LLVM  9.0.0svn
MachineFunctionPass.h
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1 //===-- MachineFunctionPass.h - Pass for MachineFunctions --------*-C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the MachineFunctionPass class. MachineFunctionPass's are
10 // just FunctionPass's, except they operate on machine code as part of a code
11 // generator. Because they operate on machine code, not the LLVM
12 // representation, MachineFunctionPass's are not allowed to modify the LLVM
13 // representation. Due to this limitation, the MachineFunctionPass class takes
14 // care of declaring that no LLVM passes are invalidated.
15 //
16 //===----------------------------------------------------------------------===//
17 
18 #ifndef LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
19 #define LLVM_CODEGEN_MACHINEFUNCTIONPASS_H
20 
22 #include "llvm/Pass.h"
23 
24 namespace llvm {
25 
26 /// MachineFunctionPass - This class adapts the FunctionPass interface to
27 /// allow convenient creation of passes that operate on the MachineFunction
28 /// representation. Instead of overriding runOnFunction, subclasses
29 /// override runOnMachineFunction.
31 public:
32  bool doInitialization(Module&) override {
33  // Cache the properties info at module-init time so we don't have to
34  // construct them for every function.
35  RequiredProperties = getRequiredProperties();
36  SetProperties = getSetProperties();
37  ClearedProperties = getClearedProperties();
38  return false;
39  }
40 protected:
41  explicit MachineFunctionPass(char &ID) : FunctionPass(ID) {}
42 
43  /// runOnMachineFunction - This method must be overloaded to perform the
44  /// desired machine code transformation or analysis.
45  ///
46  virtual bool runOnMachineFunction(MachineFunction &MF) = 0;
47 
48  /// getAnalysisUsage - Subclasses that override getAnalysisUsage
49  /// must call this.
50  ///
51  /// For MachineFunctionPasses, calling AU.preservesCFG() indicates that
52  /// the pass does not modify the MachineBasicBlock CFG.
53  ///
54  void getAnalysisUsage(AnalysisUsage &AU) const override;
55 
58  }
61  }
64  }
65 
66 private:
67  MachineFunctionProperties RequiredProperties;
68  MachineFunctionProperties SetProperties;
69  MachineFunctionProperties ClearedProperties;
70 
71  /// createPrinterPass - Get a machine function printer pass.
72  Pass *createPrinterPass(raw_ostream &O,
73  const std::string &Banner) const override;
74 
75  bool runOnFunction(Function &F) override;
76 };
77 
78 } // End llvm namespace
79 
80 #endif
Pass interface - Implemented by all 'passes'.
Definition: Pass.h:80
This class represents lattice values for constants.
Definition: AllocatorList.h:23
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:64
virtual MachineFunctionProperties getClearedProperties() const
F(f)
MachineFunctionPass - This class adapts the FunctionPass interface to allow convenient creation of pa...
virtual MachineFunctionProperties getRequiredProperties() const
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.
Represent the analysis usage information of a pass.
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:284
virtual bool runOnMachineFunction(MachineFunction &MF)=0
runOnMachineFunction - This method must be overloaded to perform the desired machine code transformat...
bool doInitialization(Module &) override
doInitialization - Virtual method overridden by subclasses to do any necessary initialization before ...
virtual MachineFunctionProperties getSetProperties() const
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
Properties which a MachineFunction may have at a given point in time.