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/Utils/MemoryOpRemark.h"
20
21 using namespace llvm;
22 using namespace llvm::ore;
23
24 #define DEBUG_TYPE "annotation-remarks"
25 #define REMARK_PASS DEBUG_TYPE
26
tryEmitAutoInitRemark(ArrayRef<Instruction * > Instructions,OptimizationRemarkEmitter & ORE,const TargetLibraryInfo & TLI)27 static void tryEmitAutoInitRemark(ArrayRef<Instruction *> Instructions,
28 OptimizationRemarkEmitter &ORE,
29 const TargetLibraryInfo &TLI) {
30 // For every auto-init annotation generate a separate remark.
31 for (Instruction *I : Instructions) {
32 if (!AutoInitRemark::canHandle(I))
33 continue;
34
35 Function &F = *I->getParent()->getParent();
36 const DataLayout &DL = F.getDataLayout();
37 AutoInitRemark Remark(ORE, REMARK_PASS, DL, TLI);
38 Remark.visit(I);
39 }
40 }
41
runImpl(Function & F,const TargetLibraryInfo & TLI)42 static void runImpl(Function &F, const TargetLibraryInfo &TLI) {
43 if (!OptimizationRemarkEmitter::allowExtraAnalysis(F, REMARK_PASS))
44 return;
45
46 // Track all annotated instructions aggregated based on their debug location.
47 DenseMap<MDNode *, SmallVector<Instruction *, 4>> DebugLoc2Annotated;
48
49 OptimizationRemarkEmitter ORE(&F);
50 // First, generate a summary of the annotated instructions.
51 MapVector<StringRef, unsigned> Mapping;
52 for (Instruction &I : instructions(F)) {
53 if (!I.hasMetadata(LLVMContext::MD_annotation))
54 continue;
55 auto Iter = DebugLoc2Annotated.insert({I.getDebugLoc().getAsMDNode(), {}});
56 Iter.first->second.push_back(&I);
57
58 for (const MDOperand &Op :
59 I.getMetadata(LLVMContext::MD_annotation)->operands()) {
60 StringRef AnnotationStr =
61 isa<MDString>(Op.get())
62 ? cast<MDString>(Op.get())->getString()
63 : cast<MDString>(cast<MDTuple>(Op.get())->getOperand(0).get())
64 ->getString();
65 auto Iter = Mapping.insert({AnnotationStr, 0});
66 Iter.first->second++;
67 }
68 }
69
70 for (const auto &KV : Mapping)
71 ORE.emit(OptimizationRemarkAnalysis(REMARK_PASS, "AnnotationSummary",
72 F.getSubprogram(), &F.front())
73 << "Annotated " << NV("count", KV.second) << " instructions with "
74 << NV("type", KV.first));
75
76 // For each debug location, look for all the instructions with annotations and
77 // generate more detailed remarks to be displayed at that location.
78 for (auto &KV : DebugLoc2Annotated) {
79 // Don't generate remarks with no debug location.
80 if (!KV.first)
81 continue;
82
83 tryEmitAutoInitRemark(KV.second, ORE, TLI);
84 }
85 }
86
run(Function & F,FunctionAnalysisManager & AM)87 PreservedAnalyses AnnotationRemarksPass::run(Function &F,
88 FunctionAnalysisManager &AM) {
89 auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
90 runImpl(F, TLI);
91 return PreservedAnalyses::all();
92 }
93