xref: /src/contrib/llvm-project/llvm/lib/CodeGen/MachineDomTreeUpdater.cpp (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1ac9a064cSDimitry Andric //===- MachineDomTreeUpdater.cpp -----------------------------------------===//
2ac9a064cSDimitry Andric //
3ac9a064cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4ac9a064cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5ac9a064cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6ac9a064cSDimitry Andric //
7ac9a064cSDimitry Andric //===----------------------------------------------------------------------===//
8ac9a064cSDimitry Andric //
9ac9a064cSDimitry Andric // This file implements the MachineDomTreeUpdater class, which provides a
10ac9a064cSDimitry Andric // uniform way to update dominator tree related data structures.
11ac9a064cSDimitry Andric //
12ac9a064cSDimitry Andric //===----------------------------------------------------------------------===//
13ac9a064cSDimitry Andric 
14ac9a064cSDimitry Andric #include "llvm/CodeGen/MachineDomTreeUpdater.h"
15ac9a064cSDimitry Andric #include "llvm/ADT/SmallSet.h"
16ac9a064cSDimitry Andric #include "llvm/Analysis/GenericDomTreeUpdaterImpl.h"
17ac9a064cSDimitry Andric #include "llvm/CodeGen/MachinePostDominators.h"
18ac9a064cSDimitry Andric #include "llvm/Support/GenericDomTree.h"
19ac9a064cSDimitry Andric #include <algorithm>
20ac9a064cSDimitry Andric #include <functional>
21ac9a064cSDimitry Andric #include <utility>
22ac9a064cSDimitry Andric 
23ac9a064cSDimitry Andric namespace llvm {
24ac9a064cSDimitry Andric 
25ac9a064cSDimitry Andric template class GenericDomTreeUpdater<
26ac9a064cSDimitry Andric     MachineDomTreeUpdater, MachineDominatorTree, MachinePostDominatorTree>;
27ac9a064cSDimitry Andric 
28ac9a064cSDimitry Andric template void
29ac9a064cSDimitry Andric GenericDomTreeUpdater<MachineDomTreeUpdater, MachineDominatorTree,
30ac9a064cSDimitry Andric                       MachinePostDominatorTree>::recalculate(MachineFunction
31ac9a064cSDimitry Andric                                                                  &MF);
32ac9a064cSDimitry Andric 
forceFlushDeletedBB()33ac9a064cSDimitry Andric bool MachineDomTreeUpdater::forceFlushDeletedBB() {
34ac9a064cSDimitry Andric   if (DeletedBBs.empty())
35ac9a064cSDimitry Andric     return false;
36ac9a064cSDimitry Andric 
37ac9a064cSDimitry Andric   for (auto *BB : DeletedBBs) {
38ac9a064cSDimitry Andric     eraseDelBBNode(BB);
39ac9a064cSDimitry Andric     BB->eraseFromParent();
40ac9a064cSDimitry Andric   }
41ac9a064cSDimitry Andric   DeletedBBs.clear();
42ac9a064cSDimitry Andric   return true;
43ac9a064cSDimitry Andric }
44ac9a064cSDimitry Andric 
45ac9a064cSDimitry Andric // The DT and PDT require the nodes related to updates
46ac9a064cSDimitry Andric // are not deleted when update functions are called.
47ac9a064cSDimitry Andric // So MachineBasicBlock deletions must be pended when the
48ac9a064cSDimitry Andric // UpdateStrategy is Lazy. When the UpdateStrategy is
49ac9a064cSDimitry Andric // Eager, the MachineBasicBlock will be deleted immediately.
deleteBB(MachineBasicBlock * DelBB)50ac9a064cSDimitry Andric void MachineDomTreeUpdater::deleteBB(MachineBasicBlock *DelBB) {
51ac9a064cSDimitry Andric   validateDeleteBB(DelBB);
52ac9a064cSDimitry Andric   if (Strategy == UpdateStrategy::Lazy) {
53ac9a064cSDimitry Andric     DeletedBBs.insert(DelBB);
54ac9a064cSDimitry Andric     return;
55ac9a064cSDimitry Andric   }
56ac9a064cSDimitry Andric 
57ac9a064cSDimitry Andric   eraseDelBBNode(DelBB);
58ac9a064cSDimitry Andric   DelBB->eraseFromParent();
59ac9a064cSDimitry Andric }
60ac9a064cSDimitry Andric 
validateDeleteBB(MachineBasicBlock * DelBB)61ac9a064cSDimitry Andric void MachineDomTreeUpdater::validateDeleteBB(MachineBasicBlock *DelBB) {
62ac9a064cSDimitry Andric   assert(DelBB && "Invalid push_back of nullptr DelBB.");
63ac9a064cSDimitry Andric   assert(DelBB->pred_empty() && "DelBB has one or more predecessors.");
64ac9a064cSDimitry Andric }
65ac9a064cSDimitry Andric 
66ac9a064cSDimitry Andric } // namespace llvm
67