re PR tree-optimization/91257 (Compile-time and memory-hog hog)

re PR tree-optimization/91257 (Compile-time and memory-hog hog)

2019-07-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91257
	* bitmap.h (bitmap_ior_into_and_free): Declare.
	* bitmap.c (bitmap_list_unlink_element): Add defaulted param
	whether to add the unliked element to the freelist.
	(bitmap_list_insert_element_after): Add defaulted param for
	an already allocated element.
	(bitmap_ior_into_and_free): New function.
	* tree-ssa-structalias.c (condense_visit): Reduce the
	ponts-to and edge bitmaps of the SCC members in a
	logarithmic fashion rather than all to one.

From-SVN: r273907