[multiple changes]

2005-04-22  Diego Novillo  <dnovillo@redhat.com>

	* Makefile.in (tree-into-ssa.o): Add dependency on PARAMS_H.
	* lambda-code.c (perfect_nestify): Mark virtual operands in
	the moved statement for renaming.
	* params.def (PARAM_MIN_VIRTUAL_MAPPINGS): Define.
	(PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO): Define.
	* params.h (MIN_VIRTUAL_MAPPINGS): Define.
	(VIRTUAL_MAPPINGS_TO_SYMS_RATIO): Define.
	* tree-flow.h (struct var_ann_d): Update comments.
	(rewrite_to_new_ssa_names_bb, rewrite_to_new_ssa_names,
	allocate_ssa_names, find_phi_node_for, dump_tree_ssa,
	debug_tree_ssa, debug_def_blocks, dump_tree_ssa_stats,
	debug_tree_ssa_stats, rewrite_ssa_into_ssa,
	dump_repl_tbl, debug_repl_tbl, dump_names_replaced_by,
	debug_names_replaced_by): Remove declarations.
	(delete_update_ssa, get_current_def, set_current_def): Declare.
	(rewrite_into_loop_closed_ssa): Add new argument.  Update
	all callers.
	* tree-into-ssa.c: Include params.h.
	(old_virtual_ssa_names): Remove.  Update all users.
	(need_to_replace_names_p): Remove.  Update all users.
	(struct update_ssa_stats_d): Declare.
	(update_ssa_stats): New local.
	(dump_tree_ssa, debug_tree_ssa, debug_def_blocks,
	dump_tree_ssa_stats, debug_tree_ssa_stats,
	dump_update_ssa, debug_update_ssa,
	dump_names_replaced_by, debug_names_replaced_by): Declare.
	(get_current_def, set current_def): Make extern.
	(is_old_name, is_new_name): Protect against references
	past the end of the sets.
	(add_new_name_mapping): Assert that OLD and NEW are
	different SSA names for the same symbol.
	When adding a virtual mapping, update stats for virtual
	mapping heuristic.
	(insert_phi_nodes_for): If UPDATE_P is true, create the
	LHS of the new PHI by duplicating SSA name VAR.
	(insert_phi_nodes_1): Remove.  Update all users.
	(insert_phi_nodes): Remove second argument.  Update all
	users.
	(maybe_replace_use, maybe_replace_def): New.
	(rewrite_update_stmt): Call them.
	(mark_def_interesting): Remove calls to is_gimple_reg.
	(prepare_phi_args_for_update): Remove.  Update all users.
	(prepare_block_for_update): Only process virtual operands
	and GIMPLE registers in normal form.
	(prepare_use_sites_for): New.
	(prepare_names_to_update): Rename from prepare_def_sites.
	Call prepare_use_sites_for.
	(dump_update_ssa): Rename from dump_repl_tbl.
	Update all users.
	Show statistics for virtual mapping heuristic.
	(debug_update_ssa): Rename from debug_debug_repl_tbl.
	(init_update_ssa): Initialize UPDATE_SSA_STATS.
	(delete_update_ssa): Make extern.
	(mark_set_for_renaming): If the set is empty, do nothing.
	(release_ssa_name_after_update_ssa): Update comment.
	(insert_updated_phi_nodes_for): Do not remove existing
	PHI nodes for symbols.
	(switch_virtuals_to_full_rewrite_p): New.
	(switch_virtuals_to_full_rewrite): New.
	(update_ssa): Call them.
	Clear REWRITE_THIS_STMT and REGISTER_DEFS_IN_THIS_STMT
	for every statement before updating.
	If all the names in NEW_SSA_NAMES have been marked for
	removal, do nothing.
	Only start at the top of the CFG if there are symbols in
	SYMS_TO_RENAME.
	(ssa_rewrite_finalize_block): Remove.
	(ssa_register_new_def): Remove.
	(ssa_rewrite_stmt): Remove.
	(ssa_rewrite_phi_arguments): Remove.
	(ssa_rewrite_initialize_block): Remove.
	(ssa_mark_def_sites): Remove.
	(ssa_mark_def_sites_initialize_block): Remove.
	(ssa_mark_phi_uses): Remove.
	(rewrite_ssa_into_ssa): Remove.
	* tree-phinodes.c (find_phi_node_for): Remove.
	* tree-ssa-loop-ivcanon.c (try_unroll_loop_completely):
	Call update_ssa.
	* tree-ssa-loop-unswitch.c (tree_ssa_unswitch_loops):
	Remove calls to verify_dominators and
	verify_loop_structure.
	(tree_unswitch_single_loop): Call update_ssa.
	* tree-ssa.c (verify_ssa): Assert that need_ssa_update_p
	returns false.
	Call verify_stmts.
	(delete_tree_ssa): Assert that need_ssa_update_p returns
	false.
	* tree-vect-transform.c (vect_transform_loop): Call update_ssa.
	* tree-vectorizer.c (allocate_new_names, rename_def_op,
	free_new_names): Remove.  Update all users.
	(rename_use_op): Call get_current_def.
	(rename_variables_in_bb): Do not handle any real or
	virtual definition.
	(slpeel_update_phis_for_duplicate_loop): Call
	get_current_def and set_current_def instead of using
	SSA_NAME_AUX.
	(slpeel_update_phi_nodes_for_guard2): Reformat comments.
	(slpeel_can_duplicate_loop_p): Call need_ssa_update_p,
	ssa_names_to_replace and delete_update_ssa.
	* doc/invoke.texi: Document --param min-virtual-mappings
	and --param virtual-mappings-ratio.

