[SCEV] Remove conversion to SCEVUnionPredicate in ExitNotTakenInfo [NFC]

This removes one of the places where we mutate an existing union predicate.
yushiqie · Feb 9, 2022 · aa845d7 · aa845d7
1 parent f2f5e9f
commit aa845d7
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Showing 2 changed files with 8 additions and 15 deletions.
diff --git a/llvm/include/llvm/Analysis/ScalarEvolution.h b/llvm/include/llvm/Analysis/ScalarEvolution.h
@@ -1372,17 +1372,17 @@ class ScalarEvolution {
     PoisoningVH<BasicBlock> ExitingBlock;
     const SCEV *ExactNotTaken;
     const SCEV *MaxNotTaken;
-    std::unique_ptr<SCEVUnionPredicate> Predicate;
+    SmallPtrSet<const SCEVPredicate *, 4> Predicates;
 
     explicit ExitNotTakenInfo(PoisoningVH<BasicBlock> ExitingBlock,
                               const SCEV *ExactNotTaken,
                               const SCEV *MaxNotTaken,
-                              std::unique_ptr<SCEVUnionPredicate> Predicate)
+                              const SmallPtrSet<const SCEVPredicate *, 4> &Predicates)
       : ExitingBlock(ExitingBlock), ExactNotTaken(ExactNotTaken),
-        MaxNotTaken(ExactNotTaken), Predicate(std::move(Predicate)) {}
+        MaxNotTaken(ExactNotTaken), Predicates(Predicates) {}
 
     bool hasAlwaysTruePredicate() const {
-      return !Predicate || Predicate->isAlwaysTrue();
+      return Predicates.empty();
     }
   };
 

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -7966,8 +7966,9 @@ ScalarEvolution::BackedgeTakenInfo::getExact(const Loop *L, ScalarEvolution *SE,
 
     Ops.push_back(BECount);
 
-    if (Preds && !ENT.hasAlwaysTruePredicate())
-      Preds->add(ENT.Predicate.get());
+    if (Preds)
+      for (auto *P : ENT.Predicates)
+        Preds->add(P);
 
     assert((Preds || ENT.hasAlwaysTruePredicate()) &&
            "Predicate should be always true!");
@@ -8082,16 +8083,8 @@ ScalarEvolution::BackedgeTakenInfo::BackedgeTakenInfo(
       [&](const EdgeExitInfo &EEI) {
         BasicBlock *ExitBB = EEI.first;
         const ExitLimit &EL = EEI.second;
-        if (EL.Predicates.empty())
-          return ExitNotTakenInfo(ExitBB, EL.ExactNotTaken, EL.MaxNotTaken,
-                                  nullptr);
-
-        std::unique_ptr<SCEVUnionPredicate> Predicate(new SCEVUnionPredicate);
-        for (auto *Pred : EL.Predicates)
-          Predicate->add(Pred);
-
         return ExitNotTakenInfo(ExitBB, EL.ExactNotTaken, EL.MaxNotTaken,
-                                std::move(Predicate));
+                                EL.Predicates);
       });
   assert((isa<SCEVCouldNotCompute>(ConstantMax) ||
           isa<SCEVConstant>(ConstantMax)) &&