tree-ssa-pre.c (do_regular_insertion): Add FIXME markers at points of…

tree-ssa-pre.c (do_regular_insertion): Add FIXME markers at points of potentially huge memset overhead.

	* tree-ssa-pre.c (do_regular_insertion): Add FIXME markers at points
	of potentially huge memset overhead.
	(do_partial_partial_insertion): Likewise.
	* cfgexpand.c (gimple_expand_cfg): Use XCNEWVEC instead of xcalloc.
	* tree-vrp.c (find_assert_locations): Use XNEWVEC instead of XCNEWVEC
	for arrays to be filled by pre_and_rev_post_order_compute.  Allocate
	the right number of slots, not that number plus NUM_FIXED_BLOCKS.
	* tree-ssa-reassoc.c (init_reassoc): Likewise.
	* cfganal.c (dfs_enumerate_from): Use XNEWVEC instead of XCNEWVEC for
	array used as stack.
	* tree-ssa-sccvn.c (init_scc_vn): Use XNEWVEC instead of XCNEWVEC for
	arrays to be filled by pre_and_rev_post_order_compute.
	* cfgloopmanip.c (find_path): Use XNEWVEC instead of XCNEWVEC for
	array to be filled by dfs_enumerate_from.
	(remove_path): Likewise.
	(duplicate_loop_to_header_edge): Use XNEWVEC instead of XCNEWVEC for
	array of loops that is filled on the next lines.
	* cfgloop.c (get_loop_body): Use XNEWVEC instead of XCNEWVEC for
	array of basic blocks to be returned.
	(get_loop_body_in_dom_order): Likewise.
	(get_loop_body_in_bfs_order): Likewise.
	* tree-ssa-loop-manip.c (loop_renamer_obstack): New static obstack
	for all bitmaps used for rewriting into loop-closed SSA form.
	(add_exit_phis_var): Allocate the def bitmap on it.  Clear the livein
	bitmap at the end to release a lot of memory.
	(add_exit_phis): Allocate the exits bitmap on the new obstack.
	(get_loops_exits): Allocate the exits bitmap on the new obstack.
	(find_uses_to_rename_use): Allocate a use_blocks bitmap if ver is
	seen for the first time.
	(find_uses_to_rename): Add "???" for why the whole function must
	be re-scanned if changed_bbs is empty.
	(rewrite_into_loop_closed_ssa): Allocate bitmaps on the new obstack.
	Use XNEWVEC to allocate the use_blocks array.  Initialize the new
	obstack, and free it at the end.  Remove loop over all SSA names.
	(check_loop_closed_ssa_stmt): Look only at SSA_OP_USE operands.
	* tree-cfg.c (move_sese_region_to_fn): Use XNEWVEC instead of
	xcalloc to allocate edge_pred and edge_flag arrays.

From-SVN: r190359

gcc/ChangeLog

+2012-08-13  Steven Bosscher  <steven@gcc.gnu.org>
+
+	* tree-ssa-pre.c (do_regular_insertion): Add FIXME markers at points
+	of potentially huge memset overhead.
+	(do_partial_partial_insertion): Likewise.
+	* cfgexpand.c (gimple_expand_cfg): Use XCNEWVEC instead of xcalloc.
+	* tree-vrp.c (find_assert_locations): Use XNEWVEC instead of XCNEWVEC
+	for arrays to be filled by pre_and_rev_post_order_compute.  Allocate
+	the right number of slots, not that number plus NUM_FIXED_BLOCKS.
+	* tree-ssa-reassoc.c (init_reassoc): Likewise.
+	* cfganal.c (dfs_enumerate_from): Use XNEWVEC instead of XCNEWVEC for
+	array used as stack.
+	* tree-ssa-sccvn.c (init_scc_vn): Use XNEWVEC instead of XCNEWVEC for
+	arrays to be filled by pre_and_rev_post_order_compute.
+	* cfgloopmanip.c (find_path): Use XNEWVEC instead of XCNEWVEC for
+	array to be filled by dfs_enumerate_from.
+	(remove_path): Likewise.
+	(duplicate_loop_to_header_edge): Use XNEWVEC instead of XCNEWVEC for
+	array of loops that is filled on the next lines.
+	* cfgloop.c (get_loop_body): Use XNEWVEC instead of XCNEWVEC for
+	array of basic blocks to be returned.
+	(get_loop_body_in_dom_order): Likewise.
+	(get_loop_body_in_bfs_order): Likewise.
+	* tree-ssa-loop-manip.c (loop_renamer_obstack): New static obstack
+	for all bitmaps used for rewriting into loop-closed SSA form.
+	(add_exit_phis_var): Allocate the def bitmap on it.  Clear the livein
+	bitmap at the end to release a lot of memory.
+	(add_exit_phis): Allocate the exits bitmap on the new obstack.
+	(get_loops_exits): Allocate the exits bitmap on the new obstack.
+	(find_uses_to_rename_use): Allocate a use_blocks bitmap if ver is
+	seen for the first time.
+	(find_uses_to_rename): Add "???" for why the whole function must
+	be re-scanned if changed_bbs is empty.
+	(rewrite_into_loop_closed_ssa): Allocate bitmaps on the new obstack.
+	Use XNEWVEC to allocate the use_blocks array.  Initialize the new
+	obstack, and free it at the end.  Remove loop over all SSA names.
+	(check_loop_closed_ssa_stmt): Look only at SSA_OP_USE operands.
+	* tree-cfg.c (move_sese_region_to_fn): Use XNEWVEC instead of
+	xcalloc to allocate edge_pred and edge_flag arrays.
+
 2012-08-13  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386.h (FIXED_REGISTERS): Do not mark REX registers here.

