xref: /llvm-project/llvm/lib/CodeGen/MachineOptimizationRemarkEmitter.cpp (revision f1bea0a6ab095840bca1a7283b3444bac45a94c3)
1 ///===- MachineOptimizationRemarkEmitter.cpp - Opt Diagnostic -*- C++ -*---===//
2 ///
3 ///                     The LLVM Compiler Infrastructure
4 ///
5 /// This file is distributed under the University of Illinois Open Source
6 /// License. See LICENSE.TXT for details.
7 ///
8 ///===---------------------------------------------------------------------===//
9 /// \file
10 /// Optimization diagnostic interfaces for machine passes.  It's packaged as an
11 /// analysis pass so that by using this service passes become dependent on MBFI
12 /// as well.  MBFI is used to compute the "hotness" of the diagnostic message.
13 ///
14 ///===---------------------------------------------------------------------===//
15 
16 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
17 #include "llvm/CodeGen/LazyMachineBlockFrequencyInfo.h"
18 #include "llvm/CodeGen/MachineInstr.h"
19 #include "llvm/IR/DebugInfo.h"
20 #include "llvm/IR/DiagnosticInfo.h"
21 #include "llvm/IR/LLVMContext.h"
22 
23 using namespace llvm;
24 
25 DiagnosticInfoMIROptimization::MachineArgument::MachineArgument(
26     StringRef MKey, const MachineInstr &MI)
27     : Argument() {
28   Key = MKey;
29 
30   raw_string_ostream OS(Val);
31   MI.print(OS, /*SkipOpers=*/false, /*SkipDebugLoc=*/true);
32 }
33 
34 Optional<uint64_t>
35 MachineOptimizationRemarkEmitter::computeHotness(const MachineBasicBlock &MBB) {
36   if (!MBFI)
37     return None;
38 
39   return MBFI->getBlockProfileCount(&MBB);
40 }
41 
42 void MachineOptimizationRemarkEmitter::computeHotness(
43     DiagnosticInfoMIROptimization &Remark) {
44   const MachineBasicBlock *MBB = Remark.getBlock();
45   if (MBB)
46     Remark.setHotness(computeHotness(*MBB));
47 }
48 
49 void MachineOptimizationRemarkEmitter::emit(
50     DiagnosticInfoOptimizationBase &OptDiagCommon) {
51   auto &OptDiag = cast<DiagnosticInfoMIROptimization>(OptDiagCommon);
52   computeHotness(OptDiag);
53 
54   LLVMContext &Ctx = MF.getFunction()->getContext();
55 
56   // If a diagnostic has a hotness value, then only emit it if its hotness
57   // meets the threshold.
58   if (OptDiag.getHotness() &&
59       *OptDiag.getHotness() < Ctx.getDiagnosticsHotnessThreshold()) {
60     return;
61   }
62 
63   yaml::Output *Out = Ctx.getDiagnosticsOutputFile();
64   if (Out) {
65     auto *P = &const_cast<DiagnosticInfoOptimizationBase &>(OptDiagCommon);
66     *Out << P;
67   }
68 
69   Ctx.diagnose(OptDiag);
70 }
71 
72 MachineOptimizationRemarkEmitterPass::MachineOptimizationRemarkEmitterPass()
73     : MachineFunctionPass(ID) {
74   initializeMachineOptimizationRemarkEmitterPassPass(
75       *PassRegistry::getPassRegistry());
76 }
77 
78 bool MachineOptimizationRemarkEmitterPass::runOnMachineFunction(
79     MachineFunction &MF) {
80   MachineBlockFrequencyInfo *MBFI;
81 
82   if (MF.getFunction()->getContext().getDiagnosticsHotnessRequested())
83     MBFI = &getAnalysis<LazyMachineBlockFrequencyInfoPass>().getBFI();
84   else
85     MBFI = nullptr;
86 
87   ORE = llvm::make_unique<MachineOptimizationRemarkEmitter>(MF, MBFI);
88   return false;
89 }
90 
91 void MachineOptimizationRemarkEmitterPass::getAnalysisUsage(
92     AnalysisUsage &AU) const {
93   AU.addRequired<LazyMachineBlockFrequencyInfoPass>();
94   AU.setPreservesAll();
95   MachineFunctionPass::getAnalysisUsage(AU);
96 }
97 
98 char MachineOptimizationRemarkEmitterPass::ID = 0;
99 static const char ore_name[] = "Machine Optimization Remark Emitter";
100 #define ORE_NAME "machine-opt-remark-emitter"
101 
102 INITIALIZE_PASS_BEGIN(MachineOptimizationRemarkEmitterPass, ORE_NAME, ore_name,
103                       false, true)
104 INITIALIZE_PASS_DEPENDENCY(LazyMachineBlockFrequencyInfoPass)
105 INITIALIZE_PASS_END(MachineOptimizationRemarkEmitterPass, ORE_NAME, ore_name,
106                     false, true)
107