
     globalData->exception = noValue();
 
-    Instruction* handlerVPC = globalData->interpreter->throwException(callFrame, exceptionValue, codeBlock->instructions().begin() + vPCIndex, false);
-
-    if (!handlerVPC) {
+    HandlerInfo* handler = globalData->interpreter->throwException(callFrame, exceptionValue, codeBlock->instructions().begin() + vPCIndex, false);
+
+    if (!handler) {
         *ARG_exception = exceptionValue;
         return JSImmediate::nullImmediate();
@@ -6108 +6107 @@
 
     ARG_setCallFrame(callFrame);
-    void* catchRoutine = callFrame->codeBlock()->nativeExceptionCodeForHandlerVPC(handlerVPC);
+    void* catchRoutine = handler->nativeCode;
     ASSERT(catchRoutine);
     CTI_SET_RETURN_ADDRESS(catchRoutine);