This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [patch] Enable -fweb and -frename-registers when unrolling
Hello,
> > PR rtl-optimization/20376
> > * toplev.c (process_options): Enable -fweb and -frename-registers when
> > unrolling.
>
> when unrolling or peeling?
just when unrolling.
> Or did you rather mean not to set these with
> only flag_peel_loops set? I regularly use only -fpeel-loops to get small
> loops peeled completely; do you expect it as a win there, too?
The loops should be peeled completely at tree level; ssa form makes -fweb
useless in this case. I am not sure about -frename-registers.
What I perhaps forgot to mention is that -frename-registers helps also
without unrolling, but less than with it. -fweb has no significant
effect without unrolling (probably because of ssa).
Zdenek