Use SSE2 instructions when available on ia32 platform.

src/ia32/assembler-ia32.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 521 matching lines @@
   void and_(const Operand& dst, const Immediate& x);
 
   void cmpb(const Operand& op, int8_t imm8);
   void cmpb_al(const Operand& op);
   void cmpw_ax(const Operand& op);
   void cmpw(const Operand& op, Immediate imm16);
   void cmp(Register reg, int32_t imm32);
   void cmp(Register reg, Handle<Object> handle);
   void cmp(Register reg, const Operand& op);
   void cmp(const Operand& op, const Immediate& imm);
+  void cmp(const Operand& op, Handle<Object> handle);
 
   void dec_b(Register dst);
 
   void dec(Register dst);
   void dec(const Operand& dst);
 
   void cdq();
 
   void idiv(Register src);
 
@@ skipping 160 matching lines @@
   void cvttss2si(Register dst, const Operand& src);
   void cvttsd2si(Register dst, const Operand& src);
 
   void cvtsi2sd(XMMRegister dst, const Operand& 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 comisd(XMMRegister dst, XMMRegister src);
+
   // Use either movsd or movlpd.
   void movdbl(XMMRegister dst, const Operand& src);
   void movdbl(const Operand& dst, XMMRegister src);
 
   // Debugging
   void Print();
 
   // Check the code size generated from label to here.
   int SizeOfCodeGeneratedSince(Label* l) { return pc_offset() - l->pos(); }
 
@@ skipping 133 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_ASSEMBLER_IA32_H_