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 D52F83861845; Thu, 15 Jul 2021 07:37:10 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D52F83861845
From: "ashimida at linux dot alibaba.com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug other/101459] Mismatch in description of option
 "-falign-functions" between source code and documentation
Date: Thu, 15 Jul 2021 07:37:10 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: other
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: documentation
X-Bugzilla-Severity: normal
X-Bugzilla-Who: ashimida at linux dot alibaba.com
X-Bugzilla-Status: RESOLVED
X-Bugzilla-Resolution: WORKSFORME
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-101459-4-wZ0aZTbaTM@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-101459-4@http.gcc.gnu.org/bugzilla/>
References: <bug-101459-4@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: <https://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: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Thu, 15 Jul 2021 07:37:11 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101459

--- Comment #3 from ashimida <ashimida at linux dot alibaba.com> ---
(In reply to Richard Biener from comment #2)
> The flag, -falign-functions is only enabled at -O2+ (but not -Os), but the
> actual alignment is recorded in the 'align_functions' data which is only
> populated when -falign-functions is specified so I think it works as
> documented.

I tested this option in gcc 7.5.0 and 9.2.0, with the source code:

int func1(void)=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=
=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=
=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20
{
    return 0;
}

int func2(void)
{
    return 0;
}

int main (void)
{
    return 1;
}

and the result is like:
ashimida@ubuntu:~/test1$ aarch64-linux-gnu-gcc -falign-functions=3D128 -O0 =
test.c
-o test
ashimida@ubuntu:~/test1$ readelf -s test|grep fun
    63: 0000000000000780     8 FUNC    GLOBAL DEFAULT   13 func1
    78: 0000000000000800     8 FUNC    GLOBAL DEFAULT   13 func2
ashimida@ubuntu:~/test1$ aarch64-linux-gnu-gcc -O0 test.c -o test
ashimida@ubuntu:~/test1$ readelf -s test|grep fun
    63: 00000000000006e4     8 FUNC    GLOBAL DEFAULT   13 func1
    78: 00000000000006ec     8 FUNC    GLOBAL DEFAULT   13 func2

so I think this flag is also worked at -O0=