2005-04-22  Zdenek Dvorak  <dvorakz@suse.cz>
	    Diego Novillo  <dnovillo@redhat.com>

	* tree-cfg.c (tree_duplicate_bb): Call create_new_def_for
	for newly created PHI nodes.
	Call create_new_def_for for every new V_MAY_DEF and
	V_MUST_DEF on the copied statement.
	(struct ssa_name_map_entry): Remove.
	(ssa_name_map_entry_hash): Remove.
	(ssa_name_map_entry_eq): Remove.
	(allocate_ssa_names): Remove.
	(rewrite_to_new_ssa_names_def): Remove.
	(rewrite_to_new_ssa_names_use): Remove.
	(rewrite_to_new_ssa_names_bb): Remove.
	(rewrite_to_new_ssa_names): Remove.
	(tree_duplicate_sese_region): Remove variables ver,
	definitions, phi, ssa_name_map and bi.
	Call need_ssa_update_p instead of any_marked_for_rewrite_p.
	Call update_ssa.
	* tree-ssa-dom.c (tree_ssa_dominator_optimize): Call
	update_ssa instead of rewrite_ssa_into_ssa.
	* tree-ssa-loop-manip.c (add_exit_phis_edge): Call
	create_new_def_for.
	(find_uses_to_rename_use): Add argument 'need_phis'.
	(find_uses_to_rename_stmt): Do not scan virtual operands.
	(find_uses_to_rename): Only scan PHI nodes for
	non-virtual names.
	(rewrite_into_loop_closed_ssa): Call update_ssa.
	(check_loop_closed_ssa_use): Ignore virtual operands.
	(check_loop_closed_ssa_stmt): Likewise.
	(verify_loop_closed_ssa): Do nothing if CURRENT_LOOPS is
	NULL.
	(rename_variables, set_phi_def_stmts): Remove.
	(tree_duplicate_loop_to_header_edge): Reformat comment.
	Remove variables BB, I and DEFINITIONS.
	Call need_ssa_update_p.
	Call update_ssa.
	(lv_adjust_loop_header_phi): Reformat comment.
	* tree-ssanames.c (ssa_names_to_rewrite): Remove.
	(marked_for_rewrite_p, any_marked_for_rewrite_p,
	mark_for_rewrite, unmark_all_for_rewrite,
	marked_ssa_names): Remove.  Update all users.
	(release_ssa_name): If VAR has been registered for SSA
	updating, do nothing.
	* tree-vrp.c (new_ssa_names, old_ssa_names): Remove.
	(build_assert_expr_for): Call register_new_name_mapping.
	(insert_range_assertions): Update call to update_ssa.
	* tree.h (mark_for_rewrite, unmark_all_for_rewrite,
	marked_for_rewrite_p, any_marked_for_rewrite_p,
	marked_ssa_names): Remove.

