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Re: Refine documentation of libm exceptions goals [committed]
- From: Joseph Myers <joseph at codesourcery dot com>
- To: Szabolcs Nagy <nsz at port70 dot net>
- Cc: <libc-alpha at sourceware dot org>
- Date: Wed, 18 Feb 2015 17:25:38 +0000
- Subject: Re: Refine documentation of libm exceptions goals [committed]
- Authentication-results: sourceware.org; auth=none
- References: <alpine dot DEB dot 2 dot 10 dot 1502172341550 dot 26150 at digraph dot polyomino dot org dot uk> <20150218164730 dot GQ32724 at port70 dot net>
On Wed, 18 Feb 2015, Szabolcs Nagy wrote:
> this is an interesting issue because iso c annex f forbids the
> omission of underflow right now, which is hard to achive unless
> libm checks <= DBL_MIN instead of the sensible < DBL_MIN and
> raises spurious underflow for a lot of exact (or non-tiny) DBL_MIN
> results (which is allowed by the standard)
I don't believe it forbids computing an imprecise result that happens to
be (exactly) DBL_MIN or more, and so doesn't underflow.
--
Joseph S. Myers
joseph@codesourcery.com