`hex.add_mul` (arity 2)¶

res += x * dst + carry_dst — one shift-and-add (multiply-accumulate) step used by hex.mul. Reads/writes the global multiplication carry.

Signature¶

def add_mul res, x @ ret < .mul.dst, .add.dst, .mul.ret, .tables.res { ... }

Defined in hex/mul.fj — lines 8–16 (view on GitHub).

Complexity¶

Time: 5@+26
Space: 4@+52

See the complexity glossary for what @, w, dw, dbit, n mean.

Requires init¶

The following must be initialised before this macro is invoked:

hex.add.init (or hex.init)

Source¶

Click to view the macro body

def add_mul res, x @ ret < .mul.dst, .add.dst, .mul.ret, .tables.res {
    .xor .mul.dst+4, x
    .xor .add.dst, res
    wflip .mul.ret+w, ret, .mul.dst
    pad 4
  ret:  // meanwhile - make @+24 fj ops there
    wflip .mul.ret+w, ret
    .xor_zero res, .tables.res
}

Depends on¶

Next: hex.add_mul/4 →