Revert "[CodeGen] Remove `applySplitCriticalEdges` in `MachineDominatorTree` (#97055)"

This reverts commit c5e5088033fed170068d818c54af6862e449b545.

Causes large compile-time regressions.

1 files changed, 3 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index 131220a..5fe7a9d 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -16,13 +16,11 @@
 #include "llvm/CodeGen/LiveIntervals.h"
 #include "llvm/CodeGen/LivePhysRegs.h"
 #include "llvm/CodeGen/LiveVariables.h"
-#include "llvm/CodeGen/MachineDomTreeUpdater.h"
 #include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
-#include "llvm/CodeGen/MachinePostDominators.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
@@ -1341,17 +1339,9 @@ MachineBasicBlock *MachineBasicBlock::SplitCriticalEdge(
     LIS->repairIntervalsInRange(this, getFirstTerminator(), end(), UsedRegs);
   }
 
-  auto *MDTWrapper =
-      P.getAnalysisIfAvailable<MachineDominatorTreeWrapperPass>();
-  auto *MPDTWrapper =
-      P.getAnalysisIfAvailable<MachinePostDominatorTreeWrapperPass>();
-  auto *MDT = MDTWrapper ? &MDTWrapper->getDomTree() : nullptr;
-  auto *MPDT = MPDTWrapper ? &MPDTWrapper->getPostDomTree() : nullptr;
-  MachineDomTreeUpdater MDTU(MDT, MPDT,
-                             MachineDomTreeUpdater::UpdateStrategy::Eager);
-  MDTU.applyUpdates({{MachineDominatorTree::Insert, this, NMBB},
-                     {MachineDominatorTree::Insert, NMBB, Succ},
-                     {MachineDominatorTree::Delete, this, Succ}});
+  if (auto *MDTWrapper =
+          P.getAnalysisIfAvailable<MachineDominatorTreeWrapperPass>())
+    MDTWrapper->getDomTree().recordSplitCriticalEdge(this, Succ, NMBB);
 
   auto *MLIWrapper = P.getAnalysisIfAvailable<MachineLoopInfoWrapperPass>();
   if (MachineLoopInfo *MLI = MLIWrapper ? &MLIWrapper->getLI() : nullptr)