0215f6b6cf
I plan to use that to optimize mask creation in VPlan predicator by `or`ing edge masks from the post-dominance frontier instead of all predecessors in a subsequent patch. Note that it would require to use the same unmodified post-dom tree for *all* the basic blocks in a VPlan that is already limited to a particular loopnest so the algorithmic complexity concerns behind the "deprecation" notice in the beggining of `DominanceFrontier.h` (and also discussion in the https://discourse.llvm.org/t/dominance-frontiers/21755 thread) don't apply for my use case (at least to the best of my understanding). The change here is to properly use graph-traits for children traversal plus inline `ForwardDominanceFrontierBase` into `DominanceFrontierBase` now that it's used for post-dom-frontier. Since the only planned use-case is in the vectorizer, I'm adding a VPlan-base unittest along with this change. Support for multiple root nodes via using virtual root node to seed the worklist is left to a subsequent PR.
75 lines
2.5 KiB
C++
75 lines
2.5 KiB
C++
//===- MachineDominanceFrontier.cpp ---------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/MachineDominanceFrontier.h"
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#include "llvm/CodeGen/MachineDominators.h"
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/InitializePasses.h"
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#include "llvm/Pass.h"
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#include "llvm/PassRegistry.h"
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using namespace llvm;
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namespace llvm {
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template class DominanceFrontierBase<MachineBasicBlock, false>;
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}
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char MachineDominanceFrontierWrapperPass::ID = 0;
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INITIALIZE_PASS_BEGIN(MachineDominanceFrontierWrapperPass,
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"machine-domfrontier",
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"Machine Dominance Frontier Construction", true, true)
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INITIALIZE_PASS_DEPENDENCY(MachineDominatorTreeWrapperPass)
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INITIALIZE_PASS_END(MachineDominanceFrontierWrapperPass, "machine-domfrontier",
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"Machine Dominance Frontier Construction", true, true)
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MachineDominanceFrontierWrapperPass::MachineDominanceFrontierWrapperPass()
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: MachineFunctionPass(ID) {}
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char &llvm::MachineDominanceFrontierID =
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MachineDominanceFrontierWrapperPass::ID;
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bool MachineDominanceFrontier::invalidate(
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MachineFunction &F, const PreservedAnalyses &PA,
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MachineFunctionAnalysisManager::Invalidator &) {
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auto PAC = PA.getChecker<MachineDominanceFrontierAnalysis>();
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return !PAC.preserved() &&
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!PAC.preservedSet<AllAnalysesOn<MachineFunction>>() &&
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!PAC.preservedSet<CFGAnalyses>();
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}
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bool MachineDominanceFrontierWrapperPass::runOnMachineFunction(
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MachineFunction &) {
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MDF.releaseMemory();
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auto &MDT = getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree();
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MDF.analyze(MDT);
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return false;
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}
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void MachineDominanceFrontierWrapperPass::releaseMemory() {
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MDF.releaseMemory();
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}
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void MachineDominanceFrontierWrapperPass::getAnalysisUsage(
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AnalysisUsage &AU) const {
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AU.setPreservesAll();
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AU.addRequired<MachineDominatorTreeWrapperPass>();
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MachineFunctionPass::getAnalysisUsage(AU);
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}
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AnalysisKey MachineDominanceFrontierAnalysis::Key;
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MachineDominanceFrontierAnalysis::Result
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MachineDominanceFrontierAnalysis::run(MachineFunction &MF,
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MachineFunctionAnalysisManager &MFAM) {
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MachineDominanceFrontier MDF;
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auto &MDT = MFAM.getResult<MachineDominatorTreeAnalysis>(MF);
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MDF.analyze(MDT);
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return MDF;
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}
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