Date: Wed, 5 Jan 2000 11:42:33 -0500 (EST) From: Thomas David Rivers <rivers@dignus.com> To: cracauer@cons.org, rfg@monkeys.com Cc: freebsd-hackers@FreeBSD.ORG, saska@acc.umu.se Subject: Re: Should -mieee-fp equal fpsetmask(0) to avoid SIGFPE on FreeBSD? Message-ID: <200001051642.LAA26756@lakes.dignus.com> In-Reply-To: <91688.947090291@monkeys.com>
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> > P.S. Actually, although Martin Cracauer's suggested replacement for > the existing Mozilla code is certainly better than what Mozilla is > using now, it may perhaps need to be slightly augmented with an > additional check to see if the value of `d' is a NaN prior to per- > forming the range check. But I'm not even sure about that. I'd > have to go and dredge my copy of IEEE 754 out of my files again to > find out what the results of <= and >= are in cases where one of > the operands is a NaN. I think however that those operations are > perhaps required to return False in that case, in which case Martin > Cracauer's suggested Mozilla replacement code is just fine as it is. > > And in any case, that is all a moot point anyway if it is known in > advance that `d' will not be a NaN. > I don't believe the C89 standard doesn't have a way to test for NaN - so, if we're talking portability here - you can't test for NaN. I think C99 does have some library functions to do tests for NaN and Inf. This is interesting because the 390 HFP format doesn't have NaN or Inf. Why would that matter to Mozilla - well, there's a LINUX port now for the mainframe and Mozilla might want to run there. [I don't know if that port is using the old-style HFP format or the new-style IEEE format.] - Dave R. - To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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