From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/15021 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Markus Wichmann Newsgroups: gmane.linux.lib.musl.general Subject: Re: max_align_t mess on i386 Date: Sun, 15 Dec 2019 06:47:46 +0100 Message-ID: <20191215054746.GD20973@voyager> References: <20191214151932.GW1666@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="79630"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.9.4 (2018-02-28) To: musl@lists.openwall.com Original-X-From: musl-return-15037-gllmg-musl=m.gmane.org@lists.openwall.com Sun Dec 15 06:48:03 2019 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.89) (envelope-from ) id 1igMl8-000KaS-Sn for gllmg-musl@m.gmane.org; Sun, 15 Dec 2019 06:48:03 +0100 Original-Received: (qmail 7518 invoked by uid 550); 15 Dec 2019 05:48:00 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 7498 invoked from network); 15 Dec 2019 05:47:59 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1576388868; bh=HmSBQYmaYxzaj3t5b1tIGyw4pr6fDrrlggGMTsveUSo=; h=X-UI-Sender-Class:Date:From:To:Subject:References:In-Reply-To; b=gWQYcN6GvSvF1eMlxn3Y8J4w5VqkPz45PWR0dO4eFNAdXJPy29PEdoEV4TLjKV9fI 03mH8w+PRT7I+dU0E/7DeHzKqBY0FTngV3KBTB5Scwzf3yp5wmGKGeR4y5bXZlwB2T tZZQJ0yRN1cyv3HjsSUDHfzlm8wxeM0dPHRxVIoc= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Content-Disposition: inline In-Reply-To: <20191214151932.GW1666@brightrain.aerifal.cx> X-Provags-ID: V03:K1:QyysB5X4dT70zlMk68A/2ZuMQOasbF010pOjZdY+KDyekPYlUhP ER3IlXVS0hclEoIYI5HI3F/jteNmwRPG4vJ5NPGQCdx2SqXO6MeV9DXgxNsAaKvamnxtK41 OebZvFpQuuuXdh27MdiLhgx9jxdpVMdIQROXKZWLlDLPJKew7ooKipTwNC8yauWHeOjQh97 YgKTyqnHPAmTIxIttjz+w== X-UI-Out-Filterresults: notjunk:1;V03:K0:scAPiDEdFCc=:hDmVGMOfWw87QPpxOm9+5v zhegZ4pxVCcb8Hz6q3LSkAakIKjTF52NWgCdN1jgY8vCh1x2wZlO3vTySLxiw5ExNynX9vTXe zGU6XuCgaUdWurOfIc5oqMj2myHFhSNin9twkIBbdsqRZLm0SshZgEVSCKKtihnOphaKia7hl 4fC+sVeAXqoaYllMFbl899c8ArCpfRnYJIRbfbVgk70QJTuMIBJn/RWN0/LL9mot2FoUNbaO6 ke8xsCdU07O/xXiqnSkabe+u8K5QH7N0SBThWqDJEhnnFgccDloZT3Gk9rb29J3/IWXCFMsRN w0PWNrSQxNHJgcY91qs6fMM2L4uwGHq4hwueYQrrPPT3RKKsRCHomkN3I++rwT5RGuVhXWU0M 8RwUDmonxaFZ92JDghM58BjJtSqLmGWbnFZpWZvTrAH8jMkba+2Xg61/iB8o5myyvTmTbfxE9 BbzKlFOzvE7YPN9s1dUnYNJnJGdV0GeXyZOgpp6Uvig1TltCuQULxpiRlPqbi1J+y+r4Oj1BB URJG+T3+ts+RGOcSQGeydR6OWCY6+GSDIGc9IcE4QLeDwJ25UbvXXnQOLn6ZGUpqkJlwp3oii ftuES69UlKkfXb/duvwEp0StX5invCSn/0K+rjylYfuz8MHu/5YcmBhsr+BRmJxfLlInGy05a PuK/oEPeTlsq4+hVRwazFzeRPyOMEwjGexDmygo90kKdCTZFfD7mGsr/1kJ23zND3aTWkJaps qrCUzg9YxqI9/EztCUee4QWVKJ5cyvWXlIG1MEua/bQZ2DbNYL2ros1vx/f92UHqyWEqI9/7 Xref: news.gmane.org gmane.linux.lib.musl.general:15021 Archived-At: On Sat, Dec 14, 2019 at 10:19:32AM -0500, Rich Felker wrote: > The disadvantage of leaving max_align_t alone is that we have to > (continue to) consider _Float128 an unsupported extension type whose > use would be outside the scope of any guarantees we make, and that > would need memalign to use. This is largely viable at present because > it's a fringe thing, but we don't know if that will continue to be > true far in the future. > It wouldn't just be that. Any application making use of SSE vector types would have to use *memalign(). Apparently, there are libraries out there that expect to get a 16byte alignment out of malloc(), or at least that's what the author of dietlibc is alleging here: https://blog.fefe.de/?ts=3Dbac7bb06 Yes, it's German, but Google Translate exists. More importantly though, it is from 2006, and he says he's "hacking about with" a bignum library, and I don't know if he means his own or a public one. In any case, though, the mere existance of SSE was cause enough for that man to change the allocator to return a higher alignment on x86. Maybe one more factor leaning towards the ABI change, right? > Rich Ciao, Markus