On Fri, 2019-02-08 at 10:34 +0300, Alexey Dobriyan wrote:
> Space savings on x86_64:
>
> add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-29 (-29)
> Function old new delta
> strncmp 67 38 -29
>
> Space savings on arm:
>
> add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-60 (-60)
> Function old new delta
> strncmp 116 56 -60
[]
> --- a/lib/string.c
> +++ b/lib/string.c
> @@ -344,16 +344,14 @@ EXPORT_SYMBOL(strcmp);
> */
> int strncmp(const char *cs, const char *ct, size_t count)
> {
> - unsigned char c1, c2;
> + while (count--) {
> + unsigned int c1 = *(unsigned char *)cs++;
> + unsigned int c2 = *(unsigned char *)ct++;
>
> - while (count) {
> - c1 = *cs++;
> - c2 = *ct++;
> if (c1 != c2)
> - return c1 < c2 ? -1 : 1;
> + return c1 - c2;
This does change the return value for most comparisons.
Wasn't there a specific reason for -1 and 1?
