Re: [RFC PATCH 3/4] sh: define __BIG_ENDIAN for math-emu

From: Geert Uytterhoeven
Date: Thu Jun 03 2021 - 03:54:14 EST


Hi Randy,

On Thu, Jun 3, 2021 at 1:17 AM Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:
> The headers in include/math-emu/ test for __BYTE_ORDER == __BIG_ENDIAN
> without checking to see if these macros are defined, so add
> a define for __BIG_ENDIAN before pulling in these headers.
>
> This placates these build warnings:
>
> In file included from ../arch/sh/math-emu/math.c:23:
> ../include/math-emu/single.h:50:21: warning: "__BIG_ENDIAN" is not defined, evaluates to 0 [-Wundef]
> 50 | #if __BYTE_ORDER == __BIG_ENDIAN
> In file included from ../arch/sh/math-emu/math.c:24:
> ../include/math-emu/double.h:59:21: warning: "__BIG_ENDIAN" is not defined, evaluates to 0 [-Wundef]
> 59 | #if __BYTE_ORDER == __BIG_ENDIAN
>
> Fixes: 4b565680d163 ("sh: math-emu support")
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

Thanks for your patch!

> --- linux-next-20210528.orig/arch/sh/math-emu/sfp-util.h
> +++ linux-next-20210528/arch/sh/math-emu/sfp-util.h
> @@ -70,4 +70,4 @@
>
> #define __BYTE_ORDER __LITTLE_ENDIAN
>
> -
> +#define __BIG_ENDIAN 0

I don't think this is the right fix.

I think the right values should be picked up from:

include/uapi/linux/byteorder/big_endian.h:#define __BIG_ENDIAN 4321
include/uapi/linux/byteorder/little_endian.h:#define __LITTLE_ENDIAN 1234

How is this picked up on other architectures using <math-emu/single.h>?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds