[llvm-commits] [llvm] r109089 - in /llvm/trunk: docs/ include/llvm/ include/llvm/Analysis/ include/llvm/Support/ lib/Analysis/ test/Analysis/RegionInfo/

Evan Cheng evan.cheng at apple.com
Tue Jul 27 00:24:13 PDT 2010


Any chance you could templatify this so someone can add a MachineRegionInfo later? It would be useful for region based register allocation, etc.  

Thanks,

Evan

On Jul 22, 2010, at 12:46 AM, Tobias Grosser <grosser at fim.uni-passau.de> wrote:

> Author: grosser
> Date: Thu Jul 22 02:46:31 2010
> New Revision: 109089
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=109089&view=rev
> Log:
> Add new RegionInfo pass.
> 
> The RegionInfo pass detects single entry single exit regions in a function,
> where a region is defined as any subgraph that is connected to the remaining
> graph at only two spots.
> Furthermore an hierarchical region tree is built.
> Use it by calling "opt -regions analyze" or "opt -view-regions".
> 
> Added:
>    llvm/trunk/include/llvm/Analysis/RegionInfo.h
>    llvm/trunk/include/llvm/Analysis/RegionIterator.h
>    llvm/trunk/include/llvm/Analysis/RegionPrinter.h
>    llvm/trunk/lib/Analysis/RegionInfo.cpp
>    llvm/trunk/lib/Analysis/RegionPrinter.cpp
>    llvm/trunk/test/Analysis/RegionInfo/
>    llvm/trunk/test/Analysis/RegionInfo/block_sort.ll
>    llvm/trunk/test/Analysis/RegionInfo/cond_loop.ll
>    llvm/trunk/test/Analysis/RegionInfo/condition_complicated.ll
>    llvm/trunk/test/Analysis/RegionInfo/condition_complicated_2.ll
>    llvm/trunk/test/Analysis/RegionInfo/condition_forward_edge.ll
>    llvm/trunk/test/Analysis/RegionInfo/condition_same_exit.ll
>    llvm/trunk/test/Analysis/RegionInfo/condition_simple.ll
>    llvm/trunk/test/Analysis/RegionInfo/dg.exp
>    llvm/trunk/test/Analysis/RegionInfo/exit_in_condition.ll
>    llvm/trunk/test/Analysis/RegionInfo/infinite_loop.ll
>    llvm/trunk/test/Analysis/RegionInfo/infinite_loop_2.ll
>    llvm/trunk/test/Analysis/RegionInfo/infinite_loop_3.ll
>    llvm/trunk/test/Analysis/RegionInfo/infinite_loop_4.ll
>    llvm/trunk/test/Analysis/RegionInfo/loop_with_condition.ll
>    llvm/trunk/test/Analysis/RegionInfo/loops_1.ll
>    llvm/trunk/test/Analysis/RegionInfo/loops_2.ll
>    llvm/trunk/test/Analysis/RegionInfo/mix_1.ll
>    llvm/trunk/test/Analysis/RegionInfo/multiple_exiting_edge.ll
>    llvm/trunk/test/Analysis/RegionInfo/nested_loops.ll
>    llvm/trunk/test/Analysis/RegionInfo/next.ll
>    llvm/trunk/test/Analysis/RegionInfo/paper.ll
>    llvm/trunk/test/Analysis/RegionInfo/two_loops_same_header.ll
> Modified:
>    llvm/trunk/docs/Passes.html
>    llvm/trunk/include/llvm/Analysis/Passes.h
>    llvm/trunk/include/llvm/LinkAllPasses.h
>    llvm/trunk/include/llvm/Support/GraphWriter.h
>    llvm/trunk/lib/Analysis/CMakeLists.txt
> 
> Modified: llvm/trunk/docs/Passes.html
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/Passes.html?rev=109089&r1=109088&r2=109089&view=diff
> ==============================================================================
> --- llvm/trunk/docs/Passes.html (original)
> +++ llvm/trunk/docs/Passes.html Thu Jul 22 02:46:31 2010
> @@ -120,6 +120,7 @@
> <tr><td><a href="#print-used-types">-print-used-types</a></td><td>Find Used Types</td></tr>
> <tr><td><a href="#profile-estimator">-profile-estimator</a></td><td>Estimate profiling information</td></tr>
> <tr><td><a href="#profile-loader">-profile-loader</a></td><td>Load profile information from llvmprof.out</td></tr>
> +<tr><td><a href="#regions">-regions</a></td><td>Detect single entry single exit regions in a function</td></tr>
> <tr><td><a href="#profile-verifier">-profile-verifier</a></td><td>Verify profiling information</td></tr>
> <tr><td><a href="#scalar-evolution">-scalar-evolution</a></td><td>Scalar Evolution Analysis</td></tr>
> <tr><td><a href="#scev-aa">-scev-aa</a></td><td>ScalarEvolution-based Alias Analysis</td></tr>
> @@ -771,6 +772,17 @@
> <div class="doc_text">
>   <p>Pass that checks profiling information for plausibility.</p>
> </div>
> +<div class="doc_subsection">
> +  <a name="regions">-regions: Detect single entry single exit regions in a function</a>
> +</div>
> +<div class="doc_text">
> +  <p>
> +  The <code>RegionInfo</code> pass detects single entry single exit regions in a
> +  function, where a region is defined as any subgraph that is connected to the
> +  remaining graph at only two spots. Furthermore, an hierarchical region tree is
> +  built.
> +  </p>
> +</div>
> 
> <!-------------------------------------------------------------------------- -->
> <div class="doc_subsection">
> 
> Modified: llvm/trunk/include/llvm/Analysis/Passes.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/Passes.h?rev=109089&r1=109088&r2=109089&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/Analysis/Passes.h (original)
> +++ llvm/trunk/include/llvm/Analysis/Passes.h Thu Jul 22 02:46:31 2010
> @@ -154,6 +154,13 @@
>   // print debug info intrinsics in human readable form
>   FunctionPass *createDbgInfoPrinterPass();
> 
> +  //===--------------------------------------------------------------------===//
> +  //
> +  // createRegionInfoPass - This pass finds all single entry single exit regions
> +  // in a function and builds the region hierarchy.
> +  //
> +  FunctionPass *createRegionInfoPass();
> +
>   // Print module-level debug info metadata in human-readable form.
>   ModulePass *createModuleDebugInfoPrinterPass();
> }
> 
> Added: llvm/trunk/include/llvm/Analysis/RegionInfo.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/RegionInfo.h?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/include/llvm/Analysis/RegionInfo.h (added)
> +++ llvm/trunk/include/llvm/Analysis/RegionInfo.h Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,601 @@
> +//===- RegionInfo.h - SESE region analysis ----------------------*- C++ -*-===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +//
> +// Calculate a program structure tree built out of single entry single exit
> +// regions.
> +// The basic ideas are taken from "The Program Structure Tree - Richard Johnson,
> +// David Pearson, Keshav Pingali - 1994", however enriched with ideas from "The
> +// Refined Process Structure Tree - Jussi Vanhatalo, Hagen Voelyer, Jana
> +// Koehler - 2009".
> +// The algorithm to calculate these data structures however is completely
> +// different, as it takes advantage of existing information already available
> +// in (Post)dominace tree and dominance frontier passes. This leads to a simpler
> +// and in practice hopefully better performing algorithm. The runtime of the
> +// algorithms described in the papers above are both linear in graph size,
> +// O(V+E), whereas this algorithm is not, as the dominance frontier information
> +// itself is not, but in practice runtime seems to be in the order of magnitude
> +// of dominance tree calculation.
> +//
> +//===----------------------------------------------------------------------===//
> +
> +#ifndef LLVM_ANALYSIS_REGION_INFO_H
> +#define LLVM_ANALYSIS_REGION_INFO_H
> +
> +#include "llvm/ADT/PointerIntPair.h"
> +#include "llvm/Analysis/Dominators.h"
> +#include "llvm/Analysis/PostDominators.h"
> +#include "llvm/Support/Allocator.h"
> +
> +namespace llvm {
> +
> +class Region;
> +class RegionInfo;
> +class raw_ostream;
> +
> +/// @brief Marker class to iterate over the elements of a Region in flat mode.
> +///
> +/// The class is used to either iterate in Flat mode or by not using it to not
> +/// iterate in Flat mode.  During a Flat mode iteration all Regions are entered
> +/// and the iteration returns every BasicBlock.  If the Flat mode is not
> +/// selected for SubRegions just one RegionNode containing the subregion is
> +/// returned.
> +template <class GraphType>
> +class FlatIt {};
> +
> +/// @brief A RegionNode represents a subregion or a BasicBlock that is part of a
> +/// Region.
> +class RegionNode {
> +  // DO NOT IMPLEMENT
> +  RegionNode(const RegionNode &);
> +  // DO NOT IMPLEMENT
> +  const RegionNode &operator=(const RegionNode &);
> +
> +  /// This is the entry basic block that starts this region node.  If this is a
> +  /// BasicBlock RegionNode, then entry is just the basic block, that this
> +  /// RegionNode represents.  Otherwise it is the entry of this (Sub)RegionNode.
> +  ///
> +  /// In the BBtoRegionNode map of the parent of this node, BB will always map
> +  /// to this node no matter which kind of node this one is.
> +  ///
> +  /// The node can hold either a Region or a BasicBlock.
> +  /// Use one bit to save, if this RegionNode is a subregion or BasicBlock
> +  /// RegionNode.
> +  PointerIntPair<BasicBlock*, 1, bool> entry;
> +
> +protected:
> +  /// @brief The parent Region of this RegionNode.
> +  /// @see getParent()
> +  Region* parent;
> +
> +public:
> +  /// @brief Create a RegionNode.
> +  ///
> +  /// @param Parent      The parent of this RegionNode.
> +  /// @param Entry       The entry BasicBlock of the RegionNode.  If this
> +  ///                    RegionNode represents a BasicBlock, this is the
> +  ///                    BasicBlock itself.  If it represents a subregion, this
> +  ///                    is the entry BasicBlock of the subregion.
> +  /// @param isSubRegion If this RegionNode represents a SubRegion.
> +  inline RegionNode(Region* Parent, BasicBlock* Entry, bool isSubRegion = 0)
> +    : entry(Entry, isSubRegion), parent(Parent) {}
> +
> +  /// @brief Get the parent Region of this RegionNode.
> +  ///
> +  /// The parent Region is the Region this RegionNode belongs to. If for
> +  /// example a BasicBlock is element of two Regions, there exist two
> +  /// RegionNodes for this BasicBlock. Each with the getParent() function
> +  /// pointing to the Region this RegionNode belongs to.
> +  ///
> +  /// @return Get the parent Region of this RegionNode.
> +  inline Region* getParent() const { return parent; }
> +
> +  /// @brief Get the entry BasicBlock of this RegionNode.
> +  ///
> +  /// If this RegionNode represents a BasicBlock this is just the BasicBlock
> +  /// itself, otherwise we return the entry BasicBlock of the Subregion
> +  ///
> +  /// @return The entry BasicBlock of this RegionNode.
> +  inline BasicBlock* getEntry() const { return entry.getPointer(); }
> +
> +  /// @brief Get the content of this RegionNode.
> +  ///
> +  /// This can be either a BasicBlock or a subregion. Before calling getNodeAs()
> +  /// check the type of the content with the isSubRegion() function call.
> +  ///
> +  /// @return The content of this RegionNode.
> +  template<class T>
> +  inline T* getNodeAs() const;
> +
> +  /// @brief Is this RegionNode a subregion?
> +  ///
> +  /// @return True if it contains a subregion. False if it contains a
> +  ///         BasicBlock.
> +  inline bool isSubRegion() const {
> +    return entry.getInt();
> +  }
> +};
> +
> +/// Print a RegionNode.
> +inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node);
> +
> +template<>
> +inline BasicBlock* RegionNode::getNodeAs<BasicBlock>() const {
> +  assert(!isSubRegion() && "This is not a BasicBlock RegionNode!");
> +  return getEntry();
> +}
> +
> +template<>
> +inline Region* RegionNode::getNodeAs<Region>() const {
> +  assert(isSubRegion() && "This is not a subregion RegionNode!");
> +  return reinterpret_cast<Region*>(const_cast<RegionNode*>(this));
> +}
> +
> +//===----------------------------------------------------------------------===//
> +/// @brief A single entry single exit Region.
> +///
> +/// A Region is a connected subgraph of a control flow graph that has exactly
> +/// two connections to the remaining graph. It can be used to analyze or
> +/// optimize parts of the control flow graph.
> +///
> +/// A <em> simple Region </em> is connected to the remaing graph by just two
> +/// edges. One edge entering the Region and another one leaving the Region.
> +///
> +/// An <em> extended Region </em> (or just Region) is a subgraph that can be
> +/// transform into a simple Region. The transformation is done by adding
> +/// BasicBlocks that merge several entry or exit edges so that after the merge
> +/// just one entry and one exit edge exists.
> +///
> +/// The \e Entry of a Region is the first BasicBlock that is passed after
> +/// entering the Region. It is an element of the Region. The entry BasicBlock
> +/// dominates all BasicBlocks in the Region.
