METHOD AND SYSTEM OF EXPANDING SET OF STANDARD CELLS WHICH COMPRISE A LIBRARY

A method includes: identifying ad hoc groups of elementary standard cells recurrent in a layout diagram; and selecting one group (selected group) of the recurrent ad hoc groups such that: the cells in the selected group have connections representing a corresponding logic circuit; each cell representing a logic gate; each ad hoc group has a number of transistors and a first number of logic gates; and the selected group providing a logical function. The method includes generating one or more macro standard cells such that: each macro standard cell has a number of transistors which is smaller than the number of transistors of a corresponding ad hoc group; or each macro standard cell has a second number of logic gates different than the first number of logic gates of the corresponding ad hoc group. The method also includes adding macro standard cells to the set of standard cells.