1//===- RegionPass.h - RegionPass class --------------------------*- 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 RegionPass class. All region based analysis,
10// optimization and transformation passes are derived from RegionPass.
11// This class is implemented following the some ideas of the LoopPass.h class.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_ANALYSIS_REGIONPASS_H
16#define LLVM_ANALYSIS_REGIONPASS_H
17
18#include "llvm/IR/LegacyPassManagers.h"
19#include "llvm/Pass.h"
20#include <deque>
21
22namespace llvm {
23class Function;
24class RGPassManager;
25class Region;
26class RegionInfo;
27
28//===----------------------------------------------------------------------===//
29/// A pass that runs on each Region in a function.
30///
31/// RegionPass is managed by RGPassManager.
32class RegionPass : public Pass {
33public:
34 explicit RegionPass(char &pid) : Pass(PT_Region, pid) {}
35
36 //===--------------------------------------------------------------------===//
37 /// @name To be implemented by every RegionPass
38 ///
39 //@{
40 /// Run the pass on a specific Region
41 ///
42 /// Accessing regions not contained in the current region is not allowed.
43 ///
44 /// @param R The region this pass is run on.
45 /// @param RGM The RegionPassManager that manages this Pass.
46 ///
47 /// @return True if the pass modifies this Region.
48 virtual bool runOnRegion(Region *R, RGPassManager &RGM) = 0;
49
50 /// Get a pass to print the LLVM IR in the region.
51 ///
52 /// @param O The output stream to print the Region.
53 /// @param Banner The banner to separate different printed passes.
54 ///
55 /// @return The pass to print the LLVM IR in the region.
56 Pass *createPrinterPass(raw_ostream &O,
57 const std::string &Banner) const override;
58
59 using llvm::Pass::doInitialization;
60 using llvm::Pass::doFinalization;
61
62 virtual bool doInitialization(Region *R, RGPassManager &RGM) { return false; }
63 virtual bool doFinalization() { return false; }
64 //@}
65
66 //===--------------------------------------------------------------------===//
67 /// @name PassManager API
68 ///
69 //@{
70 void preparePassManager(PMStack &PMS) override;
71
72 void assignPassManager(PMStack &PMS,
73 PassManagerType PMT = PMT_RegionPassManager) override;
74
75 PassManagerType getPotentialPassManagerType() const override {
76 return PMT_RegionPassManager;
77 }
78 //@}
79
80protected:
81 /// Optional passes call this function to check whether the pass should be
82 /// skipped. This is the case when optimization bisect is over the limit.
83 bool skipRegion(Region &R) const;
84};
85
86/// The pass manager to schedule RegionPasses.
87class RGPassManager : public FunctionPass, public PMDataManager {
88 std::deque<Region*> RQ;
89 RegionInfo *RI;
90 Region *CurrentRegion;
91
92public:
93 static char ID;
94 explicit RGPassManager();
95
96 /// Execute all of the passes scheduled for execution.
97 ///
98 /// @return True if any of the passes modifies the function.
99 bool runOnFunction(Function &F) override;
100
101 /// Pass Manager itself does not invalidate any analysis info.
102 /// RGPassManager needs RegionInfo.
103 void getAnalysisUsage(AnalysisUsage &Info) const override;
104
105 StringRef getPassName() const override { return "Region Pass Manager"; }
106
107 PMDataManager *getAsPMDataManager() override { return this; }
108 Pass *getAsPass() override { return this; }
109
110 /// Print passes managed by this manager.
111 void dumpPassStructure(unsigned Offset) override;
112
113 /// Get passes contained by this manager.
114 Pass *getContainedPass(unsigned N) {
115 assert(N < PassVector.size() && "Pass number out of range!");
116 Pass *FP = static_cast<Pass *>(PassVector[N]);
117 return FP;
118 }
119
120 PassManagerType getPassManagerType() const override {
121 return PMT_RegionPassManager;
122 }
123};
124
125} // End llvm namespace
126
127#endif
128

source code of llvm/include/llvm/Analysis/RegionPass.h