[llvm] [LV] Add support for cmp reductions with decreasing IVs. (PR #140451)

[Ramkumar Ramachandra via llvm-commits]

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@@ -23325,6 +23329,8 @@ class HorizontalReduction {
     case RecurKind::FMulAdd:
     case RecurKind::AnyOf:
     case RecurKind::FindLastIV:
+    case RecurKind::FindFirstIVUMin:
+    case RecurKind::FindFirstIVSMin:
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artagnon wrote:

Why is this asymmetric? Wouldn't it be nicer to first separate out FindLastIV into FindLastIVSMax/UMax?

https://github.com/llvm/llvm-project/pull/140451