re PR tree-optimization/30735 (50% slow down due to mem-ssa merge)

	PR 30735
	PR 31090
	* doc/invoke.texi: Document --params max-aliased-vops and
	avg-aliased-vops.
	* tree-ssa-operands.h (get_mpt_for, dump_memory_partitions,
	debug_memory_partitions): Move to tree-flow.h
	* params.h (AVG_ALIASED_VOPS): Define.
	* tree-ssa-alias.c (struct mp_info_def): Remove.  Update all
	users.
	(mp_info_t): Likewise.
	(get_mem_sym_stats_for): New.
	(set_memory_partition): Move from tree-flow-inline.h.
	(mark_non_addressable): Only clear the set of symbols for the
	partition if it exists.
	(dump_memory_partitions): Move from tree-ssa-operands.c
	(debug_memory_partitions): Likewise.
	(need_to_partition_p): New.
	(dump_mem_ref_stats): New.
	(debug_mem_ref_stats): New.
	(dump_mem_sym_stats): New.
	(debug_mem_sym_stats): New.
	(update_mem_sym_stats_from_stmt): New.
	(compare_mp_info_entries): New.
	(mp_info_cmp): Call it.
	(sort_mp_info): Change argument to a list of mem_sym_stats_t
	objects.
	(get_mpt_for): Move from tree-ssa-operands.c.
	(find_partition_for): New.
	(create_partition_for): Remove.
	(estimate_vop_reduction): New.
	(update_reference_counts): New.
	(build_mp_info): New.
	(compute_memory_partitions): Refactor.
	Document new heuristic.
	Call build_mp_info, update_reference_counts,
	find_partition_for and estimate_vop_reduction.
	(compute_may_aliases): Populate virtual operands before
	calling debugging dumps.
	(delete_mem_sym_stats): New.
	(delete_mem_ref_stats): New.
	(init_mem_ref_stats): New.
	(init_alias_info): Call it.
	(maybe_create_global_var): Remove alias_info argument.
	Get number of call sites and number of pure/const call sites
	from gimple_mem_ref_stats().
	(dump_alias_info): Call dump_memory_partitions first.
	(dump_points_to_info_for): Show how many times a pointer has
	been dereferenced.
	* opts.c (decode_options): For -O2 set --param
	max-aliased-vops to 500.
	For -O3 set --param max-aliased-vops to 1000 and --param
	avg-aliased-vops to 3.
	* fortran/options.c (gfc_init_options): Remove assignment to
	MAX_ALIASED_VOPS.
	* tree-flow-inline.h (gimple_mem_ref_stats): New.
	* tree-dfa.c (dump_variable): Dump memory reference
	statistics.
	Dump NO_ALIAS* settings.
	(referenced_var_lookup): Tidy.
	(mem_sym_stats): New.
	* tree-ssa-copy.c (may_propagate_copy): Return true if DEST
	and ORIG are different SSA names for a memory partition.
	* tree-ssa.c (delete_tree_ssa): Call delete_mem_ref_stats.
	* tree-flow.h (struct mem_sym_stats_d): Define.
	(mem_sym_stats_t): Define.
	(struct mem_ref_stats_d): Define.
	(struct gimple_df): Add field mem_ref_stats.
	(enum noalias_state): Define.
	(struct var_ann_d): Add bitfield noalias_state.
	(mem_sym_stats, delete_mem_ref_stats, dump_mem_ref_stats,
	debug_mem_ref_stats, debug_memory_partitions,
	debug_mem_sym_stats): Declare.
	* tree-ssa-structalias.c (update_alias_info): Update call
	sites, pure/const call sites and asm sites in structure
	returned by gimple_mem_ref_stats.
	Remove local variable IS_POTENTIAL_DEREF.
	Increase NUM_DEREFS if the memory expression is a potential
	dereference.
	Call update_mem_sym_stats_from_stmt.
	If the memory references memory, call
	update_mem_sym_stats_from_stmt for all the direct memory
	symbol references found.
	(intra_create_variable_infos): Set noalias_state field for
	pointer arguments according to the value of
	flag_argument_noalias.
	* tree-ssa-structalias.h (struct alias_info): Remove fields
	num_calls_found and num_pure_const_calls_found.
	(update_mem_sym_stats_from_stmt): Declare.
	* params.def (PARAM_MAX_ALIASED_VOPS): Change description.
	Set default value to 100.
	(PARAM_AVG_ALIASED_VOPS): Define.

From-SVN: r123719

1 files changed, 7 insertions, 0 deletions

diff --git a/gcc/opts.c b/gcc/opts.c
index 4878b07..195e4e1 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -506,6 +506,9 @@ decode_options (unsigned int argc, const char **argv)
           /* PRE tends to generate bigger code.  */
           flag_tree_pre = 1;
 	}
+
+      /* Allow more virtual operators to increase alias precision.  */
+      set_param_value ("max-aliased-vops", 500);
     }
 
   if (optimize >= 3)
@@ -513,6 +516,10 @@ decode_options (unsigned int argc, const char **argv)
       flag_inline_functions = 1;
       flag_unswitch_loops = 1;
       flag_gcse_after_reload = 1;
+
+      /* Allow even more virtual operators.  */
+      set_param_value ("max-aliased-vops", 1000);
+      set_param_value ("avg-aliased-vops", 3);
     }
 
   if (optimize < 2 || optimize_size)