Changeset 27501 in webkit for trunk/JavaScriptCore/kjs/nodes.cpp

Timestamp:

Nov 6, 2007, 10:03:20 PM (18 years ago)

Author:

oliver

Message:

Avoid unnecessarily boxing the result from post inc/decrement for 0.3% gain in sunspider

Reviewed by Maciej

We now convert the common 'for (...; ...; <var>++) ...' to the semantically identical
'for (...; ...; ++<var>) ...'.

File:

• trunk/JavaScriptCore/kjs/nodes.cpp (modified) (5 diffs)

trunk/JavaScriptCore/kjs/nodes.cpp

@@ -935 +935 @@
 }
 
+void PostIncResolveNode::optimizeForUnnecessaryResult()
+{
+    new (this) PreIncResolveNode(PlacementNewAdopt);
+}
+    
 JSValue* PostIncLocalVarNode::evaluate(ExecState* exec)
 {
@@ -940 +945 @@
     ASSERT(static_cast<ActivationImp*>(exec->variableObject()) == exec->scopeChain().top());
 
-    JSValue** slot = &exec->localStorage()[index].value;
+    JSValue** slot = &exec->localStorage()[m_index].value;
     JSValue* v = (*slot)->toJSNumber(exec);
     *slot = jsNumber(v->toNumber(exec) + 1);
     return v;
+}
+
+void PostIncLocalVarNode::optimizeForUnnecessaryResult()
+{
+    new (this) PreIncLocalVarNode(m_index);
 }
 
@@ -982 +992 @@
   return throwUndefinedVariableError(exec, m_ident);
 }
-
+    
+void PostDecResolveNode::optimizeForUnnecessaryResult()
+{
+    new (this) PreDecResolveNode(PlacementNewAdopt);
+}
+    
 JSValue* PostDecLocalVarNode::evaluate(ExecState* exec)
 {
@@ -988 +1003 @@
     ASSERT(static_cast<ActivationImp*>(exec->variableObject()) == exec->scopeChain().top());
 
-    JSValue** slot = &exec->localStorage()[index].value;
+    JSValue** slot = &exec->localStorage()[m_index].value;
     JSValue* v = (*slot)->toJSNumber(exec);
     *slot = jsNumber(v->toNumber(exec) - 1);
@@ -994 +1009 @@
 }
 
+void PostDecLocalVarNode::optimizeForUnnecessaryResult()
+{
+    new (this) PreDecLocalVarNode(m_index);
+}
+    
 // ------------------------------ PostfixBracketNode ----------------------------------