During graph scheduling, traverse the roots in one go.

src/compiler/scheduler.cc

Index: src/compiler/scheduler.cc
diff --git a/src/compiler/scheduler.cc b/src/compiler/scheduler.cc
index dc497e70efba71aef6878b04549e9fb5795aaffd..d7eb50d1c51ba4d410d2b04c64779daec359d3c1 100644
--- a/src/compiler/scheduler.cc
+++ b/src/compiler/scheduler.cc
@@ -621,13 +621,12 @@ void Scheduler::ScheduleLate() {
   // Schedule: Places nodes in dominator block of all their uses.
   ScheduleLateNodeVisitor schedule_late_visitor(this);
 
-  for (NodeVectorIter i = schedule_root_nodes_.begin();
-       i != schedule_root_nodes_.end(); ++i) {
-    // TODO(mstarzinger): Make the scheduler eat less memory.
+  {
     Zone zone(zone_->isolate());

[Michael Starzinger, 2014/08/14 13:27:54]

As experimented offline: We should now be able to get by without a temporary
zone here.

     GenericGraphVisit::Visit<ScheduleLateNodeVisitor,
                              NodeInputIterationTraits<Node> >(
-        graph_, &zone, *i, &schedule_late_visitor);
+        graph_, &zone, schedule_root_nodes_.begin(), schedule_root_nodes_.end(),
+        &schedule_late_visitor);
   }
 
   // Add collected nodes for basic blocks to their blocks in the right order.