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 E8A5F3858415; Tue, 28 Nov 2023 22:58:55 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E8A5F3858415
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1701212335;
	bh=TOnSzYALrSmFqJUEqvNu4BhKac9Z3MMPSbK2i+QiGck=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=Av98wTYsKm659JzK4EcYklut58yzqi60GOBJkxcyePw5wXjJUpkwqSTScf9OUV9Bq
	 C1GDPo63ptUtaHixsSKUAUvUqxeTB6f7Z3b4qXuFnYU4RN9pEFklNkUzsa2bgwUTi4
	 +uYSj53uQKdDDtAcaX8vwotqd40htQCAnv1ZPnP4=
From: "ebotcazou at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/111107] i686-w64-mingw32 does not realign stack when
 __attribute__((aligned)) or __attribute__((vector_size)) are used
Date: Tue, 28 Nov 2023 22:58:54 +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: 12.2.0
X-Bugzilla-Keywords: ABI, wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: ebotcazou 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: 
Message-ID: <bug-111107-4-flqqjTKsVL@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-111107-4@http.gcc.gnu.org/bugzilla/>
References: <bug-111107-4@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=3D111107

--- Comment #14 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> I'd say that
>=20
> config/i386/cygming.h:#define STACK_REALIGN_DEFAULT TARGET_SSE
>=20
> is a non-working "fix".  The appropriate default would be
> -mincoming-stack-boundary=3D2.  MIN_STACK_BOUNDARY should already be 4, so
> that leaves PREFERRED_STACK_BOUNDARY_DEFAULT is the way to go here.

This was a minimal fix to support SSE, but Solaris was indeed more radical:

sol2.h:#undef STACK_REALIGN_DEFAULT
sol2.h:#define STACK_REALIGN_DEFAULT (TARGET_64BIT ? 0 : 1)

so we could just mimic it for Windows.=