ARM: Check for minus zero when converting binary operation result to smi

src/arm/code-stubs-arm.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 3408 matching lines @@
             // If the ne condition is set, result does
             // not fit in a 32-bit integer.
             __ b(ne, &transition);
           }
 
           // Check if the result fits in a smi.
           __ vmov(scratch1, single_scratch);
           __ add(scratch2, scratch1, Operand(0x40000000), SetCC);
           // If not try to return a heap number.
           __ b(mi, &return_heap_number);
+          // Check for minus zero. Return heap number for minus zero.
+          Label not_zero;
+          __ cmp(scratch1, Operand(0));
+          __ b(ne, &not_zero);
+          __ vmov(scratch2, d5.high());
+          __ tst(scratch2, Operand(HeapNumber::kSignMask));
+          __ b(ne, &return_heap_number);
+          __ bind(&not_zero);
+
           // Tag the result and return.
           __ SmiTag(r0, scratch1);
           __ Ret();
+        } else {
+          // DIV just falls through to allocating a heap number.
         }
 
         if (result_type_ >= (op_ == Token::DIV) ? TRBinaryOpIC::HEAP_NUMBER
                                                 : TRBinaryOpIC::INT32) {
           __ bind(&return_heap_number);
           // We are using vfp registers so r5 is available.
           heap_number_result = r5;
           GenerateHeapResultAllocation(masm,
                                        heap_number_result,
                                        heap_number_map,
@@ skipping 3421 matching lines @@
   __ str(pc, MemOperand(sp, 0));
   __ Jump(target);  // Call the C++ function.
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM