[BBUtils][NFC] Delete SplitLandingPadPredecessors with DT

[caojoshua]

Summary

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

[nikic]

[BBUtils][NFC] Deprecate SplitLandingPadPredecessors with DT

Deprecate -> Remove

llvm/lib/Transforms/Utils/BasicBlockUtils.cpp

1402

Can we also remove the DT argument from this function?

[caojoshua]

llvm/lib/Transforms/Utils/BasicBlockUtils.cpp

1402

It has an incoming call from SplitBlockPredecessors(), and the DT version of it has 10+ incoming calls. Can't remove DT until those are also cleaned up.

[caojoshua]

Deprecate -> Delete

[caojoshua]

ping

[caojoshua]

ping

[caojoshua]

ping

[caojoshua]

ping

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

 /// 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
-/// 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).
 void SplitLandingPadPredecessors(
     BasicBlock *OrigBB, ArrayRef<BasicBlock *> Preds, const char *Suffix,
     const char *Suffix2, SmallVectorImpl<BasicBlock *> &NewBBs,
     DomTreeUpdater *DTU = nullptr, LoopInfo *LI = nullptr,
     MemorySSAUpdater *MSSAU = nullptr, bool PreserveLCSSA = false);
 
 /// This method duplicates the specified return instruction into a predecessor
 /// which ends in an unconditional branch. If the return instruction returns a

llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp

 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallBitVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallVector.h"
 #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"
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/MemorySSA.h"
 #include "llvm/Analysis/MemorySSAUpdater.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
if (PN->getIncomingValue(i) == LF.OperandValToReplace) {
           if (!Parent->isLandingPad()) {
             NewBB =
                 SplitCriticalEdge(BB, Parent,
                                   CriticalEdgeSplittingOptions(&DT, &LI, MSSAU)
                                       .setMergeIdenticalEdges()
                                       .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
           // phi predecessors are identical. The simple thing to do is skip
           // splitting in this case rather than complicate the API.
           if (NewBB) {
             // If PN is outside of the loop and BB is in the loop, we want to
             // move the block to be immediately before the PHI block, not

llvm/lib/Transforms/Utils/BasicBlockUtils.cpp

if (NewBB2) {
     LPad->eraseFromParent();
   }
 }
 
 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,
-                                       SmallVectorImpl<BasicBlock *> &NewBBs,
                                        DomTreeUpdater *DTU, LoopInfo *LI,
                                        MemorySSAUpdater *MSSAU,
                                        bool PreserveLCSSA) {
   return SplitLandingPadPredecessorsImpl(OrigBB, Preds, Suffix1, Suffix2,
                                          NewBBs, DTU, /*DT=*/nullptr, LI, MSSAU,
                                          PreserveLCSSA);
 }
 
 ReturnInst *llvm::FoldReturnIntoUncondBranch(ReturnInst *RI, BasicBlock *BB,
                                              BasicBlock *Pred,
                                              DomTreeUpdater *DTU) {
   Instruction *UncondBranch = Pred->getTerminator();
   // Clone the return and add it to the end of the predecessor.
   Instruction *NewRet = RI->clone();