1 //===- LoopPassManager.cpp - Loop pass management -------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "llvm/Transforms/Scalar/LoopPassManager.h" 11 #include "llvm/Analysis/LoopInfo.h" 12 13 using namespace llvm; 14 15 // Explicit template instantiations and specialization defininitions for core 16 // template typedefs. 17 namespace llvm { 18 template class PassManager<Loop, LoopAnalysisManager, 19 LoopStandardAnalysisResults &, LPMUpdater &>; 20 21 /// Explicitly specialize the pass manager's run method to handle loop nest 22 /// structure updates. 23 template <> 24 PreservedAnalyses 25 PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &, 26 LPMUpdater &>::run(Loop &L, LoopAnalysisManager &AM, 27 LoopStandardAnalysisResults &AR, LPMUpdater &U) { 28 PreservedAnalyses PA = PreservedAnalyses::all(); 29 30 if (DebugLogging) 31 dbgs() << "Starting Loop pass manager run.\n"; 32 33 for (auto &Pass : Passes) { 34 if (DebugLogging) 35 dbgs() << "Running pass: " << Pass->name() << " on " << L; 36 37 PreservedAnalyses PassPA = Pass->run(L, AM, AR, U); 38 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)); 42 break; 43 } 44 45 #ifndef NDEBUG 46 // Verify the loop structure and LCSSA form before visiting the loop. 47 L.verifyLoop(); 48 assert(L.isRecursivelyLCSSAForm(AR.DT, AR.LI) && 49 "Loops must remain in LCSSA form!"); 50 #endif 51 52 // Update the analysis manager as each pass runs and potentially 53 // invalidates analyses. 54 AM.invalidate(L, PassPA); 55 56 // Finally, we intersect the final preserved analyses to compute the 57 // aggregate preserved set for this pass manager. 58 PA.intersect(std::move(PassPA)); 59 60 // FIXME: Historically, the pass managers all called the LLVM context's 61 // yield function here. We don't have a generic way to acquire the 62 // context and it isn't yet clear what the right pattern is for yielding 63 // in the new pass manager so it is currently omitted. 64 // ...getContext().yield(); 65 } 66 67 // Invalidation for the current loop should be handled above, and other loop 68 // analysis results shouldn't be impacted by runs over this loop. Therefore, 69 // the remaining analysis results in the AnalysisManager are preserved. We 70 // mark this with a set so that we don't need to inspect each one 71 // individually. 72 // FIXME: This isn't correct! This loop and all nested loops' analyses should 73 // be preserved, but unrolling should invalidate the parent loop's analyses. 74 PA.preserveSet<AllAnalysesOn<Loop>>(); 75 76 if (DebugLogging) 77 dbgs() << "Finished Loop pass manager run.\n"; 78 79 return PA; 80 } 81 } 82 83 PrintLoopPass::PrintLoopPass() : OS(dbgs()) {} 84 PrintLoopPass::PrintLoopPass(raw_ostream &OS, const std::string &Banner) 85 : OS(OS), Banner(Banner) {} 86 87 PreservedAnalyses PrintLoopPass::run(Loop &L, LoopAnalysisManager &, 88 LoopStandardAnalysisResults &, 89 LPMUpdater &) { 90 printLoop(L, OS, Banner); 91 return PreservedAnalyses::all(); 92 } 93
