SRA: Also propagate accesses from LHS to RHS [PR92706]

SRA: Also propagate accesses from LHS to RHS [PR92706]

2020-01-29  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/92706
	* tree-sra.c (struct access): Fields first_link, last_link,
	next_queued and grp_queued renamed to first_rhs_link, last_rhs_link,
	next_rhs_queued and grp_rhs_queued respectively, new fields
	first_lhs_link, last_lhs_link, next_lhs_queued and grp_lhs_queued.
	(struct assign_link): Field next renamed to next_rhs, new field
	next_lhs.  Updated comment.
	(work_queue_head): Renamed to rhs_work_queue_head.
	(lhs_work_queue_head): New variable.
	(add_link_to_lhs): New function.
	(relink_to_new_repr): Also relink LHS lists.
	(add_access_to_work_queue): Renamed to add_access_to_rhs_work_queue.
	(add_access_to_lhs_work_queue): New function.
	(pop_access_from_work_queue): Renamed to
	pop_access_from_rhs_work_queue.
	(pop_access_from_lhs_work_queue): New function.
	(build_accesses_from_assign): Also add links to LHS lists and to LHS
	work_queue.
	(child_would_conflict_in_lacc): Renamed to
	child_would_conflict_in_acc.  Adjusted parameter names.
	(create_artificial_child_access): New parameter set_grp_read, use it.
	(subtree_mark_written_and_enqueue): Renamed to
	subtree_mark_written_and_rhs_enqueue.
	(propagate_subaccesses_across_link): Renamed to
	propagate_subaccesses_from_rhs.
	(propagate_subaccesses_from_lhs): New function.
	(propagate_all_subaccesses): Also propagate subaccesses from LHSs to
	RHSs.

	testsuite/
	* gcc.dg/tree-ssa/pr92706-1.c: New test.