[llvm] [ConstraintElim] Use constraints from bounded memory accesses (PR #155253)

[Nikita Popov via llvm-commits]

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@@ -1960,6 +2030,26 @@ static bool eliminateConstraints(Function &F, DominatorTree &DT, LoopInfo &LI,
         }
         continue;
       }
+
+      auto &DL = F.getDataLayout();
+      auto AddFactsAboutIndices = [&](Value *Ptr, Type *AccessType) {
+        CmpPredicate Pred;
+        Value *A, *B;
+        if (getConstraintFromMemoryAccess(
+                *cast<GetElementPtrInst>(Ptr),
+                DL.getTypeStoreSize(AccessType).getFixedValue(), Pred, A, B, DL,
+                TLI))
+          AddFact(Pred, A, B);
+      };
+
+      if (auto *LI = dyn_cast<LoadInst>(CB.Inst)) {
+        AddFactsAboutIndices(LI->getPointerOperand(), LI->getAccessType());
+        continue;
+      }
+      if (auto *SI = dyn_cast<StoreInst>(CB.Inst)) {
+        AddFactsAboutIndices(SI->getPointerOperand(), SI->getAccessType());
+        continue;
+      }
----------------
nikic wrote:

Why is the handling split this way with some cases handled as condition facts and others as inst facts? Why isn't this always a condition fact?

https://github.com/llvm/llvm-project/pull/155253