Critical circuit blocks are identified in a chip design layout, and are marked by a marker layer identifying a marked region. Multiplicate layers are generated for each critical circuit block within each marked region. Each multiplicate layer includes a different type of variant for each identified critical circuit block. The different types of variants correspond to different types of optimization goals to address different issues in circuit performance. Circuit simulation is performed with each type of variants in combination with adjacent circuit blocks as provided in original design. In each marked region, the results of the circuit simulations are evaluated to determine an optimal type among the variants. The optimal type is retained in each marked region, thereby providing a chip design layout in which various marked regions can include different types of variant circuit blocks to provide local circuit optimization.