Optimize string plus smi...

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 213 matching lines @@
 // -----------------------------------------------------------------------------
 // Machine instruction Operands
 
 enum ScaleFactor {
   times_1 = 0,
   times_2 = 1,
   times_4 = 2,
   times_8 = 3,
   times_int_size = times_4,
   times_half_pointer_size = times_2,
-  times_pointer_size = times_4
+  times_pointer_size = times_4,
+  times_twice_pointer_size = times_8
 };
 
 
 class Operand BASE_EMBEDDED {
  public:
   // reg
   INLINE(explicit Operand(Register reg));
 
   // [disp/r]
   INLINE(explicit Operand(int32_t disp, RelocInfo::Mode rmode));
@@ skipping 664 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_ASSEMBLER_IA32_H_