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/InitializePasses.h"
18*0b57cec5SDimitry Andric
19*0b57cec5SDimitry Andric using namespace llvm;
20*0b57cec5SDimitry Andric
21*0b57cec5SDimitry Andric #define DEBUG_TYPE "lazy-machine-block-freq"
22*0b57cec5SDimitry Andric
23*0b57cec5SDimitry Andric INITIALIZE_PASS_BEGIN(LazyMachineBlockFrequencyInfoPass, DEBUG_TYPE,
24*0b57cec5SDimitry Andric "Lazy Machine Block Frequency Analysis", true, true)
25*0b57cec5SDimitry Andric INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
26*0b57cec5SDimitry Andric INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
27*0b57cec5SDimitry Andric INITIALIZE_PASS_END(LazyMachineBlockFrequencyInfoPass, DEBUG_TYPE,
28*0b57cec5SDimitry Andric "Lazy Machine Block Frequency Analysis", true, true)
29*0b57cec5SDimitry Andric
30*0b57cec5SDimitry Andric char LazyMachineBlockFrequencyInfoPass::ID = 0;
31*0b57cec5SDimitry Andric
LazyMachineBlockFrequencyInfoPass()32*0b57cec5SDimitry Andric LazyMachineBlockFrequencyInfoPass::LazyMachineBlockFrequencyInfoPass()
33*0b57cec5SDimitry Andric : MachineFunctionPass(ID) {
34*0b57cec5SDimitry Andric initializeLazyMachineBlockFrequencyInfoPassPass(
35*0b57cec5SDimitry Andric *PassRegistry::getPassRegistry());
36*0b57cec5SDimitry Andric }
37*0b57cec5SDimitry Andric
print(raw_ostream & OS,const Module * M) const38*0b57cec5SDimitry Andric void LazyMachineBlockFrequencyInfoPass::print(raw_ostream &OS,
39*0b57cec5SDimitry Andric const Module *M) const {
40*0b57cec5SDimitry Andric getBFI().print(OS, M);
41*0b57cec5SDimitry Andric }
42*0b57cec5SDimitry Andric
getAnalysisUsage(AnalysisUsage & AU) const43*0b57cec5SDimitry Andric void LazyMachineBlockFrequencyInfoPass::getAnalysisUsage(
44*0b57cec5SDimitry Andric AnalysisUsage &AU) const {
45*0b57cec5SDimitry Andric AU.addRequired<MachineBranchProbabilityInfo>();
46*0b57cec5SDimitry Andric AU.setPreservesAll();
47*0b57cec5SDimitry Andric MachineFunctionPass::getAnalysisUsage(AU);
48*0b57cec5SDimitry Andric }
49*0b57cec5SDimitry Andric
releaseMemory()50*0b57cec5SDimitry Andric void LazyMachineBlockFrequencyInfoPass::releaseMemory() {
51*0b57cec5SDimitry Andric OwnedMBFI.reset();
52*0b57cec5SDimitry Andric OwnedMLI.reset();
53*0b57cec5SDimitry Andric OwnedMDT.reset();
54*0b57cec5SDimitry Andric }
55*0b57cec5SDimitry Andric
56*0b57cec5SDimitry Andric MachineBlockFrequencyInfo &
calculateIfNotAvailable() const57*0b57cec5SDimitry Andric LazyMachineBlockFrequencyInfoPass::calculateIfNotAvailable() const {
58*0b57cec5SDimitry Andric auto *MBFI = getAnalysisIfAvailable<MachineBlockFrequencyInfo>();
59*0b57cec5SDimitry Andric if (MBFI) {
60*0b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "MachineBlockFrequencyInfo is available\n");
61*0b57cec5SDimitry Andric return *MBFI;
62*0b57cec5SDimitry Andric }
63*0b57cec5SDimitry Andric
64*0b57cec5SDimitry Andric auto &MBPI = getAnalysis<MachineBranchProbabilityInfo>();
65*0b57cec5SDimitry Andric auto *MLI = getAnalysisIfAvailable<MachineLoopInfo>();
66*0b57cec5SDimitry Andric auto *MDT = getAnalysisIfAvailable<MachineDominatorTree>();
67*0b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "Building MachineBlockFrequencyInfo on the fly\n");
68*0b57cec5SDimitry Andric LLVM_DEBUG(if (MLI) dbgs() << "LoopInfo is available\n");
69*0b57cec5SDimitry Andric
70*0b57cec5SDimitry Andric if (!MLI) {
71*0b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "Building LoopInfo on the fly\n");
72*0b57cec5SDimitry Andric // First create a dominator tree.
73*0b57cec5SDimitry Andric LLVM_DEBUG(if (MDT) dbgs() << "DominatorTree is available\n");
74*0b57cec5SDimitry Andric
75*0b57cec5SDimitry Andric if (!MDT) {
76*0b57cec5SDimitry Andric LLVM_DEBUG(dbgs() << "Building DominatorTree on the fly\n");
77*0b57cec5SDimitry Andric OwnedMDT = std::make_unique<MachineDominatorTree>();
78*0b57cec5SDimitry Andric OwnedMDT->getBase().recalculate(*MF);
79*0b57cec5SDimitry Andric MDT = OwnedMDT.get();
80*0b57cec5SDimitry Andric }
81*0b57cec5SDimitry Andric
82*0b57cec5SDimitry Andric // Generate LoopInfo from it.
83*0b57cec5SDimitry Andric OwnedMLI = std::make_unique<MachineLoopInfo>();
84*0b57cec5SDimitry Andric OwnedMLI->getBase().analyze(MDT->getBase());
85*0b57cec5SDimitry Andric MLI = OwnedMLI.get();
86*0b57cec5SDimitry Andric }
87*0b57cec5SDimitry Andric
88*0b57cec5SDimitry Andric OwnedMBFI = std::make_unique<MachineBlockFrequencyInfo>();
89*0b57cec5SDimitry Andric OwnedMBFI->calculate(*MF, MBPI, *MLI);
90*0b57cec5SDimitry Andric return *OwnedMBFI.get();
91*0b57cec5SDimitry Andric }
92*0b57cec5SDimitry Andric
runOnMachineFunction(MachineFunction & F)93*0b57cec5SDimitry Andric bool LazyMachineBlockFrequencyInfoPass::runOnMachineFunction(
94*0b57cec5SDimitry Andric MachineFunction &F) {
95*0b57cec5SDimitry Andric MF = &F;
96*0b57cec5SDimitry Andric return false;
97 }
98