This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH rs6000] Increase register move cost for LR/CTR


David Edelsohn <dje@watson.ibm.com> wrote on 04/15/2008 06:59:19 PM:

>       * config/rs6000/rs6000.c (rs6000_register_move_cost): Increase cost
of
>       LR/CTR moves.
>
> Okay.
>
>    Does this change help IRA?
>

Yes, this change eliminated the 24% degradation I was seeing on the cpu2000
facerec benchmark with -fira on Power6.  Given Andrew's Cell concern with
this patch, would it be preferable to make the change cpu specific
(starting with just Power6 for now since that's where the bigger latencies
came in to play)?

-Pat


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]