8bb6347939
This patch adds a new !annotation metadata kind which can be used to attach annotation strings to instructions. It also adds a new pass that emits summary remarks per function with the counts for each annotation kind. The intended uses cases for this new metadata is annotating 'interesting' instructions and the remarks should provide additional insight into transformations applied to a program. To motivate this, consider these specific questions we would like to get answered: * How many stores added for automatic variable initialization remain after optimizations? Where are they? * How many runtime checks inserted by a frontend could be eliminated? Where are the ones that did not get eliminated? Discussed on llvm-dev as part of 'RFC: Combining Annotation Metadata and Remarks' (http://lists.llvm.org/pipermail/llvm-dev/2020-November/146393.html) Reviewed By: thegameg, jdoerfert Differential Revision: https://reviews.llvm.org/D91188
91 lines
2.8 KiB
C++
91 lines
2.8 KiB
C++
//===-- AnnotationRemarks.cpp - Generate remarks for annotated instrs. ----===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Generate remarks for instructions marked with !annotation.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Transforms/Scalar/AnnotationRemarks.h"
|
|
#include "llvm/ADT/MapVector.h"
|
|
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
|
|
#include "llvm/Analysis/TargetLibraryInfo.h"
|
|
#include "llvm/IR/Function.h"
|
|
#include "llvm/IR/InstIterator.h"
|
|
#include "llvm/InitializePasses.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Transforms/Scalar.h"
|
|
|
|
using namespace llvm;
|
|
using namespace llvm::ore;
|
|
|
|
#define DEBUG_TYPE "annotation-remarks"
|
|
#define REMARK_PASS DEBUG_TYPE
|
|
|
|
static void runImpl(Function &F) {
|
|
if (!OptimizationRemarkEmitter::allowExtraAnalysis(F, REMARK_PASS))
|
|
return;
|
|
|
|
OptimizationRemarkEmitter ORE(&F);
|
|
// For now, just generate a summary of the annotated instructions.
|
|
MapVector<StringRef, unsigned> Mapping;
|
|
for (Instruction &I : instructions(F)) {
|
|
if (!I.hasMetadata(LLVMContext::MD_annotation))
|
|
continue;
|
|
for (const MDOperand &Op :
|
|
I.getMetadata(LLVMContext::MD_annotation)->operands()) {
|
|
auto Iter = Mapping.insert({cast<MDString>(Op.get())->getString(), 0});
|
|
Iter.first->second++;
|
|
}
|
|
}
|
|
|
|
Instruction *IP = &*F.begin()->begin();
|
|
for (const auto &KV : Mapping)
|
|
ORE.emit(OptimizationRemarkAnalysis(REMARK_PASS, "AnnotationSummary", IP)
|
|
<< "Annotated " << NV("count", KV.second) << " instructions with "
|
|
<< NV("type", KV.first));
|
|
}
|
|
|
|
namespace {
|
|
|
|
struct AnnotationRemarksLegacy : public FunctionPass {
|
|
static char ID;
|
|
|
|
AnnotationRemarksLegacy() : FunctionPass(ID) {
|
|
initializeAnnotationRemarksLegacyPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
bool runOnFunction(Function &F) override {
|
|
runImpl(F);
|
|
return false;
|
|
}
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.setPreservesAll();
|
|
}
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
char AnnotationRemarksLegacy::ID = 0;
|
|
|
|
INITIALIZE_PASS_BEGIN(AnnotationRemarksLegacy, "annotation-remarks",
|
|
"Annotation Remarks", false, false)
|
|
INITIALIZE_PASS_END(AnnotationRemarksLegacy, "annotation-remarks",
|
|
"Annotation Remarks", false, false)
|
|
|
|
FunctionPass *llvm::createAnnotationRemarksLegacyPass() {
|
|
return new AnnotationRemarksLegacy();
|
|
}
|
|
|
|
PreservedAnalyses AnnotationRemarksPass::run(Function &F,
|
|
FunctionAnalysisManager &AM) {
|
|
runImpl(F);
|
|
return PreservedAnalyses::all();
|
|
}
|