Improve SeqStringSetChar implementation.

src/hydrogen.cc

 // Copyright 2012 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 11443 matching lines @@
 
 void HOptimizedGraphBuilder::GenerateTwoByteSeqStringSetChar(
     CallRuntime* call) {
   ASSERT(call->arguments()->length() == 3);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(1)));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(2)));
   HValue* value = Pop();
   HValue* index = Pop();
   HValue* string = Pop();
-  HValue* context = environment()->LookupContext();
-  HInstruction* char_code = BuildStringCharCodeAt(context, string, index);
-  AddInstruction(char_code);
   HSeqStringSetChar* result = new(zone()) HSeqStringSetChar(
       String::TWO_BYTE_ENCODING, string, index, value);
   return ast_context()->ReturnInstruction(result, call->id());
 }
 
 
 void HOptimizedGraphBuilder::GenerateSetValueOf(CallRuntime* call) {
   ASSERT(call->arguments()->length() == 2);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(1)));
@@ skipping 996 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal