Draft: Change CaloCellID to denseIndex conversions to be SIMD friendly
- Avoid having too many
select()
(prefer boolean operations) - Use power of two widths so we can avoid integer division (which doesn't exist for avx2)
- Use unsigned overflows to reduce the number of comparisons in validity check
- Use a substractive check instead of an additive one
For SIMD version of validity check see https://godbolt.org/z/5KeY9Wdhf
Goes with Rec!2662
Edited by Arthur Marius Hennequin