Add RegionPass support.

A RegionPass is executed like a LoopPass but on the regions detected by the
RegionInfo pass instead of the loops detected by the LoopInfo pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116905 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 130 insertions, 1 deletions

diff --git a/include/llvm/Analysis/RegionPass.h b/include/llvm/Analysis/RegionPass.h
new file mode 100644
index 0000000000..aedc06aa6c
--- /dev/null
+++ b/include/llvm/Analysis/RegionPass.h
@@ -0,0 +1,126 @@
+//===- RegionPass.h - RegionPass class ------------------------------------===//
+//
+//                     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 RegionPass class. All region based analysis,
+// optimization and transformation passes are derived from RegionPass.
+// This class is implemented following the some ideas of the LoopPass.h class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_REGION_PASS_H
+#define LLVM_REGION_PASS_H
+
+#include "llvm/Analysis/RegionInfo.h"
+
+#include "llvm/Pass.h"
+#include "llvm/PassManagers.h"
+#include "llvm/Function.h"
+
+#include <deque>
+
+namespace llvm {
+
+class RGPassManager;
+class Function;
+
+//===----------------------------------------------------------------------===//
+/// @brief A pass that runs on each Region in a function.
+///
+/// RegionPass is managed by RGPassManager.
+class RegionPass : public Pass {
+public:
+  explicit RegionPass(char &pid) : Pass(PT_Region, pid) {}
+
+  //===--------------------------------------------------------------------===//
+  /// @name To be implemented by every RegionPass
+  ///
+  //@{
+  /// @brief Run the pass on a specific Region
+  ///
+  /// Accessing regions not contained in the current region is not allowed.
+  ///
+  /// @param R The region this pass is run on.
+  /// @param RGM The RegionPassManager that manages this Pass.
+  ///
+  /// @return True if the pass modifies this Region.
+  virtual bool runOnRegion(Region *R, RGPassManager &RGM) = 0;
+
+  /// @brief Get a pass to print the LLVM IR in the region.
+  ///
+  /// @param O      The ouput stream to print the Region.
+  /// @param Banner The banner to seperate different printed passes.
+  ///
+  /// @return The pass to print the LLVM IR in the region.
+  Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const;
+
+  virtual bool doInitialization(Region *R, RGPassManager &RGM) { return false; }
+  virtual bool doFinalization() { return false; }
+  //@}
+
+  //===--------------------------------------------------------------------===//
+  /// @name PassManager API
+  ///
+  //@{
+  void preparePassManager(PMStack &PMS);
+
+  virtual void assignPassManager(PMStack &PMS,
+    PassManagerType PMT = PMT_RegionPassManager);
+
+  virtual PassManagerType getPotentialPassManagerType() const {
+    return PMT_RegionPassManager;
+  }
+  //@}
+};
+
+/// @brief The pass manager to schedule RegionPasses.
+class RGPassManager : public FunctionPass, public PMDataManager {
+  std::deque<Region*> RQ;
+  bool skipThisRegion;
+  bool redoThisRegion;
+  RegionInfo *RI;
+  Region *CurrentRegion;
+
+public:
+  static char ID;
+  explicit RGPassManager(int Depth);
+
+  /// @brief Execute all of the passes scheduled for execution.
+  ///
+  /// @return True if any of the passes modifies the function.
+  bool runOnFunction(Function &F);
+
+  /// Pass Manager itself does not invalidate any analysis info.
+  /// RGPassManager needs RegionInfo.
+  void getAnalysisUsage(AnalysisUsage &Info) const;
+
+  virtual const char *getPassName() const {
+    return "Region Pass Manager";
+  }
+
+  virtual PMDataManager *getAsPMDataManager() { return this; }
+  virtual Pass *getAsPass() { return this; }
+
+  /// @brief Print passes managed by this manager.
+  void dumpPassStructure(unsigned Offset);
+
+  /// @brief Print passes contained by this manager.
+  Pass *getContainedPass(unsigned N) {
+    assert(N < PassVector.size() && "Pass number out of range!");
+    Pass *FP = static_cast<Pass *>(PassVector[N]);
+    return FP;
+  }
+
+  virtual PassManagerType getPassManagerType() const {
+    return PMT_RegionPassManager;
+  }
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/include/llvm/Pass.h b/include/llvm/Pass.h
index f4c6eed2cf..ed0fb39f5d 100644
--- a/include/llvm/Pass.h
+++ b/include/llvm/Pass.h
@@ -57,6 +57,7 @@ enum PassManagerType {
   PMT_CallGraphPassManager,  ///< CGPassManager
   PMT_FunctionPassManager,   ///< FPPassManager
   PMT_LoopPassManager,       ///< LPPassManager
+  PMT_RegionPassManager,     ///< RGPassManager
   PMT_BasicBlockPassManager, ///< BBPassManager
   PMT_Last
 };
@@ -64,13 +65,14 @@ enum PassManagerType {
 // Different types of passes.
 enum PassKind {
   PT_BasicBlock,
+  PT_Region,
   PT_Loop,
   PT_Function,
   PT_CallGraphSCC,
   PT_Module,
   PT_PassManager
 };
-  
+
 //===----------------------------------------------------------------------===//
 /// Pass interface - Implemented by all 'passes'.  Subclass this if you are an
 /// interprocedural optimization or you do not fit into any of the more
diff --git a/include/llvm/PassManagers.h b/include/llvm/PassManagers.h
index ce34f31fc0..c4f409ef52 100644
--- a/include/llvm/PassManagers.h
+++ b/include/llvm/PassManagers.h
@@ -106,6 +106,7 @@ enum PassDebuggingString {
   ON_BASICBLOCK_MSG, // "'  on BasicBlock '" + PassName + "'...\n"
   ON_FUNCTION_MSG, // "' on Function '" + FunctionName + "'...\n"
   ON_MODULE_MSG, // "' on Module '" + ModuleName + "'...\n"
+  ON_REGION_MSG, // " 'on Region ...\n'"
   ON_LOOP_MSG, // " 'on Loop ...\n'"
   ON_CG_MSG // "' on Call Graph ...\n'"
 };