From-SVN: r98599

gcc/ChangeLog

+2005-04-22  Diego Novillo  <dnovillo@redhat.com>
+
+	* Makefile.in (tree-into-ssa.o): Add dependency on PARAMS_H.
+	* lambda-code.c (perfect_nestify): Mark virtual operands in
+	the moved statement for renaming.
+	* params.def (PARAM_MIN_VIRTUAL_MAPPINGS): Define.
+	(PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO): Define.
+	* params.h (MIN_VIRTUAL_MAPPINGS): Define.
+	(VIRTUAL_MAPPINGS_TO_SYMS_RATIO): Define.
+	* tree-flow.h (struct var_ann_d): Update comments.
+	(rewrite_to_new_ssa_names_bb, rewrite_to_new_ssa_names,
+	allocate_ssa_names, find_phi_node_for, dump_tree_ssa,
+	debug_tree_ssa, debug_def_blocks, dump_tree_ssa_stats,
+	debug_tree_ssa_stats, rewrite_ssa_into_ssa,
+	dump_repl_tbl, debug_repl_tbl, dump_names_replaced_by,
+	debug_names_replaced_by): Remove declarations.
+	(delete_update_ssa, get_current_def, set_current_def): Declare.
+	(rewrite_into_loop_closed_ssa): Add new argument.  Update
+	all callers.
+	* tree-into-ssa.c: Include params.h.
+	(old_virtual_ssa_names): Remove.  Update all users.
+	(need_to_replace_names_p): Remove.  Update all users.
+	(struct update_ssa_stats_d): Declare.
+	(update_ssa_stats): New local.
+	(dump_tree_ssa, debug_tree_ssa, debug_def_blocks,
+	dump_tree_ssa_stats, debug_tree_ssa_stats,
+	dump_update_ssa, debug_update_ssa,
+	dump_names_replaced_by, debug_names_replaced_by): Declare.
+	(get_current_def, set current_def): Make extern.
+	(is_old_name, is_new_name): Protect against references
+	past the end of the sets.
+	(add_new_name_mapping): Assert that OLD and NEW are
+	different SSA names for the same symbol.
+	When adding a virtual mapping, update stats for virtual
+	mapping heuristic.
+	(insert_phi_nodes_for): If UPDATE_P is true, create the
+	LHS of the new PHI by duplicating SSA name VAR.
+	(insert_phi_nodes_1): Remove.  Update all users.
+	(insert_phi_nodes): Remove second argument.  Update all
+	users.
+	(maybe_replace_use, maybe_replace_def): New.
+	(rewrite_update_stmt): Call them.
+	(mark_def_interesting): Remove calls to is_gimple_reg.
+	(prepare_phi_args_for_update): Remove.  Update all users.
+	(prepare_block_for_update): Only process virtual operands
+	and GIMPLE registers in normal form.
+	(prepare_use_sites_for): New.
+	(prepare_names_to_update): Rename from prepare_def_sites.
+	Call prepare_use_sites_for.
+	(dump_update_ssa): Rename from dump_repl_tbl.
+	Update all users.
+	Show statistics for virtual mapping heuristic.
+	(debug_update_ssa): Rename from debug_debug_repl_tbl.
+	(init_update_ssa): Initialize UPDATE_SSA_STATS.
+	(delete_update_ssa): Make extern.
+	(mark_set_for_renaming): If the set is empty, do nothing.
+	(release_ssa_name_after_update_ssa): Update comment.
+	(insert_updated_phi_nodes_for): Do not remove existing
+	PHI nodes for symbols.
+	(switch_virtuals_to_full_rewrite_p): New.
+	(switch_virtuals_to_full_rewrite): New.
+	(update_ssa): Call them.
+	Clear REWRITE_THIS_STMT and REGISTER_DEFS_IN_THIS_STMT
+	for every statement before updating.
+	If all the names in NEW_SSA_NAMES have been marked for
+	removal, do nothing.
+	Only start at the top of the CFG if there are symbols in
+	SYMS_TO_RENAME.
+	(ssa_rewrite_finalize_block): Remove.
+	(ssa_register_new_def): Remove.
+	(ssa_rewrite_stmt): Remove.
+	(ssa_rewrite_phi_arguments): Remove.
+	(ssa_rewrite_initialize_block): Remove.
+	(ssa_mark_def_sites): Remove.
+	(ssa_mark_def_sites_initialize_block): Remove.
