Defer creating Handles for HConstants to the code generation phase.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index dfde504339875da64727170e4d82ffa504adcad6..12d0a0577254a7fc2dca4056256a665077ff3291 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -579,13 +579,25 @@ HConstant* HGraph::GetConstant(SetOncePointer<HConstant>* pointer,
 }
 
 
+HConstant* HGraph::GetConstantInt32(SetOncePointer<HConstant>* pointer,
+                                    int32_t value) {
+  if (!pointer->is_set()) {
+    HConstant* constant =
+        new(zone()) HConstant(value, Representation::Integer32());
+    constant->InsertAfter(GetConstantUndefined());
+    pointer->set(constant);
+  }
+  return pointer->get();
+}
+
+
 HConstant* HGraph::GetConstant1() {
-  return GetConstant(&constant_1_, Handle<Smi>(Smi::FromInt(1)));
+  return GetConstantInt32(&constant_1_, 1);
 }
 
 
 HConstant* HGraph::GetConstantMinus1() {
-  return GetConstant(&constant_minus1_, Handle<Smi>(Smi::FromInt(-1)));
+  return GetConstantInt32(&constant_minus1_, -1);
 }
 
 
@@ -3051,6 +3063,12 @@ HGraph* HGraphBuilder::CreateGraph() {
   graph_ = new(zone()) HGraph(info());
   if (FLAG_hydrogen_stats) HStatistics::Instance()->Initialize(info());
 
+  Factory* f = info()->isolate()->factory();

[Michael Starzinger, 2012/07/10 12:05:51]

I don't think this change is actually needed.

+  constant_undefined_ = new(zone()) HConstant(f->undefined_value(),
+                                              Representation::Tagged());
+  constant_null_ = new(zone()) HConstant(f->null_value(),
+                                         Representation::Tagged());
+
   {
     HPhase phase("H_Block building");
     CompilationHandleScope handle_scope(info());
@@ -7872,8 +7890,8 @@ HInstruction* HGraphBuilder::BuildBinaryOperation(BinaryOperation* expr,
   // for a smi operation. If one of the operands is a constant string
   // do not generate code assuming it is a smi operation.
   if (info.IsSmi() &&
-      ((left->IsConstant() && HConstant::cast(left)->HasStringValue()) ||
-       (right->IsConstant() && HConstant::cast(right)->HasStringValue()))) {
+      ((left->IsConstant() && HConstant::cast(left)->handle()->IsString()) ||
+       (right->IsConstant() && HConstant::cast(right)->handle()->IsString()))) {
     return instr;
   }
   Representation rep = ToRepresentation(info);
@@ -8071,10 +8089,12 @@ void HGraphBuilder::HandleLiteralCompareTypeof(CompareOperation* expr,
 static bool MatchLiteralCompareNil(HValue* left,
                                    Token::Value op,
                                    HValue* right,
-                                   Handle<Object> nil,
+                                   HConstant* nil,

[Michael Starzinger, 2012/07/10 12:05:51]

I don't think any of the changes in this file from this point on are actually
needed.

                                    HValue** expr) {
+  ASSERT(nil->IsTagged());
   if (left->IsConstant() &&
-      HConstant::cast(left)->handle().is_identical_to(nil) &&
+      HConstant::cast(left)->IsTagged() &&
+      HConstant::cast(left)->handle().is_identical_to(nil->handle()) &&
       Token::IsEqualityOp(op)) {
     *expr = right;
     return true;
@@ -8091,7 +8111,7 @@ static bool MatchLiteralCompareTypeof(HValue* left,
   if (left->IsTypeof() &&
       Token::IsEqualityOp(op) &&
       right->IsConstant() &&
-      HConstant::cast(right)->HasStringValue()) {
+      HConstant::cast(right)->handle()->IsString()) {
     *typeof_expr = HTypeof::cast(left);
     *check = Handle<String>::cast(HConstant::cast(right)->handle());
     return true;
@@ -8113,7 +8133,7 @@ static bool IsLiteralCompareTypeof(HValue* left,
 static bool IsLiteralCompareNil(HValue* left,
                                 Token::Value op,
                                 HValue* right,
-                                Handle<Object> nil,
+                                HConstant* nil,
                                 HValue** expr) {
   return MatchLiteralCompareNil(left, op, right, nil, expr) ||
       MatchLiteralCompareNil(right, op, left, nil, expr);
@@ -8124,8 +8144,10 @@ static bool IsLiteralCompareBool(HValue* left,
                                  Token::Value op,
                                  HValue* right) {
   return op == Token::EQ_STRICT &&
-      ((left->IsConstant() && HConstant::cast(left)->handle()->IsBoolean()) ||
-       (right->IsConstant() && HConstant::cast(right)->handle()->IsBoolean()));
+      ((left->IsConstant() &&
+        HConstant::cast(left)->handle()->IsBoolean()) ||
+       (right->IsConstant() &&
+        HConstant::cast(right)->handle()->IsBoolean()));
 }
 
 
@@ -8169,11 +8191,10 @@ void HGraphBuilder::VisitCompareOperation(CompareOperation* expr) {
     return HandleLiteralCompareTypeof(expr, typeof_expr, check);
   }
   HValue* sub_expr = NULL;
-  Factory* f = graph()->isolate()->factory();
-  if (IsLiteralCompareNil(left, op, right, f->undefined_value(), &sub_expr)) {
+  if (IsLiteralCompareNil(left, op, right, constant_undefined_, &sub_expr)) {
     return HandleLiteralCompareNil(expr, sub_expr, kUndefinedValue);
   }
-  if (IsLiteralCompareNil(left, op, right, f->null_value(), &sub_expr)) {
+  if (IsLiteralCompareNil(left, op, right, constant_null_, &sub_expr)) {
     return HandleLiteralCompareNil(expr, sub_expr, kNullValue);
   }
   if (IsLiteralCompareBool(left, op, right)) {