Changeset 37320 in webkit for trunk/JavaScriptCore

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):

Location:

trunk/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• VM/CodeBlock.h (modified) (1 diff)
• VM/CodeGenerator.cpp (modified) (6 diffs)
• kjs/nodes.h (modified) (1 diff)

trunk/JavaScriptCore/ChangeLog

@@ +1 @@
+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):
+
 2008-10-05  Gavin Barraclough  <[email protected]>
 

trunk/JavaScriptCore/VM/CodeBlock.h

@@ -193 +193 @@
             , numVars(0)
             , numParameters(0)
-            , needsFullScopeChain(ownerNode_->usesEval() || ownerNode_->containsClosures())
+            , needsFullScopeChain(ownerNode_->needsActivation())
             , usesEval(ownerNode_->usesEval())
             , codeType(codeType_)

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;

trunk/JavaScriptCore/kjs/nodes.h

@@ -2194 +2194 @@
         void setUsesArguments() { m_features |= ArgumentsFeature; }
         bool usesThis() const { return m_features & ThisFeature; }
+        bool needsActivation() const { return m_features & (EvalFeature | ClosureFeature | WithFeature | CatchFeature); }
 
         VarStack& varStack() { return m_varStack; }