+	(ssa_mark_phi_uses): Remove.
+	(rewrite_ssa_into_ssa): Remove.
+	* tree-phinodes.c (find_phi_node_for): Remove.
+	* tree-ssa-loop-ivcanon.c (try_unroll_loop_completely):
+	Call update_ssa.
+	* tree-ssa-loop-unswitch.c (tree_ssa_unswitch_loops):
+	Remove calls to verify_dominators and
+	verify_loop_structure.
+	(tree_unswitch_single_loop): Call update_ssa.
+	* tree-ssa.c (verify_ssa): Assert that need_ssa_update_p
+	returns false.
+	Call verify_stmts.
+	(delete_tree_ssa): Assert that need_ssa_update_p returns
+	false.
+	* tree-vect-transform.c (vect_transform_loop): Call update_ssa.
+	* tree-vectorizer.c (allocate_new_names, rename_def_op,
+	free_new_names): Remove.  Update all users.
+	(rename_use_op): Call get_current_def.
+	(rename_variables_in_bb): Do not handle any real or
+	virtual definition.
+	(slpeel_update_phis_for_duplicate_loop): Call
+	get_current_def and set_current_def instead of using
+	SSA_NAME_AUX.
+	(slpeel_update_phi_nodes_for_guard2): Reformat comments.
+	(slpeel_can_duplicate_loop_p): Call need_ssa_update_p,
+	ssa_names_to_replace and delete_update_ssa.
+	* doc/invoke.texi: Document --param min-virtual-mappings
+	and --param virtual-mappings-ratio.
+
+2005-04-22  Zdenek Dvorak  <dvorakz@suse.cz>
+	    Diego Novillo  <dnovillo@redhat.com>
+
+	* tree-cfg.c (tree_duplicate_bb): Call create_new_def_for
+	for newly created PHI nodes.
+	Call create_new_def_for for every new V_MAY_DEF and
+	V_MUST_DEF on the copied statement.
+	(struct ssa_name_map_entry): Remove.
+	(ssa_name_map_entry_hash): Remove.
+	(ssa_name_map_entry_eq): Remove.
+	(allocate_ssa_names): Remove.
+	(rewrite_to_new_ssa_names_def): Remove.
+	(rewrite_to_new_ssa_names_use): Remove.
+	(rewrite_to_new_ssa_names_bb): Remove.
+	(rewrite_to_new_ssa_names): Remove.
+	(tree_duplicate_sese_region): Remove variables ver,
+	definitions, phi, ssa_name_map and bi.
+	Call need_ssa_update_p instead of any_marked_for_rewrite_p.
+	Call update_ssa.
+	* tree-ssa-dom.c (tree_ssa_dominator_optimize): Call
+	update_ssa instead of rewrite_ssa_into_ssa.
+	* tree-ssa-loop-manip.c (add_exit_phis_edge): Call
+	create_new_def_for.
+	(find_uses_to_rename_use): Add argument 'need_phis'.
+	(find_uses_to_rename_stmt): Do not scan virtual operands.
+	(find_uses_to_rename): Only scan PHI nodes for
+	non-virtual names.
+	(rewrite_into_loop_closed_ssa): Call update_ssa.
+	(check_loop_closed_ssa_use): Ignore virtual operands.
+	(check_loop_closed_ssa_stmt): Likewise.
+	(verify_loop_closed_ssa): Do nothing if CURRENT_LOOPS is
+	NULL.
+	(rename_variables, set_phi_def_stmts): Remove.
+	(tree_duplicate_loop_to_header_edge): Reformat comment.
+	Remove variables BB, I and DEFINITIONS.
+	Call need_ssa_update_p.
+	Call update_ssa.
+	(lv_adjust_loop_header_phi): Reformat comment.
+	* tree-ssanames.c (ssa_names_to_rewrite): Remove.
+	(marked_for_rewrite_p, any_marked_for_rewrite_p,
+	mark_for_rewrite, unmark_all_for_rewrite,
+	marked_ssa_names): Remove.  Update all users.
+	(release_ssa_name): If VAR has been registered for SSA
+	updating, do nothing.
+	* tree-vrp.c (new_ssa_names, old_ssa_names): Remove.
+	(build_assert_expr_for): Call register_new_name_mapping.
+	(insert_range_assertions): Update call to update_ssa.
+	* tree.h (mark_for_rewrite, unmark_all_for_rewrite,
+	marked_for_rewrite_p, any_marked_for_rewrite_p,
+	marked_ssa_names): Remove.
+
 2005-04-22  Jeff Law  <law@redhat.com>
 
