[llvm] APFloat: Add minimumnum and maximumnum (PR #96304)

[YunQiang Su via llvm-commits]

================
@@ -1483,6 +1483,19 @@ inline APFloat minimum(const APFloat &A, const APFloat &B) {
   return B < A ? B : A;
 }
 
+/// Implements IEEE 754-2019 minimumNumber semantics. Returns the smaller
+/// of 2 arguments, not propagating NaNs and treating -0 as less than +0.
+LLVM_READONLY
+inline APFloat minimumnum(const APFloat &A, const APFloat &B) {
+  if (A.isNaN())
+    return B.isNaN() ? B.makeQuiet() : B;
+  if (B.isNaN())
----------------
wzssyqa wrote:

Maybe I don't understand your question well.
If you mean about is the result correct if either/both of A or/and B is/are sNaN, I think that it can give correct result.
When we in `if (B.isNaN())`, we are sure that `A` is not NaN.

If you are talking about exception handling, in fact I am not sure.  I just noticed that `minnum`/`minimum` don't do
very special work for exception handling.

https://github.com/llvm/llvm-project/pull/96304