Used signed infinities in VRP.

	Used signed infinities in VRP.
	* tree-vrp.c (uses_overflow_infinity): New static function.
	(supports_overflow_infinity): New static function.
	(make_overflow_infinity): New static function.
	(negative_overflow_infinity): New static function.
	(positive_overflow_infinity): New static function.
	(is_negative_overflow_infinity): New static function.
	(is_positive_overflow_infinity): New static function.
	(is_overflow_infinity): New static function.
	(overflow_infinity_range_p): New static function.
	(compare_values_warnv): New function split out of compare_values.
	(compare_value): Call it.
	(set_value_range_to_nonnegative): Add overflow_infinity
	parameter.  Change caller.
	(vrp_expr_computes_nonnegative): Add strict_overflow_p parameter.
	Change callers.
	(vrp_expr_computes_nonzero): Likewise.
	(compare_ranges, compare_range_with_value): Likewise.
	(compare_name_with_value, compare_names): Likewise.
	(vrp_evaluate_conditional): Likewise.
	(set_value_range): Handle infinity
	(vrp_operand_equal_p, operand_less_p): Likewise.
	(extract_range_from_assert): Likewise.
	(vrp_int_const_binop): Likewise.
	(extract_range_from_binary_expr): Likewise.
	(extract_range_from_unary_expr): Likewise.
	(extract_range_from_comparison): Likewise.
	(extract_range_from_expr): Likewise.
	(dump_value_range): Likewise.
	(vrp_visit_cond_stmt, vrp_visit_phi_node): Likewise.
	(test_for_singularity): Likewise.
	(vrp_int_const_binop): Remove inline qualifier.
	(adjust_range_with_scev): Add comment.
	* tree-flow.h (vrp_evaluate_conditional): Update declaration.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@122487 138bc75d-0d04-0410-961f-82ee72b054a4