[llvm] select v_sat_pk from two i16 or v2i16 (PR #121124)

[via llvm-commits]

================
@@ -3298,6 +3301,32 @@ def : GCNPat <
   (v2i16 (V_LSHL_OR_B32_e64 $src1, (i32 16), (i32 (V_AND_B32_e64 (i32 (V_MOV_B32_e32 (i32 0xffff))), $src0))))
 >;
 
+multiclass V_SAT_PK_Pat<Instruction inst> {
+  def: GCNPatIgnoreCopies<
----------------
Shoreshen wrote:

Hi for global isel, there would be some COPY MIR within the pattern, this ignored the COPY MIR so that it can be matched

https://github.com/llvm/llvm-project/pull/121124