Changeset 129426 in webkit for trunk/Source/JavaScriptCore/dfg

Timestamp:

Sep 24, 2012, 4:12:00 PM (13 years ago)

Author:

[email protected]

Message:

Inlined activation tear-off in the DFG
​https://bugs.webkit.org/show_bug.cgi?id=97487

Reviewed by Filip Pizlo.

• dfg/DFGOperations.cpp:
• dfg/DFGOperations.h: Activation tear-off is always inlined now, so I

removed its out-of-line implementation.

• dfg/DFGSpeculativeJIT32_64.cpp:

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

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::compile): Inlined the variable copy and update
of JSVariableObject::m_registers. This usually turns into < 10 instructions,
which is close to pure win as compared to the operation function call.

• runtime/JSActivation.h:

(JSActivation):
(JSC::JSActivation::registersOffset):
(JSC::JSActivation::tearOff):
(JSC::JSActivation::isTornOff):
(JSC):
(JSC::JSActivation::storageOffset):
(JSC::JSActivation::storage): Tiny bit of refactoring so the JIT can
share the pointer math helper functions we use internally.

Location:

trunk/Source/JavaScriptCore/dfg

Files:

• DFGOperations.cpp (modified) (1 diff)
• DFGOperations.h (modified) (1 diff)
• DFGSpeculativeJIT32_64.cpp (modified) (2 diffs)
• DFGSpeculativeJIT64.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/dfg/DFGOperations.cpp

@@ -1166 +1166 @@
     ASSERT(!exec->globalData().exception);
     return result;
-}
-
-void DFG_OPERATION operationTearOffActivation(ExecState* exec, JSCell* activationCell)
-{
-    JSGlobalData& globalData = exec->globalData();
-    NativeCallFrameTracer tracer(&globalData, exec);
-    jsCast<JSActivation*>(activationCell)->tearOff(exec->globalData());
 }
 

trunk/Source/JavaScriptCore/dfg/DFGOperations.h

@@ -178 +178 @@
 JSCell* DFG_OPERATION operationCreateArguments(ExecState*) WTF_INTERNAL;
 JSCell* DFG_OPERATION operationCreateInlinedArguments(ExecState*, InlineCallFrame*) WTF_INTERNAL;
-void DFG_OPERATION operationTearOffActivation(ExecState*, JSCell*) WTF_INTERNAL;
 void DFG_OPERATION operationTearOffArguments(ExecState*, JSCell*, JSCell*) WTF_INTERNAL;
 void DFG_OPERATION operationTearOffInlinedArguments(ExecState*, JSCell*, JSCell*, InlineCallFrame*) WTF_INTERNAL;

trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT32_64.cpp

@@ -31 +31 @@
 
 #include "DFGSlowPathGenerator.h"
-#include "JSVariableObject.h"
+#include "JSActivation.h"
 
 namespace JSC { namespace DFG {
@@ -4071 +4071 @@
     case TearOffActivation: {
         JSValueOperand activationValue(this, node.child1());
+        GPRTemporary scratch(this);
         
         GPRReg activationValueTagGPR = activationValue.tagGPR();
         GPRReg activationValuePayloadGPR = activationValue.payloadGPR();
-
-        JITCompiler::Jump created = m_jit.branch32(JITCompiler::NotEqual, activationValueTagGPR, TrustedImm32(JSValue::EmptyValueTag));
-
-        addSlowPathGenerator(
-            slowPathCall(
-                created, this, operationTearOffActivation, NoResult, activationValuePayloadGPR));
-        
+        GPRReg scratchGPR = scratch.gpr();
+
+        JITCompiler::Jump notCreated = m_jit.branch32(JITCompiler::Equal, activationValueTagGPR, TrustedImm32(JSValue::EmptyValueTag));
+
+        SharedSymbolTable* symbolTable = m_jit.symbolTableFor(node.codeOrigin);
+        int registersOffset = JSActivation::registersOffset(symbolTable);
+
+        int captureEnd = symbolTable->captureEnd();
+        for (int i = symbolTable->captureStart(); i < captureEnd; ++i) {
+            m_jit.loadPtr(
+                JITCompiler::Address(
+                    GPRInfo::callFrameRegister, i * sizeof(Register) + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.tag)),
+                scratchGPR);
+            m_jit.storePtr(
+                scratchGPR, JITCompiler::Address(
+                    activationValuePayloadGPR, registersOffset + i * sizeof(Register) + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.tag)));
+            m_jit.loadPtr(
+                JITCompiler::Address(
+                    GPRInfo::callFrameRegister, i * sizeof(Register) + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.payload)),
+                scratchGPR);
+            m_jit.storePtr(
+                scratchGPR, JITCompiler::Address(
+                    activationValuePayloadGPR, registersOffset + i * sizeof(Register) + OBJECT_OFFSETOF(EncodedValueDescriptor, asBits.payload)));
+        }
+        m_jit.addPtr(TrustedImm32(registersOffset), activationValuePayloadGPR, scratchGPR);
+        m_jit.storePtr(scratchGPR, JITCompiler::Address(activationValuePayloadGPR, JSActivation::offsetOfRegisters()));
+        
+        notCreated.link(&m_jit);
         noResult(m_compileIndex);
         break;

trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT64.cpp

@@ -4042 +4042 @@
 
         JSValueOperand activationValue(this, node.child1());
+        GPRTemporary scratch(this);
         GPRReg activationValueGPR = activationValue.gpr();
-
-        JITCompiler::Jump created = m_jit.branchTestPtr(JITCompiler::NonZero, activationValueGPR);
-        
-        addSlowPathGenerator(
-            slowPathCall(
-                created, this, operationTearOffActivation, NoResult, activationValueGPR));
-        
+        GPRReg scratchGPR = scratch.gpr();
+
+        JITCompiler::Jump notCreated = m_jit.branchTestPtr(JITCompiler::Zero, activationValueGPR);
+
+        SharedSymbolTable* symbolTable = m_jit.symbolTableFor(node.codeOrigin);
+        int registersOffset = JSActivation::registersOffset(symbolTable);
+
+        int captureEnd = symbolTable->captureEnd();
+        for (int i = symbolTable->captureStart(); i < captureEnd; ++i) {
+            m_jit.loadPtr(
+                JITCompiler::Address(
+                    GPRInfo::callFrameRegister, i * sizeof(Register)), scratchGPR);
+            m_jit.storePtr(
+                scratchGPR, JITCompiler::Address(
+                    activationValueGPR, registersOffset + i * sizeof(Register)));
+        }
+        m_jit.addPtr(TrustedImm32(registersOffset), activationValueGPR, scratchGPR);
+        m_jit.storePtr(scratchGPR, JITCompiler::Address(activationValueGPR, JSActivation::offsetOfRegisters()));
+
+        notCreated.link(&m_jit);
         noResult(m_compileIndex);
         break;