Import LLVM, at r72732.vendor/llvm/llvm-r72732

1 files changed, 232 insertions, 0 deletions

diff --git a/include/llvm/ADT/DepthFirstIterator.h b/include/llvm/ADT/DepthFirstIterator.h
new file mode 100644
index 000000000000..517768f402df
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+++ b/include/llvm/ADT/DepthFirstIterator.h
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+//===- llvm/ADT/DepthFirstIterator.h - Depth First iterator -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file builds on the ADT/GraphTraits.h file to build generic depth
+// first graph iterator.  This file exposes the following functions/types:
+//
+// df_begin/df_end/df_iterator
+//   * Normal depth-first iteration - visit a node and then all of its children.
+//
+// idf_begin/idf_end/idf_iterator
+//   * Depth-first iteration on the 'inverse' graph.
+//
+// df_ext_begin/df_ext_end/df_ext_iterator
+//   * Normal depth-first iteration - visit a node and then all of its children.
+//     This iterator stores the 'visited' set in an external set, which allows
+//     it to be more efficient, and allows external clients to use the set for
+//     other purposes.
+//
+// idf_ext_begin/idf_ext_end/idf_ext_iterator
+//   * Depth-first iteration on the 'inverse' graph.
+//     This iterator stores the 'visited' set in an external set, which allows
+//     it to be more efficient, and allows external clients to use the set for
+//     other purposes.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_DEPTHFIRSTITERATOR_H
+#define LLVM_ADT_DEPTHFIRSTITERATOR_H
+
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include <set>
+#include <vector>
+
+namespace llvm {
+
+// df_iterator_storage - A private class which is used to figure out where to
+// store the visited set.
+template<class SetType, bool External>   // Non-external set
+class df_iterator_storage {
+public:
+  SetType Visited;
+};
+
+template<class SetType>
+class df_iterator_storage<SetType, true> {
+public:
+  df_iterator_storage(SetType &VSet) : Visited(VSet) {}
+  df_iterator_storage(const df_iterator_storage &S) : Visited(S.Visited) {}
+  SetType &Visited;
+};
+
+
+// Generic Depth First Iterator
+template<class GraphT,
+class SetType = llvm::SmallPtrSet<typename GraphTraits<GraphT>::NodeType*, 8>,
+         bool ExtStorage = false, class GT = GraphTraits<GraphT> >
+class df_iterator : public forward_iterator<typename GT::NodeType, ptrdiff_t>,
+                    public df_iterator_storage<SetType, ExtStorage> {
+  typedef forward_iterator<typename GT::NodeType, ptrdiff_t> super;
+
+  typedef typename GT::NodeType          NodeType;
+  typedef typename GT::ChildIteratorType ChildItTy;
+
+  // VisitStack - Used to maintain the ordering.  Top = current block
+  // First element is node pointer, second is the 'next child' to visit
+  std::vector<std::pair<NodeType *, ChildItTy> > VisitStack;
+private:
+  inline df_iterator(NodeType *Node) {
+    this->Visited.insert(Node);
+    VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node)));
+  }
+  inline df_iterator() { /* End is when stack is empty */ }
+
+  inline df_iterator(NodeType *Node, SetType &S)
+    : df_iterator_storage<SetType, ExtStorage>(S) {
+    if (!S.count(Node)) {
+      this->Visited.insert(Node);
+      VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node)));
+    }
+  }
+  inline df_iterator(SetType &S)
+    : df_iterator_storage<SetType, ExtStorage>(S) {
+    // End is when stack is empty
+  }
+
+public:
+  typedef typename super::pointer pointer;
+  typedef df_iterator<GraphT, SetType, ExtStorage, GT> _Self;
+
+  // Provide static begin and end methods as our public "constructors"
+  static inline _Self begin(const GraphT& G) {
+    return _Self(GT::getEntryNode(G));
+  }
+  static inline _Self end(const GraphT& G) { return _Self(); }
+
+  // Static begin and end methods as our public ctors for external iterators
+  static inline _Self begin(const GraphT& G, SetType &S) {
+    return _Self(GT::getEntryNode(G), S);
+  }
+  static inline _Self end(const GraphT& G, SetType &S) { return _Self(S); }
+
+  inline bool operator==(const _Self& x) const {
+    return VisitStack.size() == x.VisitStack.size() &&
+           VisitStack == x.VisitStack;
+  }
+  inline bool operator!=(const _Self& x) const { return !operator==(x); }
+
+  inline pointer operator*() const {
+    return VisitStack.back().first;
+  }
+
+  // This is a nonstandard operator-> that dereferences the pointer an extra
+  // time... so that you can actually call methods ON the Node, because
+  // the contained type is a pointer.  This allows BBIt->getTerminator() f.e.