> +///
> +/// The \e Exit of a Region is the first BasicBlock that is passed after
> +/// leaving the Region. It is not an element of the Region. The exit BasicBlock,
> +/// postdominates all BasicBlocks in the Region.
> +///
> +/// A <em> canonical Region </em> cannot be constructed by combining smaller
> +/// Regions.
> +///
> +/// Region A is the \e parent of Region B, if B is completely contained in A.
> +///
> +/// Two canonical Regions either do not intersect at all or one is
> +/// the parent of the other.
> +///
> +/// The <em> Program Structure Tree</em> is a graph (V, E) where V is the set of
> +/// Regions in the control flow graph and E is the \e parent relation of these
> +/// Regions.
> +///
> +/// Example:
> +///
> +/// \verbatim
> +/// A simple control flow graph, that contains two regions.
> +///
> +///        1
> +///       / |
> +///      2   |
> +///     / \   3
> +///    4   5  |
> +///    |   |  |
> +///    6   7  8
> +///     \  | /
> +///      \ |/       Region A: 1 -> 9 {1,2,3,4,5,6,7,8}
> +///        9        Region B: 2 -> 9 {2,4,5,6,7}
> +/// \endverbatim
> +///
> +/// You can obtain more examples by either calling
> +///
> +/// <tt> "opt -regions -analyze anyprogram.ll" </tt>
> +/// or
> +/// <tt> "opt -view-regions-only anyprogram.ll" </tt>
> +///
> +/// on any LLVM file you are interested in.
> +///
> +/// The first call returns a textual representation of the program structure
> +/// tree, the second one creates a graphical representation using graphviz.
> +class Region : public RegionNode {
> +  friend class RegionInfo;
> +  // DO NOT IMPLEMENT
> +  Region(const Region &);
> +  // DO NOT IMPLEMENT
> +  const Region &operator=(const Region &);
> +
> +  // Information necessary to manage this Region.
> +  RegionInfo* RI;
> +  DominatorTree *DT;
> +
> +  // The exit BasicBlock of this region.
> +  // (The entry BasicBlock is part of RegionNode)
> +  BasicBlock *exit;
> +
> +  typedef std::vector<Region*> RegionSet;
> +
> +  // The subregions of this region.
> +  RegionSet children;
> +
> +  typedef std::map<BasicBlock*, RegionNode*> BBNodeMapT;
> +
> +  // Save the BasicBlock RegionNodes that are element of this Region.
> +  mutable BBNodeMapT BBNodeMap;
> +
> +  /// verifyBBInRegion - Check if a BB is in this Region. This check also works
> +  /// if the region is incorrectly built. (EXPENSIVE!)
> +  void verifyBBInRegion(BasicBlock* BB) const;
> +
> +  /// verifyWalk - Walk over all the BBs of the region starting from BB and
> +  /// verify that all reachable basic blocks are elements of the region.
> +  /// (EXPENSIVE!)
> +  void verifyWalk(BasicBlock* BB, std::set<BasicBlock*>* visitedBB) const;
> +
> +  /// verifyRegionNest - Verify if the region and its children are valid
> +  /// regions (EXPENSIVE!)
> +  void verifyRegionNest() const;
> +
> +public:
> +  /// @brief Create a new region.
> +  ///
> +  /// @param Entry  The entry basic block of the region.
> +  /// @param Exit   The exit basic block of the region.
> +  /// @param RI     The region info object that is managing this region.
> +  /// @param DT     The dominator tree of the current function.
> +  /// @param Parent The surrounding region or NULL if this is a top level
> +  ///               region.
> +  Region(BasicBlock *Entry, BasicBlock *Exit, RegionInfo* RI,
> +         DominatorTree *DT, Region *Parent = 0);
> +
> +  /// Delete the Region and all its subregions.
> +  ~Region();
> +
> +  /// @brief Get the entry BasicBlock of the Region.
> +  /// @return The entry BasicBlock of the region.
> +  BasicBlock *getEntry() const { return RegionNode::getEntry(); }
> +
> +  /// @brief Get the exit BasicBlock of the Region.
> +  /// @return The exit BasicBlock of the Region, NULL if this is the TopLevel
> +  ///         Region.
> +  BasicBlock *getExit() const { return exit; }
> +
> +  /// @brief Get the parent of the Region.
> +  /// @return The parent of the Region or NULL if this is a top level
> +  ///         Region.
> +  Region *getParent() const { return RegionNode::getParent(); }
> +
> +  /// @brief Get the RegionNode representing the current Region.
> +  /// @return The RegionNode representing the current Region.
> +  RegionNode* getNode() const {
> +    return const_cast<RegionNode*>(reinterpret_cast<const RegionNode*>(this));
> +  }
> +
> +  /// @brief Get the nesting level of this Region.
> +  ///
> +  /// An toplevel Region has depth 0.
> +  ///
> +  /// @return The depth of the region.
> +  unsigned getDepth() const;
> +
> +  /// @brief Is this a simple region?
> +  ///
> +  /// A region is simple if it has exactly one exit and one entry edge.
> +  ///
> +  /// @return True if the Region is simple.
> +  bool isSimple() const;
> +
> +  /// @brief Returns the name of the Region.
> +  /// @return The Name of the Region.
> +  std::string getNameStr() const {
> +    std::string exitName;
> +
> +    if (getExit())
> +      exitName = getExit()->getNameStr();
> +    else
> +      exitName = "<Function Return>";
> +
> +    return getEntry()->getNameStr() + " => " + exitName;
> +  }
> +
> +  /// @brief Return the RegionInfo object, that belongs to this Region.
> +  RegionInfo *getRegionInfo() const {
> +    return RI;
> +  }
> +
> +  /// @brief Print the region.
> +  ///
> +  /// @param OS The output stream the Region is printed to.
> +  /// @param printTree Print also the tree of subregions.
> +  /// @param level The indentation level used for printing.
> +  void print(raw_ostream& OS, bool printTree = true, unsigned level = 0) const;
> +
> +  /// @brief Print the region to stderr.
> +  void dump() const;
> +
> +  /// @brief Check if the region contains a BasicBlock.
> +  ///
> +  /// @param BB The BasicBlock that might be contained in this Region.
> +  /// @return True if the block is contained in the region otherwise false.
> +  bool contains(const BasicBlock *BB) const;
> +
> +  /// @brief Check if the region contains another region.
> +  ///
> +  /// @param SubRegion The region that might be contained in this Region.
> +  /// @return True if SubRegion is contained in the region otherwise false.
> +  bool contains(const Region *SubRegion) const {
> +    // Toplevel Region.
> +    if (!getExit())
> +      return true;
> +
> +    return contains(SubRegion->getEntry())
> +      && (contains(SubRegion->getExit()) || SubRegion->getExit() == getExit());
> +  }
> +
> +  /// @brief Check if the region contains an Instruction.
> +  ///
> +  /// @param Inst The Instruction that might be contained in this region.
> +  /// @return True if the Instruction is contained in the region otherwise false.
> +  bool contains(const Instruction *Inst) const {
> +    return contains(Inst->getParent());
> +  }
> +
> +  /// @brief Get the subregion that starts at a BasicBlock
> +  ///
> +  /// @param BB The BasicBlock the subregion should start.
> +  /// @return The Subregion if available, otherwise NULL.
> +  Region* getSubRegionNode(BasicBlock *BB) const;
> +
> +  /// @brief Get the RegionNode for a BasicBlock
> +  ///
> +  /// @param BB The BasicBlock at which the RegionNode should start.
> +  /// @return If available, the RegionNode that represents the subregion
> +  ///         starting at BB. If no subregion starts at BB, the RegionNode
> +  ///         representing BB.
> +  RegionNode* getNode(BasicBlock *BB) const;
> +
> +  /// @brief Get the BasicBlock RegionNode for a BasicBlock
> +  ///
> +  /// @param BB The BasicBlock for which the RegionNode is requested.
> +  /// @return The RegionNode representing the BB.
> +  RegionNode* getBBNode(BasicBlock *BB) const;
> +
> +  /// @brief Add a new subregion to this Region.
> +  ///
> +  /// @param SubRegion The new subregion that will be added.
> +  void addSubRegion(Region *SubRegion);
> +
> +  /// @brief Remove a subregion from this Region.
> +  ///
> +  /// The subregion is not deleted, as it will probably be inserted into another
> +  /// region.
> +  /// @param SubRegion The SubRegion that will be removed.
> +  Region *removeSubRegion(Region *SubRegion);
> +
> +  /// @brief Move all direct child nodes of this Region to another Region.
> +  ///
> +  /// @param To The Region the child nodes will be transfered to.
> +  void transferChildrenTo(Region *To);
> +
> +  /// @brief Verify if the region is a correct region.
> +  ///
> +  /// Check if this is a correctly build Region. This is an expensive check, as
> +  /// the complete CFG of the Region will be walked.
> +  void verifyRegion() const;
> +
> +  /// @brief Clear the cache for BB RegionNodes.
> +  ///
> +  /// After calling this function the BasicBlock RegionNodes will be stored at
> +  /// different memory locations. RegionNodes obtained before this function is
> +  /// called are therefore not comparable to RegionNodes abtained afterwords.
> +  void clearNodeCache();
> +
> +  /// @name Subregion Iterators
> +  ///
> +  /// These iterators iterator over all subregions of this Region.
> +  //@{
> +  typedef RegionSet::iterator iterator;
> +  typedef RegionSet::const_iterator const_iterator;
> +
> +  iterator begin() { return children.begin(); }
> +  iterator end() { return children.end(); }
> +
> +  const_iterator begin() const { return children.begin(); }
> +  const_iterator end() const { return children.end(); }
> +  //@}
> +
> +  /// @name BasicBlock Iterators
> +  ///
> +  /// These iterators iterate over all BasicBlock RegionNodes that are
> +  /// contained in this Region. The iterator also iterates over BasicBlocks
> +  /// that are elements of a subregion of this Region. It is therefore called a
> +  /// flat iterator.
> +  //@{
> +  typedef df_iterator<RegionNode*, SmallPtrSet<RegionNode*, 8>, false,
> +                      GraphTraits<FlatIt<RegionNode*> > > block_iterator;
> +
> +  typedef df_iterator<const RegionNode*, SmallPtrSet<const RegionNode*, 8>,
> +                      false, GraphTraits<FlatIt<const RegionNode*> > >
> +            const_block_iterator;
> +
> +  block_iterator block_begin();
> +  block_iterator block_end();
> +
> +  const_block_iterator block_begin() const;
> +  const_block_iterator block_end() const;
> +  //@}
> +
> +  /// @name Element Iterators
> +  ///
> +  /// These iterators iterate over all BasicBlock and subregion RegionNodes that
> +  /// are direct children of this Region. It does not iterate over any
> +  /// RegionNodes that are also element of a subregion of this Region.
> +  //@{
> +  typedef df_iterator<RegionNode*, SmallPtrSet<RegionNode*, 8>, false,
> +                      GraphTraits<RegionNode*> > element_iterator;
> +
> +  typedef df_iterator<const RegionNode*, SmallPtrSet<const RegionNode*, 8>,
> +                      false, GraphTraits<const RegionNode*> >
> +            const_element_iterator;
> +
> +  element_iterator element_begin();
> +  element_iterator element_end();
> +
> +  const_element_iterator element_begin() const;
> +  const_element_iterator element_end() const;
> +  //@}
> +};
> +
> +//===----------------------------------------------------------------------===//
> +/// @brief Analysis that detects all canonical Regions.
> +///
> +/// The RegionInfo pass detects all canonical regions in a function. The Regions
> +/// are connected using the parent relation. This builds a Program Structure
> +/// Tree.
> +class RegionInfo : public FunctionPass {
> +  typedef DenseMap<BasicBlock*,BasicBlock*> BBtoBBMap;
> +  typedef DenseMap<BasicBlock*, Region*> BBtoRegionMap;
> +  typedef SmallPtrSet<Region*, 4> RegionSet;
> +
> +  // DO NOT IMPLEMENT
> +  RegionInfo(const RegionInfo &);
> +  // DO NOT IMPLEMENT
> +  const RegionInfo &operator=(const RegionInfo &);
> +
> +  DominatorTree *DT;
> +  PostDominatorTree *PDT;
> +  DominanceFrontier *DF;
> +
> +  /// The top level region.
> +  Region *TopLevelRegion;
> +
> +  /// Map every BB to the smallest region, that contains BB.
> +  BBtoRegionMap BBtoRegion;
> +
> +  // isCommonDomFrontier - Returns true if BB is in the dominance frontier of
> +  // entry, because it was inherited from exit. In the other case there is an
> +  // edge going from entry to BB without passing exit.
> +  bool isCommonDomFrontier(BasicBlock* BB, BasicBlock* entry,
> +                           BasicBlock* exit) const;
> +
> +  // isRegion - Check if entry and exit surround a valid region, based on
> +  // dominance tree and dominance frontier.
> +  bool isRegion(BasicBlock* entry, BasicBlock* exit) const;
> +
> +  // insertShortCut - Saves a shortcut pointing from entry to exit.
