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Date:      Wed, 05 Jan 2000 13:36:29 -0800
From:      "Ronald F. Guilmette" <rfg@monkeys.com>
To:        Markus Holmberg <saska@acc.umu.se>
Cc:        Martin Cracauer <cracauer@cons.org>, freebsd-hackers@FreeBSD.ORG
Subject:   Re: Should -mieee-fp equal fpsetmask(0) to avoid SIGFPE on FreeBSD? 
Message-ID:  <2604.947108189@monkeys.com>
In-Reply-To: Your message of Wed, 05 Jan 2000 22:02:18 %2B0100. <20000105220218.A77259@fysgr387.sn.umu.se> 

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In message <20000105220218.A77259@fysgr387.sn.umu.se>, you wrote:

>But I'm not sure I understand the difference between "undefined" and
>"unspecified"? (What a cast from double to int should return when the source
>doesn't fit into the destination).

The C standard talks about "undefined behavior", and when it does, that
means that *aynthing* goes.  When you get into a undefined behavior
situation, it's a lot like being catapulted into the 11th dimension...
time may flow sideways, whales may fall from the sky, and your CPU may
suddenly revert to 4004 compatibility mode. :-)  We're talking about
quantum level uncertainty, multiplied by a googleplex.

On the other hand, the word "unspecified" is usually use in conjunction
with the word "value", as in ``... and unspecified value in the range
INT_MIN .. INT_MAX''.  This is a far more constrained type of uncertainty.

>I'm about to give up on this.. For some (to me) unclear reason there are
>no intentions on making FreeBSD behave conforming to IEEE 754...

I hope that isn't true.  _I_ certainly haven't yet given up hope that
someone will do the Right Thing and disable all IEEE traps before entry
to main().

>... and it's not clear if the Mozilla code is correct or not.

It isn't.



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