Placing complex function blocks on a programmable integrated circuit

A computer-implemented method of implementing a circuit design within an integrated circuit (IC) can include, within an undirected graph representing the circuit design comprising nodes and edges, wherein each node represents a complex function block (CFB) or a pre-placed component of the circuit design and each edge represents at least one connection linking a pair of CFBs of the circuit design, determining an edge weight for each edge. The CFBs can be initially placed and a distance between each pair of CFBs joined by an edge of the undirected graph can be calculated. The CFB placement can be annealed by minimizing a cost function that calculates, for each edge, a product of the edge weight and the distance between the pair of CFBs joined by the edge. The cost function also can sum the products for each edge. The CFB placement can be stored.