Use MemOperand directly to load argv on arm.

src/arm/codegen-arm.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 6460 matching lines @@
   // Called from C, so do not pop argc and args on exit (preserve sp)
   // No need to save register-passed args
   // Save callee-saved registers (incl. cp and fp), sp, and lr
   __ stm(db_w, sp, kCalleeSaved | lr.bit());
 
   // Get address of argv, see stm above.
   // r0: code entry
   // r1: function
   // r2: receiver
   // r3: argc
-  __ add(r4, sp, Operand((kNumCalleeSaved + 1)*kPointerSize));
-  __ ldr(r4, MemOperand(r4));  // argv
+  __ ldr(r4, MemOperand(sp, (kNumCalleeSaved + 1) * kPointerSize));  // argv
 
   // Push a frame with special values setup to mark it as an entry frame.
   // r0: code entry
   // r1: function
   // r2: receiver
   // r3: argc
   // r4: argv
   __ mov(r8, Operand(-1));  // Push a bad frame pointer to fail if it is used.
   int marker = is_construct ? StackFrame::ENTRY_CONSTRUCT : StackFrame::ENTRY;
   __ mov(r7, Operand(Smi::FromInt(marker)));
@@ skipping 435 matching lines @@
   // Call the runtime; it returns -1 (less), 0 (equal), or 1 (greater)
   // tagged as a small integer.
   __ bind(&runtime);
   __ TailCallRuntime(ExternalReference(Runtime::kStringCompare), 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal