In my final round of refactoring, I accidentally broke my string...

src/ic-arm.cc

 // Copyright 2006-2008 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 172 matching lines @@
   // ----------- S t a t e -------------
   //  -- r2    : name
   //  -- lr    : return address
   //  -- [sp]  : receiver
   // -----------------------------------
 
   Label miss, load_length, check_wrapper;
 
   __ ldr(r0, MemOperand(sp, 0));
 
-  // Check if the object is a string.
+  // Check if the object is a string leaving the instance type in the
+  // r1 register.
   GenerateStringCheck(masm, r0, r1, r3, &miss, &check_wrapper);
 
   // Load length directly from the string.
   __ bind(&load_length);
   __ and_(r1, r1, Operand(kStringSizeMask));
   __ add(r1, r1, Operand(String::kHashShift));
   __ ldr(r0, FieldMemOperand(r0, String::kLengthOffset));
   __ mov(r0, Operand(r0, LSR, r1));
   __ mov(r0, Operand(r0, LSL, kSmiTagSize));
   __ Ret();
 
   // Check if the object is a JSValue wrapper.
   __ bind(&check_wrapper);
-  __ cmp(r0, Operand(JS_VALUE_TYPE));
+  __ cmp(r1, Operand(JS_VALUE_TYPE));
   __ b(ne, &miss);
 
   // Check if the wrapped value is a string and load the length
   // directly if it is.
   __ ldr(r0, FieldMemOperand(r0, JSValue::kValueOffset));
   GenerateStringCheck(masm, r0, r1, r3, &miss, &miss);
   __ b(&load_length);
 
   // Cache miss: Jump to runtime.
   __ bind(&miss);
@@ skipping 368 matching lines @@
 
   // Perform tail call to the entry.
   __ TailCallRuntime(f, 3);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal