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Re: [wg14/wg21 liaison] Comments on P2569 *_HAS_SUBNORM==0 implies what?

From: Fred J. Tydeman <tydeman_at_[hidden]>
Date: Mon, 21 Mar 2022 08:38:52 -0700 (PDT)
On Mon, 21 Mar 2022 07:04:52 -0700 (PDT) Fred J. Tydeman wrote:
>It appears that neither standard can give those a useful value if the treatment
>of subnormals can be changed at runtime (as can be done on ARM chips).
>They also do not cover the two case where:
> operands are flushed to zero, but results are not flushed.
> results are flushed, but operands are not flushed.

I forgot about the case where most operations flush subnormals to zero,
but there are some operations that do NOT flush.

>C implementations should define the macros as: -1 indeterminable.
>C++ implementations should define as: denorm_indeterminate
>While that is the correct value, it is not useful.


Fred J. Tydeman        Tydeman Consulting
tydeman_at_[hidden]      Testing, numerics, programming
+1 (702) 608-6093      Vice-chair of PL22.11 (ANSI "C")
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Received on 2022-03-21 16:38:56