X64: Change strategy for spilling to match ia32. It's just better.

src/x64/macro-assembler-x64.cc

 // Copyright 2009 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 438 matching lines @@
     movq(dst, Immediate(static_cast<int32_t>(x)));
   } else if (is_uint32(x)) {
     movl(dst, Immediate(static_cast<uint32_t>(x)));
   } else {
     movq(dst, x, RelocInfo::NONE);
   }
 }
 
 
 void MacroAssembler::Set(const Operand& dst, int64_t x) {
-  if (x == 0) {
-    xor_(kScratchRegister, kScratchRegister);
-    movq(dst, kScratchRegister);
-  } else if (is_int32(x)) {
+  if (is_int32(x)) {
     movq(dst, Immediate(static_cast<int32_t>(x)));
-  } else if (is_uint32(x)) {
-    movl(dst, Immediate(static_cast<uint32_t>(x)));
   } else {
     movq(kScratchRegister, x, RelocInfo::NONE);
     movq(dst, kScratchRegister);
   }
 }
 
 // ----------------------------------------------------------------------------
 // Smi tagging, untagging and tag detection.
 
 static int kSmiShift = kSmiTagSize + kSmiShiftSize;
@@ skipping 2285 matching lines @@
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64