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 ECAE43858415; Fri,  5 Apr 2024 12:41:27 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org ECAE43858415
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1712320887;
	bh=0qEe2cJCsk//ZYM3vIQyukChMPsOKhCHowNuZykZD/c=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=VubzX3m07RT7+IdzIIBxQJvAvt3emYz0QoC5E24aB4nldpln8nR5erYEKd1gYhwg0
	 TpPGYbhal/h7LJIY6kY9z/PbcgpLn2Ou5MFsK1+lk7am1psPjY0CyheUqEknAS7Ihv
	 1HHg07pNvSEH0CUDC/1kEAMz/K/NwiAOTxIspqiw=
From: "manolis.tsamis at vrull dot eu" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/102793] AArch64: sequential comparisons with
 equal conditional blocks don't use ccmp
Date: Fri, 05 Apr 2024 12:41:27 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: manolis.tsamis at vrull dot eu
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: 
Message-ID: <bug-102793-4-2jp406amb3@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-102793-4@http.gcc.gnu.org/bugzilla/>
References: <bug-102793-4@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
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102793

--- Comment #7 from Manolis Tsamis <manolis.tsamis at vrull dot eu> ---
Also submitted in the lists:
https://gcc.gnu.org/pipermail/gcc-patches/2024-April/648856.html

I should note that I needed to modify the test uninit-pred-6_c.c and remove
this check:

  if (l)
    if (n > 12)
      blah(v); /* { dg-bogus "uninitialized" "bogus warning" } */

because it was inconsistent. If the branch is merged to a simple if (l && (=
n >
12)) is fails (on master). With the proposed patch we get more ifcombining =
and
better codegen but this condition fails. I believe this would need an
enhancement in tree-ssa-uninit.=