MIPS: Fix register usage in commit r14239.

src/mips/simulator-mips.cc

 // Copyright 2011 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 1080 matching lines @@
 }
 
 
 // Runtime FP routines take up to two double arguments and zero
 // or one integer arguments. All are constructed here,
 // from a0-a3 or f12 and f14.
 void Simulator::GetFpArgs(double* x, double* y, int32_t* z) {
   if (!IsMipsSoftFloatABI) {
     *x = get_fpu_register_double(12);
     *y = get_fpu_register_double(14);
-    *z = registers_[1];
+    *z = get_register(a2);
   } else {
     // We use a char buffer to get around the strict-aliasing rules which
     // otherwise allow the compiler to optimize away the copy.
     char buffer[sizeof(*x)];
     int32_t* reg_buffer = reinterpret_cast<int32_t*>(buffer);
 
     // Registers a0 and a1 -> x.
     reg_buffer[0] = get_register(a0);
     reg_buffer[1] = get_register(a1);
     memcpy(x, buffer, sizeof(buffer));
     // Registers a2 and a3 -> y.
     reg_buffer[0] = get_register(a2);
     reg_buffer[1] = get_register(a3);
     memcpy(y, buffer, sizeof(buffer));
     // Register 2 -> z.
-    memcpy(buffer, registers_ + 2, sizeof(*z));
+    reg_buffer[0] = get_register(a2);
     memcpy(z, buffer, sizeof(*z));
-
-    // Register 2 -> y.
-    reg_buffer[0] = get_register(a2);
-    memcpy(y, buffer, sizeof(*y));
   }
 }
 
 
 // The return value is either in v0/v1 or f0.
 void Simulator::SetFpResult(const double& result) {
   if (!IsMipsSoftFloatABI) {
     set_fpu_register_double(0, result);
   } else {
     char buffer[2 * sizeof(registers_[0])];
@@ skipping 1770 matching lines @@
 }
 
 
 #undef UNSUPPORTED
 
 } }  // namespace v8::internal
 
 #endif  // USE_SIMULATOR
 
 #endif  // V8_TARGET_ARCH_MIPS