Introduce RegionInfoAnalysis, which compute Region Tree in the new PassManager. NFC

Differential Revision: http://reviews.llvm.org/D17571

llvm-svn: 261904

1 files changed, 76 insertions, 0 deletions

diff --git a/llvm/include/llvm/Analysis/RegionInfo.h b/llvm/include/llvm/Analysis/RegionInfo.h
index 4988386fdc8..394a50330c6 100644
--- a/llvm/include/llvm/Analysis/RegionInfo.h
+++ b/llvm/include/llvm/Analysis/RegionInfo.h
@@ -47,6 +47,11 @@
 
 namespace llvm {
 
+// FIXME: Replace this brittle forward declaration with the include of the new
+// PassManager.h when doing so doesn't break the PassManagerBuilder.
+template <typename IRUnitT> class AnalysisManager;
+class PreservedAnalyses;
+
 // Class to be specialized for different users of RegionInfo
 // (i.e. BasicBlocks or MachineBasicBlocks). This is only to avoid needing to
 // pass around an unreasonable number of template parameters.
@@ -676,6 +681,22 @@ class RegionInfoBase {
   RegionInfoBase(const RegionInfoBase &) = delete;
   const RegionInfoBase &operator=(const RegionInfoBase &) = delete;
 
+  RegionInfoBase(RegionInfoBase &&Arg)
+    : DT(std::move(Arg.DT)), PDT(std::move(Arg.PDT)), DF(std::move(Arg.DF)),
+      TopLevelRegion(std::move(Arg.TopLevelRegion)),
+      BBtoRegion(std::move(Arg.BBtoRegion)) {
+    Arg.wipe();
+  }
+  RegionInfoBase &operator=(RegionInfoBase &&RHS) {
+    DT = std::move(RHS.DT);
+    PDT = std::move(RHS.PDT);
+    DF = std::move(RHS.DF);
+    TopLevelRegion = std::move(RHS.TopLevelRegion);
+    BBtoRegion = std::move(RHS.BBtoRegion);
+    RHS.wipe();
+    return *this;
+  }
+
   DomTreeT *DT;
   PostDomTreeT *PDT;
   DomFrontierT *DF;
@@ -687,6 +708,18 @@ private:
   /// Map every BB to the smallest region, that contains BB.
   BBtoRegionMap BBtoRegion;
 
+  /// \brief Wipe this region tree's state without releasing any resources.
+  ///
+  /// This is essentially a post-move helper only. It leaves the object in an
+  /// assignable and destroyable state, but otherwise invalid.
+  void wipe() {
+    DT = nullptr;
+    PDT = nullptr;
+    DF = nullptr;
+    TopLevelRegion = nullptr;
+    BBtoRegion.clear();
+  }
+
   // Check whether the entries of BBtoRegion for the BBs of region
   // SR are correct. Triggers an assertion if not. Calls itself recursively for
   // subregions.
@@ -836,10 +869,19 @@ public:
 
 class RegionInfo : public RegionInfoBase<RegionTraits<Function>> {
 public:
+  typedef RegionInfoBase<RegionTraits<Function>> Base;
+
   explicit RegionInfo();
 
   ~RegionInfo() override;
 
+  RegionInfo(RegionInfo &&Arg)
+    : Base(std::move(static_cast<Base &>(Arg))) {}
+  RegionInfo &operator=(RegionInfo &&RHS) {
+    Base::operator=(std::move(static_cast<Base &>(RHS)));
+    return *this;
+  }
+
   // updateStatistics - Update statistic about created regions.
   void updateStatistics(Region *R) final;
 
@@ -884,6 +926,40 @@ public:
   //@}
 };
 
+/// \brief Analysis pass that exposes the \c RegionInfo for a function.
+class RegionInfoAnalysis {
+  static char PassID;
+
+public:
+  typedef RegionInfo Result;
+
+  /// \brief Opaque, unique identifier for this analysis pass.
+  static void *ID() { return (void *)&PassID; }
+
+  /// \brief Provide a name for the analysis for debugging and logging.
+  static StringRef name() { return "RegionInfoAnalysis"; }
+
+  RegionInfo run(Function &F, AnalysisManager<Function> *AM);
+};
+
+/// \brief Printer pass for the \c RegionInfo.
+class RegionInfoPrinterPass {
+  raw_ostream &OS;
+
+public:
+  explicit RegionInfoPrinterPass(raw_ostream &OS);
+  PreservedAnalyses run(Function &F, AnalysisManager<Function> *AM);
+
+  static StringRef name() { return "RegionInfoPrinterPass"; }
+};
+
+/// \brief Verifier pass for the \c RegionInfo.
+struct RegionInfoVerifierPass {
+  PreservedAnalyses run(Function &F, AnalysisManager<Function> *AM);
+
+  static StringRef name() { return "RegionInfoVerifierPass"; }
+};
+
 template <>
 template <>
 inline BasicBlock *