re PR tree-optimization/26830 (Repeated SSA update during loop header copying)

re PR tree-optimization/26830 (Repeated SSA update during loop header copying)

	PR tree-optimization/26830
	* tree-into-ssa.c (struct ssa_name_info): Add age field.
	(info_for_ssa_name, current_info_for_ssa_name_age,
	blocks_to_update): New variables.
	(get_ssa_name_ann): Use info_for_ssa_name instead of SSA_NAME_AUX.
	(clear_ssa_name_info, initialize_flags_in_bb,
	mark_block_for_update): New functions.
	(mark_def_sites, rewrite_stmt): Assert that blocks_to_update is NULL.
	(insert_phi_nodes_for, mark_use_interesting, prepare_block_for_update,
	prepare_def_site_for): Use mark_block_for_update.
	(mark_def_interesting): Assert that the processed block is marked in
	blocks_to_update.  Do not take blocks argument.
	(prepare_use_sites_for, prepare_names_to_update): Do not take blocks
	argument.
	(rewrite_update_init_block, rewrite_update_stmt): Only process
	blocks with statements to rewrite.
	(delete_update_ssa): Do not clear SSA_NAME_AUX.
	(update_ssa): Initialize and free blocks_to_update.  Do not
	clear flags on statements.  Do not use blocks bitmap.
	* tree.h (SSA_NAME_AUX): Removed.
	(struct tree_ssa_name): Removed aux field.
	* print-tree.c (print_node): Do not print SSA_NAME_AUX.

From-SVN: r113799