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

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 1736 matching lines @@
   ASSERT(kSmiTag == 0);
   ASSERT(kSmiTagShift == 1);
   __ addq(RAX, RAX);  // Smi tag RAX, setting Z flag.
   __ j(ZERO, &fall_through, Assembler::kNearJump);
   __ ret();
   __ Bind(&fall_through);
   // Hash not yet computed.
 }
 
 
+void Intrinsifier::Object_getHash(Assembler* assembler) {
+  __ movq(RAX, Address(RSP, +1 * kWordSize));  // Object.
+  __ movl(RAX, FieldAddress(RAX, String::hash_offset()));
+  __ SmiTag(RAX);
+  __ ret();
+}
+
+
+void Intrinsifier::Object_setHash(Assembler* assembler) {
+  __ movq(RAX, Address(RSP, +2 * kWordSize));  // Object.
+  __ movq(RDX, Address(RSP, +1 * kWordSize));  // Value.
+  __ SmiUntag(RDX);
+  __ movl(FieldAddress(RAX, String::hash_offset()), RDX);
+  __ ret();
+}
+
+
 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 535 matching lines @@
   __ movq(Address(THR, Thread::async_stack_trace_offset()), RAX);
   __ LoadObject(RAX, Object::null_object());
   __ ret();
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64