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 681B73858004; Tue, 19 Jan 2021 07:55:59 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 681B73858004
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/98737] Atomic operation on x86 no optimized to use flags
Date: Tue, 19 Jan 2021 07:55:59 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 11.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
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: bug_status cf_reconfirmed_on keywords
 everconfirmed cf_gcctarget
Message-ID: <bug-98737-4-VIugoNIsUh@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-98737-4@http.gcc.gnu.org/bugzilla/>
References: <bug-98737-4@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: Tue, 19 Jan 2021 07:55:59 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D98737

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-01-19
           Keywords|                            |missed-optimization
     Ever confirmed|0                           |1
             Target|x86                         |x86_64-*-* i?86-*-*

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  Probably difficult to achieve since the atomics map to
parallel/UNSPEC:

(insn 7 6 8 (parallel [
            (set (reg:DI 83 [ _2 ])
                (unspec_volatile:DI [
                        (mem/v:DI (symbol_ref:DI ("a") [flags 0x2]  <var_de=
cl
0x7ffff7ff5b40 a>) [-1  S8 A64])
                        (const_int 3 [0x3])
                    ] UNSPECV_XCHG))
            (set (mem/v:DI (symbol_ref:DI ("a") [flags 0x2]  <var_decl
0x7ffff7ff5b40 a>) [-1  S8 A64])
                (plus:DI (mem/v:DI (symbol_ref:DI ("a") [flags 0x2]  <var_d=
ecl
0x7ffff7ff5b40 a>) [-1  S8 A64])
                    (reg:DI 86)))
            (clobber (reg:CC 17 flags))
        ]) "t.c":5:10 -1
     (nil))=