1 //===- LoopAnalysisManager.h - Loop analysis management ---------*- C++ -*-===// 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 /// \file 9 /// 10 /// This header provides classes for managing per-loop analyses. These are 11 /// typically used as part of a loop pass pipeline over the loop nests of 12 /// a function. 13 /// 14 /// Loop analyses are allowed to make some simplifying assumptions: 15 /// 1) Loops are, where possible, in simplified form. 16 /// 2) Loops are *always* in LCSSA form. 17 /// 3) A collection of analysis results are available: 18 /// - LoopInfo 19 /// - DominatorTree 20 /// - ScalarEvolution 21 /// - AAManager 22 /// 23 /// The primary mechanism to provide these invariants is the loop pass manager, 24 /// but they can also be manually provided in order to reason about a loop from 25 /// outside of a dedicated pass manager. 26 /// 27 //===----------------------------------------------------------------------===// 28 29 #ifndef LLVM_ANALYSIS_LOOPANALYSISMANAGER_H 30 #define LLVM_ANALYSIS_LOOPANALYSISMANAGER_H 31 32 #include "llvm/ADT/PostOrderIterator.h" 33 #include "llvm/ADT/PriorityWorklist.h" 34 #include "llvm/ADT/STLExtras.h" 35 #include "llvm/Analysis/AliasAnalysis.h" 36 #include "llvm/Analysis/BasicAliasAnalysis.h" 37 #include "llvm/Analysis/GlobalsModRef.h" 38 #include "llvm/Analysis/LoopInfo.h" 39 #include "llvm/Analysis/MemorySSA.h" 40 #include "llvm/Analysis/ScalarEvolution.h" 41 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h" 42 #include "llvm/Analysis/TargetLibraryInfo.h" 43 #include "llvm/Analysis/TargetTransformInfo.h" 44 #include "llvm/IR/Dominators.h" 45 #include "llvm/IR/PassManager.h" 46 47 namespace llvm { 48 49 /// The adaptor from a function pass to a loop pass computes these analyses and 50 /// makes them available to the loop passes "for free". Each loop pass is 51 /// expected expected to update these analyses if necessary to ensure they're 52 /// valid after it runs. 53 struct LoopStandardAnalysisResults { 54 AAResults &AA; 55 AssumptionCache &AC; 56 DominatorTree &DT; 57 LoopInfo &LI; 58 ScalarEvolution &SE; 59 TargetLibraryInfo &TLI; 60 TargetTransformInfo &TTI; 61 MemorySSA *MSSA; 62 }; 63 64 /// Extern template declaration for the analysis set for this IR unit. 65 extern template class AllAnalysesOn<Loop>; 66 67 extern template class AnalysisManager<Loop, LoopStandardAnalysisResults &>; 68 /// The loop analysis manager. 69 /// 70 /// See the documentation for the AnalysisManager template for detail 71 /// documentation. This typedef serves as a convenient way to refer to this 72 /// construct in the adaptors and proxies used to integrate this into the larger 73 /// pass manager infrastructure. 74 typedef AnalysisManager<Loop, LoopStandardAnalysisResults &> 75 LoopAnalysisManager; 76 77 /// A proxy from a \c LoopAnalysisManager to a \c Function. 78 typedef InnerAnalysisManagerProxy<LoopAnalysisManager, Function> 79 LoopAnalysisManagerFunctionProxy; 80 81 /// A specialized result for the \c LoopAnalysisManagerFunctionProxy which 82 /// retains a \c LoopInfo reference. 83 /// 84 /// This allows it to collect loop objects for which analysis results may be 85 /// cached in the \c LoopAnalysisManager. 86 template <> class LoopAnalysisManagerFunctionProxy::Result { 87 public: 88 explicit Result(LoopAnalysisManager &InnerAM, LoopInfo &LI) 89 : InnerAM(&InnerAM), LI(&LI) {} 90 Result(Result &&Arg) : InnerAM(std::move(Arg.InnerAM)), LI(Arg.LI) { 91 // We have to null out the analysis manager in the moved-from state 92 // because we are taking ownership of the responsibilty to clear the 93 // analysis state. 94 Arg.InnerAM = nullptr; 95 } 96 Result &operator=(Result &&RHS) { 97 InnerAM = RHS.InnerAM; 98 LI = RHS.LI; 99 // We have to null out the analysis manager in the moved-from state 100 // because we are taking ownership of the responsibilty to clear the 101 // analysis state. 102 RHS.InnerAM = nullptr; 103 return *this; 104 } 105 ~Result() { 106 // InnerAM is cleared in a moved from state where there is nothing to do. 107 if (!InnerAM) 108 return; 109 110 // Clear out the analysis manager if we're being destroyed -- it means we 111 // didn't even see an invalidate call when we got invalidated. 112 InnerAM->clear(); 113 } 114 115 /// Accessor for the analysis manager. 116 LoopAnalysisManager &getManager() { return *InnerAM; } 117 118 /// Handler for invalidation of the proxy for a particular function. 119 /// 120 /// If the proxy, \c LoopInfo, and associated analyses are preserved, this 121 /// will merely forward the invalidation event to any cached loop analysis 122 /// results for loops within this function. 123 /// 124 /// If the necessary loop infrastructure is not preserved, this will forcibly 125 /// clear all of the cached analysis results that are keyed on the \c 126 /// LoopInfo for this function. 127 bool invalidate(Function &F, const PreservedAnalyses &PA, 128 FunctionAnalysisManager::Invalidator &Inv); 129 130 private: 131 LoopAnalysisManager *InnerAM; 132 LoopInfo *LI; 133 }; 134 135 /// Provide a specialized run method for the \c LoopAnalysisManagerFunctionProxy 136 /// so it can pass the \c LoopInfo to the result. 137 template <> 138 LoopAnalysisManagerFunctionProxy::Result 139 LoopAnalysisManagerFunctionProxy::run(Function &F, FunctionAnalysisManager &AM); 140 141 // Ensure the \c LoopAnalysisManagerFunctionProxy is provided as an extern 142 // template. 143 extern template class InnerAnalysisManagerProxy<LoopAnalysisManager, Function>; 144 145 extern template class OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop, 146 LoopStandardAnalysisResults &>; 147 /// A proxy from a \c FunctionAnalysisManager to a \c Loop. 148 typedef OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop, 149 LoopStandardAnalysisResults &> 150 FunctionAnalysisManagerLoopProxy; 151 152 /// Returns the minimum set of Analyses that all loop passes must preserve. 153 PreservedAnalyses getLoopPassPreservedAnalyses(); 154 } 155 156 #endif // LLVM_ANALYSIS_LOOPANALYSISMANAGER_H 157