> +  // This function may extend this shortcut if possible.
> +  void insertShortCut(BasicBlock* entry, BasicBlock* exit,
> +                      BBtoBBMap* ShortCut) const;
> +
> +  // getNextPostDom - Returns the next BB that postdominates N, while skipping
> +  // all post dominators that cannot finish a canonical region.
> +  DomTreeNode *getNextPostDom(DomTreeNode* N, BBtoBBMap *ShortCut) const;
> +
> +  // isTrivialRegion - A region is trivial, if it contains only one BB.
> +  bool isTrivialRegion(BasicBlock *entry, BasicBlock *exit) const;
> +
> +  // createRegion - Creates a single entry single exit region.
> +  Region *createRegion(BasicBlock *entry, BasicBlock *exit);
> +
> +  // findRegionsWithEntry - Detect all regions starting with bb 'entry'.
> +  void findRegionsWithEntry(BasicBlock *entry, BBtoBBMap *ShortCut);
> +
> +  // scanForRegions - Detects regions in F.
> +  void scanForRegions(Function &F, BBtoBBMap *ShortCut);
> +
> +  // getTopMostParent - Get the top most parent with the same entry block.
> +  Region *getTopMostParent(Region *region);
> +
> +  // buildRegionsTree - build the region hierarchy after all region detected.
> +  void buildRegionsTree(DomTreeNode *N, Region *region);
> +
> +  // Calculate - detecte all regions in function and build the region tree.
> +  void Calculate(Function& F);
> +
> +  void releaseMemory();
> +
> +  // updateStatistics - Update statistic about created regions.
> +  void updateStatistics(Region *R);
> +
> +  // isSimple - Check if a region is a simple region with exactly one entry
> +  // edge and exactly one exit edge.
> +  bool isSimple(Region* R) const;
> +
> +public:
> +  static char ID;
> +  explicit RegionInfo();
> +
> +  ~RegionInfo();
> +
> +  /// @name FunctionPass interface
> +  //@{
> +  virtual bool runOnFunction(Function &F);
> +  virtual void getAnalysisUsage(AnalysisUsage &AU) const;
> +  virtual void print(raw_ostream &OS, const Module *) const;
> +  virtual void verifyAnalysis() const;
> +  //@}
> +
> +  /// @brief Get the smallest region that contains a BasicBlock.
> +  ///
> +  /// @param BB The basic block.
> +  /// @return The smallest region, that contains BB or NULL, if there is no
> +  /// region containing BB.
> +  Region *getRegionFor(BasicBlock *BB) const;
> +
> +  /// @brief A shortcut for getRegionFor().
> +  ///
> +  /// @param BB The basic block.
> +  /// @return The smallest region, that contains BB or NULL, if there is no
> +  /// region containing BB.
> +  Region *operator[](BasicBlock *BB) const;
> +
> +  /// @brief Find the smallest region that contains two regions.
> +  ///
> +  /// @param A The first region.
> +  /// @param B The second region.
> +  /// @return The smallest region containing A and B.
> +  Region *getCommonRegion(Region* A, Region *B) const;
> +
> +  /// @brief Find the smallest region that contains two basic blocks.
> +  ///
> +  /// @param A The first basic block.
> +  /// @param B The second basic block.
> +  /// @return The smallest region that contains A and B.
> +  Region* getCommonRegion(BasicBlock* A, BasicBlock *B) const {
> +    return getCommonRegion(getRegionFor(A), getRegionFor(B));
> +  }
> +
> +  /// @brief Find the smallest region that contains a set of regions.
> +  ///
> +  /// @param Regions A vector of regions.
> +  /// @return The smallest region that contains all regions in Regions.
> +  Region* getCommonRegion(SmallVectorImpl<Region*> &Regions) const;
> +
> +  /// @brief Find the smallest region that contains a set of basic blocks.
> +  ///
> +  /// @param BBs A vector of basic blocks.
> +  /// @return The smallest region that contains all basic blocks in BBS.
> +  Region* getCommonRegion(SmallVectorImpl<BasicBlock*> &BBs) const;
> +
> +  Region *getTopLevelRegion() const {
> +    return TopLevelRegion;
> +  }
> +
> +  /// @brief Clear the Node Cache for all Regions.
> +  ///
> +  /// @see Region::clearNodeCache()
> +  void clearNodeCache() {
> +    if (TopLevelRegion)
> +      TopLevelRegion->clearNodeCache();
> +  }
> +};
> +
> +inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node) {
> +  if (Node.isSubRegion())
> +    return OS << Node.getNodeAs<Region>()->getNameStr();
> +  else
> +    return OS << Node.getNodeAs<BasicBlock>()->getNameStr();
> +}
> +} // End llvm namespace
> +#endif
> +
> 
> Added: llvm/trunk/include/llvm/Analysis/RegionIterator.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/RegionIterator.h?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/include/llvm/Analysis/RegionIterator.h (added)
> +++ llvm/trunk/include/llvm/Analysis/RegionIterator.h Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,342 @@
> +//===- RegionIterator.h - Iterators to iteratate over Regions ---*- C++ -*-===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +// This file defines the iterators to iterate over the elements of a Region.
> +//===----------------------------------------------------------------------===//
> +#ifndef LLVM_ANALYSIS_REGION_ITERATOR_H
> +#define LLVM_ANALYSIS_REGION_ITERATOR_H
> +
> +#include "llvm/ADT/GraphTraits.h"
> +#include "llvm/ADT/SmallPtrSet.h"
> +#include "llvm/ADT/PointerIntPair.h"
> +#include "llvm/Analysis/RegionInfo.h"
> +#include "llvm/Support/CFG.h"
> +#include "llvm/Support/raw_ostream.h"
> +
> +namespace llvm {
> +//===----------------------------------------------------------------------===//
> +/// @brief Hierachical RegionNode successor iterator.
> +///
> +/// This iterator iterates over all successors of a RegionNode.
> +///
> +/// For a BasicBlock RegionNode it skips all BasicBlocks that are not part of
> +/// the parent Region.  Furthermore for BasicBlocks that start a subregion, a
> +/// RegionNode representing the subregion is returned.
> +///
> +/// For a subregion RegionNode there is just one successor. The RegionNode
> +/// representing the exit of the subregion.
> +template<class NodeType>
> +class RNSuccIterator : public std::iterator<std::forward_iterator_tag,
> +                                           NodeType, ptrdiff_t>
> +{
> +  typedef std::iterator<std::forward_iterator_tag, NodeType, ptrdiff_t> super;
> +  // The iterator works in two modes, bb mode or region mode.
> +  enum ItMode{
> +    // In BB mode it returns all successors of this BasicBlock as its
> +    // successors.
> +    ItBB,
> +    // In region mode there is only one successor, thats the regionnode mapping
> +    // to the exit block of the regionnode
> +    ItRgBegin, // At the beginning of the regionnode successor.
> +    ItRgEnd    // At the end of the regionnode successor.
> +  };
> +
> +  // Use two bit to represent the mode iterator.
> +  PointerIntPair<NodeType*, 2, enum ItMode> Node;
> +
> +  // The block successor iterator.
> +  succ_iterator BItor;
> +
> +  // advanceRegionSucc - A region node has only one successor. It reaches end
> +  // once we advance it.
> +  void advanceRegionSucc() {
> +    assert(Node.getInt() == ItRgBegin && "Cannot advance region successor!");
> +    Node.setInt(ItRgEnd);
> +  }
> +
> +  NodeType* getNode() const{ return Node.getPointer(); }
> +
> +  // isRegionMode - Is the current iterator in region mode?
> +  bool isRegionMode() const { return Node.getInt() != ItBB; }
> +
> +  // Get the immediate successor. This function may return a Basic Block
> +  // RegionNode or a subregion RegionNode.
> +  RegionNode* getISucc(BasicBlock* BB) const {
> +    RegionNode *succ;
> +    succ = getNode()->getParent()->getNode(BB);
> +    assert(succ && "BB not in Region or entered subregion!");
> +    return succ;
> +  }
> +
> +  // getRegionSucc - Return the successor basic block of a SubRegion RegionNode.
> +  inline BasicBlock* getRegionSucc() const {
> +    assert(Node.getInt() == ItRgBegin && "Cannot get the region successor!");
> +    return getNode()->template getNodeAs<Region>()->getExit();
> +  }
> +
> +  // isExit - Is this the exit BB of the Region?
> +  inline bool isExit(BasicBlock* BB) const {
> +    return getNode()->getParent()->getExit() == BB;
> +  }
> +public:
> +  typedef RNSuccIterator<NodeType> Self;
> +
> +  typedef typename super::pointer pointer;
> +
> +  /// @brief Create begin iterator of a RegionNode.
> +  inline RNSuccIterator(NodeType* node)
> +    : Node(node, node->isSubRegion() ? ItRgBegin : ItBB),
> +    BItor(succ_begin(node->getEntry())) {
> +
> +
> +    // Skip the exit block
> +    if (!isRegionMode())
> +      while (succ_end(node->getEntry()) != BItor && isExit(*BItor))
> +        ++BItor;
> +
> +    if (isRegionMode() && isExit(getRegionSucc()))
> +      advanceRegionSucc();
> +  }
> +
> +  /// @brief Create an end iterator.
> +  inline RNSuccIterator(NodeType* node, bool)
> +    : Node(node, node->isSubRegion() ? ItRgEnd : ItBB),
> +    BItor(succ_end(node->getEntry())) {}
> +
> +  inline bool operator==(const Self& x) const {
> +    assert(isRegionMode() == x.isRegionMode() && "Broken iterator!");
> +    if (isRegionMode())
> +      return Node.getInt() == x.Node.getInt();
> +    else
> +      return BItor == x.BItor;
> +  }
> +
> +  inline bool operator!=(const Self& x) const { return !operator==(x); }
> +
> +  inline pointer operator*() const {
> +    BasicBlock* BB = isRegionMode() ? getRegionSucc() : *BItor;
> +    assert(!isExit(BB) && "Iterator out of range!");
> +    return getISucc(BB);
> +  }
> +
> +  inline Self& operator++() {
> +    if(isRegionMode()) {
> +      // The Region only has 1 successor.
> +      advanceRegionSucc();
> +    } else {
> +      // Skip the exit.
> +      do
> +        ++BItor;
> +      while (BItor != succ_end(getNode()->getEntry())
> +          && isExit(*BItor));
> +    }
> +    return *this;
> +  }
> +
> +  inline Self operator++(int) {
> +    Self tmp = *this;
> +    ++*this;
> +    return tmp;
> +  }
> +
> +  inline const Self &operator=(const Self &I) {
> +    if (this != &I) {
> +      assert(getNode()->getParent() == I.getNode()->getParent()
> +             && "Cannot assign iterators of two different regions!");
> +      Node = I.Node;
> +      BItor = I.BItor;
> +    }
> +    return *this;
> +  }
> +};
> +
> +
> +//===----------------------------------------------------------------------===//
> +/// @brief Flat RegionNode iterator.
> +///
> +/// The Flat Region iterator will iterate over all BasicBlock RegionNodes that
> +/// are contained in the Region and its subregions. This is close to a virtual
> +/// control flow graph of the Region.
> +template<class NodeType>
> +class RNSuccIterator<FlatIt<NodeType> >
> +  : public std::iterator<std::forward_iterator_tag, NodeType, ptrdiff_t>
> +{
> +  typedef std::iterator<std::forward_iterator_tag, NodeType, ptrdiff_t> super;
> +  NodeType* Node;
> +  succ_iterator Itor;
> +
> +public:
> +  typedef RNSuccIterator<FlatIt<NodeType> > Self;
> +  typedef typename super::pointer pointer;
> +
> +  /// @brief Create the iterator from a RegionNode.
> +  ///
> +  /// Note that the incoming node must be a bb node, otherwise it will trigger
> +  /// an assertion when we try to get a BasicBlock.
> +  inline RNSuccIterator(NodeType* node) : Node(node),
> +    Itor(succ_begin(node->getEntry())) {
> +      assert(!Node->isSubRegion()
> +             && "Subregion node not allowed in flat iterating mode!");
> +      assert(Node->getParent() && "A BB node must have a parent!");
> +
> +      // Skip the exit block of the iterating region.
> +      while (succ_end(Node->getEntry()) != Itor
> +          && Node->getParent()->getExit() == *Itor)
> +        ++Itor;
> +  }
> +  /// @brief Create an end iterator
> +  inline RNSuccIterator(NodeType* node, bool) : Node(node),
> +    Itor(succ_end(node->getEntry())) {
> +      assert(!Node->isSubRegion()
> +             && "Subregion node not allowed in flat iterating mode!");
> +  }
> +
> +  inline bool operator==(const Self& x) const {
> +    assert(Node->getParent() == x.Node->getParent()
> +           && "Cannot compare iterators of different regions!");
> +
> +    return Itor == x.Itor && Node == x.Node;
> +  }
> +
> +  inline bool operator!=(const Self& x) const { return !operator==(x); }
> +
> +  inline pointer operator*() const {
> +    BasicBlock* BB = *Itor;
> +
> +    // Get the iterating region.
