1*0b57cec5SDimitry Andric ///===- LazyMachineBlockFrequencyInfo.cpp - Lazy Machine Block Frequency --===//
2*0b57cec5SDimitry Andric ///
3*0b57cec5SDimitry Andric /// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*0b57cec5SDimitry Andric /// See https://llvm.org/LICENSE.txt for license information.
5*0b57cec5SDimitry Andric /// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*0b57cec5SDimitry Andric ///
7*0b57cec5SDimitry Andric ///===---------------------------------------------------------------------===//
8*0b57cec5SDimitry Andric /// \file
9*0b57cec5SDimitry Andric /// This is an alternative analysis pass to MachineBlockFrequencyInfo. The
10*0b57cec5SDimitry Andric /// difference is that with this pass the block frequencies are not computed
11*0b57cec5SDimitry Andric /// when the analysis pass is executed but rather when the BFI result is
12*0b57cec5SDimitry Andric /// explicitly requested by the analysis client.
13*0b57cec5SDimitry Andric ///
14*0b57cec5SDimitry Andric ///===---------------------------------------------------------------------===//
15*0b57cec5SDimitry Andric
16*0b57cec5SDimitry Andric #include "llvm/CodeGen/LazyMachineBlockFrequencyInfo.h"
17*0b57cec5SDimitry Andric #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
18*0b57cec5SDimitry Andric #include "llvm/InitializePasses.h"
19*0b57cec5SDimitry Andric
20*0b57cec5SDimitry Andric using namespace llvm;
21*0b57cec5SDimitry Andric
22*0b57cec5SDimitry Andric #define DEBUG_TYPE "lazy-machine-block-freq"
23*0b57cec5SDimitry Andric
24*0b57cec5SDimitry Andric INITIALIZE_PASS_BEGIN(LazyMachineBlockFrequencyInfoPass, DEBUG_TYPE,
25*0b57cec5SDimitry Andric "Lazy Machine Block Frequency Analysis", true, true)
26*0b57cec5SDimitry Andric INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
27*0b57cec5SDimitry Andric INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
28*0b57cec5SDimitry Andric INITIALIZE_PASS_END(LazyMachineBlockFrequencyInfoPass, DEBUG_TYPE,
29*0b57cec5SDimitry Andric "Lazy Machine Block Frequency Analysis", true, true)
30*0b57cec5SDimitry Andric
31*0b57cec5SDimitry Andric char LazyMachineBlockFrequencyInfoPass::ID = 0;
32*0b57cec5SDimitry Andric
LazyMachineBlockFrequencyInfoPass()33*0b57cec5SDimitry Andric LazyMachineBlockFrequencyInfoPass::LazyMachineBlockFrequencyInfoPass()
34*0b57cec5SDimitry Andric : MachineFunctionPass(ID) {
35*0b57cec5SDimitry Andric initializeLazyMachineBlockFrequencyInfoPassPass(
36*0b57cec5SDimitry Andric *PassRegistry::getPassRegistry());
37*0b57cec5SDimitry Andric }
38*0b57cec5SDimitry Andric
print(raw_ostream & OS,const Module * M) const39*0b57cec5SDimitry Andric void LazyMachineBlockFrequencyInfoPass::print(raw_ostream &OS,
40*0b57cec5SDimitry Andric const Module *M) const {
41*0b57cec5SDimitry Andric getBFI().print(OS, M);
42*0b57cec5SDimitry Andric }
43*0b57cec5SDimitry Andric
getAnalysisUsage(AnalysisUsage & AU) const44*0b57cec5SDimitry Andric void LazyMachineBlockFrequencyInfoPass::getAnalysisUsage(
45*0b57cec5SDimitry Andric AnalysisUsage &AU) const {
