From: "Yuan, Pengfei" <ypf@pku.edu.cn>
To: "Richard Biener" <richard.guenther@gmail.com>
Cc: "GCC Patches" <gcc-patches@gcc.gnu.org>, "Jan Hubicka" <hubicka@ucw.cz>
Subject: Re: [PATCH, 5.x/6.x/7.x] Be more conservative in early inliner if FDO is enabled
Date: Thu, 15 Sep 2016 10:08:00 -0000 [thread overview]
Message-ID: <5796fc24.155b.1572d414d84.Coremail.ypf@pku.edu.cn> (raw)
In-Reply-To: <CAFiYyc2Yb6Gp+4dn1UETmcLte9OdbAUBdGntE3LD3V_0jp9B_Q@mail.gmail.com>
> Yes. This means it's easy to experiment with other values than zero. Basically
> early inlining is supposed to remove abstraction penalty to
>
> a) reduce FDO instrumentation overhead
> b) get more realistic size estimates for the inliner
>
> a) was particularly important back in time for tramp3d, reducing
> profiling runtime
> 1000-fold. b) is generally important.
>
> PARAM_EARLY_INLINING_INSNS is supposed to be a reasonable value to
> get abstraction removed but IIRC we increased it quite a bit to also get more
> early optimization (to get more accurate inliner estimates).
>
> What I am saying is that reducing PARAM_EARLY_INLINING_INSNS makes
> sense for FDO but reducing it to zero is probably a bit much.
>
> Can you do your measurements with values between zero and the current
> default of 14 (wow, 14 ... didn't know it's _that_ high currently ;)).
> What's the
> value that crosses the boundary of diminishing returns regarding to code-size
> improvements for you?
>
> Richard.
>
I see. This procedure may take some time since profile data can not be reused.
Yuan, Pengfei
next prev parent reply other threads:[~2016-09-15 9:51 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-10 6:41 Yuan, Pengfei
2016-09-14 10:35 ` Richard Biener
2016-09-15 3:17 ` Yuan, Pengfei
2016-09-15 8:44 ` Richard Biener
2016-09-15 10:08 ` Yuan, Pengfei [this message]
2016-09-16 5:52 ` Yuan, Pengfei
2016-09-16 8:09 ` Jan Hubicka
2016-09-16 9:01 ` Yuan, Pengfei
2016-09-16 9:21 ` Richard Biener
2016-09-16 9:37 ` Jan Hubicka
2016-09-16 12:00 ` Yuan, Pengfei
2016-09-16 12:56 ` Jan Hubicka
2016-09-20 8:53 ` Yuan, Pengfei
2016-09-20 11:44 ` Richard Biener
2016-09-20 11:58 ` Richard Biener
2016-09-20 12:09 ` Yuan, Pengfei
2016-09-20 12:19 ` Richard Biener
2016-09-20 13:10 ` Yuan, Pengfei
2016-09-21 12:44 ` Yuan, Pengfei
2016-09-26 4:03 ` Yuan, Pengfei
2016-10-10 2:23 ` PING: [PATCH] " Yuan, Pengfei
2016-10-10 9:55 ` Richard Biener
2016-10-10 10:52 ` Yuan, Pengfei
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