Combining unary and increment/decrement operators

Some tools allow combinations of unary operators with increment/decrement operators (for example, ~retries++), while others reject this syntax. This combination is not standard-compliant and is not portable across simulators.

Sigasi reports this portability issue as a warning (rule 175).

module test;
    int retries = 3;

    always begin
        if (~retries--) begin
            $display("retry");
        end else begin
            $finish;
        end
    end
endmodule

To resolve this issue, add parentheses so the increment/decrement operation is explicitly applied first.

module test;
    int retries = 3;

    always begin
        if (~(retries--)) begin
            $display("retry");
        end else begin
            $finish;
        end
    end
endmodule

Rule configuration

This rule can be disabled for your project, or its severity and parameters can be modified in the project linting settings. Alternatively, it can be manually configured with the following template:

175/severity/${path}={error|warning|info|ignore}