# test: acceptable for output IOFF promotion
read_verilog <<EOF
module top (input clk, input a, output reg o);
    always @(posedge clk) begin
        o <= ~a;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 1 t:dff

design -reset
# test: acceptable for output IOFF promotion
read_verilog <<EOF
module top (input clk, input [3:0] a, output reg [3:0] o);
    always @(posedge clk) begin
        o <= ~a;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 4 t:dff

design -reset
# test: acceptable for output IOFF promotion; duplicate output FF
read_verilog <<EOF
module top (input clk, input [3:0] a, output [3:0] o, output [3:0] p);
    reg [3:0] r;
    always @(posedge clk) begin
        r <= ~a;
    end
    assign o = r;
    assign p = r;
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 8 t:dff

design -reset
# test: acceptable for input IOFF promotion
read_verilog <<EOF
module top (input clk, input a, output o);
    reg r;
    always @(posedge clk) begin
        r <= a;
    end
    assign o = ~r;
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 1 t:dff

design -reset
# test: acceptable for input IOFF promotion
read_verilog <<EOF
module top (input clk, input [3:0] a, output [3:0] o);
    reg [3:0] r;
    always @(posedge clk) begin
        r <= a;
    end
    assign o = ~r;
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 4 t:dff

design -reset
# test: acceptable for either IOFF promotion
read_verilog <<EOF
module top (input clk, input a, output reg o);
    always @(posedge clk) begin
        o <= a;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 1 t:dff

design -reset
# test: not acceptable for output IOFF promotion: output signal is used
read_verilog <<EOF
module top (input clk, input a, output reg o);
    always @(posedge clk) begin
        o <= ~a | o;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 0 t:dff

design -reset
# test: not acceptable for output IOFF promotion: output signal is used
read_verilog <<EOF
module top (input clk, input [3:0] a, output reg [3:0] o);
    always @(posedge clk) begin
        o <= ~a | o;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 0 t:dff

design -reset
# test: not acceptable for input IOFF promotion: input signal is used
read_verilog <<EOF
module top (input clk, input a, output o, p);
    reg r;
    always @(posedge clk) begin
        r <= a;
    end
    assign o = ~r;
    assign p = ~a;
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 0 t:dff

design -reset
# test: not acceptable for input IOFF promotion: input signal is used
read_verilog <<EOF
module top (input clk, input [3:0] a, output [3:0] o, output [3:0] p);
    reg [3:0] r;
    always @(posedge clk) begin
        r <= a;
    end
    assign o = ~r;
    assign p = ~a;
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 0 t:dff

design -reset
# test: not acceptable for IOFF promotion: FF has reset
read_verilog <<EOF
module top (input clk, input rst, input a, output reg o);
    always @(posedge clk) begin
        if (rst)
            o <= 1'b0;
        else
            o <= a;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 0 t:dff

design -reset
# test: not acceptable for IOFF promotion: FF has reset
read_verilog <<EOF
module top (input clk, input rst, input [3:0] a, output reg [3:0] o);
    always @(posedge clk) begin
        if (rst)
            o <= 4'b0;
        else
            o <= a;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 0 t:dff

design -reset
# test: not acceptable for IOFF promotion: FF has enable
read_verilog <<EOF
module top (input clk, input en, input a, output reg o);
    always @(posedge clk) begin
        if (en)
            o <= a;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 0 t:dff

design -reset
# test: not acceptable for IOFF promotion: FF has enable
read_verilog <<EOF
module top (input clk, input en, input [3:0] a, output reg [3:0] o);
    always @(posedge clk) begin
        if (en)
            o <= a;
    end
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 0 t:dff

design -reset
# test: duplicate registers driving multiple output ports
read_verilog <<EOF
module top (
    input clk,
    input en,
    input [3:0] a,
    output reg [3:0] o_1,
	output wire [3:0] o_2
);
always @(posedge clk) begin
    o_1[1:0] <= ~a[1:0];
    if (en)
        o_1[2] <= a[2];
end
always @(*) o_1[3] = a[3];
assign o_2 = o_1;
endmodule
EOF
synth_quicklogic -family qlf_k6n10f -top top
select -assert-count 4 t:dff