Il 11/03/2013 16:24, Peter Lieven ha scritto:
>
>> How would that be different in your patch? But you can solve it by
>> making two >= loops, one checking for 4*BITS_PER_LONG and one checking
>> BITS_PER_LONG.
>
> This is what I have now:
>
> diff --git a/util/bitops.c b/util/bitops.c
> index e72237a..b0dc93f 100644
> --- a/util/bitops.c
> +++ b/util/bitops.c
> @@ -24,12 +24,13 @@ unsigned long find_next_bit(const unsigned long *addr,
> unsigned long size,
> const unsigned long *p = addr + BITOP_WORD(offset);
> unsigned long result = offset & ~(BITS_PER_LONG-1);
> unsigned long tmp;
> + unsigned long d0,d1,d2,d3;
>
> if (offset >= size) {
> return size;
> }
> size -= result;
> - offset %= BITS_PER_LONG;
> + offset &= (BITS_PER_LONG-1);
> if (offset) {
> tmp = *(p++);
> tmp &= (~0UL << offset);
> @@ -42,7 +43,19 @@ unsigned long find_next_bit(const unsigned long *addr,
> unsigned long size,
> size -= BITS_PER_LONG;
> result += BITS_PER_LONG;
> }
> - while (size & ~(BITS_PER_LONG-1)) {
> + while (size >= 4*BITS_PER_LONG) {
> + d0 = *p;
> + d1 = *(p+1);
> + d2 = *(p+2);
> + d3 = *(p+3);
> + if (d0 || d1 || d2 || d3) {
> + break;
> + }
> + p+=4;
> + result += 4*BITS_PER_LONG;
> + size -= 4*BITS_PER_LONG;
> + }
> + while (size >= BITS_PER_LONG) {
> if ((tmp = *(p++))) {
> goto found_middle;
> }
>
Minus the %= vs. &=,
Reviewed-by: Paolo Bonzini <[email protected]>
Perhaps:
tmp = *p;
d1 = *(p+1);
d2 = *(p+2);
d3 = *(p+3);
if (tmp) {
goto found_middle;
}
if (d1 || d2 || d3) {
break;
}
Paolo
