Revert of [turbofan] Finally get rid of the generic algorithm.

src/compiler/generic-algorithm.h

Index: src/compiler/generic-algorithm.h
diff --git a/src/compiler/generic-algorithm.h b/src/compiler/generic-algorithm.h
new file mode 100644
index 0000000000000000000000000000000000000000..391757ecb8beefa068b528c57240144879ef8f20
--- /dev/null
+++ b/src/compiler/generic-algorithm.h
@@ -0,0 +1,120 @@
+// 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_GENERIC_ALGORITHM_H_
+#define V8_COMPILER_GENERIC_ALGORITHM_H_
+
+#include <stack>
+#include <vector>
+
+#include "src/compiler/graph.h"
+#include "src/compiler/node.h"
+#include "src/zone-containers.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+class Graph;
+class Node;
+
+// GenericGraphVisit allows visitation of graphs of nodes and edges in pre- and
+// post-order. Visitation uses an explicitly allocated stack rather than the
+// execution stack to avoid stack overflow.
+class GenericGraphVisit {
+ public:
+  // struct Visitor {
+  //   void Pre(Node* current);
+  //   void Post(Node* current);
+  //   void PreEdge(Node* from, int index, Node* to);
+  //   void PostEdge(Node* from, int index, Node* to);
+  // }
+  template <class Visitor>
+  static void Visit(Graph* graph, Zone* zone, Node** root_begin,
+                    Node** root_end, Visitor* visitor) {
+    typedef typename Node::InputEdges::iterator Iterator;
+    typedef std::pair<Iterator, Iterator> NodeState;
+    typedef std::stack<NodeState, ZoneDeque<NodeState> > NodeStateStack;
+    NodeStateStack stack((ZoneDeque<NodeState>(zone)));
+    BoolVector visited(graph->NodeCount(), false, zone);
+    Node* current = *root_begin;
+    while (true) {
+      DCHECK(current != NULL);
+      const int id = current->id();
+      DCHECK(id >= 0);
+      DCHECK(id < graph->NodeCount());  // Must be a valid id.
+      bool visit = !GetVisited(&visited, id);
+      if (visit) {
+        visitor->Pre(current);
+        SetVisited(&visited, id);
+      }
+      Iterator begin(visit ? current->input_edges().begin()
+                           : current->input_edges().end());
+      Iterator end(current->input_edges().end());
+      stack.push(NodeState(begin, end));
+      Node* post_order_node = current;
+      while (true) {
+        NodeState top = stack.top();
+        if (top.first == top.second) {
+          if (visit) {
+            visitor->Post(post_order_node);
+            SetVisited(&visited, post_order_node->id());
+          }
+          stack.pop();
+          if (stack.empty()) {
+            if (++root_begin == root_end) return;
+            current = *root_begin;
+            break;
+          }
+          post_order_node = (*stack.top().first).from();
+          visit = true;
+        } else {
+          visitor->PreEdge((*top.first).from(), (*top.first).index(),
+                           (*top.first).to());
+          current = (*top.first).to();
+          if (!GetVisited(&visited, current->id())) break;
+        }
+        top = stack.top();
+        visitor->PostEdge((*top.first).from(), (*top.first).index(),
+                          (*top.first).to());
+        ++stack.top().first;
+      }
+    }
+  }
+
+  template <class Visitor>
+  static void Visit(Graph* graph, Zone* zone, Node* current, Visitor* visitor) {
+    Node* array[] = {current};
+    Visit<Visitor>(graph, zone, &array[0], &array[1], visitor);
+  }
+
+  struct NullNodeVisitor {
+    void Pre(Node* node) {}
+    void Post(Node* node) {}
+    void PreEdge(Node* from, int index, Node* to) {}
+    void PostEdge(Node* from, int index, Node* to) {}
+  };
+
+ private:
+  static void SetVisited(BoolVector* visited, int id) {
+    if (id >= static_cast<int>(visited->size())) {
+      // Resize and set all values to unvisited.
+      visited->resize((3 * id) / 2, false);
+    }
+    visited->at(id) = true;
+  }
+
+  static bool GetVisited(BoolVector* visited, int id) {
+    if (id >= static_cast<int>(visited->size())) return false;
+    return visited->at(id);
+  }
+};
+
+typedef GenericGraphVisit::NullNodeVisitor NullNodeVisitor;
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_GENERIC_ALGORITHM_H_