Re: "A diagram of C23 basic types"

Lawrence D'Oliveiro <ldo@nz.invalid> writes:

On Mon, 28 Apr 2025 16:27:38 +0300, Michael S wrote:

IMHO, a need for a common name for IEEE binary128 exists for quite some
time. For IEEE binary256 the real need didn't emerge yet. But it will
emerge in the hopefully near future.

>
A thought: the main advantage of binary types over decimal is supposed to
be speed. Once you get up to larger precisions like that, the speed
advantage becomes less clear, particularly since hardware support doesn’t
seem forthcoming any time soon. There are already variable-precision
decimal floating-point libraries available. And with such calculations, C
no longer offers a great performance advantage over a higher-level
language, so you might as well use the higher-level language.
>
<https://docs.python.org/3/library/decimal.html>

I think there's an implicit assumption that, all else being equal,
decimal is better than binary.  That's true in some contexts,
but not in all.

If you're performing calculations on physical quantities, decimal
probably has no particular advantages, and binary is likely to be
more efficient in both time and space.

The advantagers of decimal show up if you're formatting a *lot*
of numbers in human-readable form (but nobody has time to read a
billion numbers), or if you're working with money.  But for financial
calculations, particularly compound interest, there are likely to
be precise regulations about how to round results.  A given decimal
floating-point format might or might not satisfy those regulations.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */