Messages in this thread | | | Date | Wed, 8 Jun 2016 11:20:40 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 02/10] x86, asm: use bool for bitops and other assembly outputs |
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* H. Peter Anvin <hpa@zytor.com> wrote:
> On 06/08/16 02:01, Ingo Molnar wrote: > > > > That's a divergence with an underlying reason - but not harmonizing the return > > code is an unforced error AFAICS and can be fixed. > > > > Perhaps. It is also no real question that "bool" is the right return > type for a single bit. Changing that in all architectures at one time > is a major undertaking, however, and it seems to me that it would be > better to leave that to the respective architecture maintainers.
Yeah, so extrapolating from past performance in most cases that is really a shorthand for 'it will never happen' :-/
Also, unless I'm missing something it's not really 'hard' or dangerous per se to do that change for every architecture, just incredibly boring! ;-)
I'm not sure how much it matters though, given other asymmetries in the bitops API signatures - does anyone have any preferences?
> Perhaps I'm wrong, but I'd really like to avoid the upcasting to "int" > which isn't needed, because in my testing I find that it definitely > encourages gcc to generate poor code.
Yeah, absolutely. I hate 'bool' with a vengence but if 'int' generates worse code with modern compilers then I'm not going to argue for worse code. Would a 'char' return type be very weird?
Thanks,
Ingo
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