in SocketRocket/Internal/Utilities/SRSIMDHelpers.m [28:39]
static uint8x32_t SRShiftVector(uint8x32_t vector, size_t by) {
uint8x32_t vectorCopy = vector;
by = by % _Alignof(uint8x32_t);
uint8_t *vectorPointer = (uint8_t *)&vector;
uint8_t *vectorCopyPointer = (uint8_t *)&vectorCopy;
memmove(vectorPointer + by, vectorPointer, sizeof(vector) - by);
memcpy(vectorPointer, vectorCopyPointer + (sizeof(vector) - by), by);
return vector;
}