Changeset 37320 in webkit for trunk/JavaScriptCore/VM/CodeGenerator.cpp

Timestamp:

Oct 5, 2008, 3:47:24 PM (17 years ago)

Author:

[email protected]

Message:

2008-10-05 Cameron Zwarich <​[email protected]>

Reviewed by Maciej Stachowiak.

Bug 21364: Remove the branch in op_ret for OptionalCalleeActivation and OptionalCalleeArguments
<​https://bugs.webkit.org/show_bug.cgi?id=21364>

This patch does not yet remove the branch, but it does a bit of refactoring
so that a CodeGenerator now knows whether the associated CodeBlock will need
a full scope before doing any code generation. This makes it possible to emit
explicit tear-off instructions before every op_ret.

• VM/CodeBlock.h: (JSC::CodeBlock::CodeBlock):
• VM/CodeGenerator.cpp: (JSC::CodeGenerator::generate): (JSC::CodeGenerator::CodeGenerator): (JSC::CodeGenerator::emitPushScope): (JSC::CodeGenerator::emitPushNewScope):
• kjs/nodes.h: (JSC::ScopeNode::needsActivation):

File:

• trunk/JavaScriptCore/VM/CodeGenerator.cpp (modified) (6 diffs)

trunk/JavaScriptCore/VM/CodeGenerator.cpp

@@ -132 +132 @@
     m_codeBlock->thisRegister = m_thisRegister.index();
 
-    if (m_shouldEmitDebugHooks)
-        m_codeBlock->needsFullScopeChain = true;
-
     m_scopeNode->emitCode(*this);
-
-    if (m_codeType == FunctionCode && m_codeBlock->needsFullScopeChain) {
-        ASSERT(globalData()->machine->getOpcodeID(m_codeBlock->instructions[0].u.opcode) == op_enter);
-        m_codeBlock->instructions[0] = globalData()->machine->getOpcode(op_enter_with_activation);
-    }
 
 #ifndef NDEBUG
@@ -217 +209 @@
     , m_lastOpcodeID(op_end)
 {
+    if (m_shouldEmitDebugHooks)
+        m_codeBlock->needsFullScopeChain = true;
+
     emitOpcode(op_enter);
     codeBlock->globalData = m_globalData;
@@ -290 +285 @@
     , m_lastOpcodeID(op_end)
 {
-    emitOpcode(op_enter);
+    if (m_shouldEmitDebugHooks)
+        m_codeBlock->needsFullScopeChain = true;
+
+    if (m_codeBlock->needsFullScopeChain)
+        emitOpcode(op_enter_with_activation);
+    else
+        emitOpcode(op_enter);
+
     codeBlock->globalData = m_globalData;
 
@@ -348 +350 @@
     , m_lastOpcodeID(op_end)
 {
+    if (m_shouldEmitDebugHooks)
+        m_codeBlock->needsFullScopeChain = true;
+
     emitOpcode(op_enter);
     codeBlock->globalData = m_globalData;
@@ -1201 +1206 @@
 RegisterID* CodeGenerator::emitPushScope(RegisterID* scope)
 {
-    m_codeBlock->needsFullScopeChain = true;
     ControlFlowContext context;
     context.isFinallyBlock = false;
@@ -1417 +1421 @@
 void CodeGenerator::emitPushNewScope(RegisterID* dst, Identifier& property, RegisterID* value)
 {
-    m_codeBlock->needsFullScopeChain = true;
     ControlFlowContext context;
     context.isFinallyBlock = false;