Re: [PATCH 02/10] x86, asm: use bool for bitops and other assembly outputs

From: Ingo Molnar
Date: Wed Jun 08 2016 - 05:01:25 EST



* H. Peter Anvin <hpa@xxxxxxxxx> wrote:

> On 06/08/16 01:33, Ingo Molnar wrote:
> >
> > Note that this particular build error was introduced by b0bdba9825fe, a later
> > patch in this series - but in generaly I'm uneasy about allowing function
> > signatures diverge between architectures.
> >
>
> For the bitops, they already do: PowerPC, for example, have "unsigned
> long" in places where x86 has "int". This is obviously undesirable, but
> apparently we have not found it enough of a problem to deal with.
>
> One could easily argue the ppc definition is the better one; I was myself
> considering promoting the x86 side to "long" to handle enormous bitmaps. At the
> same time, it is hard to avoid the fact that ppc has unsigned bitops operations
> and x86 has signed ones when they are both native instructions.

That's a divergence with an underlying reason - but not harmonizing the return
code is an unforced error AFAICS and can be fixed.

Thanks,

Ingo