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open Netlist_gen
let rec rep n k =
if n = 1 then k
else
let s = rep (n/2) k in
if n mod 2 = 0 then s ++ s else s ++ s ++ k
let rec eq_c n v c = (* v is a value, c is a constant *)
if n = 1 then
if c = 1 then v else not v
else
(eq_c 1 (v ** 0) (c mod 2)) ^& (eq_c (n-1) (v % (1, n-1)) (c/2))
let rec sign_extend n_a n_dest a =
a ++ rep (n_dest - n_a) (a ** (n_a - 1))
let fulladder a b c =
let s = a ^^ b ^^ c in
let r = (a ^& b) ^| ((a ^^ b) ^& c) in
s, r
let rec nadder n a b c_in =
if n = 1 then fulladder a b c_in
else
let s_n, c_n1 = fulladder (a ** 0) (b ** 0) c_in in
let s_n1, c_out = nadder (n-1) (a % (1, n-1)) (b % (1, n-1)) c_n1 in
s_n ++ s_n1, c_out
let nadder_nocarry n a b =
let a, b = nadder n a b (const "0") in
ignore b a
let rec eq_n n a b =
if n = 1 then
not (a ^^ b)
else
(not ((a ** 0) ^^ (b ** 0)))
^& (eq_n (n-1) (a % (1, n-1)) (b % (1, n-1)))
let rec ne_n n a b =
if n = 1 then
a ^^ b
else
((a ** 0) ^^ (b ** 0))
^| (ne_n (n-1) (a % (1, n-1)) (b % (1, n-1)))
let rec lt_n n a b =
const "0" (* TODO : less than *)
let rec ult_n n a b =
const "0" (* TODO : less than, unsigned *)
let rec le_n n a b =
const "0" (* TODO : less than or equal *)
let rec ule_n n a b =
const "0" (* TODO : less than or equal, unsigned *)
let alu_comparer n f0 f a b =
(*
f0 f action
-- - ------
0 0 equal
0 1 not equal
0 2 equal
0 3 not equal
1 0 lt
1 1 le
1 2 lt unsigned
1 3 le unsigned
*)
let eq_ne = mux (f ** 0) (eq_n n a b) (ne_n n a b) in
let lte_signed = mux (f ** 0) (lt_n n a b) (le_n n a b) in
let lte_unsigned = mux (f ** 0) (ult_n n a b) (ule_n n a b) in
let lte = mux (f ** 1) lte_signed lte_unsigned in
mux f0 eq_ne lte
|
