1 //===- LoopPassManager.cpp - Loop pass management -------------------------===//
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 #include "llvm/Transforms/Scalar/LoopPassManager.h"
11 #include "llvm/Analysis/LoopInfo.h"
15 // Explicit template instantiations and specialization defininitions for core
18 template class PassManager<Loop, LoopAnalysisManager,
19 LoopStandardAnalysisResults &, LPMUpdater &>;
21 /// Explicitly specialize the pass manager's run method to handle loop nest
22 /// structure updates.
25 PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
26 LPMUpdater &>::run(Loop &L, LoopAnalysisManager &AM,
27 LoopStandardAnalysisResults &AR, LPMUpdater &U) {
28 PreservedAnalyses PA = PreservedAnalyses::all();
31 dbgs() << "Starting Loop pass manager run.\n";
33 for (auto &Pass : Passes) {
35 dbgs() << "Running pass: " << Pass->name() << " on " << L;
37 PreservedAnalyses PassPA = Pass->run(L, AM, AR, U);
39 // If the loop was deleted, abort the run and return to the outer walk.
40 if (U.skipCurrentLoop()) {
41 PA.intersect(std::move(PassPA));
45 // Update the analysis manager as each pass runs and potentially
46 // invalidates analyses.
47 AM.invalidate(L, PassPA);
49 // Finally, we intersect the final preserved analyses to compute the
50 // aggregate preserved set for this pass manager.
51 PA.intersect(std::move(PassPA));
53 // FIXME: Historically, the pass managers all called the LLVM context's
54 // yield function here. We don't have a generic way to acquire the
55 // context and it isn't yet clear what the right pattern is for yielding
56 // in the new pass manager so it is currently omitted.
57 // ...getContext().yield();
60 // Invalidation for the current loop should be handled above, and other loop
61 // analysis results shouldn't be impacted by runs over this loop. Therefore,
62 // the remaining analysis results in the AnalysisManager are preserved. We
63 // mark this with a set so that we don't need to inspect each one
65 // FIXME: This isn't correct! This loop and all nested loops' analyses should
66 // be preserved, but unrolling should invalidate the parent loop's analyses.
67 PA.preserveSet<AllAnalysesOn<Loop>>();
70 dbgs() << "Finished Loop pass manager run.\n";
76 PrintLoopPass::PrintLoopPass() : OS(dbgs()) {}
77 PrintLoopPass::PrintLoopPass(raw_ostream &OS, const std::string &Banner)
78 : OS(OS), Banner(Banner) {}
80 PreservedAnalyses PrintLoopPass::run(Loop &L, LoopAnalysisManager &,
81 LoopStandardAnalysisResults &,
83 printLoop(L, OS, Banner);
84 return PreservedAnalyses::all();