gcc/cfganal.c

@@ -1019,7 +1019,7 @@ dfs_enumerate_from (basic_block bb, int reverse,
       v_size = size;
     }
 
-  st = XCNEWVEC (basic_block, rslt_max);
+  st = XNEWVEC (basic_block, rslt_max);
   rslt[tv++] = st[sp++] = bb;
   MARK_VISITED (bb);
   while (sp)

gcc/cfgexpand.c

@@ -4334,8 +4334,7 @@ gimple_expand_cfg (void)
   timevar_push (TV_OUT_OF_SSA);
   rewrite_out_of_ssa (&SA);
   timevar_pop (TV_OUT_OF_SSA);
-  SA.partition_to_pseudo = (rtx *)xcalloc (SA.map->num_partitions,
-					   sizeof (rtx));
+  SA.partition_to_pseudo = XCNEWVEC (rtx, SA.map->num_partitions);
 
   /* Make sure all values used by the optimization passes have sane
      defaults.  */

gcc/cfgloop.c

@@ -805,7 +805,7 @@ get_loop_body (const struct loop *loop)
 
   gcc_assert (loop->num_nodes);
 
-  body = XCNEWVEC (basic_block, loop->num_nodes);
+  body = XNEWVEC (basic_block, loop->num_nodes);
 
   if (loop->latch == EXIT_BLOCK_PTR)
     {
@@ -865,7 +865,7 @@ get_loop_body_in_dom_order (const struct loop *loop)
 
   gcc_assert (loop->num_nodes);
 
-  tovisit = XCNEWVEC (basic_block, loop->num_nodes);
+  tovisit = XNEWVEC (basic_block, loop->num_nodes);
 
   gcc_assert (loop->latch != EXIT_BLOCK_PTR);
 
@@ -904,7 +904,7 @@ get_loop_body_in_bfs_order (const struct loop *loop)
   gcc_assert (loop->num_nodes);
   gcc_assert (loop->latch != EXIT_BLOCK_PTR);
 
-  blocks = XCNEWVEC (basic_block, loop->num_nodes);
+  blocks = XNEWVEC (basic_block, loop->num_nodes);
   visited = BITMAP_ALLOC (NULL);
 
   bb = loop->header;

gcc/cfgloopmanip.c

@@ -71,7 +71,7 @@ find_path (edge e, basic_block **bbs)
   gcc_assert (EDGE_COUNT (e->dest->preds) <= 1);
 
   /* Find bbs in the path.  */
-  *bbs = XCNEWVEC (basic_block, n_basic_blocks);
+  *bbs = XNEWVEC (basic_block, n_basic_blocks);
   return dfs_enumerate_from (e->dest, 0, rpe_enum_p, *bbs,
 			     n_basic_blocks, e->dest);
 }
@@ -322,7 +322,7 @@ remove_path (edge e)
   nrem = find_path (e, &rem_bbs);
 
   n_bord_bbs = 0;
-  bord_bbs = XCNEWVEC (basic_block, n_basic_blocks);
+  bord_bbs = XNEWVEC (basic_block, n_basic_blocks);
   seen = sbitmap_alloc (last_basic_block);
   sbitmap_zero (seen);
 
@@ -1135,7 +1135,7 @@ duplicate_loop_to_header_edge (struct loop *loop, edge e,
   n_orig_loops = 0;
   for (aloop = loop->inner; aloop; aloop = aloop->next)
     n_orig_loops++;
-  orig_loops = XCNEWVEC (struct loop *, n_orig_loops);
+  orig_loops = XNEWVEC (struct loop *, n_orig_loops);
   for (aloop = loop->inner, i = 0; aloop; aloop = aloop->next, i++)
     orig_loops[i] = aloop;
 

