1 files changed, 19 insertions, 10 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
index 083f87436acd..8d59fdff9236 100644
--- a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
@@ -32,6 +32,7 @@
 #include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
+#include <optional>
 using namespace llvm;
 
 #define DEBUG_TYPE "loop-simplifycfg"
@@ -371,6 +372,7 @@ private:
         DeadInstructions.emplace_back(LandingPad);
 
       for (Instruction *I : DeadInstructions) {
+        SE.forgetBlockAndLoopDispositions(I);
         I->replaceAllUsesWith(PoisonValue::get(I->getType()));
         I->eraseFromParent();
       }
@@ -416,6 +418,7 @@ private:
           DTU.applyUpdates(DTUpdates);
         DTUpdates.clear();
         formLCSSARecursively(*FixLCSSALoop, DT, &LI, &SE);
+        SE.forgetBlockAndLoopDispositions();
       }
     }
 
@@ -474,7 +477,7 @@ private:
     NumLoopBlocksDeleted += DeadLoopBlocks.size();
   }
 
-  /// Constant-fold terminators of blocks acculumated in FoldCandidates into the
+  /// Constant-fold terminators of blocks accumulated in FoldCandidates into the
   /// unconditional branches.
   void foldTerminators() {
     for (BasicBlock *BB : FoldCandidates) {
@@ -595,6 +598,9 @@ public:
     LLVM_DEBUG(dbgs() << "Constant-folding " << FoldCandidates.size()
                       << " terminators in loop " << Header->getName() << "\n");
 
+    if (!DeadLoopBlocks.empty())
+      SE.forgetBlockAndLoopDispositions();
+
     // Make the actual transforms.
     handleDeadExits();
     foldTerminators();
@@ -655,7 +661,8 @@ static bool constantFoldTerminators(Loop &L, DominatorTree &DT, LoopInfo &LI,
 }
 
 static bool mergeBlocksIntoPredecessors(Loop &L, DominatorTree &DT,
-                                        LoopInfo &LI, MemorySSAUpdater *MSSAU) {
+                                        LoopInfo &LI, MemorySSAUpdater *MSSAU,
+                                        ScalarEvolution &SE) {
   bool Changed = false;
   DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Eager);
   // Copy blocks into a temporary array to avoid iterator invalidation issues
@@ -682,6 +689,9 @@ static bool mergeBlocksIntoPredecessors(Loop &L, DominatorTree &DT,
     Changed = true;
   }
 
+  if (Changed)
+    SE.forgetBlockAndLoopDispositions();
+
   return Changed;
 }
 
@@ -697,7 +707,7 @@ static bool simplifyLoopCFG(Loop &L, DominatorTree &DT, LoopInfo &LI,
     return true;
 
   // Eliminate unconditional branches by merging blocks into their predecessors.
-  Changed |= mergeBlocksIntoPredecessors(L, DT, LI, MSSAU);
+  Changed |= mergeBlocksIntoPredecessors(L, DT, LI, MSSAU, SE);
 
   if (Changed)
     SE.forgetTopmostLoop(&L);
@@ -708,12 +718,12 @@ static bool simplifyLoopCFG(Loop &L, DominatorTree &DT, LoopInfo &LI,
 PreservedAnalyses LoopSimplifyCFGPass::run(Loop &L, LoopAnalysisManager &AM,
                                            LoopStandardAnalysisResults &AR,
                                            LPMUpdater &LPMU) {
-  Optional<MemorySSAUpdater> MSSAU;
+  std::optional<MemorySSAUpdater> MSSAU;
   if (AR.MSSA)
     MSSAU = MemorySSAUpdater(AR.MSSA);
   bool DeleteCurrentLoop = false;
-  if (!simplifyLoopCFG(L, AR.DT, AR.LI, AR.SE,
-                       MSSAU ? MSSAU.getPointer() : nullptr, DeleteCurrentLoop))
+  if (!simplifyLoopCFG(L, AR.DT, AR.LI, AR.SE, MSSAU ? &*MSSAU : nullptr,
+                       DeleteCurrentLoop))
     return PreservedAnalyses::all();
 
   if (DeleteCurrentLoop)
@@ -741,15 +751,14 @@ public:
     LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
     ScalarEvolution &SE = getAnalysis<ScalarEvolutionWrapperPass>().getSE();
     auto *MSSAA = getAnalysisIfAvailable<MemorySSAWrapperPass>();
-    Optional<MemorySSAUpdater> MSSAU;
+    std::optional<MemorySSAUpdater> MSSAU;
     if (MSSAA)
       MSSAU = MemorySSAUpdater(&MSSAA->getMSSA());
     if (MSSAA && VerifyMemorySSA)
       MSSAU->getMemorySSA()->verifyMemorySSA();
     bool DeleteCurrentLoop = false;
-    bool Changed =
-        simplifyLoopCFG(*L, DT, LI, SE, MSSAU ? MSSAU.getPointer() : nullptr,
-                        DeleteCurrentLoop);
+    bool Changed = simplifyLoopCFG(*L, DT, LI, SE, MSSAU ? &*MSSAU : nullptr,
+                                   DeleteCurrentLoop);
     if (DeleteCurrentLoop)
       LPM.markLoopAsDeleted(*L);
     return Changed;