1 //===- MachineDomTreeUpdater.cpp -----------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements the MachineDomTreeUpdater class, which provides a 10 // uniform way to update dominator tree related data structures. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/CodeGen/MachineDomTreeUpdater.h" 15 #include "llvm/ADT/SmallSet.h" 16 #include "llvm/Analysis/GenericDomTreeUpdaterImpl.h" 17 #include "llvm/CodeGen/MachinePostDominators.h" 18 #include "llvm/Support/GenericDomTree.h" 19 #include <algorithm> 20 #include <functional> 21 #include <utility> 22 23 namespace llvm { 24 25 template class GenericDomTreeUpdater< 26 MachineDomTreeUpdater, MachineDominatorTree, MachinePostDominatorTree>; 27 28 template void 29 GenericDomTreeUpdater<MachineDomTreeUpdater, MachineDominatorTree, 30 MachinePostDominatorTree>::recalculate(MachineFunction 31 &MF); 32 33 bool MachineDomTreeUpdater::forceFlushDeletedBB() { 34 if (DeletedBBs.empty()) 35 return false; 36 37 for (auto *BB : DeletedBBs) { 38 eraseDelBBNode(BB); 39 BB->eraseFromParent(); 40 } 41 DeletedBBs.clear(); 42 return true; 43 } 44 45 // The DT and PDT require the nodes related to updates 46 // are not deleted when update functions are called. 47 // So MachineBasicBlock deletions must be pended when the 48 // UpdateStrategy is Lazy. When the UpdateStrategy is 49 // Eager, the MachineBasicBlock will be deleted immediately. 50 void MachineDomTreeUpdater::deleteBB(MachineBasicBlock *DelBB) { 51 validateDeleteBB(DelBB); 52 if (Strategy == UpdateStrategy::Lazy) { 53 DeletedBBs.insert(DelBB); 54 return; 55 } 56 57 eraseDelBBNode(DelBB); 58 DelBB->eraseFromParent(); 59 } 60 61 void MachineDomTreeUpdater::validateDeleteBB(MachineBasicBlock *DelBB) { 62 assert(DelBB && "Invalid push_back of nullptr DelBB."); 63 assert(DelBB->pred_empty() && "DelBB has one or more predecessors."); 64 } 65 66 } // namespace llvm 67