> +    Region* Parent = Node->getParent();
> +
> +    // The only case that the successor reaches out of the region is it reaches
> +    // the exit of the region.
> +    assert(Parent->getExit() != BB && "iterator out of range!");
> +
> +    return Parent->getBBNode(BB);
> +  }
> +
> +  inline Self& operator++() {
> +    // Skip the exit block of the iterating region.
> +    do
> +      ++Itor;
> +    while (Itor != succ_end(Node->getEntry())
> +        && Node->getParent()->getExit() == *Itor);
> +
> +    return *this;
> +  }
> +
> +  inline Self operator++(int) {
> +    Self tmp = *this;
> +    ++*this;
> +    return tmp;
> +  }
> +
> +  inline const Self &operator=(const Self &I) {
> +    if (this != &I) {
> +      assert(Node->getParent() == I.Node->getParent()
> +             && "Cannot assign iterators to two different regions!");
> +      Node = I.Node;
> +      Itor = I.Itor;
> +    }
> +    return *this;
> +  }
> +};
> +
> +template<class NodeType>
> +inline RNSuccIterator<NodeType> succ_begin(NodeType* Node) {
> +  return RNSuccIterator<NodeType>(Node);
> +}
> +
> +template<class NodeType>
> +inline RNSuccIterator<NodeType> succ_end(NodeType* Node) {
> +  return RNSuccIterator<NodeType>(Node, true);
> +}
> +
> +//===--------------------------------------------------------------------===//
> +// RegionNode GraphTraits specialization so the bbs in the region can be
> +// iterate by generic graph iterators.
> +//
> +// NodeT can either be region node or const region node, otherwise child_begin
> +// and child_end fail.
> +
> +#define RegionNodeGraphTraits(NodeT) \
> +  template<> struct GraphTraits<NodeT*> { \
> +  typedef NodeT NodeType; \
> +  typedef RNSuccIterator<NodeType> ChildIteratorType; \
> +  static NodeType *getEntryNode(NodeType* N) { return N; } \
> +  static inline ChildIteratorType child_begin(NodeType *N) { \
> +    return RNSuccIterator<NodeType>(N); \
> +  } \
> +  static inline ChildIteratorType child_end(NodeType *N) { \
> +    return RNSuccIterator<NodeType>(N, true); \
> +  } \
> +}; \
> +template<> struct GraphTraits<FlatIt<NodeT*> > { \
> +  typedef NodeT NodeType; \
> +  typedef RNSuccIterator<FlatIt<NodeT> > ChildIteratorType; \
> +  static NodeType *getEntryNode(NodeType* N) { return N; } \
> +  static inline ChildIteratorType child_begin(NodeType *N) { \
> +    return RNSuccIterator<FlatIt<NodeType> >(N); \
> +  } \
> +  static inline ChildIteratorType child_end(NodeType *N) { \
> +    return RNSuccIterator<FlatIt<NodeType> >(N, true); \
> +  } \
> +}
> +
> +#define RegionGraphTraits(RegionT, NodeT) \
> +template<> struct GraphTraits<RegionT*> \
> +  : public GraphTraits<NodeT*> { \
> +  typedef df_iterator<NodeType*> nodes_iterator; \
> +  static NodeType *getEntryNode(RegionT* R) { \
> +    return R->getNode(R->getEntry()); \
> +  } \
> +  static nodes_iterator nodes_begin(RegionT* R) { \
> +    return nodes_iterator::begin(getEntryNode(R)); \
> +  } \
> +  static nodes_iterator nodes_end(RegionT* R) { \
> +    return nodes_iterator::end(getEntryNode(R)); \
> +  } \
> +}; \
> +template<> struct GraphTraits<FlatIt<RegionT*> > \
> +  : public GraphTraits<FlatIt<NodeT*> > { \
> +  typedef df_iterator<NodeType*, SmallPtrSet<NodeType*, 8>, false, \
> +  GraphTraits<FlatIt<NodeType*> > > nodes_iterator; \
> +  static NodeType *getEntryNode(RegionT* R) { \
> +    return R->getBBNode(R->getEntry()); \
> +  } \
> +  static nodes_iterator nodes_begin(RegionT* R) { \
> +    return nodes_iterator::begin(getEntryNode(R)); \
> +  } \
> +  static nodes_iterator nodes_end(RegionT* R) { \
> +    return nodes_iterator::end(getEntryNode(R)); \
> +  } \
> +}
> +
> +RegionNodeGraphTraits(RegionNode);
> +RegionNodeGraphTraits(const RegionNode);
> +
> +RegionGraphTraits(Region, RegionNode);
> +RegionGraphTraits(const Region, const RegionNode);
> +
> +template <> struct GraphTraits<RegionInfo*>
> +  : public GraphTraits<FlatIt<RegionNode*> > {
> +  typedef df_iterator<NodeType*, SmallPtrSet<NodeType*, 8>, false,
> +                      GraphTraits<FlatIt<NodeType*> > > nodes_iterator;
> +
> +  static NodeType *getEntryNode(RegionInfo *RI) {
> +    return GraphTraits<FlatIt<Region*> >::getEntryNode(RI->getTopLevelRegion());
> +  }
> +  static nodes_iterator nodes_begin(RegionInfo* RI) {
> +    return nodes_iterator::begin(getEntryNode(RI));
> +  }
> +  static nodes_iterator nodes_end(RegionInfo *RI) {
> +    return nodes_iterator::end(getEntryNode(RI));
> +  }
> +};
> +
> +} // End namespace llvm
> +
> +#endif
> 
> Added: llvm/trunk/include/llvm/Analysis/RegionPrinter.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/RegionPrinter.h?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/include/llvm/Analysis/RegionPrinter.h (added)
> +++ llvm/trunk/include/llvm/Analysis/RegionPrinter.h Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,26 @@
> +//===-- RegionPrinter.h - Region printer external interface -----*- C++ -*-===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +//
> +// This file defines external functions that can be called to explicitly
> +// instantiate the region printer.
> +//
> +//===----------------------------------------------------------------------===//
> +
> +#ifndef LLVM_ANALYSIS_REGIONPRINTER_H
> +#define LLVM_ANALYSIS_REGIONPRINTER_H
> +
> +namespace llvm {
> +  class FunctionPass;
> +  FunctionPass *createRegionViewerPass();
> +  FunctionPass *createRegionOnlyViewerPass();
> +  FunctionPass *createRegionPrinterPass();
> +  FunctionPass *createRegionOnlyPrinterPass();
> +} // End llvm namespace
> +
> +#endif
> 
> Modified: llvm/trunk/include/llvm/LinkAllPasses.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/LinkAllPasses.h?rev=109089&r1=109088&r2=109089&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/LinkAllPasses.h (original)
> +++ llvm/trunk/include/llvm/LinkAllPasses.h Thu Jul 22 02:46:31 2010
> @@ -22,6 +22,7 @@
> #include "llvm/Analysis/Passes.h"
> #include "llvm/Analysis/PointerTracking.h"
> #include "llvm/Analysis/PostDominators.h"
> +#include "llvm/Analysis/RegionPrinter.h"
> #include "llvm/Analysis/ScalarEvolution.h"
> #include "llvm/Analysis/Lint.h"
> #include "llvm/Assembly/PrintModulePass.h"
> @@ -106,6 +107,11 @@
>       (void) llvm::createPostDomOnlyViewerPass();
>       (void) llvm::createPostDomViewerPass();
>       (void) llvm::createReassociatePass();
> +      (void) llvm::createRegionInfoPass();
> +      (void) llvm::createRegionOnlyPrinterPass();
> +      (void) llvm::createRegionOnlyViewerPass();
> +      (void) llvm::createRegionPrinterPass();
> +      (void) llvm::createRegionViewerPass();
>       (void) llvm::createSCCPPass();
>       (void) llvm::createScalarReplAggregatesPass();
>       (void) llvm::createSimplifyLibCallsPass();
> 
> Modified: llvm/trunk/include/llvm/Support/GraphWriter.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/GraphWriter.h?rev=109089&r1=109088&r2=109089&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/Support/GraphWriter.h (original)
> +++ llvm/trunk/include/llvm/Support/GraphWriter.h Thu Jul 22 02:46:31 2010
> @@ -271,6 +271,12 @@
>       O << "[" << Attrs << "]";
>     O << ";\n";
>   }
> +
> +  /// getOStream - Get the raw output stream into the graph file. Useful to
> +  /// write fancy things using addCustomGraphFeatures().
> +  raw_ostream &getOStream() {
> +    return O;
> +  }
> };
> 
> template<typename GraphType>
> 
> Modified: llvm/trunk/lib/Analysis/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/CMakeLists.txt?rev=109089&r1=109088&r2=109089&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Analysis/CMakeLists.txt (original)
> +++ llvm/trunk/lib/Analysis/CMakeLists.txt Thu Jul 22 02:46:31 2010
> @@ -38,6 +38,8 @@
>   ProfileInfoLoader.cpp
>   ProfileInfoLoaderPass.cpp
>   ProfileVerifierPass.cpp
> +  RegionInfo.cpp
> +  RegionPrinter.cpp
>   ScalarEvolution.cpp
>   ScalarEvolutionAliasAnalysis.cpp
>   ScalarEvolutionExpander.cpp
> 
> Added: llvm/trunk/lib/Analysis/RegionInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/RegionInfo.cpp?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/lib/Analysis/RegionInfo.cpp (added)
> +++ llvm/trunk/lib/Analysis/RegionInfo.cpp Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,637 @@
> +//===- RegionInfo.cpp - SESE region detection analysis --------------------===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +// Detects single entry single exit regions in the control flow graph.
> +//===----------------------------------------------------------------------===//
> +
> +#include "llvm/Analysis/RegionInfo.h"
> +#include "llvm/Analysis/RegionIterator.h"
> +
> +#include "llvm/ADT/PostOrderIterator.h"
> +#include "llvm/ADT/Statistic.h"
> +#include "llvm/Support/CommandLine.h"
> +#include "llvm/Support/ErrorHandling.h"
> +#include "llvm/Support/raw_ostream.h"
> +
> +#define DEBUG_TYPE "region"
> +#include "llvm/Support/Debug.h"
> +
> +#include <set>
> +#include <algorithm>
> +
> +using namespace llvm;
> +
> +// Always verify if expensive checking is enabled.
> +#ifdef XDEBUG
> +bool VerifyRegionInfo = true;
> +#else
> +bool VerifyRegionInfo = false;
> +#endif
> +
> +static cl::opt<bool,true>
> +VerifyRegionInfoX("verify-region-info", cl::location(VerifyRegionInfo),
> +                cl::desc("Verify region info (time consuming)"));
> +
> +STATISTIC(numRegions,       "The # of regions");
> +STATISTIC(numSimpleRegions, "The # of simple regions");
> +
> +//===----------------------------------------------------------------------===//
> +/// PrintStyle - Print region in difference ways.
> +enum PrintStyle { PrintNone, PrintBB, PrintRN  };
> +
> +cl::opt<enum PrintStyle> printStyle("print-region-style", cl::Hidden,
> +  cl::desc("style of printing regions"),
> +  cl::values(
> +    clEnumValN(PrintNone, "none",  "print no details"),
> +    clEnumValN(PrintBB, "bb",  "print regions in detail with block_iterator"),
> +    clEnumValN(PrintRN, "rn",  "print regions in detail with element_iterator"),
> +    clEnumValEnd));
> +//===----------------------------------------------------------------------===//
> +/// Region Implementation
> +Region::Region(BasicBlock *Entry, BasicBlock *Exit, RegionInfo* RInfo,
> +               DominatorTree *dt, Region *Parent)
> +               : RegionNode(Parent, Entry, 1), RI(RInfo), DT(dt), exit(Exit) {}
> +
> +Region::~Region() {
> +  // Only clean the cache for this Region. Caches of child Regions will be
> +  // cleaned when the child Regions are deleted.
> +  BBNodeMap.clear();
> +
> +  for (iterator I = begin(), E = end(); I != E; ++I)
> +    delete *I;
> +}
> +
> +bool Region::contains(const BasicBlock *B) const {
> +  BasicBlock *BB = const_cast<BasicBlock*>(B);
> +
> +  assert(DT->getNode(BB) && "BB not part of the dominance tree");
> +
> +  BasicBlock *entry = getEntry(), *exit = getExit();
> +
> +  // Toplevel region.
