Changeset 37366 in webkit for trunk/JavaScriptCore/VM/CodeGenerator.cpp

Timestamp:

Oct 6, 2008, 8:53:47 PM (17 years ago)

Author:

[email protected]

Message:

2008-10-06 Cameron Zwarich <​[email protected]>

Reviewed by Oliver Hunt.

Bug 21396: Remove the OptionalCalleeActivation call frame slot
<​https://bugs.webkit.org/show_bug.cgi?id=21396>

Remove the OptionalCalleeActivation call frame slot. We have to be
careful to store the activation object in a register, because objects
in the scope chain do not get marked.

This is a 0.3% speedup on both SunSpider and the V8 benchmark.

• VM/CTI.cpp: (JSC::CTI::privateCompileMainPass):
• VM/CodeBlock.cpp: (JSC::CodeBlock::dump):
• VM/CodeGenerator.cpp: (JSC::CodeGenerator::CodeGenerator): (JSC::CodeGenerator::emitReturn):
• VM/CodeGenerator.h:
• VM/Machine.cpp: (JSC::Machine::dumpRegisters): (JSC::Machine::unwindCallFrame): (JSC::Machine::privateExecute): (JSC::Machine::cti_op_call_JSFunction): (JSC::Machine::cti_op_push_activation): (JSC::Machine::cti_op_tear_off_activation): (JSC::Machine::cti_op_construct_JSConstruct):
• VM/Machine.h: (JSC::Machine::initializeCallFrame):
• VM/RegisterFile.h: (JSC::RegisterFile::):

File:

• trunk/JavaScriptCore/VM/CodeGenerator.cpp (modified) (3 diffs)

trunk/JavaScriptCore/VM/CodeGenerator.cpp

@@ -288 +288 @@
         m_codeBlock->needsFullScopeChain = true;
 
-    if (m_codeBlock->needsFullScopeChain)
-        emitOpcode(op_enter_with_activation);
-    else
-        emitOpcode(op_enter);
-
     codeBlock->globalData = m_globalData;
 
@@ -298 +293 @@
     codeBlock->usesArguments = usesArguments;
     if (usesArguments) {
-        emitOpcode(op_create_arguments);
         m_argumentsRegister.setIndex(RegisterFile::OptionalCalleeArguments);
         addVar(propertyNames().arguments, false);
     }
+
+    if (m_codeBlock->needsFullScopeChain) {
+        ++m_codeBlock->numVars;
+        m_activationRegisterIndex = newRegister()->index();
+        emitOpcode(op_enter_with_activation);
+        instructions().append(m_activationRegisterIndex);
+    } else
+        emitOpcode(op_enter);
+
+    if (usesArguments)
+        emitOpcode(op_create_arguments);
 
     const Node::FunctionStack& functionStack = functionBody->functionStack();
@@ -1161 +1166 @@
 RegisterID* CodeGenerator::emitReturn(RegisterID* src)
 {
-    if (m_codeBlock->needsFullScopeChain)
+    if (m_codeBlock->needsFullScopeChain) {
         emitOpcode(op_tear_off_activation);
-    else if (m_codeBlock->usesArguments)
+        instructions().append(m_activationRegisterIndex);
+    } else if (m_codeBlock->usesArguments)
         emitOpcode(op_tear_off_arguments);