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Re: __builtin_cpow((0,0),(0,0))

From: Andrew Haley <aph at redhat dot com>
To: Robert Dewar <dewar at adacore dot com>
Cc: Paolo Carlini <pcarlini at suse dot de>, gcc at gcc dot gnu dot org, libstdc++ <libstdc++ at gcc dot gnu dot org>
Date: Mon, 7 Mar 2005 15:39:23 +0000
Subject: Re: __builtin_cpow((0,0),(0,0))
References: <422C63ED.8020200@suse.de><422C6C28.6070309@suse.de><422C6FF8.6020102@adacore.com>

Robert Dewar writes:
 > Paolo Carlini wrote:
 > 
 > > Actually, sorry, __builtin_cpow returns (nan, nan) (got
 > > sidetracked by a strange issue I'm seeing in the C++ library),
 > > even "worse", so to speak...
 > 
 > Well it certainly seems the right result in this case to me. Does
 > the standard really require the wrong result here?

F9.4.4 requires pow (x, 0) to return 1 for any x, even NaN.

The controversy about what 0^0 really should be is very old, and
apparently was the subject of a long flame war in the Nineteenth
century...

Andrew.

Follow-Ups:
- Re: __builtin_cpow((0,0),(0,0))
  - From: Paolo Carlini

References:
- __builtin_cpow((0,0),(0,0))
  - From: Paolo Carlini
- Re: __builtin_cpow((0,0),(0,0))
  - From: Paolo Carlini
- Re: __builtin_cpow((0,0),(0,0))
  - From: Robert Dewar

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