[llvm] [RISCV] Enable select optimization by default (PR #178394)

[Craig Topper via llvm-commits]

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@@ -433,7 +434,8 @@ def SIFIVE_P550 : RISCVProcessorModel<"sifive-p550", SiFiveP500Model,
                                        FeatureStdExtD,
                                        FeatureStdExtC,
                                        FeatureStdExtZba,
-                                       FeatureStdExtZbb],
+                                       FeatureStdExtZbb,
+                                       FeatureEnableSelectOptimize],
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topperc wrote:

Can we add RUN lines with -mcpu= to test this?

https://github.com/llvm/llvm-project/pull/178394