46*0b57cec5SDimitry Andric AU.addRequired<MachineBranchProbabilityInfo>();
47*0b57cec5SDimitry Andric AU.setPreservesAll();
48*0b57cec5SDimitry Andric MachineFunctionPass::getAnalysisUsage(AU);
49*0b57cec5SDimitry Andric }
50*0b57cec5SDimitry Andric
releaseMemory()51*0b57cec5SDimitry Andric void LazyMachineBlockFrequencyInfoPass::releaseMemory() {
52*0b57cec5SDimitry Andric OwnedMBFI.reset();
53*0b57cec5SDimitry Andric OwnedMLI.reset();
54*0b57cec5SDimitry Andric OwnedMDT.reset();
55*0b57cec5SDimitry Andric }
56*0b57cec5SDimitry Andric
57*0b57cec5SDimitry Andric MachineBlockFrequencyInfo &
calculateIfNotAvailable() const58*0b57cec5SDimitry Andric LazyMachineBlockFrequencyInfoPass::calculateIfNotAvailable() const {
59*0b57cec5SDimitry Andric auto *MBFI = getAnalysisIfAvailable<MachineBlockFrequencyInfo>();
60*0b57cec5SDimitry Andric if (MBFI) {
61*0b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "MachineBlockFrequencyInfo is available\n");
62*0b57cec5SDimitry Andric return *MBFI;
63*0b57cec5SDimitry Andric }
64*0b57cec5SDimitry Andric
65*0b57cec5SDimitry Andric auto &MBPI = getAnalysis<MachineBranchProbabilityInfo>();
66*0b57cec5SDimitry Andric auto *MLI = getAnalysisIfAvailable<MachineLoopInfo>();
67*0b57cec5SDimitry Andric auto *MDT = getAnalysisIfAvailable<MachineDominatorTree>();
68*0b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "Building MachineBlockFrequencyInfo on the fly\n");
69*0b57cec5SDimitry Andric LLVM_DEBUG(if (MLI) dbgs() << "LoopInfo is available\n");
70*0b57cec5SDimitry Andric
71*0b57cec5SDimitry Andric if (!MLI) {
72*0b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "Building LoopInfo on the fly\n");
73*0b57cec5SDimitry Andric // First create a dominator tree.
74*0b57cec5SDimitry Andric LLVM_DEBUG(if (MDT) dbgs() << "DominatorTree is available\n");
75*0b57cec5SDimitry Andric
76*0b57cec5SDimitry Andric if (!MDT) {
77*0b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "Building DominatorTree on the fly\n");
78*0b57cec5SDimitry Andric OwnedMDT = std::make_unique<MachineDominatorTree>();
79*0b57cec5SDimitry Andric OwnedMDT->getBase().recalculate(*MF);
80*0b57cec5SDimitry Andric MDT = OwnedMDT.get();
81*0b57cec5SDimitry Andric }
82*0b57cec5SDimitry Andric
83*0b57cec5SDimitry Andric // Generate LoopInfo from it.
84*0b57cec5SDimitry Andric OwnedMLI = std::make_unique<MachineLoopInfo>();
85*0b57cec5SDimitry Andric OwnedMLI->getBase().analyze(MDT->getBase());
86*0b57cec5SDimitry Andric MLI = OwnedMLI.get();
87*0b57cec5SDimitry Andric }
88*0b57cec5SDimitry Andric
89*0b57cec5SDimitry Andric OwnedMBFI = std::make_unique<MachineBlockFrequencyInfo>();
90*0b57cec5SDimitry Andric OwnedMBFI->calculate(*MF, MBPI, *MLI);
91*0b57cec5SDimitry Andric return *OwnedMBFI;
92*0b57cec5SDimitry Andric }
93*0b57cec5SDimitry Andric
runOnMachineFunction(MachineFunction & F)94*0b57cec5SDimitry Andric bool LazyMachineBlockFrequencyInfoPass::runOnMachineFunction(
95*0b57cec5SDimitry Andric MachineFunction &F) {
96*0b57cec5SDimitry Andric MF = &F;
97 return false;
98 }
99