llvm/lib/CodeGen/MachineDomTreeUpdater.cpp

   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/Analysis/GenericDomTreeUpdaterImpl.h"
  16 #include "llvm/CodeGen/MachinePostDominators.h"
  17
  18 namespace llvm {
  19
  20 template class GenericDomTreeUpdater<
  21     MachineDomTreeUpdater, MachineDominatorTree, MachinePostDominatorTree>;
  22
  23 template void
  24 GenericDomTreeUpdater<MachineDomTreeUpdater, MachineDominatorTree,
  25                       MachinePostDominatorTree>::recalculate(MachineFunction
  26                                                                  &MF);
  27
  28 bool MachineDomTreeUpdater::forceFlushDeletedBB() {
  29   if (DeletedBBs.empty())
  30     return false;
  31
  32   for (auto *BB : DeletedBBs) {
  33     eraseDelBBNode(BB);
  34     BB->eraseFromParent();
  35   }
  36   DeletedBBs.clear();
  37   return true;
  38 }
  39
  40 // The DT and PDT require the nodes related to updates
  41 // are not deleted when update functions are called.
  42 // So MachineBasicBlock deletions must be pended when the
  43 // UpdateStrategy is Lazy. When the UpdateStrategy is
  44 // Eager, the MachineBasicBlock will be deleted immediately.
  45 void MachineDomTreeUpdater::deleteBB(MachineBasicBlock *DelBB) {
  46   validateDeleteBB(DelBB);
  47   if (Strategy == UpdateStrategy::Lazy) {
  48     DeletedBBs.insert(DelBB);
  49     return;
  50   }
  51
  52   eraseDelBBNode(DelBB);
  53   DelBB->eraseFromParent();
  54 }
  55
  56 void MachineDomTreeUpdater::validateDeleteBB(MachineBasicBlock *DelBB) {
  57   assert(DelBB && "Invalid push_back of nullptr DelBB.");
  58   assert(DelBB->pred_empty() && "DelBB has one or more predecessors.");
  59 }
  60
  61 } // namespace llvm