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List:       netbsd-port-alpha
Subject:    Re: -mieee option
From:       Wada Tatsuaki <wada () faraday ! ee ! ibaraki ! ac ! jp>
Date:       1999-01-18 9:04:16
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> Now, alpha traps,
> whereas the others just get the wrong answer. That's because NetBSD/alpha
> starts out with all the IEEE exceptions enabled, even the ones you don't
> want like underflow. That's easy to fix: I'll do that now.
> 
> Since real numeric programs don't try to output (and rarely even _use_)
> DBL_MIN, the best advice for now is: don't do that in toy programs, either.

I have made this toy program (min.cc) to point out what makes the FP error when using \
a matrix library. The matrix library, which is newmat09, uses some constant like \
DBL_MIN, .. etc., that are defined in float.h.

BTW, the same code (min.cc) do run under a Linux Alpha on the same PC164 alpha box.

	Linux version 2.1.108 (root@alpha) (gcc version 2.8.1) #1 Mon Aug 3 
	16:56:08 JST 1998

	>g++ -v
	Reading specs from /usr/local/lib/gcc-lib/alphaev56-unknown-linux-gnu/
	egcs-2.91.57/specs gcc version egcs-2.91.57 19980901 (egcs-1.1 release)

	>g++ -o min min.cc
	> min
	2.22507e-308


> I'll post another note when I check in some updates for this. (And I promise
> it won't be this long. :-)

I really appreciate it! Thank you, Ross.


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