[llvm] Try to simplify select v32i4 case by legalizing v16i4 (PR #173328)

[Matt Arsenault via llvm-commits]

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@@ -876,7 +876,7 @@ SITargetLowering::SITargetLowering(const TargetMachine &TM,
                      {MVT::v4i16, MVT::v4f16, MVT::v4bf16, MVT::v2i8, MVT::v4i8,
                       MVT::v8i8, MVT::v8i16, MVT::v8f16, MVT::v8bf16,
                       MVT::v16i16, MVT::v16f16, MVT::v16bf16, MVT::v32i16,
-                      MVT::v32f16, MVT::v32bf16},
+                      MVT::v32f16, MVT::v32bf16, MVT::v16i4},
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arsenm wrote:

You could do this combine without adding the MVT 

https://github.com/llvm/llvm-project/pull/173328