Constant-folding through HForceRepresentation fix.

src/hydrogen-instructions.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 503 matching lines @@
       !(block()->IsReachable() ||
         IsBlockEntry() ||
         IsControlInstruction() ||
         IsSimulate() ||
         IsEnterInlined() ||
         IsLeaveInlined());
 }
 
 
 bool HValue::IsInteger32Constant() {
-  HValue* value_to_check = IsForceRepresentation()
-      ? HForceRepresentation::cast(this)->value()
-      : this;
-  return value_to_check->IsConstant() &&
-      HConstant::cast(value_to_check)->HasInteger32Value();
+  return IsConstant() && HConstant::cast(this)->HasInteger32Value();
 }
 
 
 int32_t HValue::GetInteger32Constant() {
-  HValue* constant_value = IsForceRepresentation()
-      ? HForceRepresentation::cast(this)->value()
-      : this;
-  return HConstant::cast(constant_value)->Integer32Value();
+  return HConstant::cast(this)->Integer32Value();
 }
 
 
 bool HValue::EqualsInteger32Constant(int32_t value) {
   return IsInteger32Constant() && GetInteger32Constant() == value;
 }
 
 
 void HValue::SetOperandAt(int index, HValue* value) {
   RegisterUse(index, value);
@@ skipping 788 matching lines @@
   }
   return this;
 }
 
 
 void HTypeof::PrintDataTo(StringStream* stream) {
   value()->PrintNameTo(stream);
 }
 
 
+HInstruction* HForceRepresentation::New(Zone* zone, HValue* context,
+       HValue* value, Representation required_representation) {
+  if (FLAG_fold_constants && value->IsConstant()) {
+    HConstant* c = HConstant::cast(value);
+    if (c->HasNumberValue()) {
+      double double_res = c->DoubleValue();
+      if (TypeInfo::IsInt32Double(double_res)) {
+        return HConstant::New(zone, context,
+                              static_cast<int32_t>(double_res),
+                              required_representation);
+      }
+    }
+  }
+  return new(zone) HForceRepresentation(value, required_representation);
+}
+
+
 void HForceRepresentation::PrintDataTo(StringStream* stream) {
   stream->Add("%s ", representation().Mnemonic());
   value()->PrintNameTo(stream);
 }
 
 
 void HChange::PrintDataTo(StringStream* stream) {
   HUnaryOperation::PrintDataTo(stream);
   stream->Add(" %s to %s", from().Mnemonic(), to().Mnemonic());
 
@@ skipping 3010 matching lines @@
       break;
     case kExternalMemory:
       stream->Add("[external-memory]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal