1 //===-- MachineFunctionPass.h - Pass for MachineFunctions --------*-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 //
10 // This file defines the MachineFunctionPass class.  MachineFunctionPass's are
11 // just FunctionPass's, except they operate on machine code as part of a code
12 // generator.  Because they operate on machine code, not the LLVM
13 // representation, MachineFunctionPass's are not allowed to modify the LLVM
14 // representation.  Due to this limitation, the MachineFunctionPass class takes
15 // care of declaring that no LLVM passes are invalidated.
16 //
17 //===----------------------------------------------------------------------===//
18 
19 #ifndef LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
20 #define LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
21 
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/Pass.h"
24 
25 namespace llvm {
26 
27 /// MachineFunctionPass - This class adapts the FunctionPass interface to
28 /// allow convenient creation of passes that operate on the MachineFunction
29 /// representation. Instead of overriding runOnFunction, subclasses
30 /// override runOnMachineFunction.
31 class MachineFunctionPass : public FunctionPass {
32 public:
33   bool doInitialization(Module&) override {
34     // Cache the properties info at module-init time so we don't have to
35     // construct them for every function.
36     RequiredProperties = getRequiredProperties();
37     SetProperties = getSetProperties();
38     ClearedProperties = getClearedProperties();
39     return false;
40   }
41 protected:
42   explicit MachineFunctionPass(char &ID) : FunctionPass(ID) {}
43 
44   /// runOnMachineFunction - This method must be overloaded to perform the
45   /// desired machine code transformation or analysis.
46   ///
47   virtual bool runOnMachineFunction(MachineFunction &MF) = 0;
48 
49   /// getAnalysisUsage - Subclasses that override getAnalysisUsage
50   /// must call this.
51   ///
52   /// For MachineFunctionPasses, calling AU.preservesCFG() indicates that
53   /// the pass does not modify the MachineBasicBlock CFG.
54   ///
55   void getAnalysisUsage(AnalysisUsage &AU) const override;
56 
57   virtual MachineFunctionProperties getRequiredProperties() const {
Reg(R)58     return MachineFunctionProperties();
59   }
60   virtual MachineFunctionProperties getSetProperties() const {
getReg()61     return MachineFunctionProperties();
getFrameIdx()62   }
63   virtual MachineFunctionProperties getClearedProperties() const {
64     return MachineFunctionProperties();
65   }
66 
67 private:
setDstReg(unsigned SpillReg)68   MachineFunctionProperties RequiredProperties;
69   MachineFunctionProperties SetProperties;
70   MachineFunctionProperties ClearedProperties;
71 
isRestored()72   /// createPrinterPass - Get a machine function printer pass.
73   Pass *createPrinterPass(raw_ostream &O,
74                           const std::string &Banner) const override;
75 
76   bool runOnFunction(Function &F) override;
77 };
78 
79 } // End llvm namespace
80 
81 #endif
82