> +  if (!exit)
> +    return true;
> +
> +  return (DT->dominates(entry, BB)
> +    && !(DT->dominates(exit, BB) && DT->dominates(entry, exit)));
> +}
> +
> +bool Region::isSimple() const {
> +  bool isSimple = true;
> +  bool found = false;
> +
> +  BasicBlock *entry = getEntry(), *exit = getExit();
> +
> +  // TopLevelRegion
> +  if (!exit)
> +    return false;
> +
> +  for (pred_iterator PI = pred_begin(entry), PE = pred_end(entry); PI != PE;
> +       ++PI)
> +    if (!contains(*PI)) {
> +      if (found) {
> +        isSimple = false;
> +        break;
> +      }
> +      found = true;
> +    }
> +
> +  found = false;
> +
> +  for (pred_iterator PI = pred_begin(exit), PE = pred_end(exit); PI != PE;
> +       ++PI)
> +    if (contains(*PI)) {
> +      if (found) {
> +        isSimple = false;
> +        break;
> +      }
> +      found = true;
> +    }
> +
> +  return isSimple;
> +}
> +
> +void Region::verifyBBInRegion(BasicBlock *BB) const {
> +  if (!contains(BB))
> +    llvm_unreachable("Broken region found!");
> +
> +  BasicBlock *entry = getEntry(), *exit = getExit();
> +
> +  for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
> +    if (!contains(*SI) && exit != *SI)
> +      llvm_unreachable("Broken region found!");
> +
> +  if (entry != BB)
> +    for (pred_iterator SI = pred_begin(BB), SE = pred_end(BB); SI != SE; ++SI)
> +      if (!contains(*SI))
> +        llvm_unreachable("Broken region found!");
> +}
> +
> +void Region::verifyWalk(BasicBlock *BB, std::set<BasicBlock*> *visited) const {
> +  BasicBlock *exit = getExit();
> +
> +  visited->insert(BB);
> +
> +  verifyBBInRegion(BB);
> +
> +  for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
> +    if (*SI != exit && visited->find(*SI) == visited->end())
> +        verifyWalk(*SI, visited);
> +}
> +
> +void Region::verifyRegion() const {
> +  // Only do verification when user wants to, otherwise this expensive
> +  // check will be invoked by PassManager.
> +  if (!VerifyRegionInfo) return;
> +
> +  std::set<BasicBlock*> visited;
> +  verifyWalk(getEntry(), &visited);
> +}
> +
> +void Region::verifyRegionNest() const {
> +  for (Region::const_iterator RI = begin(), RE = end(); RI != RE; ++RI)
> +    (*RI)->verifyRegionNest();
> +
> +  verifyRegion();
> +}
> +
> +Region::block_iterator Region::block_begin() {
> +  return GraphTraits<FlatIt<Region*> >::nodes_begin(this);
> +}
> +
> +Region::block_iterator Region::block_end() {
> +  return GraphTraits<FlatIt<Region*> >::nodes_end(this);
> +}
> +
> +Region::const_block_iterator Region::block_begin() const {
> +  return GraphTraits<FlatIt<const Region*> >::nodes_begin(this);
> +}
> +
> +Region::const_block_iterator Region::block_end() const {
> +  return GraphTraits<FlatIt<const Region*> >::nodes_end(this);
> +}
> +
> +Region::element_iterator Region::element_begin() {
> +  return GraphTraits<Region*>::nodes_begin(this);
> +}
> +
> +Region::element_iterator Region::element_end() {
> +  return GraphTraits<Region*>::nodes_end(this);
> +}
> +
> +Region::const_element_iterator Region::element_begin() const {
> +  return GraphTraits<const Region*>::nodes_begin(this);
> +}
> +
> +Region::const_element_iterator Region::element_end() const {
> +  return GraphTraits<const Region*>::nodes_end(this);
> +}
> +
> +Region* Region::getSubRegionNode(BasicBlock *BB) const {
> +  Region *R = RI->getRegionFor(BB);
> +
> +  if (!R || R == this)
> +    return 0;
> +
> +  // If we pass the BB out of this region, that means our code is broken.
> +  assert(contains(R) && "BB not in current region!");
> +
> +  while (contains(R->getParent()) && R->getParent() != this)
> +    R = R->getParent();
> +
> +  if (R->getEntry() != BB)
> +    return 0;
> +
> +  return R;
> +}
> +
> +RegionNode* Region::getBBNode(BasicBlock *BB) const {
> +  assert(contains(BB) && "Can get BB node out of this region!");
> +
> +  BBNodeMapT::const_iterator at = BBNodeMap.find(BB);
> +
> +  if (at != BBNodeMap.end())
> +    return at->second;
> +
> +  RegionNode *NewNode = new RegionNode(const_cast<Region*>(this), BB);
> +  BBNodeMap.insert(std::make_pair(BB, NewNode));
> +  return NewNode;
> +}
> +
> +RegionNode* Region::getNode(BasicBlock *BB) const {
> +  assert(contains(BB) && "Can get BB node out of this region!");
> +  if (Region* Child = getSubRegionNode(BB))
> +    return Child->getNode();
> +
> +  return getBBNode(BB);
> +}
> +
> +void Region::transferChildrenTo(Region *To) {
> +  for (iterator I = begin(), E = end(); I != E; ++I) {
> +    (*I)->parent = To;
> +    To->children.push_back(*I);
> +  }
> +  children.clear();
> +}
> +
> +void Region::addSubRegion(Region *SubRegion) {
> +  assert(SubRegion->parent == 0 && "SubRegion already has a parent!");
> +  SubRegion->parent = this;
> +  // Set up the region node.
> +  assert(std::find(children.begin(), children.end(), SubRegion) == children.end()
> +         && "Node already exist!");
> +  children.push_back(SubRegion);
> +}
> +
> +
> +Region *Region::removeSubRegion(Region *Child) {
> +  assert(Child->parent == this && "Child is not a child of this region!");
> +  Child->parent = 0;
> +  RegionSet::iterator I = std::find(children.begin(), children.end(), Child);
> +  assert(I != children.end() && "Region does not exit. Unable to remove.");
> +  children.erase(children.begin()+(I-begin()));
> +  return Child;
> +}
> +
> +unsigned Region::getDepth() const {
> +  unsigned Depth = 0;
> +
> +  for (Region *R = parent; R != 0; R = R->parent)
> +    ++Depth;
> +
> +  return Depth;
> +}
> +
> +void Region::print(raw_ostream &OS, bool print_tree, unsigned level) const {
> +  if (print_tree)
> +    OS.indent(level*2) << "[" << level << "] " << getNameStr();
> +  else
> +    OS.indent(level*2) << getNameStr();
> +
> +  OS << "\n";
> +
> +
> +  if (printStyle != PrintNone) {
> +    OS.indent(level*2) << "{\n";
> +    OS.indent(level*2 + 2);
> +
> +    if (printStyle == PrintBB) {
> +      for (const_block_iterator I = block_begin(), E = block_end(); I!=E; ++I)
> +        OS << **I << ", "; // TODO: remove the last ","
> +    } else if (printStyle == PrintRN) {
> +      for (const_element_iterator I = element_begin(), E = element_end(); I!=E; ++I)
> +        OS << **I << ", "; // TODO: remove the last ",
> +    }
> +
> +    OS << "\n";
> +  }
> +
> +  if (print_tree)
> +    for (const_iterator RI = begin(), RE = end(); RI != RE; ++RI)
> +      (*RI)->print(OS, print_tree, level+1);
> +
> +  if (printStyle != PrintNone)
> +    OS.indent(level*2) << "} \n";
> +}
> +
> +void Region::dump() const {
> +  print(dbgs(), true, getDepth());
> +}
> +
> +void Region::clearNodeCache() {
> +  BBNodeMap.clear();
> +  for (Region::iterator RI = begin(), RE = end(); RI != RE; ++RI)
> +    (*RI)->clearNodeCache();
> +}
> +
> +//===----------------------------------------------------------------------===//
> +// RegionInfo implementation
> +//
> +
> +bool RegionInfo::isCommonDomFrontier(BasicBlock *BB, BasicBlock *entry,
> +                                     BasicBlock *exit) const {
> +  for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI)
> +    if (DT->dominates(entry, *PI) && !DT->dominates(exit, *PI))
> +      return false;
> +
> +  return true;
> +}
> +
> +bool RegionInfo::isRegion(BasicBlock *entry, BasicBlock *exit) const {
> +  assert(entry && exit && "entry and exit must not be null!");
> +  typedef DominanceFrontier::DomSetType DST;
> +
> +  DST *entrySuccs = &(*DF->find(entry)).second;
> +
> +  // Exit is the header of a loop that contains the entry. In this case,
> +  // the dominance frontier must only contain the exit.
> +  if (!DT->dominates(entry, exit)) {
> +    for (DST::iterator SI = entrySuccs->begin(), SE = entrySuccs->end();
> +         SI != SE; ++SI)
> +      if (*SI != exit && *SI != entry)
> +        return false;
> +
> +    return true;
> +  }
> +
> +  DST *exitSuccs = &(*DF->find(exit)).second;
> +
> +  // Do not allow edges leaving the region.
> +  for (DST::iterator SI = entrySuccs->begin(), SE = entrySuccs->end();
> +       SI != SE; ++SI) {
> +    if (*SI == exit || *SI == entry)
> +      continue;
> +    if (exitSuccs->find(*SI) == exitSuccs->end())
> +      return false;
> +    if (!isCommonDomFrontier(*SI, entry, exit))
> +      return false;
> +  }
> +
> +  // Do not allow edges pointing into the region.
> +  for (DST::iterator SI = exitSuccs->begin(), SE = exitSuccs->end();
> +       SI != SE; ++SI)
> +    if (DT->dominates(entry, *SI) && *SI != entry && *SI != exit)
> +      return false;
> +
> +
> +  return true;
> +}
> +
> +void RegionInfo::insertShortCut(BasicBlock *entry, BasicBlock *exit,
> +                             BBtoBBMap *ShortCut) const {
> +  assert(entry && exit && "entry and exit must not be null!");
> +
> +  BBtoBBMap::iterator e = ShortCut->find(exit);
> +
> +  if (e == ShortCut->end())
> +    // No further region at exit available.
> +    (*ShortCut)[entry] = exit;
> +  else {
> +    // We found a region e that starts at exit. Therefore (entry, e->second)
> +    // is also a region, that is larger than (entry, exit). Insert the
> +    // larger one.
> +    BasicBlock *BB = e->second;
> +    (*ShortCut)[entry] = BB;
> +  }
> +}
> +
> +DomTreeNode* RegionInfo::getNextPostDom(DomTreeNode* N,
> +                                        BBtoBBMap *ShortCut) const {
> +  BBtoBBMap::iterator e = ShortCut->find(N->getBlock());
> +
> +  if (e == ShortCut->end())
> +    return N->getIDom();
> +
> +  return PDT->getNode(e->second)->getIDom();
> +}
> +
> +bool RegionInfo::isTrivialRegion(BasicBlock *entry, BasicBlock *exit) const {
> +  assert(entry && exit && "entry and exit must not be null!");
> +
> +  unsigned num_successors = succ_end(entry) - succ_begin(entry);
> +
> +  if (num_successors <= 1 && exit == *(succ_begin(entry)))
> +    return true;
> +
> +  return false;
> +}
> +
> +void RegionInfo::updateStatistics(Region *R) {
> +  ++numRegions;
> +
> +  // TODO: Slow. Should only be enabled if -stats is used.
> +  if (R->isSimple()) ++numSimpleRegions;
> +}
> +
> +Region *RegionInfo::createRegion(BasicBlock *entry, BasicBlock *exit) {
> +  assert(entry && exit && "entry and exit must not be null!");
> +
> +  if (isTrivialRegion(entry, exit))
> +    return 0;
> +
> +  Region *region = new Region(entry, exit, this, DT);
> +  BBtoRegion.insert(std::make_pair(entry, region));
> +
> + #ifdef XDEBUG
> +    region->verifyRegion();
> + #else
> +    DEBUG(region->verifyRegion());
> + #endif
> +
> +  updateStatistics(region);
> +  return region;
> +}
> +
> +void RegionInfo::findRegionsWithEntry(BasicBlock *entry, BBtoBBMap *ShortCut) {
> +  assert(entry);
> +
> +  DomTreeNode *N = PDT->getNode(entry);
> +
> +  if (!N)
> +    return;
> +
> +  Region *lastRegion= 0;
> +  BasicBlock *lastExit = entry;
> +
> +  // As only a BasicBlock that postdominates entry can finish a region, walk the
> +  // post dominance tree upwards.
> +  while ((N = getNextPostDom(N, ShortCut))) {
> +    BasicBlock *exit = N->getBlock();
> +
> +    if (!exit)
> +      break;
> +
> +    if (isRegion(entry, exit)) {
> +      Region *newRegion = createRegion(entry, exit);
> +
> +      if (lastRegion)
> +        newRegion->addSubRegion(lastRegion);
> +
> +      lastRegion = newRegion;
> +      lastExit = exit;
> +    }
> +
> +    // This can never be a region, so stop the search.
> +    if (!DT->dominates(entry, exit))
> +      break;
> +  }
> +
> +  // Tried to create regions from entry to lastExit.  Next time take a
> +  // shortcut from entry to lastExit.
> +  if (lastExit != entry)
> +    insertShortCut(entry, lastExit, ShortCut);
> +}
> +
> +void RegionInfo::scanForRegions(Function &F, BBtoBBMap *ShortCut) {
> +  BasicBlock *entry = &(F.getEntryBlock());
> +  DomTreeNode *N = DT->getNode(entry);
> +
> +  // Iterate over the dominance tree in post order to start with the small
> +  // regions from the bottom of the dominance tree.  If the small regions are
> +  // detected first, detection of bigger regions is faster, as we can jump
> +  // over the small regions.
