Fixes integer negate intrinsic for arm and mips.

runtime/vm/intrinsifier_arm.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 "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 770 matching lines @@
   // cannot tag the result.
   __ CompareImmediate(R0, 0x40000000);
   __ SmiTag(R0, NE);  // Not equal. Okay to tag and return.
   __ bx(LR, NE);  // Return.
   __ Bind(&fall_through);
   return false;
 }
 
 
 bool Intrinsifier::Integer_negate(Assembler* assembler) {
+  Label fall_through;
   __ ldr(R0, Address(SP, + 0 * kWordSize));  // Grab first argument.
   __ tst(R0, ShifterOperand(kSmiTagMask));  // Test for Smi.
-  __ rsb(R0, R0, ShifterOperand(0), EQ);  // R0 is a Smi. R0 <- 0 - R0.
-  __ bx(LR, EQ);  // Return.
+  __ b(&fall_through, NE);
+  __ rsbs(R0, R0, ShifterOperand(0));  // R0 is a Smi. R0 <- 0 - R0.
+  __ bx(LR, VC);  // Return if there wasn't overflow, fall through otherwise.
   // R0 is not a Smi. Fall through.
+  __ Bind(&fall_through);
   return false;
 }
 
 
 bool Intrinsifier::Integer_bitAndFromInteger(Assembler* assembler) {
   Label fall_through;
 
   TestBothArgumentsSmis(assembler, &fall_through);  // checks two smis
   __ and_(R0, R0, ShifterOperand(R1));
 
@@ skipping 881 matching lines @@
   __ Bind(&ok);
   __ Ret();
 
   __ Bind(&fall_through);
   return false;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM