1562b70eaf
This relands commit #115111.
Use traditional way to update post dominator tree, i.e. break critical
edge splitting into insert, insert, delete sequence.
When splitting critical edges, the post dominator tree may change its
root node, and `setNewRoot` only works in normal dominator tree...
See
6c7e5827ed/llvm/include/llvm/Support/GenericDomTree.h (L684-L687)
69 lines
2.3 KiB
C++
69 lines
2.3 KiB
C++
//===- MachineDomTreeUpdater.cpp -----------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements the MachineDomTreeUpdater class, which provides a
|
|
// uniform way to update dominator tree related data structures.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/CodeGen/MachineDomTreeUpdater.h"
|
|
#include "llvm/Analysis/GenericDomTreeUpdaterImpl.h"
|
|
#include "llvm/CodeGen/MachinePostDominators.h"
|
|
|
|
namespace llvm {
|
|
|
|
template class GenericDomTreeUpdater<
|
|
MachineDomTreeUpdater, MachineDominatorTree, MachinePostDominatorTree>;
|
|
|
|
template void
|
|
GenericDomTreeUpdater<MachineDomTreeUpdater, MachineDominatorTree,
|
|
MachinePostDominatorTree>::recalculate(MachineFunction
|
|
&MF);
|
|
|
|
template void GenericDomTreeUpdater<
|
|
MachineDomTreeUpdater, MachineDominatorTree,
|
|
MachinePostDominatorTree>::applyUpdatesImpl</*IsForward=*/true>();
|
|
template void GenericDomTreeUpdater<
|
|
MachineDomTreeUpdater, MachineDominatorTree,
|
|
MachinePostDominatorTree>::applyUpdatesImpl</*IsForward=*/false>();
|
|
|
|
bool MachineDomTreeUpdater::forceFlushDeletedBB() {
|
|
if (DeletedBBs.empty())
|
|
return false;
|
|
|
|
for (auto *BB : DeletedBBs) {
|
|
eraseDelBBNode(BB);
|
|
BB->eraseFromParent();
|
|
}
|
|
DeletedBBs.clear();
|
|
return true;
|
|
}
|
|
|
|
// The DT and PDT require the nodes related to updates
|
|
// are not deleted when update functions are called.
|
|
// So MachineBasicBlock deletions must be pended when the
|
|
// UpdateStrategy is Lazy. When the UpdateStrategy is
|
|
// Eager, the MachineBasicBlock will be deleted immediately.
|
|
void MachineDomTreeUpdater::deleteBB(MachineBasicBlock *DelBB) {
|
|
validateDeleteBB(DelBB);
|
|
if (Strategy == UpdateStrategy::Lazy) {
|
|
DeletedBBs.insert(DelBB);
|
|
return;
|
|
}
|
|
|
|
eraseDelBBNode(DelBB);
|
|
DelBB->eraseFromParent();
|
|
}
|
|
|
|
void MachineDomTreeUpdater::validateDeleteBB(MachineBasicBlock *DelBB) {
|
|
assert(DelBB && "Invalid push_back of nullptr DelBB.");
|
|
assert(DelBB->pred_empty() && "DelBB has one or more predecessors.");
|
|
}
|
|
|
|
} // namespace llvm
|