Avoid using double temp register explicitly in lithium codegen

src/x64/macro-assembler-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
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@@ skipping 3710 matching lines @@
 
 
 void MacroAssembler::EnterExitFrameEpilogue(int arg_stack_space,
                                             bool save_doubles) {
 #ifdef _WIN64
   const int kShadowSpace = 4;
   arg_stack_space += kShadowSpace;
 #endif
   // Optionally save all XMM registers.
   if (save_doubles) {
-    int space = XMMRegister::kMaxNumRegisters * kDoubleSize +
+    int space = XMMRegister::kMaxNumAllocatableRegisters * kDoubleSize +

[mvstanton, 2013/09/25 07:00:30]

Could you do the same thing on ia32, using
Register::kMaxNumAllocatableRegisters?

         arg_stack_space * kPointerSize;
     subq(rsp, Immediate(space));
     int offset = -2 * kPointerSize;
     for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); i++) {
       XMMRegister reg = XMMRegister::FromAllocationIndex(i);
       movsd(Operand(rbp, offset - ((i + 1) * kDoubleSize)), reg);
     }
   } else if (arg_stack_space > 0) {
     subq(rsp, Immediate(arg_stack_space * kPointerSize));
   }
@@ skipping 1175 matching lines @@
   j(greater, &no_memento_available);
   CompareRoot(MemOperand(scratch_reg, -AllocationMemento::kSize),
               Heap::kAllocationMementoMapRootIndex);
   bind(&no_memento_available);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64