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
34std::optional<uint64_t>
35MachineOptimizationRemarkEmitter::computeHotness(const MachineBasicBlock &MBB) {
36 if (!MBFI)
37 return std::nullopt;
38
39 return MBFI->getBlockProfileCount(MBB: &MBB);
40}
41
42void MachineOptimizationRemarkEmitter::computeHotness(
43 DiagnosticInfoMIROptimization &Remark) {
44 const MachineBasicBlock *MBB = Remark.getBlock();
45 if (MBB)
46 Remark.setHotness(computeHotness(MBB: *MBB));
47}
48
49void MachineOptimizationRemarkEmitter::emit(
50 DiagnosticInfoOptimizationBase &OptDiagCommon) {
51 auto &OptDiag = cast<DiagnosticInfoMIROptimization>(Val&: OptDiagCommon);
52 computeHotness(Remark&: OptDiag);
53
54 LLVMContext &Ctx = MF.getFunction().getContext();
55
56 // Only emit it if its hotness meets the threshold.
57 if (OptDiag.getHotness().value_or(u: 0) < Ctx.getDiagnosticsHotnessThreshold())
58 return;
59
60 Ctx.diagnose(DI: OptDiag);
61}
62
63MachineOptimizationRemarkEmitterPass::MachineOptimizationRemarkEmitterPass()
64 : MachineFunctionPass(ID) {
65 initializeMachineOptimizationRemarkEmitterPassPass(
66 *PassRegistry::getPassRegistry());
67}
68
69bool MachineOptimizationRemarkEmitterPass::runOnMachineFunction(
70 MachineFunction &MF) {
71 MachineBlockFrequencyInfo *MBFI;
72
73 if (MF.getFunction().getContext().getDiagnosticsHotnessRequested())
74 MBFI = &getAnalysis<LazyMachineBlockFrequencyInfoPass>().getBFI();
75 else
76 MBFI = nullptr;
77
78 ORE = std::make_unique<MachineOptimizationRemarkEmitter>(args&: MF, args&: MBFI);
79 return false;
80}
81
82void MachineOptimizationRemarkEmitterPass::getAnalysisUsage(
83 AnalysisUsage &AU) const {
84 AU.addRequired<LazyMachineBlockFrequencyInfoPass>();
85 AU.setPreservesAll();
86 MachineFunctionPass::getAnalysisUsage(AU);
87}
88
89char MachineOptimizationRemarkEmitterPass::ID = 0;
90static const char ore_name[] = "Machine Optimization Remark Emitter";
91#define ORE_NAME "machine-opt-remark-emitter"
92
93INITIALIZE_PASS_BEGIN(MachineOptimizationRemarkEmitterPass, ORE_NAME, ore_name,
94 true, true)
95INITIALIZE_PASS_DEPENDENCY(LazyMachineBlockFrequencyInfoPass)
96INITIALIZE_PASS_END(MachineOptimizationRemarkEmitterPass, ORE_NAME, ore_name,
97 true, true)
98

source code of llvm/lib/CodeGen/MachineOptimizationRemarkEmitter.cpp