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From: leipold@eplrx7.uucp (Walt Leipold)
Newsgroups: comp.lang.fortran
Subject: Re: Uses for EQUIVALENCE
Message-ID: <1991Jun7.171357.3941@eplrx7.uucp>
Date: 7 Jun 91 17:13:57 GMT
References: <1991Jun1.171914.802@weyrich.UUCP> <1991Jun5.220805.4653@alchemy.chem.utoronto.ca> <1991Jun6.232026.10172@jato.jpl.nasa.gov>
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In article <1991Jun6.232026.10172@jato.jpl.nasa.gov> Van Snyder writes:
>I'd also be surprised if you could use EQUIVALENCE to discover the round-
>off level or the overflow or underflow limits.  Mike Malcolm wrote some
>routines to compute such things a long time ago.  Or you could get the
>routines R1MACH, D1MACH and I1MACH from Netlib.

Is anyone else bothered by D1MACH et al?  I mean, talk about gratuitously
non-portable code...  Why did the author use EQUIVALENCEd hex constants?
Was it to get more precision in specifying a floating point value than he
could get by writing a floating point constant?  If so, how would you print
one of these values, and what does that say about the state of the art in
FORTRAN compilers (and their users)?  And why do I have to ask for each
constant by number (1..5), instead of having a separate function (e.g.,
EPS(), HUGE()) for each constant?  And why aren't functions like this part
of X3.9-1978, so I can write portable numerical code?  Or (the real $64K
question) are these functions included in the long-expected and oft-delayed 
FORTRAN 90?

[Whew... I feel better now...]

-- 
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"As long as you've lit one candle,                            Walt Leipold
you're allowed to curse the darkness."          (leipolw%esvax@dupont.com)
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