On Thu, Jun 30, 2016 at 12:22:13AM +0800, zengzhao...@163.com wrote:
> --- a/lib/kstrtox.c
> +++ b/lib/kstrtox.c
> @@ -48,38 +48,26 @@ unsigned int _parse_integer(const char *s, unsigned int
> base, unsigned long long
> {
> unsigned long long res;
> unsigned int rv;
> - int overflow;
> + unsigned int overflow;
> + unsigned int val;
>
> res = 0;
> rv = 0;
> overflow = 0;
> - while (*s) {
> - unsigned int val;
> -
> - if ('0' <= *s && *s <= '9')
> - val = *s - '0';
> - else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f')
> - val = _tolower(*s) - 'a' + 10;
> - else
> - break;
> -
> - if (val >= base)
> - break;
> + while ((val = hex_to_bin(*s++)) < base) {
I hate this function. And it has a branch if your table patch doesn't
go it. And it is beartrap (unsigned int = -1 < base).
ACK *s++ bit, though. Should make code smaller in my experience.
Please, change to "unsigned char c; while ((c = *s++)".
This is about maximum code compression I can understand.
> /*
> * Check for overflow only if we are within range of
> * it in the max base we support (16)
> */
> if (unlikely(res & (~0ull << 60))) {
> if (res > div_u64(ULLONG_MAX - val, base))
> - overflow = 1;
> + overflow = KSTRTOX_OVERFLOW;
Just do |= KSTRTOX_OVERFLOW here directly, it is the leftmost bit.
> }
> res = res * base + val;
> rv++;
> - s++;
> }
> *p = res;
> - if (overflow)
> - rv |= KSTRTOX_OVERFLOW;
> + rv |= overflow;
> return rv;
> }
