Fix SmiCompare on 64 bit to distinguish between comparisons where...

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 638 matching lines @@
   void movq(Register dst, const Operand& src);
   void movq(Register dst, Register src);
   // Sign extends immediate 32-bit value to 64 bits.
   void movq(Register dst, Immediate x);
   // Move the offset of the label location relative to the current
   // position (after the move) to the destination.
   void movl(const Operand& dst, Label* src);
 
   // Move sign extended immediate to memory location.
   void movq(const Operand& dst, Immediate value);
-  // New x64 instructions to load a 64-bit immediate into a register.
+  // Instructions to load a 64-bit immediate into a register.
   // All 64-bit immediates must have a relocation mode.
   void movq(Register dst, void* ptr, RelocInfo::Mode rmode);
   void movq(Register dst, int64_t value, RelocInfo::Mode rmode);
   void movq(Register dst, const char* s, RelocInfo::Mode rmode);
+  void movq(Register dst, Smi* smi);
   // Moves the address of the external reference into the register.
   void movq(Register dst, ExternalReference ext);
   void movq(Register dst, Handle<Object> handle, RelocInfo::Mode rmode);
 
   void movsxbq(Register dst, const Operand& src);
   void movsxwq(Register dst, const Operand& src);
   void movsxlq(Register dst, Register src);
   void movsxlq(Register dst, const Operand& src);
   void movzxbq(Register dst, const Operand& src);
   void movzxbl(Register dst, const Operand& src);
   void movzxwq(Register dst, const Operand& src);
   void movzxwl(Register dst, const Operand& src);
 
   // Repeated moves.
 
   void repmovsb();
   void repmovsw();
   void repmovsl();
   void repmovsq();
 
-  // New x64 instruction to load from an immediate 64-bit pointer into RAX.
+  // Instruction to load from an immediate 64-bit pointer into RAX.
   void load_rax(void* ptr, RelocInfo::Mode rmode);
   void load_rax(ExternalReference ext);
 
   // Conditional moves.
   void cmovq(Condition cc, Register dst, Register src);
   void cmovq(Condition cc, Register dst, const Operand& src);
   void cmovl(Condition cc, Register dst, Register src);
   void cmovl(Condition cc, Register dst, const Operand& src);
 
   // Exchange two registers
@@ skipping 887 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_H_