More Math.abs tweaks for Intel platforms.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 3311 matching lines @@
                     RDI_UNINITIALIZED);
 }
 
 
 void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr) {
   Register input_reg = ToRegister(instr->value());
   __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
                  Heap::kHeapNumberMapRootIndex);
   DeoptimizeIf(not_equal, instr->environment());
 
-  Label done;
+  Label slow, allocated, done;
   Register tmp = input_reg.is(rax) ? rcx : rax;
   Register tmp2 = tmp.is(rcx) ? rdx : input_reg.is(rcx) ? rdx : rcx;
 
   // Preserve the value of all registers.
   PushSafepointRegistersScope scope(this);
 
-  Label negative;
   __ movl(tmp, FieldOperand(input_reg, HeapNumber::kExponentOffset));
   // Check the sign of the argument. If the argument is positive, just
   // return it. We do not need to patch the stack since |input| and
   // |result| are the same register and |input| will be restored
   // unchanged by popping safepoint registers.
   __ testl(tmp, Immediate(HeapNumber::kSignMask));
-  __ j(not_zero, &negative);
-  __ jmp(&done);
+  __ j(zero, &done);
 
-  __ bind(&negative);
-
-  Label allocated, slow;
   __ AllocateHeapNumber(tmp, tmp2, &slow);
-  __ jmp(&allocated);
+  __ jmp(&allocated, Label::kNear);
 
   // Slow case: Call the runtime system to do the number allocation.
   __ bind(&slow);
-
   CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
   // Set the pointer to the new heap number in tmp.
-  if (!tmp.is(rax)) {
-    __ movq(tmp, rax);
-  }
-
+  if (!tmp.is(rax)) __ movq(tmp, rax);
   // Restore input_reg after call to runtime.
   __ LoadFromSafepointRegisterSlot(input_reg, input_reg);
 
   __ bind(&allocated);
   __ movq(tmp2, FieldOperand(input_reg, HeapNumber::kValueOffset));
   __ shl(tmp2, Immediate(1));
   __ shr(tmp2, Immediate(1));
   __ movq(FieldOperand(tmp, HeapNumber::kValueOffset), tmp2);
   __ StoreToSafepointRegisterSlot(input_reg, tmp);
 
   __ bind(&done);
 }
 
 
 void LCodeGen::EmitIntegerMathAbs(LMathAbs* instr) {
   Register input_reg = ToRegister(instr->value());
   __ testl(input_reg, input_reg);
   Label is_positive;
-  __ j(not_sign, &is_positive);
+  __ j(not_sign, &is_positive, Label::kNear);
   __ negl(input_reg);  // Sets flags.
   DeoptimizeIf(negative, instr->environment());
   __ bind(&is_positive);
 }
 
 
 void LCodeGen::DoMathAbs(LMathAbs* instr) {
   // Class for deferred case.
   class DeferredMathAbsTaggedHeapNumber: public LDeferredCode {
    public:
@@ skipping 2135 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64