xref: /freebsd/contrib/llvm-project/llvm/lib/Transforms/Scalar/AnnotationRemarks.cpp (revision 63f537551380d2dab29fa402ad1269feae17e594)
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/Transforms/Scalar.h"
20 #include "llvm/Transforms/Utils/MemoryOpRemark.h"
21 
22 using namespace llvm;
23 using namespace llvm::ore;
24 
25 #define DEBUG_TYPE "annotation-remarks"
26 #define REMARK_PASS DEBUG_TYPE
27 
28 static void tryEmitAutoInitRemark(ArrayRef<Instruction *> Instructions,
29                                   OptimizationRemarkEmitter &ORE,
30                                   const TargetLibraryInfo &TLI) {
31   // For every auto-init annotation generate a separate remark.
32   for (Instruction *I : Instructions) {
33     if (!AutoInitRemark::canHandle(I))
34       continue;
35 
36     Function &F = *I->getParent()->getParent();
37     const DataLayout &DL = F.getParent()->getDataLayout();
38     AutoInitRemark Remark(ORE, REMARK_PASS, DL, TLI);
39     Remark.visit(I);
40   }
41 }
42 
43 static void runImpl(Function &F, const TargetLibraryInfo &TLI) {
44   if (!OptimizationRemarkEmitter::allowExtraAnalysis(F, REMARK_PASS))
45     return;
46 
47   // Track all annotated instructions aggregated based on their debug location.
48   DenseMap<MDNode *, SmallVector<Instruction *, 4>> DebugLoc2Annotated;
49 
50   OptimizationRemarkEmitter ORE(&F);
51   // First, generate a summary of the annotated instructions.
52   MapVector<StringRef, unsigned> Mapping;
53   for (Instruction &I : instructions(F)) {
54     if (!I.hasMetadata(LLVMContext::MD_annotation))
55       continue;
56     auto Iter = DebugLoc2Annotated.insert({I.getDebugLoc().getAsMDNode(), {}});
57     Iter.first->second.push_back(&I);
58 
59     for (const MDOperand &Op :
60          I.getMetadata(LLVMContext::MD_annotation)->operands()) {
61       auto Iter = Mapping.insert({cast<MDString>(Op.get())->getString(), 0});
62       Iter.first->second++;
63     }
64   }
65 
66   for (const auto &KV : Mapping)
67     ORE.emit(OptimizationRemarkAnalysis(REMARK_PASS, "AnnotationSummary",
68                                         F.getSubprogram(), &F.front())
69              << "Annotated " << NV("count", KV.second) << " instructions with "
70              << NV("type", KV.first));
71 
72   // For each debug location, look for all the instructions with annotations and
73   // generate more detailed remarks to be displayed at that location.
74   for (auto &KV : DebugLoc2Annotated) {
75     // Don't generate remarks with no debug location.
76     if (!KV.first)
77       continue;
78 
79     tryEmitAutoInitRemark(KV.second, ORE, TLI);
80   }
81 }
82 
83 PreservedAnalyses AnnotationRemarksPass::run(Function &F,
84                                              FunctionAnalysisManager &AM) {
85   auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
86   runImpl(F, TLI);
87   return PreservedAnalyses::all();
88 }
89