+  //
+  inline NodeType *operator->() const { return operator*(); }
+
+  inline _Self& operator++() {   // Preincrement
+    do {
+      std::pair<NodeType *, ChildItTy> &Top = VisitStack.back();
+      NodeType *Node = Top.first;
+      ChildItTy &It  = Top.second;
+
+      while (It != GT::child_end(Node)) {
+        NodeType *Next = *It++;
+        if (!this->Visited.count(Next)) {  // Has our next sibling been visited?
+          // No, do it now.
+          this->Visited.insert(Next);
+          VisitStack.push_back(std::make_pair(Next, GT::child_begin(Next)));
+          return *this;
+        }
+      }
+
+      // Oops, ran out of successors... go up a level on the stack.
+      VisitStack.pop_back();
+    } while (!VisitStack.empty());
+    return *this;
+  }
+
+  inline _Self operator++(int) { // Postincrement
+    _Self tmp = *this; ++*this; return tmp;
+  }
+
+  // nodeVisited - return true if this iterator has already visited the
+  // specified node.  This is public, and will probably be used to iterate over
+  // nodes that a depth first iteration did not find: ie unreachable nodes.
+  //
+  inline bool nodeVisited(NodeType *Node) const {
+    return this->Visited.count(Node) != 0;
+  }
+};
+
+
+// Provide global constructors that automatically figure out correct types...
+//
+template <class T>
+df_iterator<T> df_begin(const T& G) {
+  return df_iterator<T>::begin(G);
+}
+
+template <class T>
+df_iterator<T> df_end(const T& G) {
+  return df_iterator<T>::end(G);
+}
+
+// Provide global definitions of external depth first iterators...
+template <class T, class SetTy = std::set<typename GraphTraits<T>::NodeType*> >
+struct df_ext_iterator : public df_iterator<T, SetTy, true> {
+  df_ext_iterator(const df_iterator<T, SetTy, true> &V)
+    : df_iterator<T, SetTy, true>(V) {}
+};
+
+template <class T, class SetTy>
+df_ext_iterator<T, SetTy> df_ext_begin(const T& G, SetTy &S) {
+  return df_ext_iterator<T, SetTy>::begin(G, S);
+}
+
+template <class T, class SetTy>
+df_ext_iterator<T, SetTy> df_ext_end(const T& G, SetTy &S) {
+  return df_ext_iterator<T, SetTy>::end(G, S);
+}
+
+
+// Provide global definitions of inverse depth first iterators...
+template <class T,
+  class SetTy = llvm::SmallPtrSet<typename GraphTraits<T>::NodeType*, 8>,
+          bool External = false>
+struct idf_iterator : public df_iterator<Inverse<T>, SetTy, External> {
+  idf_iterator(const df_iterator<Inverse<T>, SetTy, External> &V)
+    : df_iterator<Inverse<T>, SetTy, External>(V) {}
+};
+
+template <class T>
+idf_iterator<T> idf_begin(const T& G) {
+  return idf_iterator<T>::begin(Inverse<T>(G));
+}
+
+template <class T>
+idf_iterator<T> idf_end(const T& G){
+  return idf_iterator<T>::end(Inverse<T>(G));
+}
+
+// Provide global definitions of external inverse depth first iterators...
+template <class T, class SetTy = std::set<typename GraphTraits<T>::NodeType*> >
+struct idf_ext_iterator : public idf_iterator<T, SetTy, true> {
+  idf_ext_iterator(const idf_iterator<T, SetTy, true> &V)
+    : idf_iterator<T, SetTy, true>(V) {}
+  idf_ext_iterator(const df_iterator<Inverse<T>, SetTy, true> &V)
+    : idf_iterator<T, SetTy, true>(V) {}
+};
+
+template <class T, class SetTy>
+idf_ext_iterator<T, SetTy> idf_ext_begin(const T& G, SetTy &S) {
+  return idf_ext_iterator<T, SetTy>::begin(Inverse<T>(G), S);
+}
+
+template <class T, class SetTy>
+idf_ext_iterator<T, SetTy> idf_ext_end(const T& G, SetTy &S) {
+  return idf_ext_iterator<T, SetTy>::end(Inverse<T>(G), S);
+}
+
+} // End llvm namespace
+
+#endif