Date: Wed, 15 Apr 1998 15:28:41 +1000 From: Bruce Evans <bde@zeta.org.au> To: ajhar@noao.edu, freebsd-bugs@hub.freebsd.org Subject: Re: i386/3895: False FPE (floating point exception) signaled Message-ID: <199804150528.PAA32452@godzilla.zeta.org.au>
index | next in thread | raw e-mail
> The second example was an assignment of an integer function to an > integer and having it give a false SIGFPE. It turns out that this > function when defined was an INTEGER but was implicitly declared a > REAL when it was called in the code (because of Fortran's implicit > rules). Again, the compilers were perfectly happy to swallow all > this, and the code was happy to run on the (Solaris) UltraSparc with > the same code (without any problem) and to run happily for a while on > the (FreeBSD) Pentium Pro machine. But, eventually, a false SIGFPE > resulted. > > All this led me to conclude that there is probably a bug somewhere in > the i386 gcc code because the results were the same whether using f2c > (which converts the Fortran code into C, which is then compiled > directly with gcc as C code) or g77 (which is the Fortran front-end of > gcc). I conclude that it is a user or g77 bug, most likely the former. Calling a C function that returns double but is implicitly or mis- declared as returning another type gives undefined behaviour. The error is actually detected under FreeBSD. I know very little about Fortran, but guess it requires less type checking/rewriting than C. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the messagehelp
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199804150528.PAA32452>