Improve SeqStringSetChar implementation.

src/ia32/lithium-ia32.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 1827 matching lines @@
   LDateField* result =
       new(zone()) LDateField(date, FixedTemp(ecx), instr->index());
   return MarkAsCall(DefineFixed(result, eax), instr, CAN_DEOPTIMIZE_EAGERLY);
 }
 
 
 LInstruction* LChunkBuilder::DoSeqStringSetChar(HSeqStringSetChar* instr) {
   LOperand* string = UseRegister(instr->string());
   LOperand* index = UseRegister(instr->index());
   ASSERT(ecx.is_byte_register());
-  // TODO(titzer): the machine code for this instruction overwrites ecx! fix!
   LOperand* value = UseFixed(instr->value(), ecx);
   LSeqStringSetChar* result =
       new(zone()) LSeqStringSetChar(instr->encoding(), string, index, value);
   return DefineSameAsFirst(result);
 }
 
 
 LInstruction* LChunkBuilder::DoNumericConstraint(HNumericConstraint* instr) {
   return NULL;
 }
@@ skipping 909 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32