From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 735833851C01; Mon,  1 Jun 2020 15:24:32 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 735833851C01
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1591025072;
 bh=R2zV/aNZ4cqPQHuv07bpLJGYx/S2TNt33v5v1EDzphE=;
 h=From:To:Subject:Date:In-Reply-To:References:From;
 b=WwhUYcqvHQm2Woe6EiTMs/UXcMutUc0e6dJZJQKMfcv99Z/xVlbN1+DmPY9MapyPR
 7JdFVHHNVgZxueh76OrJ+ECI3IV2OtWirqu+6Y/QFt+96kU5Q83XfMLpAblbDTQNgJ
 iPQWOmn+TH3Py75SEdbedLSCX8rlgaTAx+y8R2eg=
From: "qinzhao at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug gcov-profile/95348] GCC records zero functions and modules in
 the profiling data file, ICC does NOT
Date: Mon, 01 Jun 2020 15:24:32 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: gcov-profile
X-Bugzilla-Version: 11.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: qinzhao at gcc dot gnu.org
X-Bugzilla-Status: WAITING
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: marxin at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 11.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-95348-4-WpcMhMUxKH@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-95348-4@http.gcc.gnu.org/bugzilla/>
References: <bug-95348-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <http://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <http://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Mon, 01 Jun 2020 15:24:32 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95348

--- Comment #17 from qinzhao at gcc dot gnu.org ---
(In reply to Martin Li=C5=A1ka from comment #6)

more details:

>=20
> Which means one run takes 100MB is size, right? As you mentioned, having
> 1000 .gcda files, it means that one takes 0.1MB?
>=20

Out of the 14,239 processes, the amount of gcda data saved is:

- Around 6500 processes in the 120-130M range.
- Around 1000 processes in the 16M-18M range
- Around   10 processes in the 736K - 764K range
- Around 6000 processes in the 8K-32K range

we are mostly interested in those 120-130M range, a typical process in the =
130M
bucket has over 5000 gcd files per directory.

>=20
> Can you please provide dump of one directory? At least for portion of .gc=
da
> files?
> How is it common that an entire module is empty?

I compared the GCC profiling data and ICC profiling data for the similar
process, the following are some interesting data:

for GCC, among 5144 modules, there are 4308 empty modules, i.e 83% modules =
in
GCC are empty;
on function level, among all 187338 functions, only 3524 functions executed,
i.e, 98% functions have zero counts.=20

GCC records all the zero count functions and modules, But ICC ONLY records
functions and modules that have non-zero count.

So, GCC's profiling data is MUCH larger than ICC's.=20

I believe that this is a big issue that need to be fixed from GCC.=