* fold-const.c (fold_binary) <EQ_EXPR>:  Fold (~X & C) eq/ne 0 as
	(X & C) ne/eq 0, where C is a single bit, i.e. a power of two.
	Fold both "((X & C) ^ C) eq/ne 0" and "((X ^ C) & C) eq/ne 0"
	as (X & C) ne/eq 0.

	* gcc.dg/fold-eqandnot-1.c: New test case.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@111471 138bc75d-0d04-0410-961f-82ee72b054a4