1 files changed, 59 insertions, 17 deletions

diff --git a/include/llvm/Analysis/DemandedBits.h b/include/llvm/Analysis/DemandedBits.h
index 42932bfd3491d..fafd5d00b4811 100644
--- a/include/llvm/Analysis/DemandedBits.h
+++ b/include/llvm/Analysis/DemandedBits.h
@@ -26,6 +26,7 @@
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/IR/PassManager.h"
 
 namespace llvm {
 
@@ -35,40 +36,81 @@ class Instruction;
 class DominatorTree;
 class AssumptionCache;
 
-struct DemandedBits : public FunctionPass {
-  static char ID; // Pass identification, replacement for typeid
-  DemandedBits();
+class DemandedBits {
+public:
+  DemandedBits(Function &F, AssumptionCache &AC, DominatorTree &DT) :
+    F(F), AC(AC), DT(DT), Analyzed(false) {}
 
-  bool runOnFunction(Function& F) override;
-  void getAnalysisUsage(AnalysisUsage& AU) const override;
-  void print(raw_ostream &OS, const Module *M) const override;
-  
   /// Return the bits demanded from instruction I.
   APInt getDemandedBits(Instruction *I);
 
   /// Return true if, during analysis, I could not be reached.
   bool isInstructionDead(Instruction *I);
+  
+  void print(raw_ostream &OS);
 
 private:
+  Function &F;
+  AssumptionCache ∾
+  DominatorTree &DT;
+
   void performAnalysis();
   void determineLiveOperandBits(const Instruction *UserI,
-                                const Instruction *I, unsigned OperandNo,
-                                const APInt &AOut, APInt &AB,
-                                APInt &KnownZero, APInt &KnownOne,
-                                APInt &KnownZero2, APInt &KnownOne2);
-
-  AssumptionCache *AC;
-  DominatorTree *DT;
-  Function *F;
+    const Instruction *I, unsigned OperandNo,
+    const APInt &AOut, APInt &AB,
+    APInt &KnownZero, APInt &KnownOne,
+    APInt &KnownZero2, APInt &KnownOne2);
+
   bool Analyzed;
 
   // The set of visited instructions (non-integer-typed only).
-  SmallPtrSet<Instruction*, 128> Visited;
+  SmallPtrSet<Instruction*, 32> Visited;
   DenseMap<Instruction *, APInt> AliveBits;
 };
 
+class DemandedBitsWrapperPass : public FunctionPass {
+private:
+  mutable Optional<DemandedBits> DB;
+public:
+  static char ID; // Pass identification, replacement for typeid
+  DemandedBitsWrapperPass();
+
+  bool runOnFunction(Function &F) override;
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+  
+  /// Clean up memory in between runs
+  void releaseMemory() override;
+  
+  DemandedBits &getDemandedBits() { return *DB; }
+
+  void print(raw_ostream &OS, const Module *M) const override;
+};
+
+/// An analysis that produces \c DemandedBits for a function.
+class DemandedBitsAnalysis : public AnalysisInfoMixin<DemandedBitsAnalysis> {
+  friend AnalysisInfoMixin<DemandedBitsAnalysis>;
+  static char PassID;
+
+public:
+  /// \brief Provide the result typedef for this analysis pass.
+  typedef DemandedBits Result;
+
+  /// \brief Run the analysis pass over a function and produce demanded bits
+  /// information.
+  DemandedBits run(Function &F, AnalysisManager<Function> &AM);
+};
+
+/// \brief Printer pass for DemandedBits
+class DemandedBitsPrinterPass : public PassInfoMixin<DemandedBitsPrinterPass> {
+  raw_ostream &OS;
+
+public:
+  explicit DemandedBitsPrinterPass(raw_ostream &OS) : OS(OS) {}
+  PreservedAnalyses run(Function &F, AnalysisManager<Function> &AM);
+};
+
 /// Create a demanded bits analysis pass.
-FunctionPass *createDemandedBitsPass();
+FunctionPass *createDemandedBitsWrapperPass();
 
 } // End llvm namespace