Using array index hash code for string-to-number conversion.

src/x64/codegen-x64.cc

 // Copyright 2010 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 7205 matching lines @@
           Immediate(JS_REGEXP_TYPE));
   destination()->false_target()->Branch(not_equal);
   __ cmpq(tmp, FieldOperand(right, HeapObject::kMapOffset));
   destination()->false_target()->Branch(not_equal);
   __ movq(tmp, FieldOperand(left, JSRegExp::kDataOffset));
   __ cmpq(tmp, FieldOperand(right, JSRegExp::kDataOffset));
   destination()->Split(equal);
 }
 
 
+void CodeGenerator::GenerateHasCachedArrayIndex(ZoneList<Expression*>* args) {
+  ASSERT(args->length() == 1);
+  Load(args->at(0));
+  Result value = frame_->Pop();
+  value.ToRegister();
+  ASSERT(value.is_valid());
+  __ testl(FieldOperand(value.reg(), String::kHashFieldOffset),
+           Immediate(String::kContainsCachedArrayIndexMask));
+  value.Unuse();
+  destination()->Split(zero);
+}
+
+
+void CodeGenerator::GenerateGetCachedArrayIndex(ZoneList<Expression*>* args) {
+  ASSERT(args->length() == 1);
+  Load(args->at(0));
+  Result string = frame_->Pop();
+  string.ToRegister();
+
+  Result number = allocator()->Allocate();
+  ASSERT(number.is_valid());
+  __ movl(number.reg(), FieldOperand(string.reg(), String::kHashFieldOffset));
+  __ IndexFromHash(number.reg(), number.reg());
+  string.Unuse();
+  frame_->Push(&number);
+}
+
+
 void CodeGenerator::VisitCallRuntime(CallRuntime* node) {
   if (CheckForInlineRuntimeCall(node)) {
     return;
   }
 
   ZoneList<Expression*>* args = node->arguments();
   Comment cmnt(masm_, "[ CallRuntime");
   Runtime::Function* function = node->function();
 
   if (function == NULL) {
@@ skipping 1636 matching lines @@
 #undef __
 
 void RecordWriteStub::Generate(MacroAssembler* masm) {
   masm->RecordWriteHelper(object_, addr_, scratch_);
   masm->ret(0);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64