ecp5: Initial arith_map implementation

Signed-off-by: David Shah <davey1576@gmail.com>

3 files changed, 80 insertions, 6 deletions

diff --git a/techlibs/ecp5/Makefile.inc b/techlibs/ecp5/Makefile.inc
index e0900f8f4..9d3247347 100644
--- a/techlibs/ecp5/Makefile.inc
+++ b/techlibs/ecp5/Makefile.inc
@@ -5,3 +5,4 @@ $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/cells_map.v))
 $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/cells_sim.v))
 $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/drams_map.v))
 $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/dram.txt))
+$(eval $(call add_share_file,share/ecp5,techlibs/ecp5/arith_map.v))
diff --git a/techlibs/ecp5/arith_map.v b/techlibs/ecp5/arith_map.v
new file mode 100644
index 000000000..3c2b86deb
--- /dev/null
+++ b/techlibs/ecp5/arith_map.v
@@ -0,0 +1,78 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *  Copyright (C) 2018  David Shah <dave@ds0.me>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+(* techmap_celltype = "$alu" *)
+module _80_ecp5_alu (A, B, CI, BI, X, Y, CO);
+	parameter A_SIGNED = 0;
+	parameter B_SIGNED = 0;
+	parameter A_WIDTH = 1;
+	parameter B_WIDTH = 1;
+	parameter Y_WIDTH = 1;
+
+	input [A_WIDTH-1:0] A;
+	input [B_WIDTH-1:0] B;
+	output [Y_WIDTH-1:0] X, Y;
+
+	input CI, BI;
+	output [Y_WIDTH-1:0] CO;
+
+	wire _TECHMAP_FAIL_ = Y_WIDTH <= 2;
+
+	wire [Y_WIDTH-1:0] A_buf, B_buf;
+	\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
+	\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
+
+	function integer round_up2;
+		input integer N;
+		begin
+			round_up2 = ((N / 2) + 1) * 2;
+		end
+	endfunction
+
+	localparam Y_WIDTH2 = round_up2(Y_WIDTH);
+
+	wire [Y_WIDTH2-1:0] AA = A_buf;
+	wire [Y_WIDTH2-1:0] BB = BI ? ~B_buf : B_buf;
+	wire [Y_WIDTH2-1:0] C = {CO, CI};
+	wire [Y_WIDTH2-1:0] FCO;
+
+	genvar i;
+	generate for (i = 0; i < Y_WIDTH2; i = i + 2) begin:slice
+		CCU2C #(
+			.INIT0(16'b0110011010101010),
+			.INIT1(16'b0110011010101010),
+			.INJECT1_0(1'b0),
+			.INJECT1_1(1'b0)
+	   ) ccu2c_i (
+			.CIN(C[i]),
+			.A0(AA[i]), .B0(BB[i]), .C0(1'b0), .D0(1'b1),
+			.A1(AA[i+1]), .B1(BB[i]), .C1(1'b0), .D1(1'b1),
+			.S0(F0), .S1(F1),
+			.COUT(FCO[i])
+		);
+
+		assign CO[i] = (AA[i] && BB[i]) || (C[i] && (AA[i] || BB[i]));
+		if (i < Y_WIDTH)
+			assign CO[i+1] = FCO[i];
+
+	end endgenerate
+
+	assign X = AA ^ BB;
+endmodule
diff --git a/techlibs/ecp5/synth_ecp5.cc b/techlibs/ecp5/synth_ecp5.cc
index 219496738..86d2027de 100644
--- a/techlibs/ecp5/synth_ecp5.cc
+++ b/techlibs/ecp5/synth_ecp5.cc
@@ -236,15 +236,10 @@ struct SynthEcp5Pass : public ScriptPass
 			run("opt -fast -mux_undef -undriven -fine");
 			run("memory_map");
 			run("opt -undriven -fine");
-			//TODO
-#if 0
-			if (nocarry)
+			if (noccu2)
 				run("techmap");
 			else
 				run("techmap -map +/techmap.v -map +/ecp5/arith_map.v");
-#else
-				run("techmap");
-#endif
 			if (retime || help_mode)
 				run("abc -dff", "(only if -retime)");
 		}