On Freitag, 15. Dezember 2017 15:04:49 CET Lubomir I. Ivanov wrote: > On 15 December 2017 at 11:24, Berthold Stoeger > > <bstoe...@mail.tuwien.ac.at> wrote: > > On Mittwoch, 13. Dezember 2017 23:34:32 CET Dirk Hohndel wrote: > >> > On Dec 13, 2017, at 11:31 AM, Berthold Stoeger > > > > Concerning the float warning, I have a patch that turns all float > > calculations into double calculations sitting around for a few weeks. I > > think float is like short: only to be used in very specific > > circumstances. But I'll let the pros decide. > > i would post the patch as a PR. > 'float' is more like 'int' (32bit), so it's good to have a small data > type with less precision and not always rely on 'double' or (64bit > long).
From a bit-representation point of view, this is correct. From a more abstract language point of view I rather get the impression that - short ~ float - int ~ double - long ~ long double - long long ~ unsupported (is your FP algorithm numerically unstable?) The reason being that floating point literals (e.g. 1.0) represent doubles. You have to actively force single-precision floating point calculations by writing things like "x * 1000.0f". > as a rule of thumb on the "double vs float" topic: > - the compiler *should* SSE-optimize a range of floats more easily > - in terms of speed and the x87, it shouldn't matter that much > - floats take less space in memory Sure, but that's also arguments that apply to short vs. int. That's what I meant with specific circumstances. Berthold _______________________________________________ subsurface mailing list subsurface@subsurface-divelog.org http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface
