Intrinsify ExternalUint8Array.[].

runtime/vm/intrinsifier_x64.cc

 // Copyright (c) 2012, 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 682 matching lines @@
   // Load double value into XMM7.
   __ movsd(XMM7, FieldAddress(RDX, Double::value_offset()));
   // Store into array.
   __ movsd(FieldAddress(RAX, R12, TIMES_4, Float64Array::data_offset()), XMM7);
   __ ret();
   __ Bind(&fall_through);
   return false;
 }
 
 
+bool Intrinsifier::ExternalUint8Array_getIndexed(Assembler* assembler) {
+  Label fall_through;
+  TestByteArrayIndex(assembler, &fall_through);
+  __ SmiUntag(R12);
+  __ movq(RAX, FieldAddress(RAX, ExternalUint8Array::external_data_offset()));
+  __ movq(RAX, Address(RAX, ExternalByteArrayData<uint8_t>::data_offset()));
+  __ movzxb(RAX, Address(RAX, R12, TIMES_1, 0));
+  __ SmiTag(RAX);
+  __ ret();
+  __ Bind(&fall_through);
+  return false;
+}
+
+
 // Tests if two top most arguments are smis, jumps to label not_smi if not.
 // Topmost argument is in RAX.
 static void TestBothArgumentsSmis(Assembler* assembler, Label* not_smi) {
   __ movq(RAX, Address(RSP, + 1 * kWordSize));
   __ movq(RCX, Address(RSP, + 2 * kWordSize));
   __ orq(RCX, RAX);
   __ testq(RCX, Immediate(kSmiTagMask));
   __ j(NOT_ZERO, not_smi, Assembler::kNearJump);
 }
 
@@ skipping 844 matching lines @@
   __ LoadObject(RAX, bool_true);
   __ ret();
   return true;
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64