Make the CFG depth-first traversal do more work for us.

runtime/vm/flow_graph_builder.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_builder.h"
 
 #include "vm/ast_printer.h"
 #include "vm/flags.h"
 #include "vm/intermediate_language.h"
 #include "vm/longjump.h"
@@ skipping 1653 matching lines @@
   }
   const Function& function = parsed_function().function();
   EffectGraphVisitor for_effect(this, 0);
   for_effect.AddInstruction(new TargetEntryInstr());
   parsed_function().node_sequence()->Visit(&for_effect);
   // Check that the graph is properly terminated.
   ASSERT(!for_effect.is_open());
   if (for_effect.entry() != NULL) {
     // Perform a depth-first traversal of the graph to build preorder and
     // postorder block orders.
-    for_effect.entry()->DepthFirstSearch(&preorder_block_entries_,
-                                         &postorder_block_entries_);
+    GrowableArray<BlockEntryInstr*> parent;

[Kevin Millikin (Google), 2012/03/19 18:05:12]

parent is currently ignored.

+    for_effect.entry()->DiscoverBlocks(NULL,  // Entry block predecessor.
+                                       &preorder_block_entries_,
+                                       &postorder_block_entries_,
+                                       &parent);
   }
   if (FLAG_print_flow_graph) {
     intptr_t length = postorder_block_entries_.length();
     GrowableArray<BlockEntryInstr*> reverse_postorder(length);
     for (intptr_t i = length - 1; i >= 0; --i) {
       reverse_postorder.Add(postorder_block_entries_[i]);
     }
     FlowGraphPrinter printer(function, reverse_postorder);
     printer.VisitBlocks();
   }
 }
 
 
 void FlowGraphBuilder::Bailout(const char* reason) {
   const char* kFormat = "FlowGraphBuilder Bailout: %s %s";
   const char* function_name = parsed_function_.function().ToCString();
   intptr_t len = OS::SNPrint(NULL, 0, kFormat, function_name, reason) + 1;
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len));
   OS::SNPrint(chars, len, kFormat, function_name, reason);
   const Error& error = Error::Handle(
       LanguageError::New(String::Handle(String::New(chars))));
   Isolate::Current()->long_jump_base()->Jump(1, error);
 }
 
 
 }  // namespace dart