1. A method to align poly features within chain sets in an integrated circuit layout design stored in a non-transitory computer readable storage device comprising: vertically aligning a first poly feature of a first pcell instance in a first chain set with a second poly feature of a second pcell instance in a second chain set; configuring a computer to, starting with the aligned first and second poly features, successively determine multiple changed poly feature spacing values associated with at least one of the first and second pcell instances to align successive poly features in chain order in a first horizontal direction; and assigning each respective determined changed poly feature spacing value to its associated first or second pcell instance.