 	* tree-ssa-dom.c (block_defs_stack): Remove, no longer needed.

gcc/Makefile.in

@@ -1635,7 +1635,7 @@ tree-into-ssa.o : tree-into-ssa.c $(TREE_FLOW_H) $(CONFIG_H) $(SYSTEM_H) \
    $(RTL_H) $(TREE_H) $(TM_P_H) $(EXPR_H) output.h diagnostic.h \
    errors.h toplev.h function.h $(TIMEVAR_H) \
    $(TM_H) coretypes.h $(TREE_DUMP_H) langhooks.h domwalk.h tree-pass.h \
-   $(GGC_H)
+   $(GGC_H) $(PARAMS_H)
 tree-outof-ssa.o : tree-outof-ssa.c $(TREE_FLOW_H) $(CONFIG_H) $(SYSTEM_H) \
    $(RTL_H) $(TREE_H) $(TM_P_H) $(EXPR_H) output.h diagnostic.h \
    errors.h toplev.h function.h $(TIMEVAR_H) \

gcc/doc/invoke.texi

@@ -5827,6 +5827,18 @@ Small integer constants can use a shared data structure, reducing the
 compiler's memory usage and increasing its speed.  This sets the maximum
 value of a shared integer constant's.  The default value is 256.
 
+@item min-virtual-mappings
+Specifies the minimum number of virtual mappings in the incremental
+SSA updater that should be registered to trigger the virtual mappings
+heuristic defined by virtual-mappings-ratio.  The default value is
+100.
+
+@item virtual-mappings-ratio
+If the number of virtual mappings is virtual-mappings-ratio bigger
+than the number of virtual symbols to be updated, then the incremental
+SSA updater switches to a full update for those symbols.  The default
+ratio is 3.
+
 @end table
 @end table
 

gcc/lambda-code.c

@@ -2443,7 +2443,9 @@ perfect_nestify (struct loops *loops,
 	     incremented when we do.  */
 	  for (bsi = bsi_start (bbs[i]); !bsi_end_p (bsi);)
 	    { 
-	      tree stmt = bsi_stmt (bsi);
+	      ssa_op_iter i;
+	      tree n, stmt = bsi_stmt (bsi);
+
 	      if (stmt == exit_condition
 		  || not_interesting_stmt (stmt)
 		  || stmt_is_bumper_for_loop (loop, stmt))
@@ -2451,11 +2453,19 @@ perfect_nestify (struct loops *loops,
 		  bsi_next (&bsi);
 		  continue;
 		}
+
 	      replace_uses_of_x_with_y (stmt, oldivvar, ivvar);
 	      bsi_move_before (&bsi, &tobsi);
+
+	      /* If the statement has any virtual operands, they may
+		 need to be rewired because the original loop may
+		 still reference them.  */
+	      FOR_EACH_SSA_TREE_OPERAND (n, stmt, i, SSA_OP_ALL_VIRTUALS)
+		mark_sym_for_renaming (SSA_NAME_VAR (n));
 	    }
 	}
     }
+
   free (bbs);
   return perfect_nest_p (loop);
 }

gcc/params.def

@@ -443,6 +443,30 @@ DEFPARAM (PARAM_INTEGER_SHARE_LIMIT,
 	  "The upper bound for sharing integer constants",
 	  256, 2, 2)
 
+/* Incremental SSA updates for virtual operands may be very slow if
+   there is a large number of mappings to process.  In those cases, it
+   is faster to rewrite the virtual symbols from scratch as if they
+   had been recently introduced.  This heuristic cannot be applied to
+   SSA mappings for real SSA names, only symbols kept in FUD chains.
+
+   PARAM_MIN_VIRTUAL_MAPPINGS specifies the minimum number of virtual
+   mappings that should be registered to trigger the heuristic.
+   
+   PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO specifies the ratio between
+   mappings and symbols.  If the number of virtual mappings is
+   PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO bigger than the number of
+   virtual symbols to be updated, then the updater switches to a full
+   update for those symbols.  */
+DEFPARAM (PARAM_MIN_VIRTUAL_MAPPINGS,
+	  "min-virtual-mappings",
+	  "Minimum number of virtual mappings to consider switching to full virtual renames",
+	  100, 0, 0)
+
+DEFPARAM (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO,
+	  "virtual-mappings-ratio",
+	  "Ratio between virtual mappings and virtual symbols to do full virtual renames",
+	  3, 0, 0)
+
 /*
 Local variables:
 mode:c

gcc/params.h

@@ -139,4 +139,8 @@ typedef enum compiler_param
   PARAM_VALUE (PARAM_INTEGER_SHARE_LIMIT)
 #define MAX_LAST_VALUE_RTL \
   PARAM_VALUE (PARAM_MAX_LAST_VALUE_RTL)
+#define MIN_VIRTUAL_MAPPINGS \
+  PARAM_VALUE (PARAM_MIN_VIRTUAL_MAPPINGS)
+#define VIRTUAL_MAPPINGS_TO_SYMS_RATIO \
+  PARAM_VALUE (PARAM_VIRTUAL_MAPPINGS_TO_SYMS_RATIO)
 #endif /* ! GCC_PARAMS_H */

gcc/testsuite/ChangeLog

+2005-04-22  Diego Novillo  <dnovillo@redhat.com>
+
+	* gcc.dg/tree-ssa/ltrans-4.c: Fix typo in dg-options.
+
 2005-04-22  Jeff Law  <law@redhat.com>
 
 	* gcc.dg/uninit-5.c: Remove xfails.

gcc/testsuite/gcc.dg/tree-ssa/ltrans-4.c

 /* { dg-do compile } */ 
-/* { dg-options "-O20 -ftree-loop-linear -fdump-tree-ltrans-all" } */
+/* { dg-options "-O2 -ftree-loop-linear -fdump-tree-ltrans-all" } */
 
 double u[1782225];
 int foo(int N, int *res)

gcc/tree-flow.h

@@ -253,15 +253,11 @@ struct var_ann_d GTY(())
   tree default_def;
 
   /* During into-ssa and the dominator optimizer, this field holds the
-     current version of this variable (an SSA_NAME). 
-
-     This was previously two varrays (one in into-ssa the other in the
-     dominator optimizer).  That is wasteful, particularly since the
-     dominator optimizer calls into-ssa resulting in having two varrays
-     live at the same time and this can happen for each call to the
-     dominator optimizer.  */
+     current version of this variable (an SSA_NAME).  */
   tree current_def;
   
+  /* If this variable is a structure, this fields holds a list of
+     symbols representing each of the fields of the structure.  */
   subvar_t subvars;
 };
 
