sumLanePartial method
Sum part of the lane, until size
.
Implementation
int sumLanePartial(int size) {
switch (size) {
case 1:
return x;
case 2:
return x + y;
case 3:
return x + y + z;
case 4:
return x + y + z + w;
default:
throw StateError('Invalid length: $size / 4');
}
}