Tweaked FlooringDiv back to TruncatingDiv again.

src/x64/macro-assembler-x64.cc

 // Copyright 2012 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 4974 matching lines @@
   and_(scratch1, Immediate(Map::kElementsKindMask));
   shr(scratch1, Immediate(Map::kElementsKindShift));
   cmpq(scratch1, Immediate(DICTIONARY_ELEMENTS));
   j(equal, found);
   movp(current, FieldOperand(current, Map::kPrototypeOffset));
   CompareRoot(current, Heap::kNullValueRootIndex);
   j(not_equal, &loop_again);
 }
 
 
-void MacroAssembler::FlooringDiv(Register dividend, int32_t divisor) {
+void MacroAssembler::TruncatingDiv(Register dividend, int32_t divisor) {
   ASSERT(!dividend.is(rax));
   ASSERT(!dividend.is(rdx));
   MultiplierAndShift ms(divisor);
   movl(rax, Immediate(ms.multiplier()));
   imull(dividend);
   if (divisor > 0 && ms.multiplier() < 0) addl(rdx, dividend);
   if (divisor < 0 && ms.multiplier() > 0) subl(rdx, dividend);
   if (ms.shift() > 0) sarl(rdx, Immediate(ms.shift()));
+  movl(rax, dividend);
+  shrl(rax, Immediate(31));
+  addl(rdx, rax);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64