Fix uint32-to-smi conversion in Lithium

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 4403 matching lines @@
   LOperand* input = instr->value();
   LOperand* output = instr->result();
   LOperand* temp = instr->temp();
 
   __ LoadUint32(ToDoubleRegister(output),
                 ToRegister(input),
                 ToDoubleRegister(temp));
 }
 
 
+void LCodeGen::DoUint32ToSmi(LUint32ToSmi* instr) {
+  LOperand* input = instr->value();
+  ASSERT(input->IsRegister());
+  LOperand* output = instr->result();
+  if (!instr->hydrogen()->value()->HasRange() ||
+      !instr->hydrogen()->value()->range()->IsInSmiRange() ||
+      instr->hydrogen()->value()->range()->upper() == kMaxInt) {
+    // The Range class can't express upper bounds in the (kMaxInt, kMaxUint32]
+    // interval, so we treat kMaxInt as a sentinel for this entire interval.
+    __ testl(ToRegister(input), Immediate(0x80000000));
+    DeoptimizeIf(not_zero, instr->environment());
+  }
+  __ Integer32ToSmi(ToRegister(output), ToRegister(input));
+}
+
+
 void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
   LOperand* input = instr->value();
   ASSERT(input->IsRegister() && input->Equals(instr->result()));
   Register reg = ToRegister(input);
 
   __ Integer32ToSmi(reg, reg);
 }
 
 
 void LCodeGen::DoNumberTagU(LNumberTagU* instr) {
@@ skipping 1021 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64