VM: Reland Inline instance object hash code into object header on 64bit.

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 1814 matching lines @@
   __ ldr(R0, Address(SP, 0 * kWordSize));
   __ ldr(R0, FieldAddress(R0, String::hash_offset()), kUnsignedWord);
   __ adds(R0, R0, Operand(R0));  // Smi tag the hash code, setting Z flag.
   __ b(&fall_through, EQ);
   __ ret();
   // Hash not yet computed.
   __ Bind(&fall_through);
 }
 
 
+void Intrinsifier::Object_getHash(Assembler* assembler) {
+  __ ldr(R0, Address(SP, 0 * kWordSize));
+  __ ldr(R0, FieldAddress(R0, String::hash_offset()), kUnsignedWord);
+  __ SmiTag(R0);
+  __ ret();
+}
+
+
+void Intrinsifier::Object_setHash(Assembler* assembler) {
+  __ ldr(R0, Address(SP, 1 * kWordSize));  // Object.
+  __ ldr(R1, Address(SP, 0 * kWordSize));  // Value.
+  __ SmiUntag(R1);
+  __ str(R1, FieldAddress(R0, String::hash_offset()), kUnsignedWord);
+  __ ret();
+}
+
+
 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 538 matching lines @@
 
 void Intrinsifier::SetAsyncThreadStackTrace(Assembler* assembler) {
   __ ldr(R0, Address(THR, Thread::async_stack_trace_offset()));
   __ LoadObject(R0, Object::null_object());
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64