MIPS64: Fix move operations from coprocessor in simulator.

src/mips64/simulator-mips64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <cmath>
 
 #include "src/v8.h"
@@ skipping 1091 matching lines @@
   return static_cast<int32_t>(FPUregisters_[fpureg] & 0xffffffff);
 }
 
 
 int32_t Simulator::get_fpu_register_signed_word(int fpureg) const {
   DCHECK((fpureg >= 0) && (fpureg < kNumFPURegisters));
   return static_cast<int32_t>(FPUregisters_[fpureg] & 0xffffffff);
 }
 
 
-uint32_t Simulator::get_fpu_register_hi_word(int fpureg) const {
+int32_t Simulator::get_fpu_register_hi_word(int fpureg) const {
   DCHECK((fpureg >= 0) && (fpureg < kNumFPURegisters));
-  return static_cast<uint32_t>((FPUregisters_[fpureg] >> 32) & 0xffffffff);
+  return static_cast<int32_t>((FPUregisters_[fpureg] >> 32) & 0xffffffff);
 }
 
 
 float Simulator::get_fpu_register_float(int fpureg) const {
   DCHECK((fpureg >= 0) && (fpureg < kNumFPURegisters));
   return *bit_cast<float*>(const_cast<int64_t*>(&FPUregisters_[fpureg]));
 }
 
 
 double Simulator::get_fpu_register_double(int fpureg) const {
@@ skipping 2312 matching lines @@
 }
 
 
 #undef UNSUPPORTED
 
 } }  // namespace v8::internal
 
 #endif  // USE_SIMULATOR
 
 #endif  // V8_TARGET_ARCH_MIPS64