MIPS: Simplify StringCharCodeAt in non-crankshaft codegen.

src/mips/stub-cache-mips.cc

 // Copyright 2011 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 1733 matching lines @@
   GenerateDirectLoadGlobalFunctionPrototype(masm(),
                                             Context::STRING_FUNCTION_INDEX,
                                             v0,
                                             &miss);
   ASSERT(!object.is_identical_to(holder));
   CheckPrototypes(Handle<JSObject>(JSObject::cast(object->GetPrototype())),
                   v0, holder, a1, a3, t0, name, &miss);
 
   Register receiver = a1;
   Register index = t1;
-  Register scratch = a3;
   Register result = v0;
   __ lw(receiver, MemOperand(sp, argc * kPointerSize));
   if (argc > 0) {
     __ lw(index, MemOperand(sp, (argc - 1) * kPointerSize));
   } else {
     __ LoadRoot(index, Heap::kUndefinedValueRootIndex);
   }
 
   StringCharCodeAtGenerator generator(receiver,
                                       index,
-                                      scratch,
                                       result,
                                       &miss,  // When not a string.
                                       &miss,  // When not a number.
                                       index_out_of_range_label,
                                       STRING_INDEX_IS_NUMBER);
   generator.GenerateFast(masm());
   __ Drop(argc + 1);
   __ Ret();
 
   StubRuntimeCallHelper call_helper;
@@ skipping 50 matching lines @@
   GenerateDirectLoadGlobalFunctionPrototype(masm(),
                                             Context::STRING_FUNCTION_INDEX,
                                             v0,
                                             &miss);
   ASSERT(!object.is_identical_to(holder));
   CheckPrototypes(Handle<JSObject>(JSObject::cast(object->GetPrototype())),
                   v0, holder, a1, a3, t0, name, &miss);
 
   Register receiver = v0;
   Register index = t1;
-  Register scratch1 = a1;
-  Register scratch2 = a3;
+  Register scratch = a3;
   Register result = v0;
   __ lw(receiver, MemOperand(sp, argc * kPointerSize));
   if (argc > 0) {
     __ lw(index, MemOperand(sp, (argc - 1) * kPointerSize));
   } else {
     __ LoadRoot(index, Heap::kUndefinedValueRootIndex);
   }
 
   StringCharAtGenerator generator(receiver,
                                   index,
-                                  scratch1,
-                                  scratch2,
+                                  scratch,
                                   result,
                                   &miss,  // When not a string.
                                   &miss,  // When not a number.
                                   index_out_of_range_label,
                                   STRING_INDEX_IS_NUMBER);
   generator.GenerateFast(masm());
   __ Drop(argc + 1);
   __ Ret();
 
   StubRuntimeCallHelper call_helper;
@@ skipping 2457 matching lines @@
   Handle<Code> ic_miss = masm->isolate()->builtins()->KeyedStoreIC_Miss();
   __ Jump(ic_miss, RelocInfo::CODE_TARGET);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS