naive question: gcc and glibc

Tim Prince
Sun Jun 18 15:05:00 GMT 2000

I suppose it would be a large project to port glibc to cygwin.  Probably
not even advisable to do the whole thing, as long as cygnus/redhat are
maintaining newlib partly for this application.  I'd be happy to tackle
certain parts in which I have an interest, if suitably motivated.  The
ieeefp thing looks feasible.  There, I suppose we want to have the
functions both under the names they have in glibc and the ones currently
in the cygwin headers.  As we would likely end up with an add-on library
which simply fits glibc components into cygwin, it's unlikely to be
adopted as part of cygwin or newlib.

The subject of math functions and bringing x87 support into cygwin has
been brought up before.  It has the same problem, apparently, of not
being acceptable to newlib and therefore not wanted as a standard part
of cygwin.  I hope I'm not mis-characterizing what was said, and
actually I'd be happy to be wrong.

I have some disagreements with glibc as well in the way long double is
done half way in some of the math functions, so there I'd want it done
better, not totally in a compatible fashion.  I've been running a
<mathinline.h> in cygwin for some time, and I like that scheme, if it's
not carried too far.  The attitude in both glibc and gcc development is
that options like -ffast-math and <mathinline.h> are intended for
maximum speed with no care for accuracy or protection against crashes,
and I'm not the only one to say that this makes those options unusable.
I will say that -ffast-math has improved greatly, that the problems
haven't been igmored.

Tim Prince
----- Original Message -----
From: "Jerome Benoit" <>
Cc: "Cygnus" <>
Sent: Sunday, June 18, 2000 1:52 PM
Subject: Re: naive question: gcc and glibc

> Fine !
> Can we install `glibc' under Cygwin and use it ?
> Jerome
> Tim Prince wrote:
> >
> > No, the portion of the C library which comes with gcc is called
> > glibc is a large package including the bulk of the C x86 and alpha
> > run-time support and more, used in operating systems such as linux.
> > cygwin uses newlib instead.
> > I suppose the reasons for this should be an
> > FAQ, but I don't know where to look it up.  glibc appears to have
> > getting a great deal more attention.  Among the visible differences
> > missing features in newlib such as long double scanf/printf and math
> > functions, or ieee rounding modes.
> >
> > Tim Prince
> > ----- Original Message -----
> > From: "Jerome Benoit" <>
> > To: "Cygnus" <>
> > Sent: Sunday, June 18, 2000 2:31 AM
> > Subject: naive question: gcc and glibc
> >
> > > Is the GNU C library `glibc' the one include with the `gcc'
package ?
> > >
> > > Greeings !
> > > Jerome BENOIT
> > >
> > > --
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