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

runtime/vm/intrinsifier_ia32.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.
 //
 // The intrinsic code below is executed before a method has built its frame.
 // The return address is on the stack and the arguments below it.
 // Registers EDX (arguments descriptor) and ECX (function) must be preserved.
 // Each intrinsification method returns true if the corresponding
 // Dart method was intrinsified.
 
@@ skipping 1700 matching lines @@
   __ movl(EAX, Address(ESP, + 1 * kWordSize));  // String object.
   __ movl(EAX, FieldAddress(EAX, String::hash_offset()));
   __ cmpl(EAX, 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;
-  __ movl(EBX, Address(ESP, + 1 * kWordSize));  // Index.
-  __ movl(EAX, Address(ESP, + 2 * kWordSize));  // String.
-  __ testl(EBX, Immediate(kSmiTagMask));
-  __ j(NOT_ZERO, &fall_through, Assembler::kNearJump);  // Non-smi index.
-  // Range check.
-  __ cmpl(EBX, FieldAddress(EAX, String::length_offset()));
-  // Runtime throws exception.
-  __ j(ABOVE_EQUAL, &fall_through, Assembler::kNearJump);
-  __ CompareClassId(EAX, kOneByteStringCid, EDI);
-  __ j(NOT_EQUAL, &try_two_byte_string, Assembler::kNearJump);
-  __ SmiUntag(EBX);
-  __ movzxb(EAX, FieldAddress(EAX, EBX, TIMES_1, OneByteString::data_offset()));
-  __ SmiTag(EAX);
-  __ ret();
-
-  __ Bind(&try_two_byte_string);
-  __ CompareClassId(EAX, kTwoByteStringCid, EDI);
-  __ j(NOT_EQUAL, &fall_through, Assembler::kNearJump);
-  ASSERT(kSmiTagShift == 1);
-  __ movzxw(EAX, FieldAddress(EAX, EBX, TIMES_1, TwoByteString::data_offset()));
-  __ SmiTag(EAX);
-  __ ret();
-
-  __ Bind(&fall_through);
-}
-
-
 // bool _substringMatches(int start, String other)
 void Intrinsifier::StringBaseSubstringMatches(Assembler* assembler) {
   // For precompilation, not implemented on IA32.
 }
 
 
 void Intrinsifier::StringBaseCharAt(Assembler* assembler) {
   Label fall_through, try_two_byte_string;
   __ movl(EBX, Address(ESP, + 1 * kWordSize));  // Index.
   __ movl(EAX, Address(ESP, + 2 * kWordSize));  // String.
@@ skipping 397 matching lines @@
 void Intrinsifier::Profiler_getCurrentTag(Assembler* assembler) {
   __ LoadIsolate(EAX);
   __ movl(EAX, Address(EAX, Isolate::current_tag_offset()));
   __ ret();
 }
 
 #undef __
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32