Re: One more oddity with gcc and vax floats...

On 2026-06-10 19:21, Paul Koning wrote:
>=20
>=20
>> On Jun 10, 2026, at 12:33=E2=80=AFPM, Johnny Billquist <[email protected]=
> wrote:
>>
>> On 6/10/26 18:27, Mouse wrote:...
>>
>>> VAX float also doesn't have subnormals.
>>
>> Also true, but I think we could possibly ignore that one. Just as I th=
ink the rounding differences can be ignored, except for test programs tha=
t explicitly check for those.
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> Can you?  I know there are people who care about rounding modes.  Even =
the crazy "round to even" mode, what sort of drugs were involved in inven=
ting that one?

I think that's something done in financial circles.
But honestly, people who are into crazy specific math issues wouldn't be=20
trying to run things on a VAX to start with. So I do not expect that=20
anyone cares about those last few digits. But of course test software=20
will care, and the point of getting IEEE "compatibility" would be so=20
software works, so I guess we'd have to get that working.

> Then again, it may be people care because they think they should, even =
though in reality it doesn't matter.  If your code is sensitive to roundi=
ng it is skating far too close to the edge and either needs wider floats,=
or not use floats at all.  ("If you don't understand your problem well e=
nough to scale it to integers, you don't understand it well enough" -- vo=
n Neumann)

Indeed.

   Johnny

--=20
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: [email protected]             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol