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 F336A3858C60; Thu, 23 Dec 2021 08:04:47 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org F336A3858C60
From: "smal.root at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/59394] Unused code generated
Date: Thu, 23 Dec 2021 08:04:47 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: middle-end
X-Bugzilla-Version: 4.8.2
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: smal.root at gmail dot com
X-Bugzilla-Status: RESOLVED
X-Bugzilla-Resolution: INVALID
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: attachments.created
Message-ID: <bug-59394-4-uRGXG38XeI@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-59394-4@http.gcc.gnu.org/bugzilla/>
References: <bug-59394-4@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, 23 Dec 2021 08:04:48 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D59394

--- Comment #6 from smalcom <smal.root at gmail dot com> ---
Created attachment 52050
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D52050&action=3Dedit
Generated assembly when using "LTO". avr-gcc-10.2

(In reply to Andrew Pinski from comment #4)
> If I use -Wl,--gc-sections -ffunction-sections, then all of the unused
> (non-static) functions are removed.
>=20
> Also -flto is able to optimize it too.

I confirm that:
1. With set "-Wl,--gc-sections -ffunction-sections" output file do not cont=
ain
unused functions (attached gcsec.lss).
2. With "-flto" all functions are inlined and present only used code (attac=
hed
lto.lss).

Tested using gcc-10:

avr-gcc -v
Using built-in specs.
Reading specs from
/mnt/stor5/opt/=D1=81=D0=B1=D0=BE=D1=80=D0=BA=D0=B0/avr-10.2.0/bin/../lib/g=
cc/avr/10.2.0/device-specs/specs-avr2
COLLECT_GCC=3Davr-gcc
COLLECT_LTO_WRAPPER=3D/mnt/stor5/opt/=D1=81=D0=B1=D0=BE=D1=80=D0=BA=D0=B0/a=
vr-10.2.0/bin/../libexec/gcc/avr/10.2.0/lto-wrapper
Target: avr
Configured with: ../configure --prefix=3D/opt/toolchain/avr-10.2.0 --target=
=3Davr
--enable-languages=3Dc,c++ --disable-nls --disable-libssp --with-dwarf2
Thread model: single
Supported LTO compression algorithms: zlib zstd
gcc version 10.2.0 (GCC)=20

Great. Thanks!=