From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,ac9405996d0dcb7f X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!proxad.net!news.tele.dk!news.tele.dk!small.news.tele.dk!news-fra1.dfn.de!newsfeed.hanau.net!newsfeed01.sul.t-online.de!newsmm00.sul.t-online.de!t-online.de!news.t-online.com!not-for-mail From: Martin Krischik Newsgroups: comp.lang.ada Subject: Re: Would You Fly an Airplane with a Linux-Based Control System? Date: Wed, 01 Dec 2004 10:27:10 +0100 Organization: None Message-ID: <1780586.KJpDkK3SiU@linux1.krischik.com> References: <20619edc.0411251028.3e249bf3@posting.google.com> <3193657.BGZLZqeFdM@linux1.krischik.com> Reply-To: martin@krischik.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit X-Trace: news.t-online.com 1101893457 05 898 SQE5Xr7OCbgh6Bn 041201 09:30:57 X-Complaints-To: usenet-abuse@t-online.de X-ID: VOvurmZbre9xh+Prt-++BUJkmD55k9faPJL5kXminbe3I4aPmD1-rz User-Agent: KNode/0.8.0 Xref: g2news1.google.com comp.lang.ada:6685 Date: 2004-12-01T10:27:10+01:00 List-Id: Preben Randhol wrote: > In article <3193657.BGZLZqeFdM@linux1.krischik.com>, Martin Krischik > wrote: >> >>They turned of a few select runtime checks. They had proof that on an >>Ariane 4 they would not be needed as the Arinane 4 will never exceed the >>max. values. >> >>However, as Alexander pointed out, with the software checks disabled some >>hardware checks from the floating point unit kicked in instead and crashed >>the hole programm. >> >>You must understande that modern CPUs there support hardware exceptions >>and modern programming laguages support software exceptions. And they have >>nothing to do with each other. > > Yes, but if C doesn't have exceptions, then I don't see why a C program > wouldn't crashed as the Ada program did when they had turned off the > sw exceptions. Maybe you want to brush up your C and read "ISO/IEC 9899:1999 7.14". In C exceptions are called signal and in the case discussed a the "SIGFPE" would have been raised. Without a signal handler the programm would have died. With Regards Martin -- mailto://krischik@users.sourceforge.net http://www.ada.krischik.com