[Bug tree-optimization/112900] Missing optimization: canonicalize `select c, x - 1, x + 1` to `x + (select c, -1, 1)` (or reversely)

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112900

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think at least fold has/had some of this folding one variant into the other.