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Re: std::arg() bug : not repetitive ?
- From: Marco Atzeri <marco_atzeri at yahoo dot it>
- To: cygwin-apps at cygwin dot com, Dave Korn <dave dot korn dot cygwin at googlemail dot com>
- Date: Thu, 3 Sep 2009 07:29:27 +0000 (GMT)
- Subject: Re: std::arg() bug : not repetitive ?
--- Gio 3/9/09, Dave Korn ha scritto:
> Da: Dave Korn
> Oggetto: Re: std::arg() bug : not repetitive ?
> A: cygwin-apps cygwin.com
> Data: Giovedì 3 settembre 2009, 06:07
> Brian Ford wrote:
> > On Wed, 2 Sep 2009, Marco Atzeri wrote:
> >
> >> I have no clue if -march=pentium4 is acceptable
> for AMD cpu's.
> >
> > FWIW, we have been using -march=pentium4 -mfpmath=sse
> successfully in a
> > very large software project since November 2003
> without incident.? We have
> > run on AMD Opterons and a variety of Intel processors
> without issue
> > (given that they were at least Pentium 4's, of
> course).
> >
>
> In http://lkml.indiana.edu/hypermail/linux/kernel/0904.2/00818.html
> it is
> argued that:
>
> > Nvidia started requiring SSE in their binary drivers,
> but have since
> > backed out that requirement, so it is possible to make
> people realize
> > their code has unreasonable requirements.
>
> ? If we turn on SSE in the distro, we block anyone
> using Pentium2 or early
> (pre-XP) Athlon CPUs from using Cygwin.? I think that
> might be a step too far.
> In the place where I was working until only last November,
> we had a ton of
> old P2 boxes around the place, doing useful jobs, and they
> all had Cygwin on
> them.? It would have crippled us if we suddenly had to
> upgrade them all one day.
>
> ? OTOH maybe we could hack up a software SSE emulation
> for those users...
>
> ? ? cheers,
> ? ? ? DaveK
>
Hi Dave,
I am trying to convince octave developers to add
an additional z1!=z2 before the comparison of
abs(z1) < abs(z2) and
arg(z1) < arg(z2).
This should resolve the truncation problem of arg and abs
when comparing two equal complex numbers.
Eventually I will add that only for cygwin,
it seems simpler than non standard arch settings
for the package.
Thanks
Marco