Constant propagation support for type asserts.

runtime/vm/flow_graph_optimizer.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/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 6179 matching lines @@
 }
 
 
 void ConstantPropagator::VisitAssertAssignable(AssertAssignableInstr* instr) {
   const Object& value = instr->value()->definition()->constant_value();
   if (IsNonConstant(value)) {
     SetValue(instr, non_constant_);
   } else if (IsConstant(value)) {
     // We are ignoring the instantiator and instantiator_type_arguments, but
     // still monotonic and safe.
-    // TODO(kmillikin): Handle constants.
-    SetValue(instr, non_constant_);
+    if (instr->value()->Type()->IsAssignableTo(instr->dst_type())) {
+      SetValue(instr, value);
+    } else {
+      SetValue(instr, non_constant_);
+    }
   }
 }
 
 
 void ConstantPropagator::VisitAssertBoolean(AssertBooleanInstr* instr) {
   const Object& value = instr->value()->definition()->constant_value();
   if (IsNonConstant(value)) {
     SetValue(instr, non_constant_);
   } else if (IsConstant(value)) {
-    // TODO(kmillikin): Handle assertion.
-    SetValue(instr, non_constant_);
+    if (value.IsBool()) {
+      SetValue(instr, value);
+    } else {
+      SetValue(instr, non_constant_);
+    }
   }
 }
 
 
 void ConstantPropagator::VisitCurrentContext(CurrentContextInstr* instr) {
   SetValue(instr, non_constant_);
 }
 
 
 void ConstantPropagator::VisitClosureCall(ClosureCallInstr* instr) {
@@ skipping 1683 matching lines @@
   }
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits.length(); i++) {
     CreateMaterializationAt(exits[i], alloc, alloc->cls(), *fields);
   }
 }
 
 
 }  // namespace dart