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      1 //==- RegisterUsageInfo.h - Register Usage Informartion Storage --*- C++ -*-==//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 /// \file
     10 /// This pass is required to take advantage of the interprocedural register
     11 /// allocation infrastructure.
     12 ///
     13 /// This pass is simple immutable pass which keeps RegMasks (calculated based on
     14 /// actual register allocation) for functions in a module and provides simple
     15 /// API to query this information.
     16 ///
     17 //===----------------------------------------------------------------------===//
     18 
     19 #ifndef LLVM_CODEGEN_PHYSICALREGISTERUSAGEINFO_H
     20 #define LLVM_CODEGEN_PHYSICALREGISTERUSAGEINFO_H
     21 
     22 #include "llvm/ADT/DenseMap.h"
     23 #include "llvm/Pass.h"
     24 #include <cstdint>
     25 #include <vector>
     26 
     27 namespace llvm {
     28 
     29 class Function;
     30 class TargetMachine;
     31 
     32 class PhysicalRegisterUsageInfo : public ImmutablePass {
     33   virtual void anchor();
     34 
     35 public:
     36   static char ID;
     37 
     38   PhysicalRegisterUsageInfo() : ImmutablePass(ID) {
     39     PassRegistry &Registry = *PassRegistry::getPassRegistry();
     40     initializePhysicalRegisterUsageInfoPass(Registry);
     41   }
     42 
     43   void getAnalysisUsage(AnalysisUsage &AU) const override {
     44     AU.setPreservesAll();
     45   }
     46 
     47   /// To set TargetMachine *, which is used to print
     48   /// analysis when command line option -print-regusage is used.
     49   void setTargetMachine(const TargetMachine *TM_) { TM = TM_; }
     50 
     51   bool doInitialization(Module &M) override;
     52 
     53   bool doFinalization(Module &M) override;
     54 
     55   /// To store RegMask for given Function *.
     56   void storeUpdateRegUsageInfo(const Function *FP,
     57                                std::vector<uint32_t> RegMask);
     58 
     59   /// To query stored RegMask for given Function *, it will return nullptr if
     60   /// function is not known.
     61   const std::vector<uint32_t> *getRegUsageInfo(const Function *FP);
     62 
     63   void print(raw_ostream &OS, const Module *M = nullptr) const override;
     64 
     65 private:
     66   /// A Dense map from Function * to RegMask.
     67   /// In RegMask 0 means register used (clobbered) by function.
     68   /// and 1 means content of register will be preserved around function call.
     69   DenseMap<const Function *, std::vector<uint32_t>> RegMasks;
     70 
     71   const TargetMachine *TM;
     72 };
     73 
     74 } // end namespace llvm
     75 
     76 #endif // LLVM_CODEGEN_PHYSICALREGISTERUSAGEINFO_H
     77