Date: Mon, 17 Feb 2003 19:36:55 -0500 From: Mike Barcroft <mike@FreeBSD.org> To: Dag-Erling Smorgrav <des@ofug.org> Cc: Kris Kennaway <kris@obsecurity.org>, standards@freebsd.org Subject: Re: -fno-builtin world breaks in gperf Message-ID: <20030217193655.I74149@espresso.bsdmike.org> In-Reply-To: <xzp8ywezc7z.fsf@flood.ping.uio.no>; from des@ofug.org on Tue, Feb 18, 2003 at 01:03:44AM %2B0100 References: <xzp1y2755jc.fsf@flood.ping.uio.no> <20030217213405.GB71679@rot13.obsecurity.org> <xzp8ywezc7z.fsf@flood.ping.uio.no>
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Dag-Erling Smorgrav <des@ofug.org> writes: > Kris Kennaway <kris@obsecurity.org> writes: > > On Mon, Feb 17, 2003 at 03:46:15PM +0100, Dag-Erling Smorgrav wrote: > > > Our libm doesn't seem to support long double at all, yet our libstdc++ > > > requires long double support. > > I pointed this out a while ago..looks like no-one did anything about > > it yet. > > I've looked at it, and it looks Hard[tm]. The four architectures I > tested (alpha, ia32, ia64, sparc64) had four different representations > for long double: [...] You might want to take a look at the fpclassify() implementation. It doesn't look like your findings are correct. Specifically, see the bitfield layouts in _fpmath.h. IIRC, long doubles are as follows: - alpha IEEE double (64-bit) format - ia64 IEEE quad (128-bit) format - i386 IEEE double-extended (80-bit) format - sparc64 IEEE quad (128-bit) format - powerpc IEEE quad (128-bit) format Plus the following quirks: - alpha doesn't support IEEE rounding by default (compiler options needed) - i386 and ia64 have a normalization bit in the mantissa - i386 has 101 other quirks that BDE knows about :) Best regards, Mike Barcroft To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-standards" in the body of the message
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