Fix issues 5137: instance of test on constant value should return true or false, not the value itse…

runtime/vm/flow_graph_optimizer.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/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/hash_map.h"
@@ skipping 1235 matching lines @@
   // TODO(regis): Propagate NullType as well and revise the comment and code
   // below to also eliminate the test for non-null and non-constant value.
 
   // We can only eliminate an 'instance of' test when the checked value is
   // a constant time constant. Indeed, a variable of the proper compile time
   // type may still hold null at run time and therefore fail the test.
   // We do not bother checking for Object destination type, since the graph
   // builder did already.
   if (FLAG_eliminate_type_checks &&
       instr->value()->BindsToConstant() &&
-      !instr->value()->BindsToConstantNull() &&
-      instr->value()->CompileTypeIsMoreSpecificThan(instr->type())) {
-    Value* use = instr->value();
-    Definition* result = use->definition();
-    ASSERT(result != NULL);
+      !instr->value()->BindsToConstantNull()) {
+    const Bool& bool_result =
+        instr->value()->CompileTypeIsMoreSpecificThan(instr->type()) ?
+            Bool::ZoneHandle(Bool::True()) : Bool::ZoneHandle(Bool::False());
+    Definition* result = new ConstantInstr(bool_result);
+    result->set_ssa_temp_index(flow_graph_->alloc_ssa_temp_index());
+    result->InsertBefore(instr);
     // Replace uses and remove the current instruction via the iterator.
     instr->ReplaceUsesWith(result);
     ASSERT(current_iterator()->Current() == instr);
     current_iterator()->RemoveCurrentFromGraph();
     if (FLAG_trace_optimization) {
       OS::Print("Replacing v%"Pd" with v%"Pd"\n",
                 instr->ssa_temp_index(),
                 result->ssa_temp_index());
     }
 
@@ skipping 296 matching lines @@
       DirectChainedHashMap<Definition*> child_map(*map);  // Copy map.
       OptimizeRecursive(child, &child_map);
     } else {
       OptimizeRecursive(child, map);  // Reuse map for the last child.
     }
   }
 }
 
 
 }  // namespace dart