Improve memory usage in Turbofan.

src/compiler/schedule.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_SCHEDULE_H_
 #define V8_COMPILER_SCHEDULE_H_
 
 #include <vector>
 
 #include "src/v8.h"
@@ skipping 137 matching lines @@
 typedef ZoneVector<BasicBlock*> BasicBlockVector;
 typedef BasicBlockVector::iterator BasicBlockVectorIter;
 typedef BasicBlockVector::reverse_iterator BasicBlockVectorRIter;
 
 // A schedule represents the result of assigning nodes to basic blocks
 // and ordering them within basic blocks. Prior to computing a schedule,
 // a graph has no notion of control flow ordering other than that induced
 // by the graph's dependencies. A schedule is required to generate code.
 class Schedule : public GenericGraph<BasicBlock> {
  public:
-  explicit Schedule(Zone* zone)
+  explicit Schedule(Zone* zone, size_t node_count_hint = 0)
       : GenericGraph<BasicBlock>(zone),
         zone_(zone),
         all_blocks_(zone),
         nodeid_to_block_(zone),
         rpo_order_(zone) {
     SetStart(NewBasicBlock());  // entry.
     SetEnd(NewBasicBlock());    // exit.
+    nodeid_to_block_.reserve(node_count_hint);
   }
 
   // Return the block which contains {node}, if any.
   BasicBlock* block(Node* node) const {
     if (node->id() < static_cast<NodeId>(nodeid_to_block_.size())) {
       return nodeid_to_block_[node->id()];
     }
     return NULL;
   }
 
@@ skipping 121 matching lines @@
   BasicBlockVector nodeid_to_block_;      // Map from node to containing block.
   BasicBlockVector rpo_order_;            // Reverse-post-order block list.
 };
 
 OStream& operator<<(OStream& os, const Schedule& s);
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_SCHEDULE_H_