Changeset 42337 in webkit for trunk/JavaScriptCore/interpreter/Interpreter.cpp

Timestamp:

Apr 8, 2009, 4:08:28 PM (16 years ago)

Author:

[email protected]

Message:

Improve function.apply performance

Reviewed by Geoff Garen.

Jump through a few hoops to improve performance of function.apply in the general case.

In the case of zero or one arguments, or if there are only two arguments and the
second is an array literal we treat function.apply as function.call.

Otherwise we use the new opcodes op_load_varargs and op_call_varargs to do the .apply call
without re-entering the virtual machine.

File:

• trunk/JavaScriptCore/interpreter/Interpreter.cpp (modified) (1 diff)

trunk/JavaScriptCore/interpreter/Interpreter.cpp

@@ -2973 +2973 @@
         goto vm_throw;
     }
+    DEFINE_OPCODE(op_load_varargs) {
+        int argCountDst = (++vPC)->u.operand;
+        int argsOffset = (++vPC)->u.operand;
+        
+        JSValuePtr arguments = callFrame[argsOffset].jsValue(callFrame);
+        uint32_t argCount = 0;
+        if (!arguments.isUndefinedOrNull()) {
+            if (!arguments.isObject()) {
+                exceptionValue = createInvalidParamError(callFrame, "Function.prototype.apply", arguments, vPC - callFrame->codeBlock()->instructions().begin(), callFrame->codeBlock());
+                goto vm_throw;
+            }
+            if (asObject(arguments)->classInfo() == &Arguments::info) {
+                Arguments* args = asArguments(arguments);
+                argCount = args->numProvidedArguments(callFrame);
+                int32_t sizeDelta = argsOffset + argCount + RegisterFile::CallFrameHeaderSize;
+                Register* newEnd = callFrame->registers() + sizeDelta;
+                if (!registerFile->grow(newEnd) || ((newEnd - callFrame->registers()) != sizeDelta)) {
+                    exceptionValue = createStackOverflowError(callFrame);
+                    goto vm_throw;
+                }
+                args->copyToRegisters(callFrame, callFrame->registers() + argsOffset, argCount);
+            } else if (isJSArray(&callFrame->globalData(), arguments)) {
+                JSArray* array = asArray(arguments);
+                argCount = array->length();
+                int32_t sizeDelta = argsOffset + argCount + RegisterFile::CallFrameHeaderSize;
+                Register* newEnd = callFrame->registers() + sizeDelta;
+                if (!registerFile->grow(newEnd) || ((newEnd - callFrame->registers()) != sizeDelta)) {
+                    exceptionValue = createStackOverflowError(callFrame);
+                    goto vm_throw;
+                }
+                array->copyToRegisters(callFrame, callFrame->registers() + argsOffset, argCount);
+            } else if (asObject(arguments)->inherits(&JSArray::info)) {
+                JSObject* argObject = asObject(arguments);
+                argCount = argObject->get(callFrame, callFrame->propertyNames().length).toUInt32(callFrame);
+                int32_t sizeDelta = argsOffset + argCount + RegisterFile::CallFrameHeaderSize;
+                Register* newEnd = callFrame->registers() + sizeDelta;
+                if (!registerFile->grow(newEnd) || ((newEnd - callFrame->registers()) != sizeDelta)) {
+                    exceptionValue = createStackOverflowError(callFrame);
+                    goto vm_throw;
+                }
+                Register* argsBuffer = callFrame->registers() + argsOffset;
+                for (unsigned i = 0; i < argCount; ++i) {
+                    argsBuffer[i] = asObject(arguments)->get(callFrame, i);
+                    CHECK_FOR_EXCEPTION();
+                }
+            } else {
+                if (!arguments.isObject()) {
+                    exceptionValue = createInvalidParamError(callFrame, "Function.prototype.apply", arguments, vPC - callFrame->codeBlock()->instructions().begin(), callFrame->codeBlock());
+                    goto vm_throw;
+                }
+            }
+        }
+        CHECK_FOR_EXCEPTION();
+        callFrame[argCountDst] = argCount + 1;
+        ++vPC;
+        NEXT_INSTRUCTION();
+    }
+    DEFINE_OPCODE(op_call_varargs) {
+        /* call_varargs dst(r) func(r) argCountReg(r) baseRegisterOffset(n)
+         
+         Perform a function call with a dynamic set of arguments.
+         
+         registerOffset is the distance the callFrame pointer should move
+         before the VM initializes the new call frame's header, excluding
+         space for arguments.
+         
+         dst is where op_ret should store its result.
+         */
+        
+        int dst = vPC[1].u.operand;
+        int func = vPC[2].u.operand;
+        int argCountReg = vPC[3].u.operand;
+        int registerOffset = vPC[4].u.operand;
+        
+        JSValuePtr v = callFrame[func].jsValue(callFrame);
+        int argCount = callFrame[argCountReg].i();
+        registerOffset += argCount;
+        CallData callData;
+        CallType callType = v.getCallData(callData);
+        
+        if (callType == CallTypeJS) {
+            ScopeChainNode* callDataScopeChain = callData.js.scopeChain;
+            FunctionBodyNode* functionBodyNode = callData.js.functionBody;
+            CodeBlock* newCodeBlock = &functionBodyNode->bytecode(callDataScopeChain);
+            
+            CallFrame* previousCallFrame = callFrame;
+            
+            callFrame = slideRegisterWindowForCall(newCodeBlock, registerFile, callFrame, registerOffset, argCount);
+            if (UNLIKELY(!callFrame)) {
+                callFrame = previousCallFrame;
+                exceptionValue = createStackOverflowError(callFrame);
+                goto vm_throw;
+            }
+            
+            callFrame->init(newCodeBlock, vPC + 5, callDataScopeChain, previousCallFrame, dst, argCount, asFunction(v));
+            vPC = newCodeBlock->instructions().begin();
+            
+#if ENABLE(OPCODE_STATS)
+            OpcodeStats::resetLastInstruction();
+#endif
+            
+            NEXT_INSTRUCTION();
+        }
+        
+        if (callType == CallTypeHost) {
+            ScopeChainNode* scopeChain = callFrame->scopeChain();
+            CallFrame* newCallFrame = CallFrame::create(callFrame->registers() + registerOffset);
+            newCallFrame->init(0, vPC + 5, scopeChain, callFrame, dst, argCount, 0);
+            
+            Register* thisRegister = newCallFrame->registers() - RegisterFile::CallFrameHeaderSize - argCount;
+            ArgList args(thisRegister + 1, argCount - 1);
+            
+            // FIXME: All host methods should be calling toThisObject, but this is not presently the case.
+            JSValuePtr thisValue = thisRegister->jsValue(callFrame);
+            if (thisValue == jsNull())
+                thisValue = callFrame->globalThisValue();
+            
+            JSValuePtr returnValue;
+            {
+                SamplingTool::HostCallRecord callRecord(m_sampler);
+                returnValue = callData.native.function(newCallFrame, asObject(v), thisValue, args);
+            }
+            CHECK_FOR_EXCEPTION();
+            
+            callFrame[dst] = JSValuePtr(returnValue);
+            
+            vPC += 5;
+            NEXT_INSTRUCTION();
+        }
+        
+        ASSERT(callType == CallTypeNone);
+        
+        exceptionValue = createNotAFunctionError(callFrame, v, vPC - callFrame->codeBlock()->instructions().begin(), callFrame->codeBlock());
+        goto vm_throw;
+    }
     DEFINE_OPCODE(op_tear_off_activation) {
         /* tear_off_activation activation(r)