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] alternative hirate for builtin_expert


On 10/02/13 23:49, Rong Xu wrote:
Here is the new patch. Honaz: Could you take a look?

Thanks,

-Rong

On Wed, Oct 2, 2013 at 2:31 PM, Jan Hubicka <hubicka@ucw.cz> wrote:
Thanks for the suggestion. This is much cleaner than to use binary parameter.

Just want to make sure I understand it correctly about the orginal hitrate:
you want to retire the hitrate in PRED_BUILTIN_EXPECT and always use
the one specified in the biniltin-expect-probability parameter.

Yes.

Should I use 90% as the default? It's hard to fit current value 0.9996
in percent form.

Yes, 90% seems fine.  The original value was set quite arbitrarily and no real
performance study was made as far as I know except yours. I think users that
are sure they use expect to gueard completely cold edges may just use 100%
instead of 0.9996, so I would not worry much about the precision.

Honza

-Rong

OK with that change.

Honza


This broke arm-linux-gnueabihf building libstdc++-v3. I haven't dug further yet but still reducing the testcase.

See

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58619

for details.

Can you please deal with this appropriately ?

regards
Ramana



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