[llvm] [RISCV][P-ext] Add codegen for packed absolute difference sum (PR #207314)

[Craig Topper via llvm-commits]

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@@ -2414,6 +2426,22 @@ let append Predicates = [IsRV32] in {
   def : PatRedSumPair<int_riscv_predsum, PREDSUM_DHS, v4i16>;
   def : PatRedSumPair<int_riscv_predsumu, PREDSUMU_DHS, v4i16>;
 
+  // 8-bit absolute difference sum patterns
+  def : Pat<(i32 (int_riscv_pabdsumu (v8i8 GPRPair:$rs1), (v8i8 GPRPair:$rs2))),
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topperc wrote:

Can we split this during lowering?

https://github.com/llvm/llvm-project/pull/207314