1 //===- LoopPass.cpp - Loop Pass and Loop Pass Manager ---------------------===//
3 // The LLVM Compiler Infrastructure
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.
8 //===----------------------------------------------------------------------===//
10 // This file implements LoopPass and LPPassManager. All loop optimization
11 // and transformation passes are derived from LoopPass. LPPassManager is
12 // responsible for managing LoopPasses.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Analysis/LoopPass.h"
20 //===----------------------------------------------------------------------===//
25 // Compare Two loops based on their depth in loop nest.
28 bool operator()( Loop *L1, Loop *L2) const {
29 return L1->getLoopDepth() > L2->getLoopDepth();
33 // Loop queue used by Loop Pass Manager. This is a wrapper class
34 // that hides implemenation detail (use of priority_queue) inside .cpp file.
37 inline void push(Loop *L) { LPQ.push(L); }
38 inline void pop() { LPQ.pop(); }
39 inline Loop *top() { return LPQ.top(); }
40 inline bool empty() { return LPQ.empty(); }
42 std::priority_queue<Loop *, std::vector<Loop *>, LoopCompare> LPQ;
45 } // End of LLVM namespace
47 //===----------------------------------------------------------------------===//
50 /// LPPassManager manages FPPassManagers and CalLGraphSCCPasses.
52 LPPassManager::LPPassManager(int Depth) : PMDataManager(Depth) {
56 LPPassManager::~LPPassManager() {
60 /// Delete loop from the loop queue. This is used by Loop pass to inform
61 /// Loop Pass Manager that it should skip rest of the passes for this loop.
62 void LPPassManager::deleteLoopFromQueue(Loop *L) {
63 // Do not pop loop from LQ here. It will be done by runOnFunction while loop.
67 // Recurse through all subloops and all loops into LQ.
68 static void addLoopIntoQueue(Loop *L, LoopQueue *LQ) {
69 for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I)
70 addLoopIntoQueue(*I, LQ);
74 /// run - Execute all of the passes scheduled for execution. Keep track of
75 /// whether any of the passes modifies the function, and if so, return true.
76 bool LPPassManager::runOnFunction(Function &F) {
77 LoopInfo &LI = getAnalysis<LoopInfo>();
80 // Populate Loop Queue
81 for (LoopInfo::iterator I = LI.begin(), E = LI.end(); I != E; ++I)
82 addLoopIntoQueue(*I, LQ);
84 std::string Msg1 = "Executing Pass '";
85 std::string Msg3 = "' Made Modification '";
88 while (!LQ->empty()) {
93 // Run all passes on current SCC
94 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
96 Pass *P = getContainedPass(Index);
97 AnalysisUsage AnUsage;
98 P->getAnalysisUsage(AnUsage);
100 std::string Msg2 = "' on Loop ...\n'";
101 dumpPassInfo(P, Msg1, Msg2);
102 dumpAnalysisSetInfo("Required", P, AnUsage.getRequiredSet());
104 initializeAnalysisImpl(P);
107 LoopPass *LP = dynamic_cast<LoopPass *>(P);
108 assert (LP && "Invalid LPPassManager member");
109 LP->runOnLoop(*L, *this);
113 dumpPassInfo(P, Msg3, Msg2);
114 dumpAnalysisSetInfo("Preserved", P, AnUsage.getPreservedSet());
116 removeNotPreservedAnalysis(P);
117 recordAvailableAnalysis(P);
118 removeDeadPasses(P, Msg2);
121 // Do not run other passes on this loop.
125 // Pop the loop from queue after running all passes.