[Bug tree-optimization/126035] Missed CTZ32 to CTZ64 optimisations

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126035

--- Comment #4 from ktkachov at gcc dot gnu.org ---
(In reply to Drea Pinski from comment #3)
> Created attachment 64895 [details]
> Prototype patch
> 
> This is the start I have. It still need to support clz and maybe a few
> helper functions instead of doing things inline.  Needs testcases.
> But it works for your original case but not the case in PR 95752.
> 
> If you want to finish it up go ahead; otherwise I will put some time in
> tomorrow to finish it up.
> 
> Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>

Thanks! I'll polish it up. I'm also interested in handling the open-coded
DeBruijn form of these testcases so I'll have a look at how they can be tackled
too