80 lines
2.4 KiB
C++
80 lines
2.4 KiB
C++
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//===- MachinePostDominators.cpp -Machine Post Dominator Calculation ------===//
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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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//
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// This file implements simple dominator construction algorithms for finding
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// post dominators on machine functions.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/MachinePostDominators.h"
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#include "llvm/InitializePasses.h"
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using namespace llvm;
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namespace llvm {
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template class DominatorTreeBase<MachineBasicBlock, true>; // PostDomTreeBase
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extern bool VerifyMachineDomInfo;
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} // namespace llvm
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char MachinePostDominatorTree::ID = 0;
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//declare initializeMachinePostDominatorTreePass
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INITIALIZE_PASS(MachinePostDominatorTree, "machinepostdomtree",
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"MachinePostDominator Tree Construction", true, true)
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MachinePostDominatorTree::MachinePostDominatorTree()
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: MachineFunctionPass(ID), PDT(nullptr) {
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initializeMachinePostDominatorTreePass(*PassRegistry::getPassRegistry());
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}
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FunctionPass *MachinePostDominatorTree::createMachinePostDominatorTreePass() {
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return new MachinePostDominatorTree();
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}
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bool MachinePostDominatorTree::runOnMachineFunction(MachineFunction &F) {
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PDT = std::make_unique<PostDomTreeT>();
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PDT->recalculate(F);
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return false;
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}
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void MachinePostDominatorTree::getAnalysisUsage(AnalysisUsage &AU) const {
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AU.setPreservesAll();
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MachineFunctionPass::getAnalysisUsage(AU);
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}
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MachineBasicBlock *MachinePostDominatorTree::findNearestCommonDominator(
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ArrayRef<MachineBasicBlock *> Blocks) const {
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assert(!Blocks.empty());
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MachineBasicBlock *NCD = Blocks.front();
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for (MachineBasicBlock *BB : Blocks.drop_front()) {
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NCD = PDT->findNearestCommonDominator(NCD, BB);
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// Stop when the root is reached.
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if (PDT->isVirtualRoot(PDT->getNode(NCD)))
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return nullptr;
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}
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return NCD;
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}
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void MachinePostDominatorTree::verifyAnalysis() const {
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if (PDT && VerifyMachineDomInfo)
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if (!PDT->verify(PostDomTreeT::VerificationLevel::Basic)) {
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errs() << "MachinePostDominatorTree verification failed\n";
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abort();
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}
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}
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void MachinePostDominatorTree::print(llvm::raw_ostream &OS,
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const Module *M) const {
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PDT->print(OS);
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}
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