Reuse the gap move resolver.

src/lithium.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 42 matching lines @@
   void set_assigned_from(LGapNode* n) { assigned_from_.set(n); }
 
  private:
   LOperand* operand_;
   SetOncePointer<LGapNode> assigned_from_;
   bool resolved_;
   int visited_id_;
 };
 
 
-LGapResolver::LGapResolver(const ZoneList<LMoveOperands>* moves,
-                           LOperand* marker_operand)
-    : nodes_(4),
+LGapResolver::LGapResolver()
+    : nodes_(32),
       identified_cycles_(4),
-      result_(4),
-      marker_operand_(marker_operand),
+      result_(16),
       next_visited_id_(0) {
+}
+
+
+const ZoneList<LMoveOperands>* LGapResolver::Resolve(
+    const ZoneList<LMoveOperands>* moves,
+    LOperand* marker_operand) {
+  nodes_.Rewind(0);
+  identified_cycles_.Rewind(0);
+  result_.Rewind(0);
+  next_visited_id_ = 0;
+
   for (int i = 0; i < moves->length(); ++i) {
     LMoveOperands move = moves->at(i);
     if (!move.IsRedundant()) RegisterMove(move);
   }
-}
 
-
-const ZoneList<LMoveOperands>* LGapResolver::ResolveInReverseOrder() {
   for (int i = 0; i < identified_cycles_.length(); ++i) {
-    ResolveCycle(identified_cycles_[i]);
+    ResolveCycle(identified_cycles_[i], marker_operand);
   }
 
   int unresolved_nodes;
   do {
     unresolved_nodes = 0;
     for (int j = 0; j < nodes_.length(); j++) {
       LGapNode* node = nodes_[j];
       if (!node->IsResolved() && node->assigned_from()->IsResolved()) {
         AddResultMove(node->assigned_from(), node);
         node->MarkResolved();
       }
       if (!node->IsResolved()) ++unresolved_nodes;
     }
   } while (unresolved_nodes > 0);
   return &result_;
 }
 
 
 void LGapResolver::AddResultMove(LGapNode* from, LGapNode* to) {
   AddResultMove(from->operand(), to->operand());
 }
 
 
 void LGapResolver::AddResultMove(LOperand* from, LOperand* to) {
   result_.Add(LMoveOperands(from, to));
 }
 
 
-void LGapResolver::ResolveCycle(LGapNode* start) {
-  ZoneList<LOperand*> circle_operands(8);
-  circle_operands.Add(marker_operand_);
+void LGapResolver::ResolveCycle(LGapNode* start, LOperand* marker_operand) {
+  ZoneList<LOperand*> cycle_operands(8);
+  cycle_operands.Add(marker_operand);
   LGapNode* cur = start;
   do {
     cur->MarkResolved();
-    circle_operands.Add(cur->operand());
+    cycle_operands.Add(cur->operand());
     cur = cur->assigned_from();
   } while (cur != start);
-  circle_operands.Add(marker_operand_);
+  cycle_operands.Add(marker_operand);
 
-  for (int i = circle_operands.length() - 1; i > 0; --i) {
-    LOperand* from = circle_operands[i];
-    LOperand* to = circle_operands[i - 1];
+  for (int i = cycle_operands.length() - 1; i > 0; --i) {
+    LOperand* from = cycle_operands[i];
+    LOperand* to = cycle_operands[i - 1];
     AddResultMove(from, to);
   }
 }
 
 
 bool LGapResolver::CanReach(LGapNode* a, LGapNode* b, int visited_id) {
   ASSERT(a != b);
   LGapNode* cur = a;
   while (cur != b && cur->visited_id() != visited_id && cur->IsAssigned()) {
     cur->set_visited_id(visited_id);
@@ skipping 17 matching lines @@
     AddResultMove(move.from(), move.to());
   } else {
     LGapNode* from = LookupNode(move.from());
     LGapNode* to = LookupNode(move.to());
     if (to->IsAssigned() && to->assigned_from() == from) {
       move.Eliminate();
       return;
     }
     ASSERT(!to->IsAssigned());
     if (CanReach(from, to)) {
-      // This introduces a circle. Save.
+      // This introduces a cycle. Save.
       identified_cycles_.Add(from);
     }
     to->set_assigned_from(from);
   }
 }
 
 
 LGapNode* LGapResolver::LookupNode(LOperand* operand) {
   for (int i = 0; i < nodes_.length(); ++i) {
     if (nodes_[i]->operand()->Equals(operand)) return nodes_[i];
@@ skipping 26 matching lines @@
         stream->Add(" = ");
         from->PrintTo(stream);
       }
       stream->Add("; ");
     }
   }
 }
 
 
 } }  // namespace v8::internal