2 files changed, 24 insertions, 0 deletions
diff --git a/tests/opt/opt_ff.v b/tests/opt/opt_ff.v
new file mode 100644
index 000000000..a01b64b61
--- /dev/null
+++ b/tests/opt/opt_ff.v
@@ -0,0 +1,21 @@
+module top(
+    input clk,
+    input rst,
+    input [2:0] a,
+    output [1:0] b
+);
+    reg [2:0] b_reg;
+    initial begin
+        b_reg <= 3'b0;
+    end
+
+    assign b = b_reg[1:0];
+    always @(posedge clk or posedge rst) begin
+        if(rst) begin
+            b_reg <= 3'b0;
+        end else begin
+            b_reg <= a;
+        end
+    end
+endmodule
+
diff --git a/tests/opt/opt_ff.ys b/tests/opt/opt_ff.ys
new file mode 100644
index 000000000..704c7acf3
--- /dev/null
+++ b/tests/opt/opt_ff.ys
@@ -0,0 +1,3 @@
+read_verilog opt_ff.v
+synth_ice40
+ice40_unlut