@@ -540,9 +536,6 @@ extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 					basic_block *);
 extern void add_phi_args_after_copy_bb (basic_block);
 extern void add_phi_args_after_copy (basic_block *, unsigned);
-extern void rewrite_to_new_ssa_names_bb (basic_block, struct htab *);
-extern void rewrite_to_new_ssa_names (basic_block *, unsigned, htab_t);
-extern void allocate_ssa_names (bitmap, struct htab **);
 extern bool tree_purge_dead_eh_edges (basic_block);
 extern bool tree_purge_all_dead_eh_edges (bitmap);
 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
@@ -565,7 +558,6 @@ extern tree create_phi_node (tree, basic_block);
 extern void add_phi_arg (tree, tree, edge);
 extern void remove_phi_args (edge);
 extern void remove_phi_node (tree, tree);
-extern tree find_phi_node_for (basic_block, tree, tree *);
 extern tree phi_reverse (tree);
 extern void dump_dfa_stats (FILE *);
 extern void debug_dfa_stats (void);
@@ -612,11 +604,6 @@ typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 
 /* In tree-ssa.c  */
 extern void init_tree_ssa (void);
-extern void dump_tree_ssa (FILE *);
-extern void debug_tree_ssa (void);
-extern void debug_def_blocks (void);
-extern void dump_tree_ssa_stats (FILE *);
-extern void debug_tree_ssa_stats (void);
 extern edge ssa_redirect_edge (edge, basic_block);
 extern void flush_pending_stmts (edge);
 extern bool tree_ssa_useless_type_conversion (tree);
@@ -628,23 +615,20 @@ extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 extern bool stmt_references_memory_p (tree);
 
 /* In tree-into-ssa.c  */
-extern void rewrite_ssa_into_ssa (void);
-
 void update_ssa (unsigned);
+void delete_update_ssa (void);
 void register_new_name_mapping (tree, tree);
 tree create_new_def_for (tree, tree, def_operand_p);
 bool need_ssa_update_p (void);
 bool name_registered_for_update_p (tree);
 bitmap ssa_names_to_replace (void);
 void release_ssa_name_after_update_ssa (tree name);
-void dump_repl_tbl (FILE *);
-void debug_repl_tbl (void);
-void dump_names_replaced_by (FILE *, tree);
-void debug_names_replaced_by (tree);
 void compute_global_livein (bitmap, bitmap);
 tree duplicate_ssa_name (tree, tree);
 void mark_sym_for_renaming (tree);
 void mark_set_for_renaming (bitmap);
+tree get_current_def (tree);
+void set_current_def (tree, tree);
 
 /* In tree-ssa-ccp.c  */
 bool fold_stmt (tree *);
@@ -724,7 +708,7 @@ tree find_loop_niter_by_eval (struct loop *, edge *);
 void estimate_numbers_of_iterations (struct loops *);
 tree can_count_iv_in_wider_type (struct loop *, tree, tree, tree, tree);
 void free_numbers_of_iterations_estimates (struct loops *);
-void rewrite_into_loop_closed_ssa (bitmap);
+void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 void verify_loop_closed_ssa (void);
 void loop_commit_inserts (void);
 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);

gcc/tree-loop-linear.c

@@ -373,6 +373,5 @@ linear_transform_loops (struct loops *loops)
   VEC_free (tree, heap, oldivs);
   VEC_free (tree, heap, invariants);
   scev_reset ();
-  update_ssa (TODO_update_ssa);
-  rewrite_into_loop_closed_ssa (NULL);
+  rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa_full_phi);
 }

gcc/tree-phinodes.c

@@ -466,30 +466,6 @@ remove_phi_node (tree phi, tree prev)
 }
 
 
-/* Find the first PHI node P in basic block BB for symbol SYM.  If
-   PREV_P is given, the PHI node preceding P is stored in *PREV_P.  */
-
-tree
-find_phi_node_for (basic_block bb, tree sym, tree *prev_p)
-{
-  tree phi;
-
-  if (prev_p)
-    *prev_p = NULL_TREE;
-
-  for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
-    {
-      if (SSA_NAME_VAR (PHI_RESULT (phi)) == sym)
-	return phi;
-
-      if (prev_p)
-	*prev_p = phi;
-    }
-
-  return NULL_TREE;
-}
-
-
 /* Reverse the order of PHI nodes in the chain PHI.
    Return the new head of the chain (old last PHI node).  */
 

gcc/tree-ssa-dom.c

@@ -474,7 +474,7 @@ tree_ssa_dominator_optimize (void)
 
       calculate_dominance_info (CDI_DOMINATORS);
 
-      rewrite_ssa_into_ssa ();
+      update_ssa (TODO_update_ssa);
 
       /* Reinitialize the various tables.  */
       bitmap_clear (nonzero_vars);

gcc/tree-ssa-loop-ch.c

@@ -136,7 +136,7 @@ copy_loop_headers (void)
   loops = loop_optimizer_init (dump_file);
   if (!loops)
     return;
-  rewrite_into_loop_closed_ssa (NULL);
+  rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
   
