[PATCH RFC libdrm 1/2] intel: Improve checks for big-endian

[Robin Murphy]

On 2022-03-07 20:53, Geert Uytterhoeven wrote:
>    - sparc64-linux-gnu-gcc does not define __BIG_ENDIAN__ or SPARC, but
>      does define __sparc__, hence replace the check for SPARC by a check
>      for __sparc__,
>    - powerpc{,64,64}-linux-gnu-gcc does not define __ppc__ or __ppc64__,
>      but does define __BIG_ENDIAN__.
>      powerpc64le-linux-gnu-gcc does not define __ppc__ or __ppc64__, but
>      does define __LITTLE_ENDIAN__.
>      Hence remove the checks for __ppc__ and __ppc64__.
>    - mips{,64}-linux-gnu{,abi64}-gcc does not define __BIG_ENDIAN__, but
>      does define __MIPSEB__, so add a check for the latter,
>    - m68k-linux-gnu-gcc does not define __BIG_ENDIAN__, but does define
>      __mc68000__, so add a check for the latter,
>    - hppa{,64}-linux-gnu-gcc defines __BIG_ENDIAN__, and thus should work
>      out-of-the-box.

FWIW there's also __ARM_BIG_ENDIAN for arm-* and aarch64-* targets in BE 
mode, if you want to flesh out the list even more. In principle there's 
also "__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__" which should supposedly be 
consistent across platforms, but I don't know if that's even more of a 
specific GCC-ism.

Robin.

> Signed-off-by: Geert Uytterhoeven <geert at linux-m68k.org>
> ---
> Untested due to lack of hardware.
> ---
>   intel/uthash.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/intel/uthash.h b/intel/uthash.h
> index 45d1f9fc12a1d6f9..0f5480be6e8ca033 100644
> --- a/intel/uthash.h
> +++ b/intel/uthash.h
> @@ -648,7 +648,7 @@ do {
>   #define MUR_PLUS2_ALIGNED(p) (((unsigned long)p & 3UL) == 2UL)
>   #define MUR_PLUS3_ALIGNED(p) (((unsigned long)p & 3UL) == 3UL)
>   #define WP(p) ((uint32_t*)((unsigned long)(p) & ~3UL))
> -#if (defined(__BIG_ENDIAN__) || defined(SPARC) || defined(__ppc__) || defined(__ppc64__))
> +#if (defined(__BIG_ENDIAN__) || defined(__sparc__) || defined(__mc68000__) || defined(__MIPSEB__))
>   #define MUR_THREE_ONE(p) ((((*WP(p))&0x00ffffff) << 8) | (((*(WP(p)+1))&0xff000000) >> 24))
>   #define MUR_TWO_TWO(p)   ((((*WP(p))&0x0000ffff) <<16) | (((*(WP(p)+1))&0xffff0000) >> 16))
>   #define MUR_ONE_THREE(p) ((((*WP(p))&0x000000ff) <<24) | (((*(WP(p)+1))&0xffffff00) >>  8))