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(PT_Loop, pid) {}
32 explicit LoopPass(void *pid) : Pass(PT_Loop, 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) {
43 // Finalization hook does not supply Loop because at this time
44 // loop nest is completely different.
45 virtual bool doFinalization() { return false; }
47 // Check if this pass is suitable for the current LPPassManager, if
48 // available. This pass P is not suitable for a LPPassManager if P
49 // is not preserving higher level analysis info used by other
50 // LPPassManager passes. In such case, pop LPPassManager from the
51 // stack. This will force assignPassManager() to create new
52 // LPPassManger as expected.
53 void preparePassManager(PMStack &PMS);
55 /// Assign pass manager to manage this pass
56 virtual void assignPassManager(PMStack &PMS,
57 PassManagerType PMT = PMT_LoopPassManager);
59 /// Return what kind of Pass Manager can manage this pass.
60 virtual PassManagerType getPotentialPassManagerType() const {
61 return PMT_LoopPassManager;
64 //===--------------------------------------------------------------------===//
65 /// SimpleAnalysis - Provides simple interface to update analysis info
66 /// maintained by various passes. Note, if required this interface can
67 /// be extracted into a separate abstract class but it would require
68 /// additional use of multiple inheritance in Pass class hierarchy, something
69 /// we are trying to avoid.
71 /// Each loop pass can override these simple analysis hooks to update
72 /// desired analysis information.
73 /// cloneBasicBlockAnalysis - Clone analysis info associated with basic block.
74 virtual void cloneBasicBlockAnalysis(BasicBlock *F, BasicBlock *T, Loop *L) {}
76 /// deleteAnalysisValue - Delete analysis info associated with value V.
77 virtual void deleteAnalysisValue(Value *V, Loop *L) {}
80 class LPPassManager : public FunctionPass, public PMDataManager {
83 explicit LPPassManager(int Depth);
85 /// run - Execute all of the passes scheduled for execution. Keep track of
86 /// whether any of the passes modifies the module, and if so, return true.
87 bool runOnFunction(Function &F);
89 /// Pass Manager itself does not invalidate any analysis info.
90 // LPPassManager needs LoopInfo.
91 void getAnalysisUsage(AnalysisUsage &Info) const;
93 virtual const char *getPassName() const {
94 return "Loop Pass Manager";
97 virtual PMDataManager *getAsPMDataManager() { return this; }
98 virtual Pass *getAsPass() { return this; }
100 /// Print passes managed by this manager
101 void dumpPassStructure(unsigned Offset);
103 Pass *getContainedPass(unsigned N) {
104 assert(N < PassVector.size() && "Pass number out of range!");
105 Pass *FP = static_cast<Pass *>(PassVector[N]);
109 virtual PassManagerType getPassManagerType() const {
110 return PMT_LoopPassManager;
114 // Delete loop from the loop queue and loop nest (LoopInfo).
115 void deleteLoopFromQueue(Loop *L);
117 // Insert loop into the loop queue and add it as a child of the
119 void insertLoop(Loop *L, Loop *ParentLoop);
121 // Insert a loop into the loop queue.
122 void insertLoopIntoQueue(Loop *L);
124 // Reoptimize this loop. LPPassManager will re-insert this loop into the
125 // queue. This allows LoopPass to change loop nest for the loop. This
126 // utility may send LPPassManager into infinite loops so use caution.
127 void redoLoop(Loop *L);
129 //===--------------------------------------------------------------------===//
130 /// SimpleAnalysis - Provides simple interface to update analysis info
131 /// maintained by various passes. Note, if required this interface can
132 /// be extracted into a separate abstract class but it would require
133 /// additional use of multiple inheritance in Pass class hierarchy, something
134 /// we are trying to avoid.
136 /// cloneBasicBlockSimpleAnalysis - Invoke cloneBasicBlockAnalysis hook for
137 /// all passes that implement simple analysis interface.
138 void cloneBasicBlockSimpleAnalysis(BasicBlock *From, BasicBlock *To, Loop *L);
140 /// deleteSimpleAnalysisValue - Invoke deleteAnalysisValue hook for all passes
141 /// that implement simple analysis interface.
142 void deleteSimpleAnalysisValue(Value *V, Loop *L);
145 std::deque<Loop *> LQ;
152 } // End llvm namespace