   /* We do not try to keep the information about irreducible regions
      up-to-date.  */

gcc/tree-ssa-loop-im.c

@@ -757,14 +757,8 @@ move_computations (void)
   fini_walk_dominator_tree (&walk_data);
 
   loop_commit_inserts ();
-
   if (need_ssa_update_p ())
-    update_ssa (TODO_update_ssa);
-
-  /* The movement of LI code may cause violation of loop closed SSA
-     form invariants.  TODO -- avoid these rewrites completely.
-     Information in virtual phi nodes is sufficient for it.  */
-  rewrite_into_loop_closed_ssa (NULL);
+    rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
 }
 
 /* Checks whether the statement defining variable *INDEX can be hoisted

gcc/tree-ssa-loop-ivcanon.c

@@ -185,6 +185,8 @@ try_unroll_loop_completely (struct loops *loops ATTRIBUTE_UNUSED,
   COND_EXPR_COND (cond) = do_exit;
   update_stmt (cond);
 
+  update_ssa (TODO_update_ssa);
+
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "Unrolled loop %d completely.\n", loop->num);
 

gcc/tree-ssa-loop-ivopts.c

@@ -5416,10 +5416,8 @@ tree_ssa_iv_optimize (struct loops *loops)
       FOR_EACH_BB (bb)
 	for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
 	  update_stmt (bsi_stmt (si));
-
-      update_ssa (TODO_update_ssa);
     }
 
-  rewrite_into_loop_closed_ssa (NULL);
+  rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
   tree_ssa_iv_optimize_finalize (loops, &data);
 }

gcc/tree-ssa-loop-unswitch.c

@@ -101,10 +101,6 @@ tree_ssa_unswitch_loops (struct loops *loops)
 	continue;
 
       changed |= tree_unswitch_single_loop (loops, loop, 0);
-#ifdef ENABLE_CHECKING
-      verify_dominators (CDI_DOMINATORS);
-      verify_loop_structure (loops);
-#endif
     }
 
   if (changed)
@@ -260,6 +256,9 @@ tree_unswitch_single_loop (struct loops *loops, struct loop *loop, int num)
   if (!nloop)
     return changed;
 
+  /* Update the SSA form after unswitching.  */
+  update_ssa (TODO_update_ssa);
+
   /* Invoke itself on modified loops.  */
   tree_unswitch_single_loop (loops, nloop, num + 1);
   tree_unswitch_single_loop (loops, loop, num + 1);

gcc/tree-ssa-loop.c

@@ -40,7 +40,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 
 /* The loop tree currently optimized.  */
 
-struct loops *current_loops;
+struct loops *current_loops = NULL;
 
 /* Initializes the loop structures.  DUMP is the file to that the details
    about the analysis should be dumped.  */
@@ -53,8 +53,7 @@ tree_loop_optimizer_init (FILE *dump)
   if (!loops)
     return NULL;
 
-  update_ssa (TODO_update_ssa);
-  rewrite_into_loop_closed_ssa (NULL);
+  rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
 
   return loops;
 }

gcc/tree-ssa.c

@@ -644,6 +644,10 @@ verify_ssa (bool check_modified_stmt)
   enum dom_state orig_dom_state = dom_computed[CDI_DOMINATORS];
   bitmap names_defined_in_bb = BITMAP_ALLOC (NULL);
 
+  gcc_assert (!need_ssa_update_p ());
+
+  verify_stmts ();
+
   timevar_push (TV_TREE_SSA_VERIFY);
 
   /* Keep track of SSA names present in the IL.  */
@@ -751,9 +755,7 @@ verify_ssa (bool check_modified_stmt)
 	    }
 
 	  FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_ALL_DEFS)
-	    {
-	      bitmap_set_bit (names_defined_in_bb, SSA_NAME_VERSION (op));
-	    }
+	    bitmap_set_bit (names_defined_in_bb, SSA_NAME_VERSION (op));
 	}
 
       bitmap_clear (names_defined_in_bb);
@@ -763,6 +765,7 @@ verify_ssa (bool check_modified_stmt)
   verify_alias_info ();
 
   free (definition_block);
+
   /* Restore the dominance information to its prior known state, so
      that we do not perturb the compiler's subsequent behavior.  */
   if (orig_dom_state == DOM_NONE)
@@ -835,6 +838,7 @@ delete_tree_ssa (void)
   addressable_vars = NULL;
   modified_noreturn_calls = NULL;
   aliases_computed_p = false;
+  gcc_assert (!need_ssa_update_p ());
 }
 
 

gcc/tree-ssanames.c

@@ -61,9 +61,6 @@ Boston, MA 02111-1307, USA.  */
 /* Array of all SSA_NAMEs used in the function.  */
 varray_type ssa_names;
 
