1///===- MachineOptimizationRemarkEmitter.cpp - Opt Diagnostic -*- C++ -*---===//
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/// \file
9/// Optimization diagnostic interfaces for machine passes.  It's packaged as an
10/// analysis pass so that by using this service passes become dependent on MBFI
11/// as well.  MBFI is used to compute the "hotness" of the diagnostic message.
12///
13///===---------------------------------------------------------------------===//
14
15#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
16#include "llvm/CodeGen/LazyMachineBlockFrequencyInfo.h"
17#include "llvm/CodeGen/MachineInstr.h"
18#include "llvm/IR/DiagnosticInfo.h"
19#include "llvm/IR/LLVMContext.h"
20#include "llvm/InitializePasses.h"
21
22using namespace llvm;
23
24DiagnosticInfoMIROptimization::MachineArgument::MachineArgument(
25    StringRef MKey, const MachineInstr &MI)
26    : Argument() {
27  Key = MKey;
28
29  raw_string_ostream OS(Val);
30  MI.print(OS, /*IsStandalone=*/true, /*SkipOpers=*/false,
31           /*SkipDebugLoc=*/true);
32}
33
34Optional<uint64_t>
35MachineOptimizationRemarkEmitter::computeHotness(const MachineBasicBlock &MBB) {
36  if (!MBFI)
37    return None;
38
39  return MBFI->getBlockProfileCount(&MBB);
40}
41
42void MachineOptimizationRemarkEmitter::computeHotness(
43    DiagnosticInfoMIROptimization &Remark) {
44  const MachineBasicBlock *MBB = Remark.getBlock();
45  if (MBB)
46    Remark.setHotness(computeHotness(*MBB));
47}
48
49void MachineOptimizationRemarkEmitter::emit(
50    DiagnosticInfoOptimizationBase &OptDiagCommon) {
51  auto &OptDiag = cast<DiagnosticInfoMIROptimization>(OptDiagCommon);
52  computeHotness(OptDiag);
53
54  LLVMContext &Ctx = MF.getFunction().getContext();
55
56  // Only emit it if its hotness meets the threshold.
57  if (OptDiag.getHotness().getValueOr(0) <
58      Ctx.getDiagnosticsHotnessThreshold()) {
59    return;
60  }
61
62  Ctx.diagnose(OptDiag);
63}
64
65MachineOptimizationRemarkEmitterPass::MachineOptimizationRemarkEmitterPass()
66    : MachineFunctionPass(ID) {
67  initializeMachineOptimizationRemarkEmitterPassPass(
68      *PassRegistry::getPassRegistry());
69}
70
71bool MachineOptimizationRemarkEmitterPass::runOnMachineFunction(
72    MachineFunction &MF) {
73  MachineBlockFrequencyInfo *MBFI;
74
75  if (MF.getFunction().getContext().getDiagnosticsHotnessRequested())
76    MBFI = &getAnalysis<LazyMachineBlockFrequencyInfoPass>().getBFI();
77  else
78    MBFI = nullptr;
79
80  ORE = std::make_unique<MachineOptimizationRemarkEmitter>(MF, MBFI);
81  return false;
82}
83
84void MachineOptimizationRemarkEmitterPass::getAnalysisUsage(
85    AnalysisUsage &AU) const {
86  AU.addRequired<LazyMachineBlockFrequencyInfoPass>();
87  AU.setPreservesAll();
88  MachineFunctionPass::getAnalysisUsage(AU);
89}
90
91char MachineOptimizationRemarkEmitterPass::ID = 0;
92static const char ore_name[] = "Machine Optimization Remark Emitter";
93#define ORE_NAME "machine-opt-remark-emitter"
94
95INITIALIZE_PASS_BEGIN(MachineOptimizationRemarkEmitterPass, ORE_NAME, ore_name,
96                      false, true)
97INITIALIZE_PASS_DEPENDENCY(LazyMachineBlockFrequencyInfoPass)
98INITIALIZE_PASS_END(MachineOptimizationRemarkEmitterPass, ORE_NAME, ore_name,
99                    false, true)
100