[llvm] [SLP] Create SLP trees starting from constant stride stores (PR #185964)

[Alexey Bataev via llvm-commits]

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@@ -12586,6 +12607,18 @@ void BoUpSLP::buildTreeRec(ArrayRef<Value *> VLRef, unsigned Depth,
       return;
     }
     case Instruction::Store: {
+      if (State == TreeEntry::StridedVectorize) {
+        TreeEntry *TE =
+            newTreeEntry(VL, TreeEntry::StridedVectorize, Bundle, S,
+                         UserTreeIdx, ReuseShuffleIndices, CurrentOrder);
+        TreeEntryToStridedPtrInfoMap[TE] = SPtrInfo;
+        LLVM_DEBUG(
+            dbgs() << "SLP: added a new TreeEntry (strided StoreInst).\n";
+            TE->dump());
+        TE->setOperands(Operands);
+        buildTreeRec(TE->getOperand(0), Depth + 1, {TE, 0});
+        return;
+      }
       bool Consecutive = CurrentOrder.empty();
       if (!Consecutive)
         fixupOrderingIndices(CurrentOrder);
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alexey-bataev wrote:

Potentially, on reordering. But here is the tree building, so it should be in direct order. Worth trying to remove it and replace it with an assertion

https://github.com/llvm/llvm-project/pull/185964