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] Add statistical printout of rank_for_schedule decisions


On Jul 17, 2014, at 5:34 AM, Jeff Law <law@redhat.com> wrote:

> On 07/13/14 22:17, Maxim Kuvyrkov wrote:
>> Hi,
>> 
>> This patch adds dump printouts for scheduling heuristics in
>> rank_for_schedule.  Rank_for_schedule is one of the cornerstones of
>> haifa scheduler, yet its decisions are hard to track and debug.
>> 
>> This patch adds statistical gathering for each branch of
>> rank_for_schedule, and prints them out according to sched verbosity.
>> This patch helped me track down several bugs in rank_for_schedule
>> that result is stupid scheduling decisions.
>> 
>> Bootstrapped and tested on x86_64-linux-gnu.
>> 
>> OK to apply?
> Presmably you use the
> 
> return increment, retval;
> 
> construct to avoid the need for braces?
> 
> I can see how it's useful here, but I don't think we've generally used comma operators like that and it's a style that I've never liked all that much.
> 
> Could you go ahead and split it into two statements and add the necessary braces? Approved with that change.

Code in rank_for_schedule is difficult to understand already, so I want to keep amount of "extra" code to a minimum.  How about for following instead: "return rfs_result (RFS_xxx, <return value>)" ?

Updated patch attached (the rest of the patch is unchanged).

--
Maxim Kuvyrkov
www.linaro.org

Attachment: 0001-Add-statistical-printout-of-rank_for_schedule-decisi.patch
Description: Binary data






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