Copy of changelist from issue 16450. Converts compare operation...

src/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 481 matching lines @@
 
   void movzx_b(Register dst, const Operand& src);
 
   void movzx_w(Register dst, const Operand& src);
 
   // Conditional moves
   void cmov(Condition cc, Register dst, int32_t imm32);
   void cmov(Condition cc, Register dst, Handle<Object> handle);
   void cmov(Condition cc, Register dst, const Operand& src);
 
+  // Exchange two registers
+  void xchg(Register dst, Register src);
+
   // Arithmetics
   void adc(Register dst, int32_t imm32);
   void adc(Register dst, const Operand& src);
 
   void add(Register dst, const Operand& src);
   void add(const Operand& dst, const Immediate& x);
 
   void and_(Register dst, int32_t imm32);
   void and_(Register dst, const Operand& src);
   void and_(const Operand& src, Register dst);
@@ skipping 327 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_IA32_H_