A64: Synchronize with r16679.

src/ia32/macro-assembler-ia32.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 264 matching lines @@
 }
 
 
 void MacroAssembler::DoubleToI(Register result_reg,
                                XMMRegister input_reg,
                                XMMRegister scratch,
                                MinusZeroMode minus_zero_mode,
                                Label* conversion_failed,
                                Label::Distance dst) {
   ASSERT(!input_reg.is(scratch));
-  Label done;
   cvttsd2si(result_reg, Operand(input_reg));
   cvtsi2sd(scratch, Operand(result_reg));
   ucomisd(scratch, input_reg);
   j(not_equal, conversion_failed, dst);
   j(parity_even, conversion_failed, dst);  // NaN.
   if (minus_zero_mode == FAIL_ON_MINUS_ZERO) {
+    Label done;
+    // The integer converted back is equal to the original. We
+    // only have to test if we got -0 as an input.
     test(result_reg, Operand(result_reg));
     j(not_zero, &done, Label::kNear);
     movmskpd(result_reg, input_reg);
+    // Bit 0 contains the sign of the double in input_reg.
+    // If input was positive, we are ok and return 0, otherwise
+    // jump to conversion_failed.
     and_(result_reg, 1);
     j(not_zero, conversion_failed, dst);
+    bind(&done);
   }
-  bind(&done);
 }
 
 
 void MacroAssembler::TruncateHeapNumberToI(Register result_reg,
                                            Register input_reg) {
   Label done, slow_case;
 
   if (CpuFeatures::IsSupported(SSE3)) {
     CpuFeatureScope scope(this, SSE3);
     Label convert;
@@ skipping 3108 matching lines @@
   j(greater, &no_memento_available);
   cmp(MemOperand(scratch_reg, -AllocationMemento::kSize),
       Immediate(Handle<Map>(isolate()->heap()->allocation_memento_map())));
   bind(&no_memento_available);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32