1 //===- LoopPass.h - LoopPass class ----------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines LoopPass class. All loop optimization
11 // and transformation passes are derived from LoopPass.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_LOOP_PASS_H
16 #define LLVM_LOOP_PASS_H
18 #include "llvm/Analysis/LoopInfo.h"
19 #include "llvm/Pass.h"
20 #include "llvm/PassManagers.h"
21 #include "llvm/Function.h"
29 class LoopPass : public Pass {
31 explicit LoopPass(intptr_t pid) : Pass(pid) {}
32 explicit LoopPass(void *pid) : Pass(pid) {}
34 // runOnLoop - This method should be implemented by the subclass to perform
35 // whatever action is necessary for the specified Loop.
36 virtual bool runOnLoop(Loop *L, LPPassManager &LPM) = 0;
38 // Initialization and finalization hooks.
39 virtual bool doInitialization(Loop *L, LPPassManager &LPM) {
40 Context = L->getHeader()->getContext();
44 // Finalization hook does not supply Loop because at this time
45 // loop nest is completely different.
46 virtual bool doFinalization() { return false; }
48 // Check if this pass is suitable for the current LPPassManager, if
49 // available. This pass P is not suitable for a LPPassManager if P
50 // is not preserving higher level analysis info used by other
51 // LPPassManager passes. In such case, pop LPPassManager from the
52 // stack. This will force assignPassManager() to create new
53 // LPPassManger as expected.
54 void preparePassManager(PMStack &PMS);
56 /// Assign pass manager to manager this pass
57 virtual void assignPassManager(PMStack &PMS,
58 PassManagerType PMT = PMT_LoopPassManager);
60 /// Return what kind of Pass Manager can manage this pass.
61 virtual PassManagerType getPotentialPassManagerType() const {
62 return PMT_LoopPassManager;
65 //===--------------------------------------------------------------------===//
66 /// SimpleAnalysis - Provides simple interface to update analysis info
67 /// maintained by various passes. Note, if required this interface can
68 /// be extracted into a separate abstract class but it would require
69 /// additional use of multiple inheritance in Pass class hierarchy, something
70 /// we are trying to avoid.
72 /// Each loop pass can override these simple analysis hooks to update
73 /// desired analysis information.
74 /// cloneBasicBlockAnalysis - Clone analysis info associated with basic block.
75 virtual void cloneBasicBlockAnalysis(BasicBlock *F, BasicBlock *T, Loop *L) {}
77 /// deletekAnalysisValue - Delete analysis info associated with value V.
78 virtual void deleteAnalysisValue(Value *V, Loop *L) {}
81 class LPPassManager : public FunctionPass, public PMDataManager {
84 explicit LPPassManager(int Depth);
86 /// run - Execute all of the passes scheduled for execution. Keep track of
87 /// whether any of the passes modifies the module, and if so, return true.
88 bool runOnFunction(Function &F);
90 /// Pass Manager itself does not invalidate any analysis info.
91 // LPPassManager needs LoopInfo.
92 void getAnalysisUsage(AnalysisUsage &Info) const;
94 virtual const char *getPassName() const {
95 return "Loop Pass Manager";
98 /// Print passes managed by this manager
99 void dumpPassStructure(unsigned Offset);
101 Pass *getContainedPass(unsigned N) {
102 assert(N < PassVector.size() && "Pass number out of range!");
103 Pass *FP = static_cast<Pass *>(PassVector[N]);
107 virtual PassManagerType getPassManagerType() const {
108 return PMT_LoopPassManager;
112 // Delete loop from the loop queue and loop nest (LoopInfo).
113 void deleteLoopFromQueue(Loop *L);
115 // Insert loop into the loop nest(LoopInfo) and loop queue(LQ).
116 void insertLoop(Loop *L, Loop *ParentLoop);
118 // Reoptimize this loop. LPPassManager will re-insert this loop into the
119 // queue. This allows LoopPass to change loop nest for the loop. This
120 // utility may send LPPassManager into infinite loops so use caution.
121 void redoLoop(Loop *L);
123 //===--------------------------------------------------------------------===//
124 /// SimpleAnalysis - Provides simple interface to update analysis info
125 /// maintained by various passes. Note, if required this interface can
126 /// be extracted into a separate abstract class but it would require
127 /// additional use of multiple inheritance in Pass class hierarchy, something
128 /// we are trying to avoid.
130 /// cloneBasicBlockSimpleAnalysis - Invoke cloneBasicBlockAnalysis hook for
131 /// all passes that implement simple analysis interface.
132 void cloneBasicBlockSimpleAnalysis(BasicBlock *From, BasicBlock *To, Loop *L);
134 /// deleteSimpleAnalysisValue - Invoke deleteAnalysisValue hook for all passes
135 /// that implement simple analysis interface.
136 void deleteSimpleAnalysisValue(Value *V, Loop *L);
139 std::deque<Loop *> LQ;
146 } // End llvm namespace