tree-vrp.c (get_single_symbol): Add assert that we don't get overflowed constants...

tree-vrp.c (get_single_symbol): Add assert that we don't get overflowed constants as invariant part.

2017-05-09  Richard Biener  <rguenther@suse.de>

	* tree-vrp.c (get_single_symbol): Add assert that we don't
	get overflowed constants as invariant part.
	(compare_values_warnv): Add comment before the TREE_NO_WARNING
	checks.  Use wi::cmp instead of recursing for integer constants.
	(compare_values): Just ignore whether we assumed undefined
	overflow instead of failing the compare.
	(extract_range_for_var_from_comparison_expr): Add comment before the
	TREE_NO_WARNING sets.
	(test_for_singularity): Likewise.
	(extract_range_from_comparison): Do not disable optimization
	when we assumed undefined overflow.
	(extract_range_basic): Remove init of unused var.

From-SVN: r247781