LLVM  6.0.0svn
MachineFunctionPass.h
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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 
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.
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 
59  }
62  }
65  }
66 
67 private:
68  MachineFunctionProperties RequiredProperties;
69  MachineFunctionProperties SetProperties;
70  MachineFunctionProperties ClearedProperties;
71 
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
Pass interface - Implemented by all 'passes'.
Definition: Pass.h:81
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:63
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:285
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:44
Properties which a MachineFunction may have at a given point in time.