Verilator

Verilator generates incorrect code for the comparison

~a[m:0] == 0

where the total width of "a" is larger than m. The comparison in the following example

module select_invert(input logic clk, input logic [15:0] a);
    always @(posedge clk) begin
        if ((~a[5:0] == 0) == 0) begin
            $write("[%0t] %%Error: t_select_invert: failed\n", $time);
            $stop;
        end
    end
endmodule

should produce the value 1 when a is 0xffff. However, it produces the value 0.

An example in the verilator test_regress style is attached.