[Bug tree-optimization/65492] Bad optimization in -O3 due to if-conversion and/or unrolling

[hubicka at ucw dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65492

--- Comment #7 from Jan Hubicka <hubicka at ucw dot cz> ---
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65492
> 
> Richard Biener <rguenth at gcc dot gnu.org> changed:
> 
>            What    |Removed                     |Added
> ----------------------------------------------------------------------------
>                  CC|                            |hubicka at gcc dot gnu.org
> 
> --- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
> --param max-peel-branches default of 32 seems to be quite high.  For this
> loop we have two branches on the hot path and 4 times unrolling.
> 
> Honza - how did you arrive at the default of 32?  Shouldn't that depend
> on the number of other stmts thus rather look at branch density?

In https://gcc.gnu.org/ml/gcc-patches/2012-10/msg02716.html I claim value
around 32 is needed for apply. (not that I would recall that)

I do not have really strong opinion concerning the branch density.

Honza