> +  for (po_iterator<DomTreeNode*> FI = po_begin(N), FE = po_end(N); FI != FE;
> +    ++FI) {
> +    findRegionsWithEntry((*FI)->getBlock(), ShortCut);
> +  }
> +}
> +
> +Region *RegionInfo::getTopMostParent(Region *region) {
> +  while (region->parent)
> +    region = region->getParent();
> +
> +  return region;
> +}
> +
> +void RegionInfo::buildRegionsTree(DomTreeNode *N, Region *region) {
> +  BasicBlock *BB = N->getBlock();
> +
> +  // Passed region exit
> +  while (BB == region->getExit())
> +    region = region->getParent();
> +
> +  BBtoRegionMap::iterator it = BBtoRegion.find(BB);
> +
> +  // This basic block is a start block of a region. It is already in the
> +  // BBtoRegion relation. Only the child basic blocks have to be updated.
> +  if (it != BBtoRegion.end()) {
> +    Region *newRegion = it->second;;
> +    region->addSubRegion(getTopMostParent(newRegion));
> +    region = newRegion;
> +  } else {
> +    BBtoRegion[BB] = region;
> +  }
> +
> +  for (DomTreeNode::iterator CI = N->begin(), CE = N->end(); CI != CE; ++CI)
> +    buildRegionsTree(*CI, region);
> +}
> +
> +void RegionInfo::releaseMemory() {
> +  BBtoRegion.clear();
> +  if (TopLevelRegion)
> +    delete TopLevelRegion;
> +  TopLevelRegion = 0;
> +}
> +
> +RegionInfo::RegionInfo() : FunctionPass(&ID) {
> +  TopLevelRegion = 0;
> +}
> +
> +RegionInfo::~RegionInfo() {
> +  releaseMemory();
> +}
> +
> +void RegionInfo::Calculate(Function &F) {
> +  // ShortCut a function where for every BB the exit of the largest region
> +  // starting with BB is stored. These regions can be threated as single BBS.
> +  // This improves performance on linear CFGs.
> +  BBtoBBMap ShortCut;
> +
> +  scanForRegions(F, &ShortCut);
> +  BasicBlock *BB = &F.getEntryBlock();
> +  buildRegionsTree(DT->getNode(BB), TopLevelRegion);
> +}
> +
> +bool RegionInfo::runOnFunction(Function &F) {
> +  releaseMemory();
> +
> +  DT = &getAnalysis<DominatorTree>();
> +  PDT = &getAnalysis<PostDominatorTree>();
> +  DF = &getAnalysis<DominanceFrontier>();
> +
> +  TopLevelRegion = new Region(&F.getEntryBlock(), 0, this, DT, 0);
> +  updateStatistics(TopLevelRegion);
> +
> +  Calculate(F);
> +
> +  return false;
> +}
> +
> +void RegionInfo::getAnalysisUsage(AnalysisUsage &AU) const {
> +  AU.setPreservesAll();
> +  AU.addRequiredTransitive<DominatorTree>();
> +  AU.addRequired<PostDominatorTree>();
> +  AU.addRequired<DominanceFrontier>();
> +}
> +
> +void RegionInfo::print(raw_ostream &OS, const Module *) const {
> +  OS << "Region tree:\n";
> +  TopLevelRegion->print(OS, true, 0);
> +  OS << "End region tree\n";
> +}
> +
> +void RegionInfo::verifyAnalysis() const {
> +  // Only do verification when user wants to, otherwise this expensive check
> +  // will be invoked by PMDataManager::verifyPreservedAnalysis when
> +  // a regionpass (marked PreservedAll) finish.
> +  if (!VerifyRegionInfo) return;
> +
> +  TopLevelRegion->verifyRegionNest();
> +}
> +
> +// Region pass manager support.
> +Region *RegionInfo::getRegionFor(BasicBlock *BB) const {
> +  BBtoRegionMap::const_iterator I=
> +    BBtoRegion.find(BB);
> +  return I != BBtoRegion.end() ? I->second : 0;
> +}
> +
> +Region *RegionInfo::operator[](BasicBlock *BB) const {
> +  return getRegionFor(BB);
> +}
> +
> +Region*
> +RegionInfo::getCommonRegion(Region *A, Region *B) const {
> +  assert (A && B && "One of the Regions is NULL");
> +
> +  if (A->contains(B)) return A;
> +
> +  while (!B->contains(A))
> +    B = B->getParent();
> +
> +  return B;
> +}
> +
> +Region*
> +RegionInfo::getCommonRegion(SmallVectorImpl<Region*> &Regions) const {
> +  Region* ret = Regions.back();
> +  Regions.pop_back();
> +
> +  for (SmallVectorImpl<Region*>::const_iterator I = Regions.begin(),
> +       E = Regions.end(); I != E; ++I)
> +      ret = getCommonRegion(ret, *I);
> +
> +  return ret;
> +}
> +
> +Region*
> +RegionInfo::getCommonRegion(SmallVectorImpl<BasicBlock*> &BBs) const {
> +  Region* ret = getRegionFor(BBs.back());
> +  BBs.pop_back();
> +
> +  for (SmallVectorImpl<BasicBlock*>::const_iterator I = BBs.begin(),
> +       E = BBs.end(); I != E; ++I)
> +      ret = getCommonRegion(ret, getRegionFor(*I));
> +
> +  return ret;
> +}
> +
> +char RegionInfo::ID = 0;
> +INITIALIZE_PASS(RegionInfo, "regions",
> +                "Detect single entry single exit regions", true, true);
> +
> +// Create methods available outside of this file, to use them
> +// "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by
> +// the link time optimization.
> +
> +namespace llvm {
> +  FunctionPass *createRegionInfoPass() {
> +    return new RegionInfo();
> +  }
> +}
> +
> 
> Added: llvm/trunk/lib/Analysis/RegionPrinter.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/RegionPrinter.cpp?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/lib/Analysis/RegionPrinter.cpp (added)
> +++ llvm/trunk/lib/Analysis/RegionPrinter.cpp Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,182 @@
> +//===- RegionPrinter.cpp - Print regions tree pass ------------------------===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +// Print out the region tree of a function using dotty/graphviz.
> +//===----------------------------------------------------------------------===//
> +
> +#include "llvm/Analysis/RegionInfo.h"
> +#include "llvm/Analysis/RegionIterator.h"
> +#include "llvm/Analysis/RegionPrinter.h"
> +#include "llvm/Analysis/Passes.h"
> +#include "llvm/Analysis/DOTGraphTraitsPass.h"
> +#include "llvm/ADT/Statistic.h"
> +#include "llvm/ADT/PostOrderIterator.h"
> +#include "llvm/ADT/DepthFirstIterator.h"
> +#include "llvm/Support/Debug.h"
> +#include "llvm/Support/CommandLine.h"
> +#include "llvm/Support/raw_ostream.h"
> +
> +using namespace llvm;
> +
> +//===----------------------------------------------------------------------===//
> +/// onlySimpleRegion - Show only the simple regions in the RegionViewer.
> +static cl::opt<bool>
> +onlySimpleRegions("only-simple-regions",
> +                  cl::desc("Show only simple regions in the graphviz viewer"),
> +                  cl::Hidden,
> +                  cl::init(false));
> +
> +namespace llvm {
> +template<>
> +struct DOTGraphTraits<RegionNode*> : public DefaultDOTGraphTraits {
> +
> +  DOTGraphTraits (bool isSimple=false)
> +    : DefaultDOTGraphTraits(isSimple) {}
> +
> +  std::string getNodeLabel(RegionNode *Node, RegionNode *Graph) {
> +
> +    if (!Node->isSubRegion()) {
> +      BasicBlock *BB = Node->getNodeAs<BasicBlock>();
> +
> +      if (isSimple())
> +        return DOTGraphTraits<const Function*>
> +          ::getSimpleNodeLabel(BB, BB->getParent());
> +      else
> +        return DOTGraphTraits<const Function*>
> +          ::getCompleteNodeLabel(BB, BB->getParent());
> +    }
> +
> +    return "Not implemented";
> +  }
> +};
> +
> +template<>
> +struct DOTGraphTraits<RegionInfo*> : public DOTGraphTraits<RegionNode*> {
> +
> +  DOTGraphTraits (bool isSimple=false)
> +    : DOTGraphTraits<RegionNode*>(isSimple) {}
> +
> +  static std::string getGraphName(RegionInfo *DT) {
> +    return "Region Graph";
> +  }
> +
> +  std::string getNodeLabel(RegionNode *Node, RegionInfo *G) {
> +    return DOTGraphTraits<RegionNode*>::getNodeLabel(Node,
> +                                                     G->getTopLevelRegion());
> +  }
> +
> +  // Print the cluster of the subregions. This groups the single basic blocks
> +  // and adds a different background color for each group.
> +  static void printRegionCluster(const Region *R, GraphWriter<RegionInfo*> &GW,
> +                                 unsigned depth = 0) {
> +    raw_ostream &O = GW.getOStream();
> +    O.indent(2 * depth) << "subgraph cluster_" << static_cast<const void*>(R)
> +      << " {\n";
> +    O.indent(2 * (depth + 1)) << "label = \"\";\n";
> +
> +    if (!onlySimpleRegions || R->isSimple()) {
> +      O.indent(2 * (depth + 1)) << "style = filled;\n";
> +      O.indent(2 * (depth + 1)) << "color = "
> +        << ((R->getDepth() * 2 % 12) + 1) << "\n";
> +
> +    } else {
> +      O.indent(2 * (depth + 1)) << "style = solid;\n";
> +      O.indent(2 * (depth + 1)) << "color = "
> +        << ((R->getDepth() * 2 % 12) + 2) << "\n";
> +    }
> +
> +    for (Region::const_iterator RI = R->begin(), RE = R->end(); RI != RE; ++RI)
> +      printRegionCluster(*RI, GW, depth + 1);
> +
> +    RegionInfo *RI = R->getRegionInfo();
> +
> +    for (Region::const_block_iterator BI = R->block_begin(),
> +         BE = R->block_end(); BI != BE; ++BI) {
> +      BasicBlock *BB = (*BI)->getNodeAs<BasicBlock>();
> +      if (RI->getRegionFor(BB) == R)
> +        O.indent(2 * (depth + 1)) << "Node"
> +          << static_cast<const void*>(RI->getTopLevelRegion()->getBBNode(BB))
> +          << ";\n";
> +    }
> +
> +    O.indent(2 * depth) << "}\n";
> +  }
> +
> +  static void addCustomGraphFeatures(const RegionInfo* RI,
> +                                     GraphWriter<RegionInfo*> &GW) {
> +    raw_ostream &O = GW.getOStream();
> +    O << "\tcolorscheme = \"paired12\"\n";
> +    printRegionCluster(RI->getTopLevelRegion(), GW, 4);
> +  }
> +};
> +} //end namespace llvm
> +
> +namespace {
> +
> +struct RegionViewer
> +  : public DOTGraphTraitsViewer<RegionInfo, false> {
> +  static char ID;
> +  RegionViewer() : DOTGraphTraitsViewer<RegionInfo, false>("reg", &ID){}
> +};
> +
> +char RegionViewer::ID = 0;
> +INITIALIZE_PASS(RegionViewer, "view-regions", "View regions of function",
> +                true, true);
> +
> +struct RegionOnlyViewer
> +  : public DOTGraphTraitsViewer<RegionInfo, true> {
> +  static char ID;
> +  RegionOnlyViewer() : DOTGraphTraitsViewer<RegionInfo, true>("regonly", &ID){}
> +};
> +
> +char RegionOnlyViewer::ID = 0;
> +INITIALIZE_PASS(RegionOnlyViewer, "view-regions-only",
> +                "View regions of function (with no function bodies)",
> +                true, true);
> +
> +struct RegionPrinter
> +  : public DOTGraphTraitsPrinter<RegionInfo, false> {
> +  static char ID;
> +  RegionPrinter() :
> +    DOTGraphTraitsPrinter<RegionInfo, false>("reg", &ID) {}
> +};
> +} //end anonymous namespace
> +
> +char RegionPrinter::ID = 0;
> +INITIALIZE_PASS(RegionPrinter, "dot-regions",
> +                "Print regions of function to 'dot' file", true, true);
> +
> +struct RegionOnlyPrinter
> +  : public DOTGraphTraitsPrinter<RegionInfo, true> {
> +  static char ID;
> +  RegionOnlyPrinter() :
> +    DOTGraphTraitsPrinter<RegionInfo, true>("reg", &ID) {}
> +};
> +
> +char RegionOnlyPrinter::ID = 0;
> +INITIALIZE_PASS(RegionOnlyPrinter, "dot-regions-only",
> +                "Print regions of function to 'dot' file "
> +                "(with no function bodies)",
> +                true, true);
> +
> +FunctionPass* llvm::createRegionViewerPass() {
> +  return new RegionViewer();
> +}
> +
> +FunctionPass* llvm::createRegionOnlyViewerPass() {
> +  return new RegionOnlyViewer();
> +}
> +
> +FunctionPass* llvm::createRegionPrinterPass() {
> +  return new RegionPrinter();
> +}
> +
> +FunctionPass* llvm::createRegionOnlyPrinterPass() {
> +  return new RegionOnlyPrinter();
> +}
> +
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/block_sort.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/block_sort.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/block_sort.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/block_sort.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,42 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats -analyze < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @BZ2_blockSort() nounwind {
> +start:
> +  br label %while
> +
> +while:
> +  br label %while.body134.i.i
> +
> +while.body134.i.i:
> +  br i1 1, label %end, label %w
> +
> +w:
> +  br label %if.end140.i.i
> +
> +if.end140.i.i:
> +  br i1 1, label %while.end186.i.i, label %if.end183.i.i
> +
> +if.end183.i.i:
> +  br label %while.body134.i.i
> +
> +while.end186.i.i:
> +  br label %while
> +
> +end:
> +  ret void
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] start => <Function Return>
> +; CHECK: [1] while => end
> +
> +; STAT: 2 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: start, while, while.body134.i.i, end, w, if.end140.i.i, while.end186.i.i, if.end183.i.i,
> +; BBIT: while, while.body134.i.i, w, if.end140.i.i, while.end186.i.i, if.end183.i.i,
> +
> +; RNIT: start, while => end, end,
> +; RNIT: while, while.body134.i.i, w, if.end140.i.i, while.end186.i.i, if.end183.i.i,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/cond_loop.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/cond_loop.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/cond_loop.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/cond_loop.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,33 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition() nounwind {
