1 //===-- AnnotationRemarks.cpp - Generate remarks for annotated instrs. ----===// 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 // Generate remarks for instructions marked with !annotation. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Transforms/Scalar/AnnotationRemarks.h" 14 #include "llvm/ADT/MapVector.h" 15 #include "llvm/Analysis/OptimizationRemarkEmitter.h" 16 #include "llvm/Analysis/TargetLibraryInfo.h" 17 #include "llvm/IR/Function.h" 18 #include "llvm/IR/InstIterator.h" 19 #include "llvm/IR/Instructions.h" 20 #include "llvm/IR/IntrinsicInst.h" 21 #include "llvm/InitializePasses.h" 22 #include "llvm/Pass.h" 23 #include "llvm/Support/Debug.h" 24 #include "llvm/Transforms/Scalar.h" 25 #include "llvm/Transforms/Utils/AutoInitRemark.h" 26 27 using namespace llvm; 28 using namespace llvm::ore; 29 30 #define DEBUG_TYPE "annotation-remarks" 31 #define REMARK_PASS DEBUG_TYPE 32 33 static void tryEmitAutoInitRemark(ArrayRef<Instruction *> Instructions, 34 OptimizationRemarkEmitter &ORE, 35 const TargetLibraryInfo &TLI) { 36 // For every auto-init annotation generate a separate remark. 37 for (Instruction *I : Instructions) { 38 if (!I->hasMetadata(LLVMContext::MD_annotation)) 39 continue; 40 for (const MDOperand &Op : 41 I->getMetadata(LLVMContext::MD_annotation)->operands()) { 42 if (cast<MDString>(Op.get())->getString() != "auto-init") 43 continue; 44 45 Function &F = *I->getParent()->getParent(); 46 const DataLayout &DL = F.getParent()->getDataLayout(); 47 AutoInitRemark Remark(ORE, REMARK_PASS, DL, TLI); 48 // For some of them, we can provide more information: 49 50 // For stores: 51 // * size 52 // * volatile / atomic 53 if (auto *SI = dyn_cast<StoreInst>(I)) { 54 Remark.inspectStore(*SI); 55 continue; 56 } 57 58 // For intrinsics: 59 // * user-friendly name 60 // * size 61 if (auto *II = dyn_cast<IntrinsicInst>(I)) { 62 Remark.inspectIntrinsicCall(*II); 63 continue; 64 } 65 66 // For calls: 67 // * known/unknown function (e.g. the compiler knows bzero, but it doesn't 68 // know my_bzero) 69 // * memory operation size 70 if (auto *CI = dyn_cast<CallInst>(I)) { 71 Remark.inspectCall(*CI); 72 continue; 73 } 74 75 Remark.inspectUnknown(*I); 76 } 77 } 78 } 79 80 static void runImpl(Function &F, const TargetLibraryInfo &TLI) { 81 if (!OptimizationRemarkEmitter::allowExtraAnalysis(F, REMARK_PASS)) 82 return; 83 84 // Track all annotated instructions aggregated based on their debug location. 85 DenseMap<MDNode *, SmallVector<Instruction *, 4>> DebugLoc2Annotated; 86 87 OptimizationRemarkEmitter ORE(&F); 88 // First, generate a summary of the annotated instructions. 89 MapVector<StringRef, unsigned> Mapping; 90 for (Instruction &I : instructions(F)) { 91 if (!I.hasMetadata(LLVMContext::MD_annotation)) 92 continue; 93 auto Iter = DebugLoc2Annotated.insert({I.getDebugLoc().getAsMDNode(), {}}); 94 Iter.first->second.push_back(&I); 95 96 for (const MDOperand &Op : 97 I.getMetadata(LLVMContext::MD_annotation)->operands()) { 98 auto Iter = Mapping.insert({cast<MDString>(Op.get())->getString(), 0}); 99 Iter.first->second++; 100 } 101 } 102 103 for (const auto &KV : Mapping) 104 ORE.emit(OptimizationRemarkAnalysis(REMARK_PASS, "AnnotationSummary", 105 F.getSubprogram(), &F.front()) 106 << "Annotated " << NV("count", KV.second) << " instructions with " 107 << NV("type", KV.first)); 108 109 // For each debug location, look for all the instructions with annotations and 110 // generate more detailed remarks to be displayed at that location. 111 for (auto &KV : DebugLoc2Annotated) { 112 // Don't generate remarks with no debug location. 113 if (!KV.first) 114 continue; 115 116 tryEmitAutoInitRemark(KV.second, ORE, TLI); 117 } 118 } 119 120 namespace { 121 122 struct AnnotationRemarksLegacy : public FunctionPass { 123 static char ID; 124 125 AnnotationRemarksLegacy() : FunctionPass(ID) { 126 initializeAnnotationRemarksLegacyPass(*PassRegistry::getPassRegistry()); 127 } 128 129 bool runOnFunction(Function &F) override { 130 const TargetLibraryInfo &TLI = 131 getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F); 132 runImpl(F, TLI); 133 return false; 134 } 135 136 void getAnalysisUsage(AnalysisUsage &AU) const override { 137 AU.setPreservesAll(); 138 AU.addRequired<TargetLibraryInfoWrapperPass>(); 139 } 140 }; 141 142 } // end anonymous namespace 143 144 char AnnotationRemarksLegacy::ID = 0; 145 146 INITIALIZE_PASS_BEGIN(AnnotationRemarksLegacy, "annotation-remarks", 147 "Annotation Remarks", false, false) 148 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass) 149 INITIALIZE_PASS_END(AnnotationRemarksLegacy, "annotation-remarks", 150 "Annotation Remarks", false, false) 151 152 FunctionPass *llvm::createAnnotationRemarksLegacyPass() { 153 return new AnnotationRemarksLegacy(); 154 } 155 156 PreservedAnalyses AnnotationRemarksPass::run(Function &F, 157 FunctionAnalysisManager &AM) { 158 auto &TLI = AM.getResult<TargetLibraryAnalysis>(F); 159 runImpl(F, TLI); 160 return PreservedAnalyses::all(); 161 } 162