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 AAEAC3857C4D; Thu,  7 Dec 2023 07:21:57 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org AAEAC3857C4D
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1701933717;
	bh=fl8Q8ckOjoiMWffwmNQ8ZfbX+ubY8bVU0rtw5+yphIc=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=V1ID0My5U/48TryqgoXcdNtgvQfa6RtuK2QZMxPRvfpWkNN3JKvMM0akMPtKdfBTm
	 C6JMozHdrRowaWVgyFqYTBmXSx/GbzhAkRo/jNySH4813j6BJfJcEd1h7xD21SaQeV
	 INngPVu3P3QGKzLU4snT4nB+dPlkUP+FwpBY0pCQ=
From: "wwwhhhyyy333 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/112824] Stack spills and vector splitting with
 vector builtins
Date: Thu, 07 Dec 2023 07:21:56 +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: 14.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: wwwhhhyyy333 at gmail dot com
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: cc
Message-ID: <bug-112824-4-tBmOlt9ZlY@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-112824-4@http.gcc.gnu.org/bugzilla/>
References: <bug-112824-4@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=3D112824

Hongyu Wang <wwwhhhyyy333 at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |wwwhhhyyy333 at gmail dot =
com

--- Comment #9 from Hongyu Wang <wwwhhhyyy333 at gmail dot com> ---
(In reply to Hongtao Liu from comment #4)
> there're 2 reasons.

> 2. There's still spills for (subreg:DF (reg: V8DF) since
> ix86_modes_tieable_p return false for DF and V8DF.
>=20

There could be some issue in sra that the aggregates are not properly
scalarized due to size limit.

The sra considers maximum aggregate size using move_ratio * UNITS_PER_WORD,=
 but
here the aggregate Dual<Dual<double, 8l>, 2l> actually contains several V8DF
component that can be handled in zmm under avx512f.=20

Add --param sra-max-scalarization-size-Ospeed=3D2048 will eliminate those s=
pills

So for sra we can consider using MOVE_MAX * move_ratio as the size limit for
Ospeed which represents real backend instruction count.=