-/* Bitmap of ssa names marked for rewriting.  */
-static bitmap ssa_names_to_rewrite;
-
 /* Free list of SSA_NAMEs.  This list is wiped at the end of each function
    after we leave SSA form.  */
 static GTY (()) tree free_ssanames;
@@ -77,54 +74,6 @@ unsigned int ssa_name_nodes_reused;
 unsigned int ssa_name_nodes_created;
 #endif
 
-/* Returns true if ssa name VAR is marked for rewrite.  */
-
-bool
-marked_for_rewrite_p (tree var)
-{
-  return bitmap_bit_p (ssa_names_to_rewrite, SSA_NAME_VERSION (var));
-}
-
-/* Returns true if any ssa name is marked for rewrite.  */
-
-bool
-any_marked_for_rewrite_p (void)
-{
-  if (!ssa_names_to_rewrite)
-    return false;
-
-  return !bitmap_empty_p (ssa_names_to_rewrite);
-}
-
-/* Mark ssa name VAR for rewriting.  */
-
-void
-mark_for_rewrite (tree var)
-{
-  bitmap_set_bit (ssa_names_to_rewrite, SSA_NAME_VERSION (var));
-}
-
-/* Unmark all ssa names marked for rewrite.  */
-
-void
-unmark_all_for_rewrite (void)
-{
-  bitmap_clear (ssa_names_to_rewrite);
-}
-
-/* Return the bitmap of ssa names to rewrite.  Copy the bitmap,
-   so that the optimizers cannot access internals directly  */
-
-bitmap
-marked_ssa_names (void)
-{
-  bitmap ret = BITMAP_ALLOC (NULL);
-
-  bitmap_copy (ret, ssa_names_to_rewrite);
-
-  return ret;
-}
-
 /* Initialize management of SSA_NAMEs.  */
 
 void
@@ -138,7 +87,6 @@ init_ssanames (void)
      large.  */
   VARRAY_PUSH_TREE (ssa_names, NULL_TREE);
   free_ssanames = NULL;
-  ssa_names_to_rewrite = BITMAP_ALLOC (NULL);
 }
 
 /* Finalize management of SSA_NAMEs.  */
@@ -146,7 +94,6 @@ init_ssanames (void)
 void
 fini_ssanames (void)
 {
-  BITMAP_FREE (ssa_names_to_rewrite);
   ggc_free (ssa_names);
   ssa_names = NULL;
   free_ssanames = NULL;
@@ -237,11 +184,13 @@ release_ssa_name (tree var)
   if (var == var_ann (SSA_NAME_VAR (var))->default_def)
     return;
 
-  /* If the ssa name is marked for rewriting, it may have multiple definitions,
-     but we may happen to remove just one of them.  So do not remove the
-     ssa name now.  */
-  if (marked_for_rewrite_p (var))
-    return;
+  /* If VAR has been registered for SSA updating, don't remove it.
+     After update_ssa has run, the name will be released.  */
+  if (name_registered_for_update_p (var))
+    {
+      release_ssa_name_after_update_ssa (var);
+      return;
+    }
 
   /* release_ssa_name can be called multiple times on a single SSA_NAME.
      However, it should only end up on our free list one time.   We
@@ -304,7 +253,7 @@ duplicate_ssa_name (tree name, tree stmt)
 
 
 /* Creates a duplicate of the ptr_info_def at PTR_INFO for use by
-   the ssa name NAME.  */
+   the SSA name NAME.  */
 
 void
 duplicate_ssa_name_ptr_info (tree name, struct ptr_info_def *ptr_info)

gcc/tree-vect-transform.c

@@ -1991,6 +1991,11 @@ vect_transform_loop (loop_vec_info loop_vinfo,
 
   slpeel_make_loop_iterate_ntimes (loop, ratio);
 
+  /* The memory tags and pointers in vectorized statements need to
+     have their SSA forms updated.  FIXME, why can't this be delayed
+     until all the loops have been transformed?  */
+  update_ssa (TODO_update_ssa);
+
   if (vect_print_dump_info (REPORT_VECTORIZED_LOOPS, LOOP_LOC (loop_vinfo)))
     fprintf (vect_dump, "LOOP VECTORIZED.");
 }

gcc/tree.h

@@ -2833,13 +2833,6 @@ extern void replace_ssa_name_symbol (tree, tree);
 extern void ssanames_print_statistics (void);
 #endif
 
-extern void mark_for_rewrite (tree);
-extern void unmark_all_for_rewrite (void);
-extern bool marked_for_rewrite_p (tree);
-extern bool any_marked_for_rewrite_p (void);
-extern struct bitmap_head_def *marked_ssa_names (void);
-
-
 /* Return the (unique) IDENTIFIER_NODE node for a given name.
    The name is supplied as a char *.  */