Fix uint32-to-smi conversion in Lithium

src/x64/lithium-x64.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 1865 matching lines @@
         return AssignEnvironment(AssignPointerMap(DefineSameAsFirst(result)));
       } else if (val->HasRange() && val->range()->IsInSmiRange()) {
         return DefineSameAsFirst(new(zone()) LSmiTag(value));
       } else {
         LNumberTagI* result = new(zone()) LNumberTagI(value);
         return AssignEnvironment(AssignPointerMap(DefineSameAsFirst(result)));
       }
     } else if (to.IsSmi()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
-      LInstruction* result =
-          DefineAsRegister(new(zone()) LInteger32ToSmi(value));
-      if (val->HasRange() && val->range()->IsInSmiRange()) {
-        return result;
+      LInstruction* result = NULL;
+      if (val->CheckFlag(HInstruction::kUint32)) {
+        result = DefineAsRegister(new(zone()) LUint32ToSmi(value));
+        if (val->HasRange() && val->range()->IsInSmiRange() &&
+            val->range()->upper() != kMaxInt) {
+          return result;
+        }
+      } else {
+        result = DefineAsRegister(new(zone()) LInteger32ToSmi(value));
+        if (val->HasRange() && val->range()->IsInSmiRange()) {
+          return result;
+        }
       }
       return AssignEnvironment(result);
     } else {
       if (instr->value()->CheckFlag(HInstruction::kUint32)) {
         LOperand* temp = FixedTemp(xmm1);
         return DefineAsRegister(
             new(zone()) LUint32ToDouble(UseRegister(instr->value()), temp));
       } else {
         ASSERT(to.IsDouble());
         LOperand* value = Use(instr->value());
@@ skipping 637 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64