[BBUtils][NFC] Delete SplitLandingPadPredecessors with DT (#73406)

Function is marked for deprecation. There is only one consumer which is
converted to use DomTreeUpdater.

Author: caojoshua

llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h

@@ -367,27 +367,6 @@ BasicBlock *SplitBlockPredecessors(BasicBlock *BB, ArrayRef<BasicBlock *> Preds,
                                    MemorySSAUpdater *MSSAU = nullptr,
                                    bool PreserveLCSSA = false);
 
-/// This method transforms the landing pad, OrigBB, by introducing two new basic
-/// blocks into the function. One of those new basic blocks gets the
-/// predecessors listed in Preds. The other basic block gets the remaining
-/// predecessors of OrigBB. The landingpad instruction OrigBB is clone into both
-/// of the new basic blocks. The new blocks are given the suffixes 'Suffix1' and
-/// 'Suffix2', and are returned in the NewBBs vector.
-///
-/// This currently updates the LLVM IR, DominatorTree, LoopInfo, and LCCSA but
-/// no other analyses. In particular, it does not preserve LoopSimplify
-/// (because it's complicated to handle the case where one of the edges being
-/// split is an exit of a loop with other exits).
-///
-/// FIXME: deprecated, switch to the DomTreeUpdater-based one.
-void SplitLandingPadPredecessors(BasicBlock *OrigBB,
-                                 ArrayRef<BasicBlock *> Preds,
-                                 const char *Suffix, const char *Suffix2,
-                                 SmallVectorImpl<BasicBlock *> &NewBBs,
-                                 DominatorTree *DT, LoopInfo *LI = nullptr,
-                                 MemorySSAUpdater *MSSAU = nullptr,
-                                 bool PreserveLCSSA = false);
-
 /// This method transforms the landing pad, OrigBB, by introducing two new basic
 /// blocks into the function. One of those new basic blocks gets the
 /// predecessors listed in Preds. The other basic block gets the remaining

llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp

@@ -67,6 +67,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/DomTreeUpdater.h"
 #include "llvm/Analysis/IVUsers.h"
 #include "llvm/Analysis/LoopAnalysisManager.h"
 #include "llvm/Analysis/LoopInfo.h"
@@ -5599,7 +5600,8 @@ void LSRInstance::RewriteForPHI(
                                       .setKeepOneInputPHIs());
           } else {
             SmallVector<BasicBlock*, 2> NewBBs;
-            SplitLandingPadPredecessors(Parent, BB, "", "", NewBBs, &DT, &LI);
+            DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Eager);
+            SplitLandingPadPredecessors(Parent, BB, "", "", NewBBs, &DTU, &LI);
             NewBB = NewBBs[0];
           }
           // If NewBB==NULL, then SplitCriticalEdge refused to split because all

llvm/lib/Transforms/Utils/BasicBlockUtils.cpp

@@ -1452,17 +1452,6 @@ static void SplitLandingPadPredecessorsImpl(
   }
 }
 
-void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
-                                       ArrayRef<BasicBlock *> Preds,
-                                       const char *Suffix1, const char *Suffix2,
-                                       SmallVectorImpl<BasicBlock *> &NewBBs,
-                                       DominatorTree *DT, LoopInfo *LI,
-                                       MemorySSAUpdater *MSSAU,
-                                       bool PreserveLCSSA) {
-  return SplitLandingPadPredecessorsImpl(
-      OrigBB, Preds, Suffix1, Suffix2, NewBBs,
-      /*DTU=*/nullptr, DT, LI, MSSAU, PreserveLCSSA);
-}
 void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
                                        ArrayRef<BasicBlock *> Preds,
                                        const char *Suffix1, const char *Suffix2,