`hex/math_basic.fj`¶

———- Basic Mathematics:

Macros¶

hex.add_count_bits — dst[:n] += src.#on-bits (between 0->4)
hex.count_bits — dst[:small_n] = x[:n].#on-bits
hex.inc1 — hex++ (if overflows - jump to carry1; else jump to carry0)
hex.inc — hex[:n]++
hex.dec1 — hex-- (if underflows - jump to borrow1; else jump to borrow0)
hex.dec — hex[:n]--
hex.neg — x[:n] = -x[:n]
hex.abs — x[:n] = |x[:n]| (two’s complement; the minimal value -2^(4n-1) stays itself)
hex.sign_extend — sign-extends hex[:signed_n] into hex[:full_n]

hex.inc.step — One nibble of a propagating increment: increment hex by 1; on overflow continue to the next nibble, else jump to end.

hex.dec.step — One nibble of a propagating decrement: decrement hex by 1; on underflow continue to the next nibble, else jump to end.