2008-06-24 Cameron Zwarich <cwzwarich@uwaterloo.ca>

        Reviewed by Maciej.

        Make the conversion of the pair (less, jtrue) to jless use register
        reference counting information for safety instead of requiring callers
        to decide whether it is safe.

        No changes on SunSpider codegen.

        * VM/CodeGenerator.cpp:
        (KJS::CodeGenerator::emitJumpIfTrue):
        * VM/CodeGenerator.h:
        * kjs/nodes.cpp:
        (KJS::DoWhileNode::emitCode):
        (KJS::WhileNode::emitCode):
        (KJS::ForNode::emitCode):
        (KJS::CaseBlockNode::emitCodeForBlock):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@34784 268f45cc-cd09-0410-ab3c-d52691b4dbfc

JavaScriptCore/ChangeLog

+2008-06-24  Cameron Zwarich  <cwzwarich@uwaterloo.ca>
+
+        Reviewed by Maciej.
+
+        Make the conversion of the pair (less, jtrue) to jless use register
+        reference counting information for safety instead of requiring callers
+        to decide whether it is safe.
+
+        No changes on SunSpider codegen.
+
+        * VM/CodeGenerator.cpp:
+        (KJS::CodeGenerator::emitJumpIfTrue):
+        * VM/CodeGenerator.h:
+        * kjs/nodes.cpp:
+        (KJS::DoWhileNode::emitCode):
+        (KJS::WhileNode::emitCode):
+        (KJS::ForNode::emitCode):
+        (KJS::CaseBlockNode::emitCodeForBlock):
+
 2008-06-24  Kevin McCullough  <kmccullough@apple.com>
 
         Reviewed by Tim.

JavaScriptCore/VM/CodeGenerator.cpp

@@ -425,7 +425,7 @@ PassRefPtr<LabelID> CodeGenerator::emitJump(LabelID* target)
     return target;
 }
 
-PassRefPtr<LabelID> CodeGenerator::emitJumpIfTrueMayCombine(RegisterID* cond, LabelID* target)
+PassRefPtr<LabelID> CodeGenerator::emitJumpIfTrue(RegisterID* cond, LabelID* target)
 {
     if (m_lastOpcodeID == op_less) {
         int dstIndex;
@@ -434,7 +434,7 @@ PassRefPtr<LabelID> CodeGenerator::emitJumpIfTrueMayCombine(RegisterID* cond, La
         
         retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
         
-        if (cond->index() == dstIndex) {
+        if (cond->index() == dstIndex && !cond->refCount()) {
             rewindBinaryOp();
             emitOpcode(op_jless);
             instructions().append(src1Index);
@@ -444,11 +444,6 @@ PassRefPtr<LabelID> CodeGenerator::emitJumpIfTrueMayCombine(RegisterID* cond, La
         }
     }
     
-    return emitJumpIfTrue(cond, target);
-}
-
-PassRefPtr<LabelID> CodeGenerator::emitJumpIfTrue(RegisterID* cond, LabelID* target)
-{
     emitOpcode(op_jtrue);
     instructions().append(cond->index());
     instructions().append(target->offsetFrom(instructions().size()));

JavaScriptCore/VM/CodeGenerator.h

@@ -245,7 +245,6 @@ namespace KJS {
 
         PassRefPtr<LabelID> emitLabel(LabelID*);
         PassRefPtr<LabelID> emitJump(LabelID* target);
-        PassRefPtr<LabelID> emitJumpIfTrueMayCombine(RegisterID* cond, LabelID* target);
         PassRefPtr<LabelID> emitJumpIfTrue(RegisterID* cond, LabelID* target);
         PassRefPtr<LabelID> emitJumpIfFalse(RegisterID* cond, LabelID* target);
         PassRefPtr<LabelID> emitJumpScopes(LabelID* target, int targetScopeDepth);

JavaScriptCore/kjs/nodes.cpp

@@ -1200,7 +1200,7 @@ RegisterID* DoWhileNode::emitCode(CodeGenerator& generator, RegisterID* dst)
     
     generator.emitLabel(continueTarget.get());
     RegisterID* cond = generator.emitNode(m_expr.get());
-    generator.emitJumpIfTrueMayCombine(cond, topOfLoop.get());
+    generator.emitJumpIfTrue(cond, topOfLoop.get());
     generator.emitLabel(breakTarget.get());
     return result.get();
 }
@@ -1222,7 +1222,7 @@ RegisterID* WhileNode::emitCode(CodeGenerator& generator, RegisterID* dst)
 
     generator.emitLabel(continueTarget.get());
     RegisterID* cond = generator.emitNode(m_expr.get());
-    generator.emitJumpIfTrueMayCombine(cond, topOfLoop.get());
+    generator.emitJumpIfTrue(cond, topOfLoop.get());
 
     generator.emitLabel(breakTarget.get());
     
@@ -1254,7 +1254,7 @@ RegisterID* ForNode::emitCode(CodeGenerator& generator, RegisterID* dst)
     generator.emitLabel(beforeCondition.get());
     if (m_expr2) {
         RegisterID* cond = generator.emitNode(m_expr2.get());
-        generator.emitJumpIfTrueMayCombine(cond, topOfLoop.get());
+        generator.emitJumpIfTrue(cond, topOfLoop.get());
     } else {
         generator.emitJump(topOfLoop.get());
     }
@@ -1422,14 +1422,14 @@ RegisterID* CaseBlockNode::emitCodeForBlock(CodeGenerator& generator, RegisterID
         RegisterID* clauseVal = generator.emitNode(list->getClause()->expr());
         generator.emitBinaryOp(op_stricteq, clauseVal, clauseVal, switchExpression);
         labelVector.append(generator.newLabel());
-        generator.emitJumpIfTrueMayCombine(clauseVal, labelVector[labelVector.size() - 1].get());
+        generator.emitJumpIfTrue(clauseVal, labelVector[labelVector.size() - 1].get());
     }
 
     for (ClauseListNode* list = m_list2.get(); list; list = list->getNext()) {
         RegisterID* clauseVal = generator.emitNode(list->getClause()->expr());
         generator.emitBinaryOp(op_stricteq, clauseVal, clauseVal, switchExpression);
         labelVector.append(generator.newLabel());
-        generator.emitJumpIfTrueMayCombine(clauseVal, labelVector[labelVector.size() - 1].get());
+        generator.emitJumpIfTrue(clauseVal, labelVector[labelVector.size() - 1].get());
     }
 
     RefPtr<LabelID> defaultLabel;