[llvm] Vectorize: Support fminimumnum and fmaximumnum (PR #131781)

[YunQiang Su via llvm-commits]

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@@ -2776,6 +2776,27 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
       }
       return Cost;
     }
+    case Intrinsic::maximumnum:
+    case Intrinsic::minimumnum: {
+      // On platform that support FMAXNUM_IEEE/FMINNUM_IEEE, we expand
+      // maximumnum/minimumnum to
+      //    ARG0 = fcanonicalize ARG0, ARG0  // to quiet ARG0
+      //    ARG1 = fcanonicalize ARG1, ARG1  // to quiet ARG1
+      //    RESULT = MAXNUM_IEEE ARG0, ARG1  // or MINNUM_IEEE
+      // FIXME: In LangRef, we claimed FMAXNUM has the same behaviour of
+      //        FMAXNUM_IEEE, while the backend hasn't migrated the code yet.
+      //        Finally, we will remove FMAXNUM_IEEE and FMINNUM_IEEE.
+      int IeeeISD =
+          IID == Intrinsic::maximumnum ? ISD::FMAXNUM_IEEE : ISD::FMINNUM_IEEE;
+      if (TLI->isOperationLegalOrPromote(IeeeISD, LT.second)) {
+        IntrinsicCostAttributes FCanonicalizeAttrs(Intrinsic::canonicalize,
+                                                   RetTy, Tys[0]);
+        InstructionCost FCanonicalizeCost =
+            thisT()->getIntrinsicInstrCost(FCanonicalizeAttrs, CostKind);
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wzssyqa wrote:

I have some try of promote, in fact it cannot work. So I remove it.
The problem is the indexes of input and output are different when it's promote.
We need shuffle for this case while LLVM doesn't support it yet.

https://github.com/llvm/llvm-project/pull/131781