re PR target/72851 (memory hog with -O3 on s390x-linux-gnu)

re PR target/72851 (memory hog with -O3 on s390x-linux-gnu)

2016-08-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/72851
	* tree-ssa-propagate.c: Include cfganal.h.  Rewrite block and stmt
	worklists to use bitmaps indexed in execution order.
	(executable_blocks, cfg_blocks_num, cfg_blocks_tail, cfg_blocks_head,
	bb_in_list, interesting_ssa_edges, varying_ssa_edges): Remove.
	(cfg_blocks): Make a bitmap.
	(bb_to_cfg_order, cfg_order_to_bb, ssa_edge_worklist, uid_to_stmt):
	New globals.
	(cfg_blocks_empty_p): Adjust.
	(cfg_blocks_add): Likewise.
	(cfg_blocks_get): Likewise.
	(add_ssa_edge): Likewise.
	(add_control_edge): Likewise.
	(simulate_stmt): Likewise.
	(process_ssa_edge_worklist): Likewise.
	(simulate_block): Likewise.
	(ssa_prop_init): Compute PRE order and stmt UIDs.
	(ssa_prop_fini): Adjust.
	(ssa_propagate): Adjust.

	* gcc.dg/torture/pr72851.c: New testcase.

From-SVN: r239405