On Tue, 28 Feb 2017, Matt Redfearn wrote:
> diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
> index 5b1e932ae973..6ba5b775579c 100644
> --- a/arch/mips/kernel/process.c
> +++ b/arch/mips/kernel/process.c
> @@ -386,8 +386,9 @@ static int get_frame_info(struct mips_frame_info *info)
>
> if (ip->halfword[0] & mm_addiusp_func)
> {
> - tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2);
> - info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0));
> + tmp = (ip->halfword[0] >> 1) & 0x1ff;
> + tmp = tmp | ((tmp & 0x100) ? 0xfe00 : 0);
> + info->frame_size = -(signed short)(tmp << 2);
Ugh, this is unreadable -- can you please figure out a way to fit it in
79 columns? Perhaps by factoring this piece out?
Also this:
tmp = (ip->halfword[0] >> 1) & 0x1ff;
tmp = tmp | ((tmp & 0x100) ? 0xfe00 : 0);
will likely result in better code without the conditional, e.g.:
tmp = (((ip->halfword[0] >> 1) & 0x1ff) ^ 0x100) - 0x100;
(the usual way to sign-extend).
Maciej
