VM: Simplify lowering of is-tests.

runtime/vm/constants_dbc.h

 // Copyright (c) 2016, 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 RUNTIME_VM_CONSTANTS_DBC_H_
 #define RUNTIME_VM_CONSTANTS_DBC_H_
 
 #include "platform/globals.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 513 matching lines @@
 //    catch handler.
 //
 //  - InstantiateType D
 //
 //    Instantiate type PP[D] with instantiator type arguments SP[0].
 //
 //  - InstantiateTypeArgumentsTOS D
 //
 //    Instantiate type arguments PP[D] with instantiator SP[0].
 //
-//  - InstanceOf A
+//  - InstanceOf
 //
-//    Test if instance SP[-3] with type arguments SP[-2] is (A = 0) or is not
-//    (A = 1) a subtype of SP[-1] using SubtypeTestCache SP[0], with result
-//    placed at top of stack.
+//    Test if instance SP[-3] with type arguments SP[-2] is  a subtype of SP[-1]
+//    using SubtypeTestCache SP[0], with result placed at top of stack.
 //
 //  - AssertAssignable A, D
 //
 //    Assert that SP[-3] is assignable to variable named SP[0] of type
 //    SP[-1] with type arguments SP[-2] using SubtypeTestCache PP[D].
 //    If A is 1, then the instance may be a Smi.
 //
 //  - BadTypeError
 //
 //    If SP[-3] is non-null, throws a BadType error by calling into the runtime.
@@ skipping 253 matching lines @@
   V(EntryOptional,               A_B_C, num, num, num) \
   V(EntryOptimized,                A_D, num, num, ___) \
   V(Frame,                           D, num, ___, ___) \
   V(SetFrame,                        A, num, ___, num) \
   V(AllocateContext,                 D, num, ___, ___) \
   V(AllocateUninitializedContext,  A_D, reg, num, ___) \
   V(CloneContext,                    0, ___, ___, ___) \
   V(MoveSpecial,                   A_D, reg, num, ___) \
   V(InstantiateType,                 D, lit, ___, ___) \
   V(InstantiateTypeArgumentsTOS,   A_D, num, lit, ___) \
-  V(InstanceOf,                      A, num, ___, ___) \
+  V(InstanceOf,                      0, ___, ___, ___) \
   V(BadTypeError,                    0, ___, ___, ___) \
   V(AssertAssignable,              A_D, num, lit, ___) \
   V(AssertBoolean,                   A, num, ___, ___) \
   V(TestSmi,                       A_D, reg, reg, ___) \
   V(TestCids,                      A_D, reg, num, ___) \
   V(CheckSmi,                        A, reg, ___, ___) \
   V(CheckEitherNonSmi,             A_D, reg, reg, ___) \
   V(CheckClassId,                  A_D, reg, num, ___) \
   V(CheckDenseSwitch,              A_D, reg, num, ___) \
   V(CheckCids,                   A_B_C, reg, num, num) \
@@ skipping 140 matching lines @@
 
 // After a comparison, the condition NEXT_IS_TRUE means the following
 // instruction is executed if the comparision is true and skipped over overwise.
 // Conidition NEXT_IS_FALSE means the following instruction is executed if the
 // comparison is false and skipped over otherwise.
 enum Condition { NEXT_IS_TRUE, NEXT_IS_FALSE };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_CONSTANTS_DBC_H_