[Bug target/104912] [12 Regression] 416.gamess regression after r12-7612-g69619acd8d9b58

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104912

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to CVS Commits from comment #8)
> The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:
> 
> https://gcc.gnu.org/g:ac8340ee4d1e65f3fd41c547b16895875f4aefa7
> 
> commit r12-8132-gac8340ee4d1e65f3fd41c547b16895875f4aefa7
> Author: Richard Biener <rguenther@suse.de>
> Date:   Mon Mar 21 14:08:25 2022 +0100
> 
>     tree-optimization/104912 - ensure cost model is checked first
>     
>     The following makes sure that when we build the versioning condition
>     for vectorization including the cost model check, we check for the
>     cost model and branch over other versioning checks.  That is what
>     the cost modeling assumes, since the cost model check is the only
>     one accounted for in the scalar outside cost.  Currently we emit
>     all checks as straight-line code combined with bitwise ops which
>     can result in surprising ordering of checks in the final assembly.
>     
>     Since loop_version accepts only a single versioning condition
>     the splitting is done after the fact.
>     
>     The result is a 1.5% speedup of 416.gamess on x86_64 when compiling
>     with -Ofast and tuning for generic or skylake.  That's not enough
>     to recover from the slowdown when vectorizing but it now cuts off
>     the expensive alias versioning test.
>     
>     2022-03-21  Richard Biener  <rguenther@suse.de>
>     
>             PR tree-optimization/104912
>             * tree-vect-loop-manip.cc (vect_loop_versioning): Split
>             the cost model check to a separate BB to make sure it is
>             checked first and not combined with other version checks.

I've wrongly pushed this and reverted it again.