[llvm] [LV] Vectorize maxnum/minnum w/o fast-math flags. (PR #148239)

[Florian Hahn via llvm-commits]

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@@ -941,10 +941,28 @@ RecurrenceDescriptor::InstDesc RecurrenceDescriptor::isRecurrenceInstr(
                   m_Intrinsic<Intrinsic::minimumnum>(m_Value(), m_Value())) ||
             match(I, m_Intrinsic<Intrinsic::maximumnum>(m_Value(), m_Value()));
     };
-    if (isIntMinMaxRecurrenceKind(Kind) ||
-        (HasRequiredFMF() && isFPMinMaxRecurrenceKind(Kind)))
+    if (isIntMinMaxRecurrenceKind(Kind))
       return isMinMaxPattern(I, Kind, Prev);
-    else if (isFMulAddIntrinsic(I))
+    if (isFPMinMaxRecurrenceKind(Kind)) {
+      InstDesc Res = isMinMaxPattern(I, Kind, Prev);
+      if (HasRequiredFMF())
+        return Res;
+
+      if (!Res.isRecurrence())
+        return InstDesc(false, I);
+
+      // We may be able to vectorize FMax/FMin reductions using maxnum/minnum
+      // intrinsics with extra checks ensuring the vector loop handles only
+      // non-NaN inputs.
+      if (Kind == RecurKind::FMax &&
+          match(I, m_Intrinsic<Intrinsic::maxnum>(m_Value(), m_Value())))
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fhahn wrote:

Yep, turned check into assert, thanks!

https://github.com/llvm/llvm-project/pull/148239