// There's no equivalent in libc, you'd think so ... std::mismatch exists, but it's not optimized at all. :(
static inline size_t find_change(const uint16_t * a, const uint16_t * b)
{
const __m128i * a128=(const __m128i*)a;
const __m128i * b128=(const __m128i*)b;
while (true)
{
__m128i v0 = _mm_loadu_si128(a128);
__m128i v1 = _mm_loadu_si128(b128);
__m128i c = _mm_cmpeq_epi32(v0, v1);
uint32_t mask = _mm_movemask_epi8(c);
a128++;
b128++;
__m128i v0b = _mm_loadu_si128(a128);
__m128i v1b = _mm_loadu_si128(b128);
__m128i cb = _mm_cmpeq_epi32(v0b, v1b);
uint32_t maskb = _mm_movemask_epi8(cb);
if (mask != 0xffff || maskb != 0xffff) // Something has changed, figure out where.
{
if (mask == 0xffff) mask=maskb;
else a128--;//ignore b128 since we'll return anyways
size_t ret=(((char*)a128-(char*)a) | (compat_ctz(~mask))) >> 1;
return (ret | (a[ret]==b[ret]));
}
a128++;
b128++;
}
}
static INLINE size_t find_change(const uint16_t *a, const uint16_t *b)
{
const __m128i *a128 = (const __m128i*)a;
const __m128i *b128 = (const __m128i*)b;
for (;;)
{
__m128i v0 = _mm_loadu_si128(a128);
__m128i v1 = _mm_loadu_si128(b128);
__m128i c = _mm_cmpeq_epi32(v0, v1);
uint32_t mask = _mm_movemask_epi8(c);
if (mask != 0xffff) /* Something has changed, figure out where. */
{
size_t ret = (((uint8_t*)a128 - (uint8_t*)a) |
(compat_ctz(~mask))) >> 1;
return ret | (a[ret] == b[ret]);
}
a128++;
b128++;
}
