llvm-for-llvmta/lib/CodeGen/PseudoProbeInserter.cpp

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//===- PseudoProbeInserter.cpp - Insert annotation for callsite profiling -===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements PseudoProbeInserter pass, which inserts pseudo probe
// annotations for call instructions with a pseudo-probe-specific dwarf
// discriminator. such discriminator indicates that the call instruction comes
// with a pseudo probe, and the discriminator value holds information to
// identify the corresponding counter.
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/PseudoProbe.h"
#include "llvm/InitializePasses.h"
#include "llvm/Target/TargetMachine.h"
#include <unordered_map>
#define DEBUG_TYPE "pseudo-probe-inserter"
using namespace llvm;
namespace {
class PseudoProbeInserter : public MachineFunctionPass {
public:
static char ID;
PseudoProbeInserter() : MachineFunctionPass(ID) {
initializePseudoProbeInserterPass(*PassRegistry::getPassRegistry());
}
StringRef getPassName() const override { return "Pseudo Probe Inserter"; }
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool runOnMachineFunction(MachineFunction &MF) override {
const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
bool Changed = false;
for (MachineBasicBlock &MBB : MF) {
for (MachineInstr &MI : MBB) {
if (MI.isCall()) {
if (DILocation *DL = MI.getDebugLoc()) {
auto Value = DL->getDiscriminator();
if (DILocation::isPseudoProbeDiscriminator(Value)) {
BuildMI(MBB, MI, DL, TII->get(TargetOpcode::PSEUDO_PROBE))
.addImm(getFuncGUID(MF.getFunction().getParent(), DL))
.addImm(
PseudoProbeDwarfDiscriminator::extractProbeIndex(Value))
.addImm(
PseudoProbeDwarfDiscriminator::extractProbeType(Value))
.addImm(PseudoProbeDwarfDiscriminator::extractProbeAttributes(
Value));
Changed = true;
}
}
}
}
}
return Changed;
}
private:
uint64_t getFuncGUID(Module *M, DILocation *DL) {
auto *SP = DL->getScope()->getSubprogram();
auto Name = SP->getLinkageName();
if (Name.empty())
Name = SP->getName();
return Function::getGUID(Name);
}
};
} // namespace
char PseudoProbeInserter::ID = 0;
INITIALIZE_PASS_BEGIN(PseudoProbeInserter, DEBUG_TYPE,
"Insert pseudo probe annotations for value profiling",
false, false)
INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
INITIALIZE_PASS_END(PseudoProbeInserter, DEBUG_TYPE,
"Insert pseudo probe annotations for value profiling",
false, false)
FunctionPass *llvm::createPseudoProbeInserter() {
return new PseudoProbeInserter();
}