Changeset 34528 in webkit for trunk/JavaScriptCore/VM/CodeGenerator.h

Timestamp:

Jun 13, 2008, 9:40:45 PM (17 years ago)

Author:

[email protected]

Message:

2008-06-13 Cameron Zwarich <​[email protected]>

Reviewed by Maciej.

Eliminate the use of temporaries to store the left hand side of an
expression when the right hand side is a constant. This slightly
improves the generated bytecode for a few SunSpider tests, but it is
mostly in preparation for fixing

Bug 19484: More instructions needs to use temporary registers
<​https://bugs.webkit.org/show_bug.cgi?id=19484>

• VM/CodeGenerator.h: (KJS::CodeGenerator::leftHandSideNeedsCopy): (KJS::CodeGenerator::emitNodeForLeftHandSide):
• kjs/nodes.cpp: (KJS::BracketAccessorNode::emitCode): (KJS::ReadModifyResolveNode::emitCode): (KJS::AssignDotNode::emitCode): (KJS::ReadModifyDotNode::emitCode): (KJS::AssignBracketNode::emitCode): (KJS::ReadModifyBracketNode::emitCode):
• kjs/nodes.h: (KJS::ExpressionNode::): (KJS::FalseNode::): (KJS::TrueNode::): (KJS::NumberNode::): (KJS::StringNode::):

File:

• trunk/JavaScriptCore/VM/CodeGenerator.h (modified) (1 diff)

trunk/JavaScriptCore/VM/CodeGenerator.h

@@ -172 +172 @@
         }
 
-        ALWAYS_INLINE bool leftHandSideNeedsCopy(bool rightHasAssignments)
-        {
-            return m_codeType != FunctionCode || m_codeBlock->needsFullScopeChain || rightHasAssignments;
-        }
-
-        ALWAYS_INLINE PassRefPtr<RegisterID> emitNodeForLeftHandSide(ExpressionNode* n, bool rightHasAssignments)
-        {
-            if (leftHandSideNeedsCopy(rightHasAssignments)) {
+        ALWAYS_INLINE bool leftHandSideNeedsCopy(bool rightHasAssignments, bool rightIsConstant)
+        {
+            return (m_codeType != FunctionCode || m_codeBlock->needsFullScopeChain || rightHasAssignments) && !rightIsConstant;
+        }
+
+        ALWAYS_INLINE PassRefPtr<RegisterID> emitNodeForLeftHandSide(ExpressionNode* n, bool rightHasAssignments, bool rightIsConstant)
+        {
+            if (leftHandSideNeedsCopy(rightHasAssignments, rightIsConstant)) {
                 PassRefPtr<RegisterID> dst = newTemporary();
                 emitNode(dst.get(), n);