> +5:
> +        br label %"0"
> +
> +0:
> +	br label %"1"
> +1:
> +	br i1 1, label %"2", label %"3"
> +2:
> +	ret void
> +3:
> +	br i1 1, label %"1", label %"4"
> +4:
> +        br label %"0"
> +}
> +
> +; CHECK-NOT: =>
> +; CHECK: [0] 5 => <Function Return>
> +; CHECK: [1] 0 => 2
> +
> +; STAT: 2 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: 5, 0, 1, 2, 3, 4,
> +; BBIT: 0, 1, 3, 4,
> +
> +; RNIT: 5, 0 => 2, 2,
> +; RNIT: 0, 1, 3, 4,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/condition_complicated.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/condition_complicated.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/condition_complicated.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/condition_complicated.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,60 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define internal fastcc zeroext i8 @handle_compress() nounwind {
> +end165:
> +  br i1 1, label %false239, label %true181
> +
> +true181:
> +  br i1 1, label %then187, label %else232
> +
> +then187:
> +  br label %end265
> +
> +else232:
> +  br i1 1, label %false239, label %then245
> +
> +false239:
> +  br i1 1, label %then245, label %else259
> +
> +then245:
> +  br i1 1, label %then251, label %end253
> +
> +then251:
> +  br label %end253
> +
> +end253:
> +  br label %end265
> +
> +else259:
> +  br label %end265
> +
> +end265:
> +  br i1 1, label %then291, label %end298
> +
> +then291:
> +  br label %end298
> +
> +end298:
> +  ret i8 1
> +}
> +
> +; CHECK-NOT: =>
> +; CHECK: [0] end165 => <Function Return>
> +; CHECK-NEXT: [1] end165 => end265
> +; CHECK-NEXT: [2] then245 => end253
> +; CHECK-NEXT: [1] end265 => end298
> +
> +; STAT: 4 region - The # of regions
> +
> +; BBIT: end165, false239, then245, then251, end253, end265, then291, end298, else259, true181, then187, else232,
> +; BBIT: end165, false239, then245, then251, end253, else259, true181, then187, else232,
> +; BBIT: then245, then251,
> +; BBIT: end265, then291,
> +
> +; RNIT: end165 => end265, end265 => end298, end298,
> +; RNIT: end165, false239, then245 => end253, end253, else259, true181, then187, else232,
> +; RNIT: then245, then251,
> +; RNIT: end265, then291,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/condition_complicated_2.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/condition_complicated_2.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/condition_complicated_2.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/condition_complicated_2.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,44 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define internal fastcc void @compress() nounwind {
> +end33:
> +  br i1 1, label %end124, label %lor.lhs.false95
> +
> +lor.lhs.false95:
> +  br i1 1, label %then107, label %end172
> +
> +then107:
> +  br i1 1, label %end124, label %then113
> +
> +then113:
> +  br label %end124
> +
> +end124:
> +  br label %exit
> +
> +end172:
> +  br label %exit
> +
> +
> +exit:
> +  unreachable
> +
> +
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] end33 => <Function Return>
> +; CHECK-NEXT:      [1] end33 => exit
> +; CHECK-NEXT:   [2] then107 => end124
> +
> +; STAT: 3 region - The # of regions
> +
> +; BBIT: end33, end124, exit, lor.lhs.false95, then107, then113, end172,
> +; BBIT: end33, end124, lor.lhs.false95, then107, then113, end172,
> +; BBIT: then107, then113,
> +
> +; RNIT: end33 => exit, exit,
> +; RNIT: end33, end124, lor.lhs.false95, then107 => end124, end172,
> +; RNIT: then107, then113,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/condition_forward_edge.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/condition_forward_edge.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/condition_forward_edge.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/condition_forward_edge.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,26 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition() nounwind {
> +0:
> +	br label %"1"
> +1:
> +	br i1 1, label %"2", label %"3"
> +2:
> +	br label %"3"
> +3:
> +	ret void
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK: [1] 1 => 3
> +
> +; STAT: 2 region - The # of regions
> +
> +; BBIT: 0, 1, 2, 3,
> +; BBIT: 1, 2,
> +
> +; RNIT: 0, 1 => 3, 3,
> +; RNIT: 1, 2,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/condition_same_exit.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/condition_same_exit.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/condition_same_exit.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/condition_same_exit.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,31 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition() nounwind {
> +0:
> +	br i1 1, label %"1", label %"4"
> +
> +1:
> +	br i1 1, label %"2", label %"3"
> +2:
> +	br label %"4"
> +3:
> +	br label %"4"
> +4:
> +	ret void
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK-NEXT: [1] 0 => 4
> +; CHECK-NEXT:   [2] 1 => 4
> +; STAT: 3 region - The # of regions
> +
> +; BBIT: 0, 1, 2, 4, 3,
> +; BBIT: 0, 1, 2, 3,
> +; BBIT: 1, 2, 3,
> +
> +; RNIT: 0 => 4, 4,
> +; RNIT: 0, 1 => 4,
> +; RNIT: 1, 2, 3,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/condition_simple.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/condition_simple.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/condition_simple.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/condition_simple.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,28 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition() nounwind {
> +0:
> +	br label %"1"
> +1:
> +	br i1 1, label %"2", label %"3"
> +2:
> +	br label %"4"
> +3:
> +	br label %"4"
> +4:
> +	ret void
> +}
> +
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK-NEXT: [1] 1 => 4
> +; STAT: 2 region - The # of regions
> +
> +; BBIT: 0, 1, 2, 4, 3,
> +; BBIT: 1, 2, 3,
> +
> +; RNIT: 0, 1 => 4, 4,
> +; RNIT: 1, 2, 3,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/dg.exp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/dg.exp?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/dg.exp (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/dg.exp Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,3 @@
> +load_lib llvm.exp
> +
> +RunLLVMTests [lsort [glob -nocomplain $srcdir/$subdir/*.{ll,c,cpp}]]
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/exit_in_condition.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/exit_in_condition.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/exit_in_condition.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/exit_in_condition.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,38 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define internal fastcc zeroext i8 @handle_compress() nounwind {
> +entry:
> +  br label %outer
> +
> +outer:
> +  br label %body
> +
> +body:
> +  br i1 1, label %body.i, label %if.end
> +
> +body.i:
> +  br i1 1, label %end, label %if.end
> +
> +if.end:
> +  br label %if.then64
> +
> +if.then64:
> +  br label %outer
> +
> +end:
> +  ret i8 1
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] entry => <Function Return>
> +; CHECK-NEXT: [1] outer => end
> +; STAT: 2 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: entry, outer, body, body.i, end, if.end, if.then64,
> +; BBIT: outer, body, body.i, if.end, if.then64,
> +
> +; RNIT: entry, outer => end, end,
> +; RNIT: outer, body, body.i, if.end, if.then64,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/infinite_loop.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/infinite_loop.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/infinite_loop.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/infinite_loop.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,20 @@
> +; RUN: opt -regions -analyze < %s 
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +
> +define void @normal_condition() nounwind {
> +0:
> +	br label %"1"
> +1:
> +	br i1 1, label %"2", label %"3"
> +2:
> +	br label %"2"
> +3:
> +	br label %"4"
> +4:
> +	ret void
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK: [1] 1 => 4
> +; STAT: 2 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/infinite_loop_2.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/infinite_loop_2.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/infinite_loop_2.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/infinite_loop_2.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,36 @@
> +; RUN: opt -regions -analyze < %s 
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition() nounwind {
> +0:
> +	br label %"1"
> +1:
> +	br i1 1, label %"2", label %"3"
> +2:
> +	br label %"5"
> +5:
> +	br i1 1, label %"11", label %"12"
> +11:
> +        br label %"6"
> +12:
> +        br label %"6"
> +6:
> +        br label %"2"
> +3:
> +	br label %"4"
> +4:
> +	ret void
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK: [1] 1 => 3
> +; STAT: 2 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: 0, 1, 2, 5, 11, 6, 12, 3, 4,
> +; BBIT: 1, 2, 5, 11, 6, 12,
> +
> +; RNIT: 0, 1 => 3, 3, 4,
> +; RNIT: 1, 2, 5, 11, 6, 12,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/infinite_loop_3.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/infinite_loop_3.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/infinite_loop_3.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/infinite_loop_3.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,52 @@
> +; RUN: opt -regions -analyze < %s 
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition() nounwind {
> +0:
> +	br label %"7"
> +7:
> +	br i1 1, label %"1", label %"8"
> +1:
> +	br i1 1, label %"2", label %"3"
> +2:
> +	br label %"5"
> +5:
> +	br i1 1, label %"11", label %"12"
> +11:
> +        br label %"6"
> +12:
> +        br label %"6"
> +6:
> +        br label %"2"
> +8:
> +	br label %"9"
> +9:
> +	br i1 1, label %"13", label %"14"
> +13:
> +        br label %"10"
> +14:
> +        br label %"10"
> +10:
> +        br label %"8"
> +3:
> +	br label %"4"
> +4:
> +	ret void
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK-NEXT: [1] 1 => 3
> +; CHECK-NEXT: [1] 7 => 1
> +; STAT: 3 region - The # of regions
> +; STAT: 2 region - The # of simple regions
> +
> +; BBIT: 0, 7, 1, 2, 5, 11, 6, 12, 3, 4, 8, 9, 13, 10, 14,
> +; BBIT: 7, 8, 9, 13, 10, 14,
> +; BBIT: 1, 2, 5, 11, 6, 12,
> +
> +; RNIT: 0, 7 => 1, 1 => 3, 3, 4,
> +; RNIT: 7, 8, 9, 13, 10, 14,
> +; RNIT: 1, 2, 5, 11, 6, 12,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/infinite_loop_4.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/infinite_loop_4.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/infinite_loop_4.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/infinite_loop_4.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,48 @@
> +; RUN: opt -regions -analyze < %s 
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition() nounwind {
> +0:
> +	br label %"7"
> +7:
> +	br i1 1, label %"1", label %"8"
> +1:
> +	br i1 1, label %"2", label %"3"
> +2:
> +	br label %"5"
> +5:
> +	br i1 1, label %"11", label %"12"
> +11:
> +        br label %"6"
> +12:
> +        br label %"6"
> +6:
> +	br i1 1, label %"2", label %"10"
> +8:
> +	br label %"9"
> +9:
> +	br i1 1, label %"13", label %"14"
> +13:
> +        br label %"10"
> +14:
> +        br label %"10"
> +10:
> +        br label %"8"
> +3:
> +	br label %"4"
> +4:
> +	ret void
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK-NEXT: [1] 7 => 3
> +; STAT: 2 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: 0, 7, 1, 2, 5, 11, 6, 10, 8, 9, 13, 14, 12, 3, 4,
> +; BBIT: 7, 1, 2, 5, 11, 6, 10, 8, 9, 13, 14, 12,
> +
> +; RNIT: 0, 7 => 3, 3, 4,
> +; RNIT: 7, 1, 2, 5, 11, 6, 10, 8, 9, 13, 14, 12,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/loop_with_condition.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/loop_with_condition.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/loop_with_condition.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/loop_with_condition.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,46 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition() nounwind {
> +0:
> +        br label %"1"
> +1:
> +	br i1 1, label %"6", label %"2"
> +2:
> +	br i1 1, label %"3", label %"4"
> +3:
> +	br label %"5"
> +4:
> +	br label %"5"
> +5:
> +        br label %"8"
> +8:
> +        br i1 1, label %"7", label %"9"
> +9:
