diff --git a/hw/arith/lib/add_bk8.v b/hw/arith/lib/add_bk8.v
index 1ef80593cc8f88c3bf1e3801699875e0b5c4d089..8134f18f877f78016cf5073e3cc49b696866894a 100644
--- a/hw/arith/lib/add_bk8.v
+++ b/hw/arith/lib/add_bk8.v
@@ -14,47 +14,6 @@
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-/* 8-bit Brent-Kung adder, with inputs g0 = x & y, p0 = x ^ y */
-module add_bk8x (input [7:0] g0, input [7:0] p0, input cin,
- output [8:0] s);
- wire [3:0] g1; /* 7, 5, 3, 1, */
- wire [3:0] p1; /* 7, 5, 3, 1, */
- wire [1:0] g2; /* 7, 3, */
- wire [1:0] p2; /* 7, 3, */
- wire [1:0] g3; /* 7, 5, */
- wire [1:0] p3; /* 7, 5, */
- wire [2:0] g4; /* 6, 4, 2 */
- wire [2:0] p4; /* 6, 4, 2 */
- reg [7:0] G;
- reg [7:0] P;
- reg [7:0] c;
-
- add_gp d0 (g0[1], p0[1], g0[0], p0[0], g1[0], p1[0]);
- add_gp d1 (g0[3], p0[3], g0[2], p0[2], g1[1], p1[1]);
- add_gp d2 (g0[5], p0[5], g0[4], p0[4], g1[2], p1[2]);
- add_gp d3 (g0[7], p0[7], g0[6], p0[6], g1[3], p1[3]);
-
- add_gp d4 (g1[1], p1[1], g1[0], p1[0], g2[0], p2[0]);
- add_gp d5 (g1[3], p1[3], g1[2], p1[2], g2[1], p2[1]);
-
- add_gp d6 (g1[2], p1[2], g2[0], p2[0], g3[0], p3[0]);
- add_gp d7 (g2[1], p2[1], g2[0], p2[0], g3[1], p3[1]);
-
- add_gp d8 (g0[2], p0[2], g1[0], p1[0], g4[0], p4[0]);
- add_gp d9 (g0[4], p0[4], g2[0], p2[0], g4[1], p4[1]);
- add_gp d10 (g0[6], p0[6], g3[0], p3[0], g4[2], p4[2]);
-
- always @(*) begin
- G = {g3[1], g4[2], g3[0], g4[1], g2[0], g4[0], g1[0], g0[0] };
- P = {p3[1], p4[2], p3[0], p4[1], p2[0], p4[0], p1[0], p0[0] };
-
- c = G | (P & {8{cin}});
- end
-
- assign s[7:0] = p0[7:0] ^ {c[6:0],cin};
- assign s[8] = c[7];
-endmodule
-
/* 8-bit Brent-Kung adder */
module add_bk8 (input [7:0] x, input [7:0] y, input cin,
output [8:0] s);
diff --git a/hw/arith/lib/add_bk8x.v b/hw/arith/lib/add_bk8x.v
new file mode 100644
index 0000000000000000000000000000000000000000..1bcf4adabdf30aedf1d5423a1ecde608b2c8c56c
--- /dev/null
+++ b/hw/arith/lib/add_bk8x.v
@@ -0,0 +1,56 @@
+/* Copyright (C) 2014, 2015, 2021 Niels Möller
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* 8-bit Brent-Kung adder, with inputs g0 = x & y, p0 = x ^ y */
+module add_bk8x (input [7:0] g0, input [7:0] p0, input cin,
+ output [8:0] s);
+ wire [3:0] g1; /* 7, 5, 3, 1, */
+ wire [3:0] p1; /* 7, 5, 3, 1, */
+ wire [1:0] g2; /* 7, 3, */
+ wire [1:0] p2; /* 7, 3, */
+ wire [1:0] g3; /* 7, 5, */
+ wire [1:0] p3; /* 7, 5, */
+ wire [2:0] g4; /* 6, 4, 2 */
+ wire [2:0] p4; /* 6, 4, 2 */
+ reg [7:0] G;
+ reg [7:0] P;
+ reg [7:0] c;
+
+ add_gp d0 (g0[1], p0[1], g0[0], p0[0], g1[0], p1[0]);
+ add_gp d1 (g0[3], p0[3], g0[2], p0[2], g1[1], p1[1]);
+ add_gp d2 (g0[5], p0[5], g0[4], p0[4], g1[2], p1[2]);
+ add_gp d3 (g0[7], p0[7], g0[6], p0[6], g1[3], p1[3]);
+
+ add_gp d4 (g1[1], p1[1], g1[0], p1[0], g2[0], p2[0]);
+ add_gp d5 (g1[3], p1[3], g1[2], p1[2], g2[1], p2[1]);
+
+ add_gp d6 (g1[2], p1[2], g2[0], p2[0], g3[0], p3[0]);
+ add_gp d7 (g2[1], p2[1], g2[0], p2[0], g3[1], p3[1]);
+
+ add_gp d8 (g0[2], p0[2], g1[0], p1[0], g4[0], p4[0]);
+ add_gp d9 (g0[4], p0[4], g2[0], p2[0], g4[1], p4[1]);
+ add_gp d10 (g0[6], p0[6], g3[0], p3[0], g4[2], p4[2]);
+
+ always @(*) begin
+ G = {g3[1], g4[2], g3[0], g4[1], g2[0], g4[0], g1[0], g0[0] };
+ P = {p3[1], p4[2], p3[0], p4[1], p2[0], p4[0], p1[0], p0[0] };
+
+ c = G | (P & {8{cin}});
+ end
+
+ assign s[7:0] = p0[7:0] ^ {c[6:0],cin};
+ assign s[8] = c[7];
+endmodule