LLVM  16.0.0git
LoopPass.h
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1 //===- LoopPass.h - LoopPass class ----------------------------------------===//
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 LoopPass class. All loop optimization
10 // and transformation passes are derived from LoopPass.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ANALYSIS_LOOPPASS_H
15 #define LLVM_ANALYSIS_LOOPPASS_H
16 
18 #include "llvm/Pass.h"
19 #include <deque>
20 
21 namespace llvm {
22 
23 class Loop;
24 class LoopInfo;
25 class LPPassManager;
26 class Function;
27 
28 class LoopPass : public Pass {
29 public:
30  explicit LoopPass(char &pid) : Pass(PT_Loop, pid) {}
31 
32  /// getPrinterPass - Get a pass to print the function corresponding
33  /// to a Loop.
35  const std::string &Banner) const override;
36 
37  // runOnLoop - This method should be implemented by the subclass to perform
38  // whatever action is necessary for the specified Loop.
39  virtual bool runOnLoop(Loop *L, LPPassManager &LPM) = 0;
40 
43 
44  // Initialization and finalization hooks.
45  virtual bool doInitialization(Loop *L, LPPassManager &LPM) {
46  return false;
47  }
48 
49  // Finalization hook does not supply Loop because at this time
50  // loop nest is completely different.
51  virtual bool doFinalization() { return false; }
52 
53  // Check if this pass is suitable for the current LPPassManager, if
54  // available. This pass P is not suitable for a LPPassManager if P
55  // is not preserving higher level analysis info used by other
56  // LPPassManager passes. In such case, pop LPPassManager from the
57  // stack. This will force assignPassManager() to create new
58  // LPPassManger as expected.
59  void preparePassManager(PMStack &PMS) override;
60 
61  /// Assign pass manager to manage this pass
62  void assignPassManager(PMStack &PMS, PassManagerType PMT) override;
63 
64  /// Return what kind of Pass Manager can manage this pass.
66  return PMT_LoopPassManager;
67  }
68 
69 protected:
70  /// Optional passes call this function to check whether the pass should be
71  /// skipped. This is the case when Attribute::OptimizeNone is set or when
72  /// optimization bisect is over the limit.
73  bool skipLoop(const Loop *L) const;
74 };
75 
76 class LPPassManager : public FunctionPass, public PMDataManager {
77 public:
78  static char ID;
79  explicit LPPassManager();
80 
81  /// run - Execute all of the passes scheduled for execution. Keep track of
82  /// whether any of the passes modifies the module, and if so, return true.
83  bool runOnFunction(Function &F) override;
84 
85  /// Pass Manager itself does not invalidate any analysis info.
86  // LPPassManager needs LoopInfo.
87  void getAnalysisUsage(AnalysisUsage &Info) const override;
88 
89  StringRef getPassName() const override { return "Loop Pass Manager"; }
90 
91  PMDataManager *getAsPMDataManager() override { return this; }
92  Pass *getAsPass() override { return this; }
93 
94  /// Print passes managed by this manager
95  void dumpPassStructure(unsigned Offset) override;
96 
98  assert(N < PassVector.size() && "Pass number out of range!");
99  LoopPass *LP = static_cast<LoopPass *>(PassVector[N]);
100  return LP;
101  }
102 
104  return PMT_LoopPassManager;
105  }
106 
107 public:
108  // Add a new loop into the loop queue.
109  void addLoop(Loop &L);
110 
111  // Mark \p L as deleted.
112  void markLoopAsDeleted(Loop &L);
113 
114 private:
115  std::deque<Loop *> LQ;
116  LoopInfo *LI;
117  Loop *CurrentLoop;
118  bool CurrentLoopDeleted;
119 };
120 
121 // This pass is required by the LCSSA transformation. It is used inside
122 // LPPassManager to check if current pass preserves LCSSA form, and if it does
123 // pass manager calls lcssa verification for the current loop.
125  static char ID;
127 
128  bool runOnFunction(Function &F) override { return false; }
129 
130  void getAnalysisUsage(AnalysisUsage &AU) const override {
131  AU.setPreservesAll();
132  }
133 };
134 
135 } // End llvm namespace
136 
137 #endif
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
llvm::LoopPass::createPrinterPass
Pass * createPrinterPass(raw_ostream &O, const std::string &Banner) const override
getPrinterPass - Get a pass to print the function corresponding to a Loop.
Definition: LoopPass.cpp:304
llvm::Function
Definition: Function.h:60
llvm::Loop
Represents a single loop in the control flow graph.
Definition: LoopInfo.h:547
Pass.h
llvm::LoopPass::doInitialization
virtual bool doInitialization(Loop *L, LPPassManager &LPM)
Definition: LoopPass.h:45
llvm::LPPassManager::LPPassManager
LPPassManager()
Definition: LoopPass.cpp:70
llvm::PassManagerType
PassManagerType
Different types of internal pass managers.
