VM: Improve and fix double negation on MIPS.

runtime/vm/simulator_mips.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <setjmp.h>  // NOLINT
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_MIPS)
 
@@ skipping 1795 matching lines @@
         ASSERT(instr->FormatField() == FMT_D);  // Only D supported.
         set_fregister_double(instr->FdField(), sqrt(fs_val));
         break;
       }
       case COP1_MOV: {
         // Format(instr, "mov.'fmt 'fd, 'fs");
         ASSERT(instr->FormatField() == FMT_D);  // Only D supported.
         set_fregister_double(instr->FdField(), fs_val);
         break;
       }
+      case COP1_NEG: {
+        // Format(instr, "neg.'fmt 'fd, 'fs");
+        ASSERT(instr->FormatField() == FMT_D);
+        set_fregister_double(instr->FdField(), -fs_val);
+        break;
+      }
       case COP1_C_F: {
         ASSERT(instr->FormatField() == FMT_D);  // Only D supported.
         ASSERT(instr->FdField() == F0);
         set_fcsr_bit(fcsr_cc, false);
         break;
       }
       case COP1_C_UN: {
         ASSERT(instr->FormatField() == FMT_D);  // Only D supported.
         ASSERT(instr->FdField() == F0);
         set_fcsr_bit(fcsr_cc, isnan(fs_val) || isnan(ft_val));
@@ skipping 657 matching lines @@
   set_register(kExceptionObjectReg, bit_cast<int32_t>(raw_exception));
   set_register(kStackTraceObjectReg, bit_cast<int32_t>(raw_stacktrace));
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // defined(USING_SIMULATOR)
 
 #endif  // defined TARGET_ARCH_MIPS