98 lines
3.3 KiB
C++
98 lines
3.3 KiB
C++
///===- LazyMachineBlockFrequencyInfo.cpp - Lazy Machine Block Frequency --===//
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///
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/// The LLVM Compiler Infrastructure
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///
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/// This file is distributed under the University of Illinois Open Source
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/// License. See LICENSE.TXT for details.
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///
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///===---------------------------------------------------------------------===//
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/// \file
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/// This is an alternative analysis pass to MachineBlockFrequencyInfo. The
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/// difference is that with this pass the block frequencies are not computed
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/// when the analysis pass is executed but rather when the BFI result is
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/// explicitly requested by the analysis client.
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///
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///===---------------------------------------------------------------------===//
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#include "llvm/CodeGen/LazyMachineBlockFrequencyInfo.h"
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using namespace llvm;
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#define DEBUG_TYPE "lazy-machine-block-freq"
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INITIALIZE_PASS_BEGIN(LazyMachineBlockFrequencyInfoPass, DEBUG_TYPE,
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"Lazy Machine Block Frequency Analysis", true, true)
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INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
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INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
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INITIALIZE_PASS_END(LazyMachineBlockFrequencyInfoPass, DEBUG_TYPE,
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"Lazy Machine Block Frequency Analysis", true, true)
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char LazyMachineBlockFrequencyInfoPass::ID = 0;
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LazyMachineBlockFrequencyInfoPass::LazyMachineBlockFrequencyInfoPass()
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: MachineFunctionPass(ID) {
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initializeLazyMachineBlockFrequencyInfoPassPass(
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*PassRegistry::getPassRegistry());
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}
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void LazyMachineBlockFrequencyInfoPass::print(raw_ostream &OS,
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const Module *M) const {
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getBFI().print(OS, M);
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}
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void LazyMachineBlockFrequencyInfoPass::getAnalysisUsage(
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AnalysisUsage &AU) const {
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AU.addRequired<MachineBranchProbabilityInfo>();
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AU.setPreservesAll();
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MachineFunctionPass::getAnalysisUsage(AU);
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}
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void LazyMachineBlockFrequencyInfoPass::releaseMemory() {
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OwnedMBFI.reset();
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OwnedMLI.reset();
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OwnedMDT.reset();
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}
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MachineBlockFrequencyInfo &
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LazyMachineBlockFrequencyInfoPass::calculateIfNotAvailable() const {
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auto *MBFI = getAnalysisIfAvailable<MachineBlockFrequencyInfo>();
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if (MBFI) {
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LLVM_DEBUG(dbgs() << "MachineBlockFrequencyInfo is available\n");
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return *MBFI;
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}
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auto &MBPI = getAnalysis<MachineBranchProbabilityInfo>();
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auto *MLI = getAnalysisIfAvailable<MachineLoopInfo>();
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auto *MDT = getAnalysisIfAvailable<MachineDominatorTree>();
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LLVM_DEBUG(dbgs() << "Building MachineBlockFrequencyInfo on the fly\n");
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LLVM_DEBUG(if (MLI) dbgs() << "LoopInfo is available\n");
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if (!MLI) {
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LLVM_DEBUG(dbgs() << "Building LoopInfo on the fly\n");
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// First create a dominator tree.
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LLVM_DEBUG(if (MDT) dbgs() << "DominatorTree is available\n");
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if (!MDT) {
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LLVM_DEBUG(dbgs() << "Building DominatorTree on the fly\n");
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OwnedMDT = make_unique<MachineDominatorTree>();
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OwnedMDT->getBase().recalculate(*MF);
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MDT = OwnedMDT.get();
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}
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// Generate LoopInfo from it.
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OwnedMLI = make_unique<MachineLoopInfo>();
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OwnedMLI->getBase().analyze(MDT->getBase());
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MLI = OwnedMLI.get();
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}
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OwnedMBFI = make_unique<MachineBlockFrequencyInfo>();
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OwnedMBFI->calculate(*MF, MBPI, *MLI);
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return *OwnedMBFI.get();
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}
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bool LazyMachineBlockFrequencyInfoPass::runOnMachineFunction(
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MachineFunction &F) {
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MF = &F;
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return false;
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}
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