in sample-code/hwcaps-test.c [19:31]
uint64_t sum_all_sve2(uint32_t *values, int length)
{
svuint64_t sum = svdup_u64(0);
int i = 0;
svbool_t predicate = svwhilelt_b32(i, length);
do {
svuint32_t a = svld1(predicate, (uint32_t *) &values[i]);
sum = svadalp_u64_x(predicate, sum, a);
i += svcntw();
predicate = svwhilelt_b32(i, length);
} while (svptest_any(svptrue_b32(), predicate));
return svaddv_u64(svptrue_b64(), sum);
}