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 D206B3858403; Fri, 22 Apr 2022 14:11:50 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D206B3858403
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/105338] [12 Regression] Regression: jump or
 cmove generated for pattern (x ? CST : 0)
Date: Fri, 22 Apr 2022 14:11:50 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: rtl-optimization
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jakub 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: 12.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-105338-4-ix5e32oAGg@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-105338-4@http.gcc.gnu.org/bugzilla/>
References: <bug-105338-4@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: Fri, 22 Apr 2022 14:11:50 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105338

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Note, in both the first and second function if_info->original_cost is small=
er
than seq_cost of the new sequence, but in the first function
if_info->max_seq_cost is larger than seq_cost of the new sequence, in the
second it is 0.
And the reason for that difference is that predictable_p is true in the sec=
ond
function and not the first one, I presume because of the negative return va=
lue
predictor that predicts returning -2 as unlikely.  But if the negative value
return heuristic is right (at least most of the time), then using condition=
al
jump seems to be the right choice.=