llvm-project/llvm/lib/Transforms/Instrumentation/CGProfile.cpp

100 lines
3.3 KiB
C++

//===-- CGProfile.cpp -----------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Instrumentation/CGProfile.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/Analysis/BlockFrequencyInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/PassManager.h"
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Transforms/Instrumentation.h"
#include <array>
using namespace llvm;
PreservedAnalyses CGProfilePass::run(Module &M, ModuleAnalysisManager &MAM) {
MapVector<std::pair<Function *, Function *>, uint64_t> Counts;
FunctionAnalysisManager &FAM =
MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
InstrProfSymtab Symtab;
auto UpdateCounts = [&](TargetTransformInfo &TTI, Function *F,
Function *CalledF, uint64_t NewCount) {
if (!CalledF || !TTI.isLoweredToCall(CalledF))
return;
uint64_t &Count = Counts[std::make_pair(F, CalledF)];
Count = SaturatingAdd(Count, NewCount);
};
// Ignore error here. Indirect calls are ignored if this fails.
(void)(bool)Symtab.create(M);
for (auto &F : M) {
if (F.isDeclaration())
continue;
auto &BFI = FAM.getResult<BlockFrequencyAnalysis>(F);
if (BFI.getEntryFreq() == 0)
continue;
TargetTransformInfo &TTI = FAM.getResult<TargetIRAnalysis>(F);
for (auto &BB : F) {
Optional<uint64_t> BBCount = BFI.getBlockProfileCount(&BB);
if (!BBCount)
continue;
for (auto &I : BB) {
CallSite CS(&I);
if (!CS)
continue;
if (CS.isIndirectCall()) {
InstrProfValueData ValueData[8];
uint32_t ActualNumValueData;
uint64_t TotalC;
if (!getValueProfDataFromInst(*CS.getInstruction(),
IPVK_IndirectCallTarget, 8, ValueData,
ActualNumValueData, TotalC))
continue;
for (const auto &VD :
ArrayRef<InstrProfValueData>(ValueData, ActualNumValueData)) {
UpdateCounts(TTI, &F, Symtab.getFunction(VD.Value), VD.Count);
}
continue;
}
UpdateCounts(TTI, &F, CS.getCalledFunction(), *BBCount);
}
}
}
addModuleFlags(M, Counts);
return PreservedAnalyses::all();
}
void CGProfilePass::addModuleFlags(
Module &M,
MapVector<std::pair<Function *, Function *>, uint64_t> &Counts) const {
if (Counts.empty())
return;
LLVMContext &Context = M.getContext();
MDBuilder MDB(Context);
std::vector<Metadata *> Nodes;
for (auto E : Counts) {
Metadata *Vals[] = {ValueAsMetadata::get(E.first.first),
ValueAsMetadata::get(E.first.second),
MDB.createConstant(ConstantInt::get(
Type::getInt64Ty(Context), E.second))};
Nodes.push_back(MDNode::get(Context, Vals));
}
M.addModuleFlag(Module::Append, "CG Profile", MDNode::get(Context, Nodes));
}