[llvm] [DAG] Support saturated truncate (PR #99418)

[via llvm-commits]

================
@@ -5343,9 +5343,13 @@ def VImm8000: PatLeaf<(AArch64mvni_msl (i32 127), (i32 264))>;
 // trunc(umin(X, 255)) -> UQXTRN v8i8
 def : Pat<(v8i8 (trunc (umin (v8i16 V128:$Vn), (v8i16 VImmFF)))),
           (UQXTNv8i8 V128:$Vn)>;
+def : Pat<(v8i8 (truncusat (v8i16 V128:$Vn))),
----------------
ParkHanbum wrote:

This is not possible with the current logic. However, I think it would be possible with additional logic. Would you like to see it included in this patch?

https://github.com/llvm/llvm-project/pull/99418