Use shorter write-barrier filtering sequence when value is known to be non-smi.

runtime/vm/assembler_x64_test.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"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/os.h"
 #include "vm/unit_test.h"
@@ skipping 2007 matching lines @@
 }
 
 
 ASSEMBLER_TEST_RUN(TestNot, test) {
   typedef int (*TestNot)();
   unsigned int res = reinterpret_cast<TestNot>(test->entry())();
   EXPECT_EQ(0xFFFFFFFF, res);
 }
 
 
+ASSEMBLER_TEST_GENERATE(TestNotInt32, assembler) {
+  __ movq(RAX, Immediate(0x0));
+  __ notl(RAX);
+  __ ret();
+}
+
+
+ASSEMBLER_TEST_RUN(TestNotInt32, test) {
+  typedef int (*TestNot)();
+  unsigned int res = reinterpret_cast<TestNot>(test->entry())();
+  EXPECT_EQ(0xFFFFFFFF, res);
+}
+
+
 ASSEMBLER_TEST_GENERATE(XorpdZeroing, assembler) {
   __ pushq(RAX);
   __ movsd(Address(RSP, 0), XMM0);
   __ xorpd(XMM0, Address(RSP, 0));
   __ popq(RAX);
   __ ret();
 }
 
 
 ASSEMBLER_TEST_RUN(XorpdZeroing, test) {
@@ skipping 201 matching lines @@
   EXPECT_EQ(0, res);
   res = reinterpret_cast<ExtractSignBits>(test->entry())(-1.0);
   EXPECT_EQ(1, res);
   res = reinterpret_cast<ExtractSignBits>(test->entry())(-0.0);
   EXPECT_EQ(1, res);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64