[PR 80898] Propagate grp_write from disqualified SRA candidates

[PR 80898] Propagate grp_write from disqualified SRA candidates

2017-06-01  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/80898
	* tree-sra.c (process_subtree_disqualification): Removed.
	(disqualify_candidate): Do not acll
	process_subtree_disqualification.
	(subtree_mark_written_and_enqueue): New function.
	(propagate_all_subaccesses): Set grp_write of LHS subtree if the
	RHS has been disqualified and re-queue LHS if necessary.  Apart
	from that, ignore disqualified RHS.

testsuite/
	* gcc.dg/tree-ssa/pr80898.c: New test.
	* gcc.dg/tree-ssa/pr80898-2.c: Likewise.

From-SVN: r248790