[PATCH] lib/mpi: fix build with clang

[Arnd Bergmann]

On Thu, Apr 20, 2017 at 5:40 AM, Stefan Agner <stefan at agner.ch> wrote:
> Use just @ to denote comments which works with gcc and clang.
> Otherwise clang reports an escape sequence error:
>   error: invalid % escape in inline assembly string
>
> Use %0-%3 as operand references, this avoids:
>   error: invalid operand in inline asm: 'umull ${1:r}, ${0:r}, ${2:r}, ${3:r}'
>
> Also remove superfluous casts on output operands to avoid warnings
> such as:
>   warning: invalid use of a cast in an inline asm context requiring an l-value
>
> Signed-off-by: Stefan Agner <stefan at agner.ch>
> ---
> I checked the output of gcc with -S switch before and after this change,
> gcc generated the same assembly.

I've done a lot of build testing on a tree that contains a very similar patch.

Acked-by: Arnd Bergmann <arnd at arndb.de>