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Date:      Mon, 30 Jul 2012 08:27:06 +1000
From:      Peter Jeremy <peter@rulingia.com>
To:        freebsd-numerics@freebsd.org
Cc:        Diane Bruce <db@db.net>, Bruce Evans <brde@optusnet.com.au>, John Baldwin <jhb@freebsd.org>, David Chisnall <theraven@freebsd.org>, Stephen Montgomery-Smith <stephen@missouri.edu>, Bruce Evans <bde@freebsd.org>, Steve Kargl <sgk@troutmask.apl.washington.edu>, David Schultz <das@freebsd.org>, Warner Losh <imp@bsdimp.com>
Subject:   Re: Use of C99 extra long double math functions after r236148
Message-ID:  <20120729222706.GA29048@server.rulingia.com>
In-Reply-To: <50148F02.4020104@missouri.edu>
References:  <20120718123627.D1575@besplex.bde.org> <20120722121219.GC73662@server.rulingia.com> <500DAD41.5030104@missouri.edu> <20120724113214.G934@besplex.bde.org> <501204AD.30605@missouri.edu> <20120727032611.GB25690@server.rulingia.com> <20120728125824.GA26553@server.rulingia.com> <501460BB.30806@missouri.edu> <20120728231300.GA20741@server.rulingia.com> <50148F02.4020104@missouri.edu>

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[For anyone not previously in on this discussion, this is part of an
ongoing discussion that has been occurring off-list in the absence of
a suitable list.  It is planned to archive that discussion here,
subject to all the participants agreeing].

On 2012-Jul-28 20:16:50 -0500, Stephen Montgomery-Smith <stephen@missouri.e=
du> wrote:
>One thing your program doesn't check are things like:
>
>real part of casinh(-0+I*x) is -0
>imaginary part of casinh(x-I*0) is -0
>
>etc, where x is finite, non-zero.  (This follows from casinh being odd=20
>and conjugate invariant.)

As it currently exists, my program solely implements the checks in
WG14/N1256 G.6.  I hadn't considered extending that to verifying that
purely real or imaginary inputs give purely real or imaginary outputs,
with the appropriately signed zero.  This might be reasonable but it's
not completely trivial to implement in general since the domains of
the real part can be different.  I'm less sure of the next logical
step, which is to check things like
  casinh(x + I*0) =3D asinh(x) + I*0

--=20
Peter Jeremy

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