1 | //===- PruneUnprofitable.cpp ----------------------------------------------===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // Mark a SCoP as unfeasible if not deemed profitable to optimize. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #include "polly/PruneUnprofitable.h" |
14 | #include "polly/ScopDetection.h" |
15 | #include "polly/ScopInfo.h" |
16 | #include "polly/ScopPass.h" |
17 | #include "llvm/ADT/Statistic.h" |
18 | #include "llvm/IR/DebugLoc.h" |
19 | #include "llvm/Support/Debug.h" |
20 | #include "llvm/Support/raw_ostream.h" |
21 | |
22 | using namespace llvm; |
23 | using namespace polly; |
24 | |
25 | #define DEBUG_TYPE "polly-prune-unprofitable" |
26 | |
27 | namespace { |
28 | |
29 | STATISTIC(ScopsProcessed, |
30 | "Number of SCoPs considered for unprofitability pruning" ); |
31 | STATISTIC(ScopsPruned, "Number of pruned SCoPs because it they cannot be " |
32 | "optimized in a significant way" ); |
33 | STATISTIC(ScopsSurvived, "Number of SCoPs after pruning" ); |
34 | |
35 | STATISTIC(NumPrunedLoops, "Number of pruned loops" ); |
36 | STATISTIC(NumPrunedBoxedLoops, "Number of pruned boxed loops" ); |
37 | STATISTIC(NumPrunedAffineLoops, "Number of pruned affine loops" ); |
38 | |
39 | STATISTIC(NumLoopsInScop, "Number of loops in scops after pruning" ); |
40 | STATISTIC(NumBoxedLoops, "Number of boxed loops in SCoPs after pruning" ); |
41 | STATISTIC(NumAffineLoops, "Number of affine loops in SCoPs after pruning" ); |
42 | |
43 | static void updateStatistics(Scop &S, bool Pruned) { |
44 | Scop::ScopStatistics ScopStats = S.getStatistics(); |
45 | if (Pruned) { |
46 | ScopsPruned++; |
47 | NumPrunedLoops += ScopStats.NumAffineLoops + ScopStats.NumBoxedLoops; |
48 | NumPrunedBoxedLoops += ScopStats.NumBoxedLoops; |
49 | NumPrunedAffineLoops += ScopStats.NumAffineLoops; |
50 | } else { |
51 | ScopsSurvived++; |
52 | NumLoopsInScop += ScopStats.NumAffineLoops + ScopStats.NumBoxedLoops; |
53 | NumBoxedLoops += ScopStats.NumBoxedLoops; |
54 | NumAffineLoops += ScopStats.NumAffineLoops; |
55 | } |
56 | } |
57 | |
58 | static bool runPruneUnprofitable(Scop &S) { |
59 | if (PollyProcessUnprofitable) { |
60 | LLVM_DEBUG( |
61 | dbgs() << "NOTE: -polly-process-unprofitable active, won't prune " |
62 | "anything\n" ); |
63 | return false; |
64 | } |
65 | |
66 | ScopsProcessed++; |
67 | |
68 | if (!S.isProfitable(ScalarsAreUnprofitable: true)) { |
69 | LLVM_DEBUG( |
70 | dbgs() << "SCoP pruned because it probably cannot be optimized in " |
71 | "a significant way\n" ); |
72 | S.invalidate(Kind: PROFITABLE, Loc: DebugLoc()); |
73 | updateStatistics(S, Pruned: true); |
74 | } else { |
75 | updateStatistics(S, Pruned: false); |
76 | } |
77 | |
78 | return false; |
79 | } |
80 | |
81 | class PruneUnprofitableWrapperPass final : public ScopPass { |
82 | public: |
83 | static char ID; |
84 | |
85 | explicit PruneUnprofitableWrapperPass() : ScopPass(ID) {} |
86 | PruneUnprofitableWrapperPass(const PruneUnprofitableWrapperPass &) = delete; |
87 | PruneUnprofitableWrapperPass & |
88 | operator=(const PruneUnprofitableWrapperPass &) = delete; |
89 | |
90 | void getAnalysisUsage(AnalysisUsage &AU) const override { |
91 | AU.addRequired<ScopInfoRegionPass>(); |
92 | AU.setPreservesAll(); |
93 | } |
94 | |
95 | bool runOnScop(Scop &S) override { return runPruneUnprofitable(S); } |
96 | }; |
97 | } // namespace |
98 | |
99 | char PruneUnprofitableWrapperPass::ID; |
100 | |
101 | Pass *polly::createPruneUnprofitableWrapperPass() { |
102 | return new PruneUnprofitableWrapperPass(); |
103 | } |
104 | |
105 | INITIALIZE_PASS_BEGIN(PruneUnprofitableWrapperPass, "polly-prune-unprofitable" , |
106 | "Polly - Prune unprofitable SCoPs" , false, false) |
107 | INITIALIZE_PASS_END(PruneUnprofitableWrapperPass, "polly-prune-unprofitable" , |
108 | "Polly - Prune unprofitable SCoPs" , false, false) |
109 | |
110 | llvm::PreservedAnalyses |
111 | PruneUnprofitablePass::run(Scop &S, ScopAnalysisManager &SAM, |
112 | ScopStandardAnalysisResults &SAR, SPMUpdater &U) { |
113 | bool Changed = runPruneUnprofitable(S); |
114 | |
115 | if (!Changed) |
116 | return PreservedAnalyses::all(); |
117 | |
118 | PreservedAnalyses PA; |
119 | PA.preserveSet<AllAnalysesOn<Module>>(); |
120 | PA.preserveSet<AllAnalysesOn<Function>>(); |
121 | PA.preserveSet<AllAnalysesOn<Loop>>(); |
122 | return PA; |
123 | } |
124 | |