re PR middle-end/63155 (memory hog)

re PR middle-end/63155 (memory hog)

2018-10-05  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/63155
	* tree-ssa-ccp.c (ccp_propagate::visit_phi): Avoid excess
	vertical space in dumpfiles.
	* tree-ssa-propagate.h
	(ssa_propagation_engine::process_ssa_edge_worklist): Remove.
	* tree-ssa-propagate.c (cfg_blocks_back): New global.
	(ssa_edge_worklist_back): Likewise.
	(curr_order): Likewise.
	(cfg_blocks_get): Remove abstraction.
	(cfg_blocks_add): Likewise.
	(cfg_blocks_empty_p): Likewise.
	(add_ssa_edge): Add to current or next worklist based on
	RPO index.
	(add_control_edge): Likewise.
	(ssa_propagation_engine::process_ssa_edge_worklist): Fold
	into ...
	(ssa_propagation_engine::ssa_propagate): ... here.  Unify
	iteration from CFG and SSA edge worklist so we process
	everything in RPO order, prioritizing forward progress
	over iteration.
	(ssa_prop_init): Allocate new worklists, do not dump
	immediate uses.
	(ssa_prop_fini): Free new worklists.

From-SVN: r264869