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From: Andi Kleen <andi@firstfloor.org>
To: Jan Hubicka <hubicka@ucw.cz>
Cc: Dehao Chen <dehao@google.com>,
	 GCC Patches <gcc-patches@gcc.gnu.org>,
	 David Li <davidxl@google.com>
Subject: Re: [google] AutoFDO implementation
Date: Sun, 07 Oct 2012 01:13:00 -0000	[thread overview]
Message-ID: <m2vcenuls2.fsf@firstfloor.org> (raw)
In-Reply-To: <20121006175508.GB29814@atrey.karlin.mff.cuni.cz> (Jan Hubicka's	message of "Sat, 6 Oct 2012 19:55:08 +0200")

Jan Hubicka <hubicka@ucw.cz> writes:
>
> I think it is useful feature, yes (and was in my TODO list for quite some
> time). Unlike edge profiles, these profiles should be also more independent of
> source code/configuration changes.

It would be good to look at the tool, but:

- Does it use the perf LBR support to estimate the last 16 basic blocks
for each sample?

- It doesn't seem to use callgraphs for estimating common indirect calls
for devirtualization? 

I always disliked the limitation of the current indirect call profiling
to only support a single translation unit. Using callgraphs around
that would be quite nice.

This would only work for non tail calls and with frame pointers, or
using LBRs again.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only

  reply	other threads:[~2012-10-07  1:13 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-29  3:26 Dehao Chen
2012-09-29  9:32 ` Andi Kleen
     [not found] ` <CAAkRFZLB8hd=1hcwSNxuDtXzt+7NktgmQrZ0a4GvE_RfGmB9Xg@mail.gmail.com>
     [not found]   ` <CAO2gOZWq0BC1QH8XUrDpGeLKiWY=WJQAAO8i_J21EcMxXh_USw@mail.gmail.com>
2012-10-05 21:11     ` Xinliang David Li
2012-10-06 17:55 ` Jan Hubicka
2012-10-07  1:13   ` Andi Kleen [this message]
2012-10-07  5:56     ` Dehao Chen
2012-10-07  5:48   ` Dehao Chen

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