Simplify and improve optimization of is-tests in the precompiler.

runtime/vm/raw_object.h

 // 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.
 
 #ifndef VM_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/atomic.h"
 #include "vm/globals.h"
@@ skipping 2263 matching lines @@
   return (index == kOneByteStringCid || index == kExternalOneByteStringCid);
 }
 
 
 inline bool RawObject::IsTwoByteStringClassId(intptr_t index) {
   // Make sure this function is updated when new StringCid types are added.
   COMPILE_ASSERT(kOneByteStringCid == kStringCid + 1 &&
                  kTwoByteStringCid == kStringCid + 2 &&
                  kExternalOneByteStringCid == kStringCid + 3 &&
                  kExternalTwoByteStringCid == kStringCid + 4);
-  return (index == kOneByteStringCid ||

[Vyacheslav Egorov (Google), 2016/06/16 08:37:37]

I wonder how this worked

-          index == kTwoByteStringCid ||
-          index == kExternalOneByteStringCid ||
-          index == kExternalTwoByteStringCid);
+  return (index == kTwoByteStringCid || index == kExternalTwoByteStringCid);
 }
 
 
 inline bool RawObject::IsExternalStringClassId(intptr_t index) {
   // Make sure this function is updated when new StringCid types are added.
   COMPILE_ASSERT(kOneByteStringCid == kStringCid + 1 &&
                  kTwoByteStringCid == kStringCid + 2 &&
                  kExternalOneByteStringCid == kStringCid + 3 &&
                  kExternalTwoByteStringCid == kStringCid + 4);
   return (index == kExternalOneByteStringCid ||
@@ skipping 134 matching lines @@
   COMPILE_ASSERT(kExternalTypedDataInt8ArrayCid ==
                  kTypedDataInt8ArrayViewCid + 15);
   COMPILE_ASSERT(kByteBufferCid == kExternalTypedDataInt8ArrayCid + 14);
   COMPILE_ASSERT(kNullCid == kByteBufferCid + 1);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_