Ported ia32 optimization of revision 3487 to x64.

src/x64/assembler-x64.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 1104 matching lines @@
   void cvtlsi2sd(XMMRegister dst, const Operand& src);
   void cvtlsi2sd(XMMRegister dst, Register src);
   void cvtqsi2sd(XMMRegister dst, const Operand& src);
   void cvtqsi2sd(XMMRegister dst, Register src);
 
   void addsd(XMMRegister dst, XMMRegister src);
   void subsd(XMMRegister dst, XMMRegister src);
   void mulsd(XMMRegister dst, XMMRegister src);
   void divsd(XMMRegister dst, XMMRegister src);
 
+  void xorpd(XMMRegister dst, XMMRegister src);
+
+  void comisd(XMMRegister dst, XMMRegister src);
+  void ucomisd(XMMRegister dst, XMMRegister src);
 
   void emit_sse_operand(XMMRegister dst, XMMRegister src);
   void emit_sse_operand(XMMRegister reg, const Operand& adr);
   void emit_sse_operand(XMMRegister dst, Register src);
 
   // Use either movsd or movlpd.
   // void movdbl(XMMRegister dst, const Operand& src);
   // void movdbl(const Operand& dst, XMMRegister src);
 
   // Debugging
@@ skipping 26 matching lines @@
 
   // Get the number of bytes available in the buffer.
   inline int available_space() const {
     return static_cast<int>(reloc_info_writer.pos() - pc_);
   }
 
   // Avoid overflows for displacements etc.
   static const int kMaximalBufferSize = 512*MB;
   static const int kMinimalBufferSize = 4*KB;
 
- protected:
-  // void movsd(XMMRegister dst, const Operand& src);
-  // void movsd(const Operand& dst, XMMRegister src);
-
-  // void emit_sse_operand(XMMRegister reg, const Operand& adr);
-  // void emit_sse_operand(XMMRegister dst, XMMRegister src);
-
-
  private:
   byte* addr_at(int pos)  { return buffer_ + pos; }
   byte byte_at(int pos)  { return buffer_[pos]; }
   uint32_t long_at(int pos)  {
     return *reinterpret_cast<uint32_t*>(addr_at(pos));
   }
   void long_at_put(int pos, uint32_t x)  {
     *reinterpret_cast<uint32_t*>(addr_at(pos)) = x;
   }
 
@@ skipping 217 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_H_