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 B0A34392DFF6; Fri,  7 Jun 2024 08:17:58 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B0A34392DFF6
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1717748278;
	bh=tLbiWt+Iz2qxWYKTzuNMsdSZOI24db6xCgkkutArxe0=;
	h=From:To:Subject:Date:From;
	b=FhqAP5CTxGjy22Rl0TeIiB7czAvJu7Ls4TqNtmKc+/73kJbDrk88UznBIPfLcXbAH
	 QK6U+2OxLQIUhrroSNyREaa35+p+CUqbqtQFBAbLAbYOZ2GKXbiqIVy7Ej7PG77zwv
	 WR3aWlpRcrWzI0ZicRD38uUVwy87pzFh0DCJNFsQ=
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/115382] New: Wrong code with in-order
 conditional reduction and masked loops
Date: Fri, 07 Jun 2024 08:17:55 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 15.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
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_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-115382-4@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=3D115382

            Bug ID: 115382
           Summary: Wrong code with in-order conditional reduction and
                    masked loops
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

vectorize_fold_left_reduction does

      if (LOOP_VINFO_FULLY_MASKED_P (loop_vinfo))
        mask =3D vect_get_loop_mask (loop_vinfo, gsi, masks, vec_num, vecty=
pe_in,
i);
      else if (is_cond_op)
        mask =3D vec_opmask[i];

that doesn't work - both masks have to be combined.  This for example shows
in a runfail of gcc.dg/vect/vect-cond-reduc-in-order-2-signed-zero.c
with -march=3Dcascadelake --param vect-partial-vector-usage=3D2 on x86_64.

The len-masking code looks good.=