LoopPass.h revision 1997473cf72957d0e70322e2fe6fe2ab141c58a6 
1//===- LoopPass.h - LoopPass class ----------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Devang Patel and is distributed under
6// the University of Illinois Open Source 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_LOOP_PASS_H
16#define LLVM_LOOP_PASS_H
17
18#include "llvm/Analysis/LoopInfo.h"
19#include "llvm/Pass.h"
20#include "llvm/PassManagers.h"
21#include "llvm/Function.h"
22
23namespace llvm {
24
25class LPPassManager;
26class Loop;
27class Function;
28
29class LoopPass : public Pass {
30
31 public:
32 LoopPass(intptr_t pid) : Pass(pid) {}
33
34  // runOnLoop - THis method should be implemented by the subclass to perform
35  // whatever action is necessary for the specfied Loop.
36  virtual bool runOnLoop (Loop *L, LPPassManager &LPM) = 0;
37  virtual bool runOnFunctionBody (Function &F, LPPassManager &LPM) {
38    return false;
39  }
40
41  // Initialization and finalization hooks.
42  virtual bool doInitialization(Loop *L, LPPassManager &LPM) {
43    return false;
44  }
45
46  // Finalization hook does not supply Loop because at this time
47  // loop nest is completely different.
48  virtual bool doFinalization() { return false; }
49
50  // Check if this pass is suitable for the current LPPassManager, if
51  // available. This pass P is not suitable for a LPPassManager if P
52  // is not preserving higher level analysis info used by other
53  // LPPassManager passes. In such case, pop LPPassManager from the
54  // stack. This will force assignPassManager() to create new
55  // LPPassManger as expected.
56  void preparePassManager(PMStack &PMS);
57
58  /// Assign pass manager to manager this pass
59  virtual void assignPassManager(PMStack &PMS,
60                                 PassManagerType PMT = PMT_LoopPassManager);
61
62  ///  Return what kind of Pass Manager can manage this pass.
63  virtual PassManagerType getPotentialPassManagerType() const {
64    return PMT_LoopPassManager;
65  }
66};
67
68class LPPassManager : public FunctionPass, public PMDataManager {
69
70public:
71  static char ID;
72  LPPassManager(int Depth);
73
74  /// run - Execute all of the passes scheduled for execution.  Keep track of
75  /// whether any of the passes modifies the module, and if so, return true.
76  bool runOnFunction(Function &F);
77
78  /// Pass Manager itself does not invalidate any analysis info.
79  // LPPassManager needs LoopInfo.
80  void getAnalysisUsage(AnalysisUsage &Info) const;
81
82  virtual const char *getPassName() const {
83    return "Loop Pass Manager";
84  }
85
86  // Print passes managed by this manager
87  void dumpPassStructure(unsigned Offset) {
88    llvm::cerr << std::string(Offset*2, ' ') << "Loop Pass Manager\n";
89    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
90      Pass *P = getContainedPass(Index);
91      P->dumpPassStructure(Offset + 1);
92      dumpLastUses(P, Offset+1);
93    }
94  }
95
96  Pass *getContainedPass(unsigned N) {
97    assert ( N < PassVector.size() && "Pass number out of range!");
98    Pass *FP = static_cast<Pass *>(PassVector[N]);
99    return FP;
100  }
101
102  virtual PassManagerType getPassManagerType() const {
103    return PMT_LoopPassManager;
104  }
105
106public:
107  // Delete loop from the loop queue and loop nest (LoopInfo).
108  void deleteLoopFromQueue(Loop *L);
109
110  // Inset loop into the loop nest(LoopInfo) and loop queue(LQ).
111  void insertLoop(Loop *L, Loop *ParentLoop);
112
113  // Reoptimize this loop. LPPassManager will re-insert this loop into the
114  // queue. This allows LoopPass to change loop nest for the loop. This
115  // utility may send LPPassManager into infinite loops so use caution.
116  void redoLoop(Loop *L);
117private:
118  std::deque<Loop *> LQ;
119  bool skipThisLoop;
120  bool redoThisLoop;
121  LoopInfo *LI;
122  Loop *CurrentLoop;
123};
124
125} // End llvm namespace
126
127#endif
128