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Re: iso c9x unordered fp cmp builtins
- To: egcs at cygnus dot com
- Subject: Re: iso c9x unordered fp cmp builtins
- From: Ulrich Drepper <drepper at cygnus dot com>
- Date: 02 Mar 1998 12:58:37 -0800
- Newsgroups: cygnus.egcs
- Organization: Cygnus Solutions
- References: <19980301213842.10263@dot.cygnus.com>, <9803020551.AA24480.cygnus.egcs@rios1.watson.ibm.com>
- Reply-To: drepper at cygnus dot com (Ulrich Drepper)
dje@watson.ibm.com (David Edelsohn) writes:
> The "rs6000" port always has used fcmpu and never has signal QNaN.
> This also is the behavior of IBM's XLC. Does iso9x now mandate that the
> regular comparison operators signal QNaN?
IEEE 754 and 854 demand this behaviour since the ISO C operators
== != < <= > >=
are mapped to the IEEE 754 operators (table 4)
= ?<> < <= > >=
ISO C 9x defines new functions
isunordered isless islessequal isgreater isgreaterequal islessgreater
which are mapped to the IEEE 754 operators
? ?< ?<= ?> ?>= NOT(?)
-- Uli
---------------. drepper at gnu.org ,-. 1325 Chesapeake Terrace
Ulrich Drepper \ ,-------------------' \ Sunnyvale, CA 94089 USA
Cygnus Solutions `--' drepper at cygnus.com `------------------------