xilinx_dffopt: Don't crash on missing IS_*_INVERTED.

The presence of IS_*_INVERTED on FD* cells follows Vivado, which
apparently has been decided by a dice roll.  Just assume false if the
parameter doesn't exist.

Fixes #2559.

1 files changed, 46 insertions, 0 deletions

diff --git a/tests/arch/xilinx/xilinx_dffopt.ys b/tests/arch/xilinx/xilinx_dffopt.ys
index 2c729832e..c09699411 100644
--- a/tests/arch/xilinx/xilinx_dffopt.ys
+++ b/tests/arch/xilinx/xilinx_dffopt.ys
@@ -223,3 +223,49 @@ select -assert-count 1 t:LUT2
 select -assert-none t:FDRSE t:LUT4 t:LUT2 %% t:* %D
 
 design -reset
+
+
+read_verilog << EOT
+
+// FDSE_1, mergeable CE and S, but CE only not worth it.
+
+module t0 (...);
+input wire clk;
+input wire [7:0] i;
+output wire [7:0] o;
+
+wire [7:0] tmp ;
+
+LUT2 #(.INIT(4'h6)) lut0 (.I0(i[0]), .I1(i[1]), .O(tmp[0]));
+LUT2 #(.INIT(4'h6)) lut1 (.I0(i[1]), .I1(i[2]), .O(tmp[1]));
+
+FDSE_1 ff (.D(tmp[0]), .CE(i[7]), .S(tmp[1]), .Q(o[0]));
+
+endmodule
+
+EOT
+
+read_verilog -lib +/xilinx/cells_sim.v
+design -save t0
+
+equiv_opt -blacklist xilinx_dffopt_blacklist.txt -assert -map +/xilinx/cells_sim.v xilinx_dffopt
+design -load postopt
+clean
+
+cd t0
+select -assert-count 1 t:FDSE_1
+select -assert-count 1 t:LUT5
+select -assert-none t:FDSE_1 t:LUT5 %% t:* %D
+
+design -load t0
+
+equiv_opt -blacklist xilinx_dffopt_blacklist.txt -assert -map +/xilinx/cells_sim.v xilinx_dffopt -lut4
+design -load postopt
+clean
+
+cd t0
+select -assert-count 1 t:FDSE_1
+select -assert-count 2 t:LUT2
+select -assert-none t:FDSE_1 t:LUT2 %% t:* %D
+
+design -reset