Eliminate condition type check when possible.

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/flow_graph_builder.h"
 #include "vm/il_printer.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
 #include "vm/scopes.h"
+#include "vm/symbols.h"
 
 namespace dart {
 
 DECLARE_FLAG(bool, eliminate_type_checks);
 DECLARE_FLAG(bool, enable_type_checks);
 DEFINE_FLAG(bool, trace_optimization, false, "Print optimization details.");
 DECLARE_FLAG(bool, trace_type_check_elimination);
 
 void FlowGraphOptimizer::ApplyICData() {
   VisitBlocks();
@@ skipping 562 matching lines @@
                                        comp->token_pos(),
                                        comp->value(),
                                        comp->dst_type(),
                                        comp->dst_name(),
                                        comp->IsEliminated());
     }
   }
 }
 
 
+void FlowGraphTypePropagator::VisitAssertBoolean(AssertBooleanComp* comp,
+                                                 BindInstr* instr) {
+  if (FLAG_eliminate_type_checks &&
+      !comp->IsEliminated() &&
+      comp->value()->CompileTypeIsMoreSpecificThan(
+          Type::Handle(Type::BoolInterface()))) {
+    comp->Eliminate();
+    if (FLAG_trace_type_check_elimination) {
+      const String& name = String::Handle(Symbols::New("boolean expression"));
+      FlowGraphPrinter::PrintTypeCheck(parsed_function(),
+                                       comp->token_pos(),
+                                       comp->value(),
+                                       Type::Handle(Type::BoolInterface()),
+                                       name,
+                                       comp->IsEliminated());
+    }
+  }
+}
+
+
 void FlowGraphTypePropagator::VisitGraphEntry(GraphEntryInstr* graph_entry) {
   if (graph_entry->start_env() == NULL) {
     return;
   }
   // Visit incoming parameters.
   for (intptr_t i = 0; i < graph_entry->start_env()->values().length(); i++) {
     Value* val = graph_entry->start_env()->values()[i];
     if (val->IsUse()) {
       ParameterInstr* param = val->AsUse()->definition()->AsParameter();
       if (param != NULL) {
@@ skipping 86 matching lines @@
       LocationSummary* locs = it.Current()->locs();
       if ((locs != NULL) && locs->is_call()) {
         is_leaf_ = false;
         return;
       }
     }
   }
 }
 
 }  // namespace dart