Re: [PATCH v2 7/8] qemu/bswap: Use compiler __builtin_bswap() on NetBSD

[Kamil Rytarowski]

On 29.09.2020 10:58, Peter Maydell wrote:
> On Mon, 28 Sep 2020 at 23:02, Kamil Rytarowski <kamil@netbsd.org> wrote:
>>
>> Personally, I prefer using the system headers. but if you want to use
>> the GCC builtins, please go for it.
> 
> I'd agree if the system header approach was cross-platform
> or if this was a BSD-only program or if we were aiming for
> complete compiler-implementation independence, but since we
> rely on GCC/clang all over the place already it seems nicer to
> avoid all the machinery for identifying which of the multiple
> different system header implementations is present, and
> instead just have a single implementation that works on
> all the hosts we care about...
> 

This is already a part of POSIX:

https://www.austingroupbugs.net/view.php?id=162

We have got everything needed from the standard now to implement bswap
without relying on compiler builtins. Every modern enough POSIX-like OS
already ships with <endian.h>.

> thanks
> -- PMM
>