1. A method for reducing X-pessimism, the method comprising: identifying a set of reconvergent inputs of a combinational block in a gate-level design; and in response to determining that the combinational block is expected to exhibit X-pessimism during gate-level simulation, adding, by computer, a correcting block to the gate-level design, wherein an output of the combinational block or the correcting block is selected based on the values of the set of reconvergent inputs.