llvm/lib/Transforms/Scalar/AnnotationRemarks.cpp

   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
  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
  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     DebugLoc2Annotated[I.getDebugLoc().getAsMDNode()].push_back(&I);
  56
  57     for (const MDOperand &Op :
  58          I.getMetadata(LLVMContext::MD_annotation)->operands()) {
  59       StringRef AnnotationStr =
  60           isa<MDString>(Op.get())
  61               ? cast<MDString>(Op.get())->getString()
  62               : cast<MDString>(cast<MDTuple>(Op.get())->getOperand(0).get())
  63                     ->getString();
  64       Mapping[AnnotationStr]++;
  65     }
  66   }
  67
  68   for (const auto &KV : Mapping)
  69     ORE.emit(OptimizationRemarkAnalysis(REMARK_PASS, "AnnotationSummary",
  70                                         F.getSubprogram(), &F.front())
  71              << "Annotated " << NV("count", KV.second) << " instructions with "
  72              << NV("type", KV.first));
  73
  74   // For each debug location, look for all the instructions with annotations and
  75   // generate more detailed remarks to be displayed at that location.
  76   for (auto &KV : DebugLoc2Annotated) {
  77     // Don't generate remarks with no debug location.
  78     if (!KV.first)
  79       continue;
  80
  81     tryEmitAutoInitRemark(KV.second, ORE, TLI);
  82   }
  83 }
  84
  85 PreservedAnalyses AnnotationRemarksPass::run(Function &F,
  86                                              FunctionAnalysisManager &AM) {
  87   auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
  88   runImpl(F, TLI);
  89   return PreservedAnalyses::all();
  90 }