Local Change

• Local change is a special case of arbitrary change.
• One common reason for incremental modification to a program is optimizing compilation.
• Some clauses are replaced by optimized versions of those clauses.
• Changes from optimization are special in the sense that usually the answers to the modified clause do not change (local variants).
• Incremental analysis is essentially restricted to computing the new call patterns that these clauses generate.
• Local change algorithm is obtained from bottom-up deletion algorithm and is more efficient than arbitrary change.
• ``Local_change'' algorithm produces the same analysis results as non-incremental analysis.
• Useful for ``Optimize then Re-analyze cycle''.