DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 745C5385841F
Subject: Re: Just updated cygutils and cygstart no longer works
To: cygwin@cygwin.com
References: <CAF+S4qKGwt7tuAMRFoBMsKRc5SKjZLynTDYoKO_vAhoJeJ_Y2A@mail.gmail.com>
 <CAF+S4qKrR2yTRZDPb8LceFHeGLGe8kyoYA-s9zonx+9ouRc0bw@mail.gmail.com>
 <1318f7eb-abf0-bcc9-c040-3edc71602d6c@maxrnd.com>
 <20210814105405.50c21fe7f450ca23dc774ebe@nifty.ne.jp>
 <73b4ce0e-f703-1723-6f0e-72469a78b206@maxrnd.com>
 <87eeawlccv.fsf@Rainer.invalid> <87a6lklaav.fsf@Rainer.invalid>
From: Mark Geisert <mark@maxrnd.com>
Message-ID: <c3112cf0-3c34-c359-e3e9-94deb814f418@maxrnd.com>
Date: Sat, 14 Aug 2021 01:46:02 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101
 Firefox/52.0 SeaMonkey/2.49.4
MIME-Version: 1.0
In-Reply-To: <87a6lklaav.fsf@Rainer.invalid>
Precedence: list
Content-Type: text/plain; charset="utf-8"; Format="flowed"
Errors-To: cygwin-bounces+archive-cygwin=delorie.com@cygwin.com
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie.com@cygwin.com>
Content-Transfer-Encoding: 8bit

Hi Achim,

Achim Gratz wrote:
> Achim Gratz writes:
>> The Cygwin gcc is configured to use -mtune=generic,
> 
> …and -march=x86_64 on 64bit and -march=i686 on 32bit.
> 
> While I'd love to switch to x86_64-v2, that would cut off a few
> processors that Win7 can be installed on.

Thanks for the tips.  Will do.

What I've figured out is that it's not the cygstart code itself that's been 
mis-compiled, it's apparently code pulled in from libcygwin.a as cygstart.exe is 
being built (on my machine before packaging).

I do have different gcc/g++ options for building local cygwin1.dll and 
libcygwin.a: "-O2 -march=native -mtune=native".  The offending AVX instructions 
are located in _cygwin_crt0_common().  I also see a couple hundred other cases of 
AVX instructions within locally-built cygwin1.dll but those aren't important for 
resolving this issue.

Sorry to any users who have or will run into this before it's fixed.  If you're on 
a machine that supports AVX instructions you'll be OK.  Otherwise, downgrading 
your cygutils packages to 1.4.16-2 will avoid the problem.

..mark

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple