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

[David Green via llvm-commits]

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@@ -5418,64 +5418,60 @@ def VImm7FFF: PatLeaf<(AArch64movi_msl (i32 127), (i32 264))>;
 def VImm8000: PatLeaf<(AArch64mvni_msl (i32 127), (i32 264))>;
 
 // trunc(umin(X, 255)) -> UQXTRN v8i8
-def : Pat<(v8i8 (trunc (umin (v8i16 V128:$Vn), (v8i16 VImmFF)))),
+def : Pat<(v8i8 (truncusat_u (v8i16 V128:$Vn))),
           (UQXTNv8i8 V128:$Vn)>;
 // trunc(umin(X, 65535)) -> UQXTRN v4i16
-def : Pat<(v4i16 (trunc (umin (v4i32 V128:$Vn), (v4i32 VImmFFFF)))),
+def : Pat<(v4i16 (truncusat_u (v4i32 V128:$Vn))),
           (UQXTNv4i16 V128:$Vn)>;
 // trunc(smin(smax(X, -128), 128)) -> SQXTRN
 //  with reversed min/max
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davemgreen wrote:

The "reversed min/max" lines can be removed now.

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