From: cinap_lenrek@gmx.de
To: 9fans@9fans.net
Subject: [9fans] broken floating point exceptions and fpregs
Date: Fri, 24 May 2013 23:29:27 +0200 [thread overview]
Message-ID: <643973b9c0074170145322ddf82ea07c@gmx.de> (raw)
the sse change broke floating point exception handling.
from /sys/src/9/pc/main.c:^matherror()
/*
* save floating point state to check out error
*/
fpenv(&up->fpsave);
mathnote();
this is wrong, because fpenv() will store the enviroment
in x87 format, but mathnote() uses mathstate() which intreprets
the FPsave structure depending on if sse was enabled or not.
a fix for this was just commited in 9front which passes the
status word and fppc explicitely to mathnode() and uses
mathnote(up->fpsave.status, up->fpsave.pc); in matherror()
and the values extracted by mathstate() in mathemu().
the 2nd problem is how we'r going to handle the fpregs file
in devproc. as this change changes the format. fpr() in acid
returns garbage right now. any thoughts on it how to move
forward on this?
--
cinap
next reply other threads:[~2013-05-24 21:29 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-24 21:29 cinap_lenrek [this message]
2013-05-25 2:10 ` cinap_lenrek
2013-05-25 13:47 ` erik quanstrom
2013-05-25 13:58 ` Kurt H Maier
2013-05-25 15:02 ` erik quanstrom
2013-05-25 15:40 ` Kurt H Maier
2013-05-25 15:59 ` erik quanstrom
2013-05-25 19:21 ` Francisco J Ballesteros
2013-05-26 6:00 ` lucio
2013-05-26 8:40 ` Francisco J Ballesteros
2013-05-26 5:57 ` lucio
2013-05-27 3:51 ` Anthony Sorace
2013-05-27 5:35 ` lucio
2013-05-25 14:54 ` cinap_lenrek
2013-05-25 15:00 ` erik quanstrom
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