[Mesa-dev] [PATCH 1/3] util: Cope with LONG_BIT not being defined on Windows.

[Matt Turner]

On Sun, Aug 9, 2015 at 3:57 AM, Jose Fonseca <jfonseca at vmware.com> wrote:
> Neither MSVC nor MinGW defines LONG_BIT.  For MSVC this was not a problem as
> it doesn't define __x86_64__ macro (it's GCC specific.)
>
> However on Windows long type is guaranteed to be 32bits.
>
> Also add an #error, as GCC will just warn, not throw any error, when no
> value is returned.
>
> Trivial.
> ---
>  src/util/rounding.h | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/src/util/rounding.h b/src/util/rounding.h
> index b0c9918..ec31b47 100644
> --- a/src/util/rounding.h
> +++ b/src/util/rounding.h
> @@ -96,8 +96,10 @@ _mesa_lroundevenf(float x)
>  #ifdef __x86_64__
>  #if LONG_BIT == 64
>     return _mm_cvtss_si64(_mm_load_ss(&x));
> -#elif LONG_BIT == 32
> +#elif LONG_BIT == 32 || defined(_WIN32)

Not clear to me that you want to do this, since on x86-32 using SSE
intrinsics will force a few memory transfers to and from the x87 FPU.

>     return _mm_cvtss_si32(_mm_load_ss(&x));
> +#else
> +#error "Unsupported or undefined LONG_BIT"

MSVC... sigh.