[PATCH] D83360: [InstSimplify] Remove select ?, undef, X -> X and select ?, X, undef -> X

[John Regehr via Phabricator via cfe-commits]

regehr added a comment.

> Did you mean to check something like the following?
> 
>   define i32 @src(i1 %cond, i32 %x) {
>     %x2 = freeze i32 %x
>     %s = select i1 %cond, i32 %x2, i32 undef
>     ret i32 %s
>   }
>   
>   define i32 @tgt(i1 %cond, i32 %x) {
>     %x2 = freeze i32 %x
>     ret i32 %x2
>   }

that's fine but I still don't understand why the counterexample to my version says %x2 in @src can be undef


Repository:
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  https://reviews.llvm.org/D83360/new/

https://reviews.llvm.org/D83360