Add cld before doing rep movs.

src/ia32/codegen-ia32.cc

 // Copyright 2010 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 10904 matching lines @@
   }
 
   // Don't enter the rep movs if there are less than 4 bytes to copy.
   Label last_bytes;
   __ test(count, Immediate(~3));
   __ j(zero, &last_bytes);
 
   // Copy from edi to esi using rep movs instruction.
   __ mov(scratch, count);
   __ sar(count, 2);  // Number of doublewords to copy.
+  __ cld();
   __ rep_movs();
 
   // Find number of bytes left.
   __ mov(count, scratch);
   __ and_(count, 3);
 
   // Check if there are more bytes to copy.
   __ bind(&last_bytes);
   __ test(count, Operand(count));
   __ j(zero, &done);
@@ skipping 448 matching lines @@
 
   // Call the runtime; it returns -1 (less), 0 (equal), or 1 (greater)
   // tagged as a small integer.
   __ bind(&runtime);
   __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
 }
 
 #undef __
 
 } }  // namespace v8::internal