The 'can_reshape' parameter in Node::Ideal(PhaseGVN *phase, bool can_reshape) is redundant, as it is equivalent to phase->is_IterGVN() != NULL. It could be removed for clarity and to reflect that 'can_reshape' is, as of now, a property of 'phase' (true if and only if 'phase' is a PhaseIterGVN). Checks of 'can_reshape' could be replaced by checks of phase->is_IterGVN() != NULL, or by checks of a virtual method phase->can_reshape(). A draft of the latter idea is available here: https://github.com/openjdk/jdk/compare/master...robcasloz:igvn-cleanup. Introducing a virtual method phase->can_reshape(), as opposed to checking phase->is_IterGVN() != NULL, has the advantage that it preserves the intention to communicate what level of transformation is allowed on the graph.