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1 : //===- LoopPass.h - LoopPass class ----------------------------------------===//
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 LoopPass class. All loop optimization
11 : // and transformation passes are derived from LoopPass.
12 : //
13 : //===----------------------------------------------------------------------===//
14 :
15 : #ifndef LLVM_ANALYSIS_LOOPPASS_H
16 : #define LLVM_ANALYSIS_LOOPPASS_H
17 :
18 : #include "llvm/Analysis/LoopInfo.h"
19 : #include "llvm/IR/LegacyPassManagers.h"
20 : #include "llvm/Pass.h"
21 : #include <deque>
22 :
23 : namespace llvm {
24 :
25 : class LPPassManager;
26 : class Function;
27 : class PMStack;
28 :
29 : class LoopPass : public Pass {
30 : public:
31 : explicit LoopPass(char &pid) : Pass(PT_Loop, pid) {}
32 :
33 : /// getPrinterPass - Get a pass to print the function corresponding
34 : /// to a Loop.
35 : Pass *createPrinterPass(raw_ostream &O,
36 : const std::string &Banner) const override;
37 :
38 : // runOnLoop - This method should be implemented by the subclass to perform
39 : // whatever action is necessary for the specified Loop.
40 : virtual bool runOnLoop(Loop *L, LPPassManager &LPM) = 0;
41 :
42 : using llvm::Pass::doInitialization;
43 : using llvm::Pass::doFinalization;
44 :
45 : // Initialization and finalization hooks.
46 74079 : virtual bool doInitialization(Loop *L, LPPassManager &LPM) {
47 74079 : return false;
48 : }
49 :
50 : // Finalization hook does not supply Loop because at this time
51 : // loop nest is completely different.
52 35354 : virtual bool doFinalization() { return false; }
53 :
54 : // Check if this pass is suitable for the current LPPassManager, if
55 : // available. This pass P is not suitable for a LPPassManager if P
56 : // is not preserving higher level analysis info used by other
57 : // LPPassManager passes. In such case, pop LPPassManager from the
58 : // stack. This will force assignPassManager() to create new
59 : // LPPassManger as expected.
60 : void preparePassManager(PMStack &PMS) override;
61 :
62 : /// Assign pass manager to manage this pass
63 : void assignPassManager(PMStack &PMS, PassManagerType PMT) override;
64 :
65 : /// Return what kind of Pass Manager can manage this pass.
66 284712 : PassManagerType getPotentialPassManagerType() const override {
67 284712 : return PMT_LoopPassManager;
68 : }
69 :
70 : //===--------------------------------------------------------------------===//
71 : /// SimpleAnalysis - Provides simple interface to update analysis info
72 : /// maintained by various passes. Note, if required this interface can
73 : /// be extracted into a separate abstract class but it would require
74 : /// additional use of multiple inheritance in Pass class hierarchy, something
75 : /// we are trying to avoid.
76 :
77 : /// Each loop pass can override these simple analysis hooks to update
78 : /// desired analysis information.
79 : /// cloneBasicBlockAnalysis - Clone analysis info associated with basic block.
80 725 : virtual void cloneBasicBlockAnalysis(BasicBlock *F, BasicBlock *T, Loop *L) {}
81 :
82 : /// deleteAnalysisValue - Delete analysis info associated with value V.
83 262 : virtual void deleteAnalysisValue(Value *V, Loop *L) {}
84 :
85 : /// Delete analysis info associated with Loop L.
86 : /// Called to notify a Pass that a loop has been deleted and any
87 : /// associated analysis values can be deleted.
88 2323 : virtual void deleteAnalysisLoop(Loop *L) {}
89 :
90 : protected:
91 : /// Optional passes call this function to check whether the pass should be
92 : /// skipped. This is the case when Attribute::OptimizeNone is set or when
93 : /// optimization bisect is over the limit.
94 : bool skipLoop(const Loop *L) const;
95 : };
96 :
97 : class LPPassManager : public FunctionPass, public PMDataManager {
98 : public:
99 : static char ID;
100 : explicit LPPassManager();
101 :
102 : /// run - Execute all of the passes scheduled for execution. Keep track of
103 : /// whether any of the passes modifies the module, and if so, return true.
104 : bool runOnFunction(Function &F) override;
105 :
106 : /// Pass Manager itself does not invalidate any analysis info.
107 : // LPPassManager needs LoopInfo.
108 : void getAnalysisUsage(AnalysisUsage &Info) const override;
109 :
110 0 : StringRef getPassName() const override { return "Loop Pass Manager"; }
111 :
112 37225 : PMDataManager *getAsPMDataManager() override { return this; }
113 121504 : Pass *getAsPass() override { return this; }
114 :
115 : /// Print passes managed by this manager
116 : void dumpPassStructure(unsigned Offset) override;
117 :
118 : LoopPass *getContainedPass(unsigned N) {
119 : assert(N < PassVector.size() && "Pass number out of range!");
120 395350 : LoopPass *LP = static_cast<LoopPass *>(PassVector[N]);
121 : return LP;
122 : }
123 :
124 105943 : PassManagerType getPassManagerType() const override {
125 105943 : return PMT_LoopPassManager;
126 : }
127 :
128 : public:
129 : // Add a new loop into the loop queue.
130 : void addLoop(Loop &L);
131 :
132 : // Mark \p L as deleted.
133 : void markLoopAsDeleted(Loop &L);
134 :
135 : //===--------------------------------------------------------------------===//
136 : /// SimpleAnalysis - Provides simple interface to update analysis info
137 : /// maintained by various passes. Note, if required this interface can
138 : /// be extracted into a separate abstract class but it would require
139 : /// additional use of multiple inheritance in Pass class hierarchy, something
140 : /// we are trying to avoid.
141 :
142 : /// cloneBasicBlockSimpleAnalysis - Invoke cloneBasicBlockAnalysis hook for
143 : /// all passes that implement simple analysis interface.
144 : void cloneBasicBlockSimpleAnalysis(BasicBlock *From, BasicBlock *To, Loop *L);
145 :
146 : /// deleteSimpleAnalysisValue - Invoke deleteAnalysisValue hook for all passes
147 : /// that implement simple analysis interface.
148 : void deleteSimpleAnalysisValue(Value *V, Loop *L);
149 :
150 : /// Invoke deleteAnalysisLoop hook for all passes that implement simple
151 : /// analysis interface.
152 : void deleteSimpleAnalysisLoop(Loop *L);
153 :
154 : private:
155 : std::deque<Loop *> LQ;
156 : LoopInfo *LI;
157 : Loop *CurrentLoop;
158 : bool CurrentLoopDeleted;
159 : };
160 :
161 : // This pass is required by the LCSSA transformation. It is used inside
162 : // LPPassManager to check if current pass preserves LCSSA form, and if it does
163 : // pass manager calls lcssa verification for the current loop.
164 : struct LCSSAVerificationPass : public FunctionPass {
165 : static char ID;
166 14174 : LCSSAVerificationPass() : FunctionPass(ID) {
167 14174 : initializeLCSSAVerificationPassPass(*PassRegistry::getPassRegistry());
168 : }
169 :
170 213832 : bool runOnFunction(Function &F) override { return false; }
171 :
172 14174 : void getAnalysisUsage(AnalysisUsage &AU) const override {
173 : AU.setPreservesAll();
174 14174 : }
175 : };
176 :
177 : } // End llvm namespace
178 :
179 : #endif
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