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SubjectRe: [PATCH] lib: string.c: A speed optimized for strncpy
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On Sun, 2014-10-05 at 15:29 +0200, Rickard Strandqvist wrote:
> This variant is in my tests about 7-10% faster, and also think
> it is perhaps even clearer code than before.
[]
> diff --git a/lib/string.c b/lib/string.c
[]
> @@ -123,12 +123,12 @@ char *strncpy(char *dest, const char *src, size_t count)
> {
> char *tmp = dest;
>
> - while (count) {
> - if ((*tmp = *src) != 0)
> - src++;
> - tmp++;
> - count--;
> - }
> + while (count && (*tmp++ = *src++))
> + --count;
> +
> + while (count--)
> + *tmp++ = '\0';

Perhaps it could be faster to use memset.
It might depend on the value of count.

{
while (count && (*tmp++ = *src++))
count--;

if (count > 0)
memset(tmp, 0, count);
}



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