* c-typeck.c (c_tree_expr_nonnegative_p): New function.
	(build_binary_op): Call c_tree_expr_nonnegative_p rather than
	tree_expr_nonnegative_p.
	(build_conditional_expr): Likewise.
        * c-tree.h (c_tree_expr_nonnegative_p): Declare.

        * gcc.dg/compare2.c: Remove xfail from cases 10 and 12.

From-SVN: r56927