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/ArrayRef.h"
23 #include "llvm/ADT/DenseMap.h"
24 #include "llvm/IR/Instructions.h"
25 #include "llvm/Pass.h"
26 #include <cstdint>
27 #include <vector>
28 
29 namespace llvm {
30 
31 class Function;
32 class LLVMTargetMachine;
33 
34 class PhysicalRegisterUsageInfo : public ImmutablePass {
35 public:
36   static char ID;
37 
PhysicalRegisterUsageInfo()38   PhysicalRegisterUsageInfo() : ImmutablePass(ID) {
39     PassRegistry &Registry = *PassRegistry::getPassRegistry();
40     initializePhysicalRegisterUsageInfoPass(Registry);
41   }
42 
43   /// Set TargetMachine which is used to print analysis.
44   void setTargetMachine(const LLVMTargetMachine &TM);
45 
46   bool doInitialization(Module &M) override;
47 
48   bool doFinalization(Module &M) override;
49 
50   /// To store RegMask for given Function *.
51   void storeUpdateRegUsageInfo(const Function &FP,
52                                ArrayRef<uint32_t> RegMask);
53 
54   /// To query stored RegMask for given Function *, it will returns ane empty
55   /// array if function is not known.
56   ArrayRef<uint32_t> getRegUsageInfo(const Function &FP);
57 
58   void print(raw_ostream &OS, const Module *M = nullptr) const override;
59 
60 private:
61   /// A Dense map from Function * to RegMask.
62   /// In RegMask 0 means register used (clobbered) by function.
63   /// and 1 means content of register will be preserved around function call.
64   DenseMap<const Function *, std::vector<uint32_t>> RegMasks;
65 
66   const LLVMTargetMachine *TM;
67 };
68 
69 } // end namespace llvm
70 
71 #endif // LLVM_CODEGEN_PHYSICALREGISTERUSAGEINFO_H
72