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#include <optional>
22
23using namespace llvm;
24
25DiagnosticInfoMIROptimization::MachineArgument::MachineArgument(
26 StringRef MKey, const MachineInstr &MI) {
27 Key = std::string(MKey);
28
29 raw_string_ostream OS(Val);
30 MI.print(OS, /*IsStandalone=*/true, /*SkipOpers=*/false,
31 /*SkipDebugLoc=*/true);
32}
33
34bool MachineOptimizationRemarkEmitter::invalidate(
35 MachineFunction &MF, const PreservedAnalyses &PA,
36 MachineFunctionAnalysisManager::Invalidator &Inv) {
37 // This analysis has no state and so can be trivially preserved but it needs
38 // a fresh view of BFI if it was constructed with one.
39 return MBFI && Inv.invalidate<MachineBlockFrequencyAnalysis>(IR&: MF, PA);
40}
41
42std::optional<uint64_t>
43MachineOptimizationRemarkEmitter::computeHotness(const MachineBasicBlock &MBB) {
44 if (!MBFI)
45 return std::nullopt;
46
47 return MBFI->getBlockProfileCount(MBB: &MBB);
48}
49
50void MachineOptimizationRemarkEmitter::computeHotness(
51 DiagnosticInfoMIROptimization &Remark) {
52 const MachineBasicBlock *MBB = Remark.getBlock();
53 if (MBB)
54 Remark.setHotness(computeHotness(MBB: *MBB));
55}
56
57void MachineOptimizationRemarkEmitter::emit(
58 DiagnosticInfoOptimizationBase &OptDiagCommon) {
59 auto &OptDiag = cast<DiagnosticInfoMIROptimization>(Val&: OptDiagCommon);
60 computeHotness(Remark&: OptDiag);
61
62 LLVMContext &Ctx = MF.getFunction().getContext();
63
64 // Only emit it if its hotness meets the threshold.
65 if (OptDiag.getHotness().value_or(u: 0) < Ctx.getDiagnosticsHotnessThreshold())
66 return;
67
68 Ctx.diagnose(DI: OptDiag);
69}
70
71MachineOptimizationRemarkEmitterPass::MachineOptimizationRemarkEmitterPass()
72 : MachineFunctionPass(ID) {
73 initializeMachineOptimizationRemarkEmitterPassPass(
74 *PassRegistry::getPassRegistry());
75}
76
77bool MachineOptimizationRemarkEmitterPass::runOnMachineFunction(
78 MachineFunction &MF) {
79 MachineBlockFrequencyInfo *MBFI;
80
81 if (MF.getFunction().getContext().getDiagnosticsHotnessRequested())
82 MBFI = &getAnalysis<LazyMachineBlockFrequencyInfoPass>().getBFI();
83 else
84 MBFI = nullptr;
85
86 ORE = std::make_unique<MachineOptimizationRemarkEmitter>(args&: MF, args&: MBFI);
87 return false;
88}
89
90void MachineOptimizationRemarkEmitterPass::getAnalysisUsage(
91 AnalysisUsage &AU) const {
92 AU.addRequired<LazyMachineBlockFrequencyInfoPass>();
93 AU.setPreservesAll();
94 MachineFunctionPass::getAnalysisUsage(AU);
95}
96
97AnalysisKey MachineOptimizationRemarkEmitterAnalysis::Key;
98
99MachineOptimizationRemarkEmitterAnalysis::Result
100MachineOptimizationRemarkEmitterAnalysis::run(
101 MachineFunction &MF, MachineFunctionAnalysisManager &MFAM) {
102 MachineBlockFrequencyInfo *MBFI =
103 MF.getFunction().getContext().getDiagnosticsHotnessRequested()
104 ? &MFAM.getResult<MachineBlockFrequencyAnalysis>(IR&: MF)
105 : nullptr;
106 return Result(MF, MBFI);
107}
108
109char MachineOptimizationRemarkEmitterPass::ID = 0;
110static const char ore_name[] = "Machine Optimization Remark Emitter";
111#define ORE_NAME "machine-opt-remark-emitter"
112
113INITIALIZE_PASS_BEGIN(MachineOptimizationRemarkEmitterPass, ORE_NAME, ore_name,
114 true, true)
115INITIALIZE_PASS_DEPENDENCY(LazyMachineBlockFrequencyInfoPass)
116INITIALIZE_PASS_END(MachineOptimizationRemarkEmitterPass, ORE_NAME, ore_name,
117 true, true)
118