VM: Optimized code for all of [External]{One|Two}ByteString::codeUnitAt.

runtime/vm/intrinsifier_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 1555 matching lines @@
   __ movq(RAX, Address(RSP, + 1 * kWordSize));  // String object.
   __ movq(RAX, FieldAddress(RAX, String::hash_offset()));
   __ cmpq(RAX, Immediate(0));
   __ j(EQUAL, &fall_through, Assembler::kNearJump);
   __ ret();
   __ Bind(&fall_through);
   // Hash not yet computed.
 }
 
 
-void Intrinsifier::StringBaseCodeUnitAt(Assembler* assembler) {
-  Label fall_through, try_two_byte_string;
-  __ movq(RCX, Address(RSP, + 1 * kWordSize));  // Index.
-  __ movq(RAX, Address(RSP, + 2 * kWordSize));  // String.
-  __ testq(RCX, Immediate(kSmiTagMask));
-  __ j(NOT_ZERO, &fall_through, Assembler::kNearJump);  // Non-smi index.
-  // Range check.
-  __ cmpq(RCX, FieldAddress(RAX, String::length_offset()));
-  // Runtime throws exception.
-  __ j(ABOVE_EQUAL, &fall_through, Assembler::kNearJump);
-  __ CompareClassId(RAX, kOneByteStringCid);
-  __ j(NOT_EQUAL, &try_two_byte_string, Assembler::kNearJump);
-  __ SmiUntag(RCX);
-  __ movzxb(RAX, FieldAddress(RAX, RCX, TIMES_1, OneByteString::data_offset()));
-  __ SmiTag(RAX);
-  __ ret();
-
-  __ Bind(&try_two_byte_string);
-  __ CompareClassId(RAX, kTwoByteStringCid);
-  __ j(NOT_EQUAL, &fall_through, Assembler::kNearJump);
-  ASSERT(kSmiTagShift == 1);
-  __ movzxw(RAX, FieldAddress(RAX, RCX, TIMES_1, OneByteString::data_offset()));
-  __ SmiTag(RAX);
-  __ ret();
-
-  __ Bind(&fall_through);
-}
-
-
 void GenerateSubstringMatchesSpecialization(Assembler* assembler,
                                             intptr_t receiver_cid,
                                             intptr_t other_cid,
                                             Label* return_true,
                                             Label* return_false) {
   __ movq(R8, FieldAddress(RAX, String::length_offset()));
   __ movq(R9, FieldAddress(RCX, String::length_offset()));
 
   // if (other.length == 0) return true;
   __ testq(R9, R9);
@@ skipping 498 matching lines @@
   __ LoadIsolate(RAX);
   __ movq(RAX, Address(RAX, Isolate::current_tag_offset()));
   __ ret();
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64