VM: Simplify lowering of is-tests.

runtime/vm/constant_propagator.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/constant_propagator.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/flow_graph_range_analysis.h"
@@ skipping 737 matching lines @@
         (checked_type.IsInt32x4Type() && (rep == kUnboxedInt32x4)) ||
         (checked_type.IsDoubleType() && (rep == kUnboxedDouble) &&
          FlowGraphCompiler::SupportsUnboxedDoubles()) ||
         (checked_type.IsIntType() && (rep == kUnboxedMint))) {
       // Ensure that compile time type matches representation.
       ASSERT(((rep == kUnboxedFloat32x4) && (value_cid == kFloat32x4Cid)) ||
              ((rep == kUnboxedInt32x4) && (value_cid == kInt32x4Cid)) ||
              ((rep == kUnboxedDouble) && (value_cid == kDoubleCid)) ||
              ((rep == kUnboxedMint) && (value_cid == kMintCid)));
       // The representation guarantees the type check to be true.
-      SetValue(instr, instr->negate_result() ? Bool::False() : Bool::True());
+      SetValue(instr, Bool::True());
     } else {
       SetValue(instr, non_constant_);
     }
   } else if (IsConstant(value)) {
     if (value.IsInstance()) {
       const Instance& instance = Instance::Cast(value);
       const AbstractType& checked_type = instr->type();
       if (instr->instantiator_type_arguments()->BindsToConstantNull()) {
         const TypeArguments& checked_type_arguments = TypeArguments::Handle();
         Error& bound_error = Error::Handle();
         bool is_instance = instance.IsInstanceOf(
             checked_type, checked_type_arguments, &bound_error);
         // Can only have bound error with generics.
         ASSERT(bound_error.IsNull());
-        SetValue(instr, Bool::Get(instr->negate_result() ? !is_instance
-                                                         : is_instance));
+        SetValue(instr, Bool::Get(is_instance));
         return;
       }
     }
     SetValue(instr, non_constant_);
   }
 }
 
 
 void ConstantPropagator::VisitCreateArray(CreateArrayInstr* instr) {
   SetValue(instr, non_constant_);
@@ skipping 928 matching lines @@
   GrowableArray<BitVector*> dominance_frontier;
   graph_->ComputeDominators(&dominance_frontier);
 
   if (FLAG_trace_constant_propagation &&
       FlowGraphPrinter::ShouldPrint(graph_->function())) {
     FlowGraphPrinter::PrintGraph("After CP", graph_);
   }
 }
 
 }  // namespace dart