Current PRE methods insert an expression e at point p only if all control flow paths emanating from p must evaluate e before any operands of e are redefined. The expression is said to be anticipable at point p. [0]

[0] Horspool, R. Nigel, and H. C. Ho. “Partial redundancy elimination driven by a cost-benefit analysis.” Computer Systems and Software Engineering, 1997., Proceedings of the Eighth Israeli Conference on. IEEE, 1997.