Definition: Pass.h:52
llvm::LPPassManager::getContainedPass
LoopPass * getContainedPass(unsigned N)
Definition: LoopPass.h:97
llvm::LCSSAVerificationPass::LCSSAVerificationPass
LCSSAVerificationPass()
Definition: LoopPass.cpp:390
llvm::LCSSAVerificationPass::ID
static char ID
Definition: LoopPass.h:125
llvm::LPPassManager::ID
static char ID
Definition: LoopPass.h:78
llvm::LoopPass::LoopPass
LoopPass(char &pid)
Definition: LoopPass.h:30
llvm::LPPassManager::addLoop
void addLoop(Loop &L)
Definition: LoopPass.cpp:76
F
#define F(x, y, z)
Definition: MD5.cpp:55
llvm::PMDataManager
PMDataManager provides the common place to manage the analysis data used by pass managers.
Definition: LegacyPassManagers.h:295
llvm::PT_Loop
@ PT_Loop
Definition: Pass.h:65
llvm::LPPassManager::getAsPMDataManager
PMDataManager * getAsPMDataManager() override
Definition: LoopPass.h:91
llvm::LPPassManager::dumpPassStructure
void dumpPassStructure(unsigned Offset) override
Print passes managed by this manager.
Definition: LoopPass.cpp:291
llvm::LPPassManager::getPassName
StringRef getPassName() const override
getPassName - Return a nice clean name for a pass.
Definition: LoopPass.h:89
llvm::LoopPass::runOnLoop
virtual bool runOnLoop(Loop *L, LPPassManager &LPM)=0
llvm::LoopPass::skipLoop
bool skipLoop(const Loop *L) const
Optional passes call this function to check whether the pass should be skipped.
Definition: LoopPass.cpp:370
LegacyPassManagers.h
llvm::AnalysisUsage
Represent the analysis usage information of a pass.
Definition: PassAnalysisSupport.h:47
llvm::LoopPass::getPotentialPassManagerType
PassManagerType getPotentialPassManagerType() const override
Return what kind of Pass Manager can manage this pass.
Definition: LoopPass.h:65
llvm::raw_ostream
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:53
llvm::LCSSAVerificationPass::runOnFunction
bool runOnFunction(Function &F) override
runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass.
Definition: LoopPass.h:128
llvm::LPPassManager
Definition: LoopPass.h:76
Info
Analysis containing CSE Info
Definition: CSEInfo.cpp:27
llvm::LPPassManager::getAnalysisUsage
void getAnalysisUsage(AnalysisUsage &Info) const override
Pass Manager itself does not invalidate any analysis info.
Definition: LoopPass.cpp:102
llvm::LoopPass::preparePassManager
void preparePassManager(PMStack &PMS) override
Check if available pass managers are suitable for this pass or not.
Definition: LoopPass.cpp:315
llvm::LPPassManager::getAsPass
Pass * getAsPass() override
Definition: LoopPass.h:92
llvm::RISCVFenceField::O
@ O
Definition: RISCVBaseInfo.h:264
llvm::LoopPass
Definition: LoopPass.h:28
llvm::LoopPass::assignPassManager
void assignPassManager(PMStack &PMS, PassManagerType PMT) override
Assign pass manager to manage this pass.
Definition: LoopPass.cpp:331
llvm::LCSSAVerificationPass
Definition: LoopPass.h:124
assert
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
llvm::LCSSAVerificationPass::getAnalysisUsage
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - This function should be overriden by passes that need analysis information to do t...
Definition: LoopPass.h:130
llvm::Pass::doFinalization
virtual bool doFinalization(Module &)
doFinalization - Virtual method overriden by subclasses to do any necessary clean up after all passes...
Definition: Pass.h:120
llvm::LPPassManager::getPassManagerType
PassManagerType getPassManagerType() const override
Definition: LoopPass.h:103
llvm::LoopInfo
Definition: LoopInfo.h:1108
llvm::Pass::doInitialization
virtual bool doInitialization(Module &)
doInitialization - Virtual method overridden by subclasses to do any necessary initialization before ...
Definition: Pass.h:116
llvm::StringRef
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
llvm::PMT_LoopPassManager
@ PMT_LoopPassManager
LPPassManager.
Definition: Pass.h:57
llvm::PMStack
PMStack - This class implements a stack data structure of PMDataManager pointers.
Definition: LegacyPassManagers.h:136
llvm::LoopPass::doFinalization
virtual bool doFinalization()
Definition: LoopPass.h:51
llvm::AnalysisUsage::setPreservesAll
void setPreservesAll()
Set by analyses that do not transform their input at all.
Definition: PassAnalysisSupport.h:130
llvm::LPPassManager::markLoopAsDeleted
void markLoopAsDeleted(Loop &L)
Definition: LoopPass.cpp:110
llvm::PMDataManager::PassVector
SmallVector< Pass *, 16 > PassVector
Definition: LegacyPassManagers.h:422
llvm::LPPassManager::runOnFunction
bool runOnFunction(Function &F) override
run - Execute all of the passes scheduled for execution.
Definition: LoopPass.cpp:128
llvm::Pass
Pass interface - Implemented by all 'passes'.
Definition: Pass.h:91
N
#define N
llvm::FunctionPass
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:308
llvm::codeview::PublicSymFlags::Function
@ Function