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

runtime/vm/intrinsifier_arm64.cc

 // Copyright (c) 2014, 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_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 1637 matching lines @@
   __ ldr(R0, Address(SP, 0 * kWordSize));
   __ ldr(R0, FieldAddress(R0, String::hash_offset()));
   __ CompareRegisters(R0, ZR);
   __ b(&fall_through, EQ);
   __ ret();
   // Hash not yet computed.
   __ Bind(&fall_through);
 }
 
 
-void Intrinsifier::StringBaseCodeUnitAt(Assembler* assembler) {
-  Label fall_through, try_two_byte_string;
-
-  __ ldr(R1, Address(SP, 0 * kWordSize));  // Index.
-  __ ldr(R0, Address(SP, 1 * kWordSize));  // String.
-  __ tsti(R1, Immediate(kSmiTagMask));
-  __ b(&fall_through, NE);  // Index is not a Smi.
-  // Range check.
-  __ ldr(R2, FieldAddress(R0, String::length_offset()));
-  __ cmp(R1, Operand(R2));
-  __ b(&fall_through, CS);  // Runtime throws exception.
-  __ CompareClassId(R0, kOneByteStringCid);
-  __ b(&try_two_byte_string, NE);
-  __ SmiUntag(R1);
-  __ AddImmediate(R0, R0, OneByteString::data_offset() - kHeapObjectTag);
-  __ ldr(R0, Address(R0, R1), kUnsignedByte);
-  __ SmiTag(R0);
-  __ ret();
-
-  __ Bind(&try_two_byte_string);
-  __ CompareClassId(R0, kTwoByteStringCid);
-  __ b(&fall_through, NE);
-  ASSERT(kSmiTagShift == 1);
-  __ AddImmediate(R0, R0, TwoByteString::data_offset() - kHeapObjectTag);
-  __ ldr(R0, Address(R0, R1), kUnsignedHalfword);
-  __ SmiTag(R0);
-  __ ret();
-
-  __ Bind(&fall_through);
-}
-
-
 void GenerateSubstringMatchesSpecialization(Assembler* assembler,
                                             intptr_t receiver_cid,
                                             intptr_t other_cid,
                                             Label* return_true,
                                             Label* return_false) {
   __ SmiUntag(R1);
   __ ldr(R8, FieldAddress(R0, String::length_offset()));  // this.length
   __ SmiUntag(R8);
   __ ldr(R9, FieldAddress(R2, String::length_offset()));  // other.length
   __ SmiUntag(R9);
@@ skipping 506 matching lines @@
 
 void Intrinsifier::Profiler_getCurrentTag(Assembler* assembler) {
   __ LoadIsolate(R0);
   __ ldr(R0, Address(R0, Isolate::current_tag_offset()));
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64