> +        br label %"2"
> +7:
> +        br label %"6"
> +6:
> +	ret void
> +}
> +
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK-NEXT: [1] 1 => 6
> +; CHECK-NEXT:   [2] 2 => 7
> +; CHECK-NEXT:     [3] 2 => 5
> +; STAT: 4 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: 0, 1, 6, 2, 3, 5, 8, 7, 9, 4,
> +; BBIT: 1, 2, 3, 5, 8, 7, 9, 4,
> +; BBIT: 2, 3, 5, 8, 9, 4,
> +; BBIT: 2, 3, 4,
> +
> +; RNIT: 0, 1 => 6, 6,
> +; RNIT: 1, 2 => 7, 7,
> +; RNIT: 2 => 5, 5, 8, 9,
> +; RNIT: 2, 3, 4,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/loops_1.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/loops_1.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/loops_1.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/loops_1.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,40 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define internal fastcc zeroext i8 @loops_1() nounwind {
> +entry:
> +  br i1 1, label %outer , label %a
> +
> +a:
> +  br label %body
> +
> +outer:
> +  br label %body
> +
> +body:
> +  br i1 1, label %land, label %if
> +
> +land:
> +  br i1 1, label %exit, label %end
> +
> +exit:
> +  br i1 1, label %if, label %end
> +
> +if:
> +  br label %outer
> +
> +end:
> +  ret i8 1
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] entry => <Function Return>
> +; CHECK-NEXT: [1] entry => end
> +; STAT: 2 region - The # of regions
> +
> +; BBIT: entry, outer, body, land, exit, if, end, a,
> +; BBIT: entry, outer, body, land, exit, if, a,
> +
> +; RNIT: entry => end, end,
> +; RNIT: entry, outer, body, land, exit, if, a,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/loops_2.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/loops_2.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/loops_2.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/loops_2.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,49 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @meread_() nounwind {
> +entry:
> +  br label %bb23
> +
> +bb23:
> +  br label %bb.i
> +
> +bb.i:                                             ; preds = %bb.i, %bb54
> +  br label %pflini_.exit
> +
> +pflini_.exit:                                     ; preds = %bb.i
> +  br label %bb58thread-split
> +
> +bb58thread-split:                                 ; preds = %bb64, %bb61, %pflini_.exit
> +  br label %bb58
> +
> +bb58:                                             ; preds = %bb60, %bb58thread-split
> +  br i1 1, label %bb59, label %bb23
> +
> +bb59:                                             ; preds = %bb58
> +  switch i32 1, label %bb60 [
> +    i32 1, label %l98
> +  ]
> +
> +bb60:                                             ; preds = %bb59
> +  br i1 1, label %bb61, label %bb58
> +
> +bb61:                                             ; preds = %bb60
> +  br label %bb58thread-split
> +
> +l98:                                   ; preds = %bb69, %bb59
> +  ret void
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] entry => <Function Return>
> +; CHECK: [1] bb23 => l98
> +; STAT: 2 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: entry, bb23, bb.i, pflini_.exit, bb58thread-split, bb58, bb59, bb60, bb61, l98,
> +; BBIT: bb23, bb.i, pflini_.exit, bb58thread-split, bb58, bb59, bb60, bb61,
> +
> +; RNIT: entry, bb23 => l98, l98,
> +; RNIT: bb23, bb.i, pflini_.exit, bb58thread-split, bb58, bb59, bb60, bb61,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/mix_1.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/mix_1.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/mix_1.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/mix_1.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,69 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @a_linear_impl_fig_1() nounwind {
> +0:
> +
> +	br i1 1, label %"1", label %"15"
> +1:
> + 	switch i32 0, label %"2" [ i32 0, label %"3"
> +                                  i32 1, label %"7"]
> +2:
> +	br label %"4"
> +3:
> +	br label %"5"
> +4:
> +	br label %"6"
> +5:
> +	br label %"6"
> +6:
> +	br label %"7"
> +7:
> +	br label %"15"
> +15:
> +	br label %"8"
> +8:
> +	br label %"16"
> +16:
> +        br label %"9"
> +9:
> +	br i1 1, label %"10", label %"11"
> +11:
> +	br i1 1, label %"13", label %"12"
> +13:
> +	br label %"14"
> +12:
> +	br label %"14"
> +14:
> +	br label %"8"
> +10:
> +        br label %"17"
> +17:
> +        br label %"18"
> +18:
> +        ret void
> +}
> +
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK-NEXT: [1] 0 => 15
> +; CHECK-NEXT:  [2] 1 => 7
> +; CHECK-NEXT: [1] 8 => 10
> +; CHECK-NEXT:  [2] 11 => 14
> +; STAT: 5 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: 0, 1, 2, 4, 6, 7, 15, 8, 16, 9, 10, 17, 18, 11, 13, 14, 12, 3, 5,
> +; BBIT: 0, 1, 2, 4, 6, 7, 3, 5,
> +; BBIT: 1, 2, 4, 6, 3, 5,
> +; BBIT: 8, 16, 9, 11, 13, 14, 12,
> +; BBIT: 11, 13, 12,
> +
> +; RNIT: 0 => 15, 15, 8 => 10, 10, 17, 18,
> +; RNIT: 0, 1 => 7, 7,
> +; RNIT: 1, 2, 4, 6, 3, 5,
> +; RNIT: 8, 16, 9, 11 => 14, 14,
> +; RNIT: 11, 13, 12,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/multiple_exiting_edge.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/multiple_exiting_edge.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/multiple_exiting_edge.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/multiple_exiting_edge.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,38 @@
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @normal_condition_0() nounwind {
> +bb38:                                             ; preds = %bb34, %bb34, %bb37
> +  switch i32 undef, label %bb42 [
> +    i32 67, label %bb42
> +    i32 90, label %bb41
> +  ]
> +bb41:                                             ; preds = %bb38
> +  br label %bb42
> +bb42:                                             ; preds = %bb38, %bb38, %bb41
> +  ret void
> +}
> +
> +; BBIT: bb38, bb42, bb41,
> +; BBIT: bb38, bb41,
> +
> +; RNIT: bb38 => bb42, bb42,
> +; RNIT: bb38, bb41,
> +
> +define void @normal_condition_1() nounwind {
> +bb38:                                             ; preds = %bb34, %bb34, %bb37
> +  switch i32 undef, label %bb41 [
> +    i32 67, label %bb42
> +    i32 90, label %bb42
> +  ]
> +bb41:                                             ; preds = %bb38
> +  br label %bb42
> +bb42:                                             ; preds = %bb38, %bb38, %bb41
> +  ret void
> +}
> +
> +; BBIT: bb38, bb41, bb42,
> +; BBIT: bb38, bb41,
> +
> +; RNIT: bb38 => bb42, bb42,
> +; RNIT: bb38, bb41,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/nested_loops.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/nested_loops.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/nested_loops.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/nested_loops.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,33 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define internal fastcc zeroext i8 @handle_compress() nounwind {
> +entry:
> +  br label %outer
> +
> +outer:
> +  br label %body
> +
> +body:
> +  br i1 1, label %exit172, label %end
> +
> +exit172:
> +  br i1 1, label %end, label %outer
> +
> +end:
> +  ret i8 1
> +}
> +; CHECK-NOT: =>
> +; CHECK: [0] entry => <Function Return>
> +; CHECK-NEXT: [1] outer => end
> +
> +; STAT: 2 region - The # of regions
> +
> +; BBIT: entry, outer, body, exit172, end,
> +; BBIT: outer, body, exit172,
> +
> +; RNIT: entry, outer => end, end,
> +; RNIT: outer, body, exit172,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/next.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/next.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/next.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/next.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,49 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @MAIN__() nounwind {
> +entry:
> +  br label %__label_002001.outer
> +
> +__label_002001.outer:                             ; preds = %bb236, %bb92
> +  br label %__label_002001
> +
> +__label_002001:                                   ; preds = %bb229, %__label_002001.outer
> +  br i1  1, label %bb93, label %__label_000020
> +
> +bb93:                                             ; preds = %__label_002001
> +  br i1  1, label %__label_000020, label %bb197
> +
> +bb197:                                            ; preds = %bb193
> +  br i1  1, label %bb229, label %bb224
> +
> +bb224:                                            ; preds = %bb223, %bb227
> +  br i1  1, label %bb229, label %bb224
> +
> +bb229:                                            ; preds = %bb227, %bb223
> +  br i1  1, label %__label_002001, label %__label_002001.outer
> +
> +__label_000020:                                   ; preds = %__label_002001, %bb194
> +  ret void
> +}
> +
> +; CHECK-NOT: =>
> +; CHECK: [0] entry => <Function Return>
> +; CHECK-NEXT:  [1] __label_002001.outer => __label_000020
> +; CHECK-NEXT;      [2] bb197 => bb229
> +; CHECK-NEXT;            [3] bb224 => bb229
> +
> +; STAT: 4 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: entry, __label_002001.outer, __label_002001, bb93, __label_000020, bb197, bb229, bb224,
> +; BBIT: __label_002001.outer, __label_002001, bb93, bb197, bb229, bb224,
> +; BBIT: bb197, bb224,
> +; BBIT: bb224,
> +
> +; RNIT: entry, __label_002001.outer => __label_000020, __label_000020,
> +; RNIT: __label_002001.outer, __label_002001, bb93, bb197 => bb229, bb229,
> +; RNIT: bb197, bb224 => bb229,
> +; RNIT: bb224,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/paper.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/paper.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/paper.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/paper.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,55 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define void @a_linear_impl_fig_1() nounwind {
> +0:
> +        br label %"1"
> +1:
> +	br label %"2"
> +2:
> +	br label %"3"
> +3:
> +	br i1 1, label %"13", label %"4"
> +4:
> +	br i1 1, label %"5", label %"1"
> +5:
> +	br i1 1, label %"8", label %"6"
> +6:
> +	br i1 1, label %"7", label %"4"
> +7:
> +	ret void
> +8:
> +	br i1 1, label %"9", label %"1"
> +9:
> +	br label %"10"
> +10:
> +	br i1 1, label %"12", label %"11"
> +11:
> +	br i1 1, label %"9", label %"8"
> +13:
> +	br i1 1, label %"2", label %"1"
> +12:
> + 	switch i32 0, label %"1" [ i32 0, label %"9"
> +                                  i32 1, label %"8"]
> +}
> +
> +; CHECK-NOT: =>
> +; CHECK: [0] 0 => <Function Return>
> +; CHECK-NEXT: [1] 1 => 7
> +; CHECK-NEXT:   [2] 1 => 4
> +; CHECK-NEXT:   [2] 8 => 1
> +
> +; STAT: 4 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: 0, 1, 2, 3, 13, 4, 5, 8, 9, 10, 12, 11, 6, 7,
> +; BBIT: 1, 2, 3, 13, 4, 5, 8, 9, 10, 12, 11, 6,
> +; BBIT: 1, 2, 3, 13,
> +; BBIT: 8, 9, 10, 12, 11,
> +
> +; RNIT: 0, 1 => 7, 7,
> +; RNIT: 1 => 4, 4, 5, 8 => 1, 6,
> +; RNIT: 1, 2, 3, 13,
> +; RNIT: 8, 9, 10, 12, 11,
> 
> Added: llvm/trunk/test/Analysis/RegionInfo/two_loops_same_header.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/RegionInfo/two_loops_same_header.ll?rev=109089&view=auto
> ==============================================================================
> --- llvm/trunk/test/Analysis/RegionInfo/two_loops_same_header.ll (added)
> +++ llvm/trunk/test/Analysis/RegionInfo/two_loops_same_header.ll Thu Jul 22 02:46:31 2010
> @@ -0,0 +1,46 @@
> +; RUN: opt -regions -analyze < %s | FileCheck %s
> +; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
> +; RUN: opt -regions -print-region-style=bb  -analyze < %s |& FileCheck -check-prefix=BBIT %s
> +; RUN: opt -regions -print-region-style=rn  -analyze < %s |& FileCheck -check-prefix=RNIT %s
> +
> +define internal fastcc zeroext i8 @handle_compress() nounwind {
> +entry:
> +  br label %outer
> +
> +outer:
> +  br label %body
> +
> +body:
> +  br i1 1, label %else, label %true77
> +
> +true77:
> +  br i1 1, label %then83, label %else
> +
> +then83:
> +  br label %outer
> +
> +else:
> +  br label %else106
> +
> +else106:
> +  br i1 1, label %end, label %outer
> +
> +end:
> +  ret i8 1
> +}
> +
> +; CHECK-NOT: =>
> +; CHECK: [0] entry => <Function Return>
> +; CHECK-NEXT: [1] outer => end
> +; CHECK-NEXT:   [2] outer => else
> +
> +; STAT: 3 region - The # of regions
> +; STAT: 1 region - The # of simple regions
> +
> +; BBIT: entry, outer, body, else, else106, end, true77, then83,
> +; BBIT: outer, body, else, else106, true77, then83,
> +; BBIT: outer, body, true77, then83,
> +
> +; RNIT: entry, outer => end, end,
> +; RNIT: outer => else, else, else106,
> +; RNIT: outer, body, true77, then83,
> 
> 
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