Tentative implementation of string slices (hidden under the flag --string-slices).

src/arm/lithium-arm.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 1988 matching lines @@
 
 
 LInstruction* LChunkBuilder::DoStringAdd(HStringAdd* instr) {
   LOperand* left = UseRegisterAtStart(instr->left());
   LOperand* right = UseRegisterAtStart(instr->right());
   return MarkAsCall(DefineFixed(new LStringAdd(left, right), r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoStringCharCodeAt(HStringCharCodeAt* instr) {
-  LOperand* string = UseRegister(instr->string());
+  LOperand* string = UseTempRegister(instr->string());
   LOperand* index = UseRegisterOrConstant(instr->index());
   LStringCharCodeAt* result = new LStringCharCodeAt(string, index);
   return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
 }

[Yang, 2011/08/04 09:19:53]

Legacy bug. The register 'string' is being altered in the generated code.

 
 
 LInstruction* LChunkBuilder::DoStringCharFromCode(HStringCharFromCode* instr) {
   LOperand* char_code = UseRegister(instr->value());
   LStringCharFromCode* result = new LStringCharFromCode(char_code);
   return AssignPointerMap(DefineAsRegister(result));
 }
 
 
 LInstruction* LChunkBuilder::DoStringLength(HStringLength* instr) {
@@ skipping 164 matching lines @@
 
 LInstruction* LChunkBuilder::DoIn(HIn* instr) {
   LOperand* key = UseRegisterAtStart(instr->key());
   LOperand* object = UseRegisterAtStart(instr->object());
   LIn* result = new LIn(key, object);
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
 
 } }  // namespace v8::internal