gcc/tree-cfg.c

@@ -6467,8 +6467,8 @@ move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
      EXIT_BB so that we can re-attach them to the new basic block that
      will replace the region.  */
   num_entry_edges = EDGE_COUNT (entry_bb->preds);
-  entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block));
-  entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int));
+  entry_pred = XNEWVEC (basic_block, num_entry_edges);
+  entry_flag = XNEWVEC (int, num_entry_edges);
   entry_prob = XNEWVEC (unsigned, num_entry_edges);
   i = 0;
   for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;)
@@ -6482,9 +6482,8 @@ move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb,
   if (exit_bb)
     {
       num_exit_edges = EDGE_COUNT (exit_bb->succs);
-      exit_succ = (basic_block *) xcalloc (num_exit_edges,
-					   sizeof (basic_block));
-      exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int));
+      exit_succ = XNEWVEC (basic_block, num_exit_edges);
+      exit_flag = XNEWVEC (int, num_exit_edges);
       exit_prob = XNEWVEC (unsigned, num_exit_edges);
       i = 0;
       for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;)

gcc/tree-ssa-loop-manip.c

@@ -34,6 +34,10 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-inline.h"
 #include "langhooks.h"
 
+/* All bitmaps for rewriting into loop-closed SSA go on this obstack,
+   so that we can free them all at once.  */
+static bitmap_obstack loop_renamer_obstack;
+
 /* Creates an induction variable with value BASE + STEP * iteration in LOOP.
    It is expected that neither BASE nor STEP are shared with other expressions
    (unless the sharing rules allow this).  Use VAR as a base var_decl for it
@@ -168,7 +172,7 @@ add_exit_phis_var (tree var, bitmap livein, bitmap exits)
   gcc_checking_assert (is_gimple_reg (var));
   bitmap_clear_bit (livein, def_bb->index);
 
-  def = BITMAP_ALLOC (NULL);
+  def = BITMAP_ALLOC (&loop_renamer_obstack);
   bitmap_set_bit (def, def_bb->index);
   compute_global_livein (livein, def);
   BITMAP_FREE (def);
@@ -177,6 +181,10 @@ add_exit_phis_var (tree var, bitmap livein, bitmap exits)
     {
       add_exit_phis_edge (BASIC_BLOCK (index), var);
     }
+
+  /* Free the livein bitmap.  We'll not be needing it anymore, and
+     it may have grown quite large.  No reason to hold on to it.  */
+  bitmap_clear (livein);
 }
 
 /* Add exit phis for the names marked in NAMES_TO_RENAME.
@@ -200,7 +208,7 @@ add_exit_phis (bitmap names_to_rename, bitmap *use_blocks, bitmap loop_exits)
 static bitmap
 get_loops_exits (void)
 {
-  bitmap exits = BITMAP_ALLOC (NULL);
+  bitmap exits = BITMAP_ALLOC (&loop_renamer_obstack);
   basic_block bb;
   edge e;
   edge_iterator ei;
@@ -253,11 +261,11 @@ find_uses_to_rename_use (basic_block bb, tree use, bitmap *use_blocks,
   if (flow_bb_inside_loop_p (def_loop, bb))
     return;
 
-  if (!use_blocks[ver])
-    use_blocks[ver] = BITMAP_ALLOC (NULL);
+  /* If we're seeing VER for the first time, we still have to allocate
+     a bitmap for its uses.  */
+  if (bitmap_set_bit (need_phis, ver))
+    use_blocks[ver] = BITMAP_ALLOC (&loop_renamer_obstack);
   bitmap_set_bit (use_blocks[ver], bb->index);
-
-  bitmap_set_bit (need_phis, ver);
 }
 
 /* For uses in STMT, mark names that are used outside of the loop they are
@@ -312,6 +320,7 @@ find_uses_to_rename (bitmap changed_bbs, bitmap *use_blocks, bitmap need_phis)
   unsigned index;
   bitmap_iterator bi;
 
+  /* ??? If CHANGED_BBS is empty we rewrite the whole function -- why?  */
   if (changed_bbs && !bitmap_empty_p (changed_bbs))
     {
       EXECUTE_IF_SET_IN_BITMAP (changed_bbs, 0, index, bi)
@@ -365,22 +374,25 @@ rewrite_into_loop_closed_ssa (bitmap changed_bbs, unsigned update_flag)
 {
   bitmap loop_exits;
   bitmap *use_blocks;
-  unsigned i, old_num_ssa_names;
   bitmap names_to_rename;
 
   loops_state_set (LOOP_CLOSED_SSA);
   if (number_of_loops () <= 1)
     return;
 
+  bitmap_obstack_initialize (&loop_renamer_obstack);
+
   loop_exits = get_loops_exits ();
-  names_to_rename = BITMAP_ALLOC (NULL);
+  names_to_rename = BITMAP_ALLOC (&loop_renamer_obstack);
 
   /* If the pass has caused the SSA form to be out-of-date, update it
      now.  */
   update_ssa (update_flag);
 
-  old_num_ssa_names = num_ssa_names;
-  use_blocks = XCNEWVEC (bitmap, old_num_ssa_names);
+  /* Uses of names to rename.  We don't have to initialize this array,
+     because we know that we will only have entries for the SSA names
+     in NAMES_TO_RENAME.  */
+  use_blocks = XCNEWVEC (bitmap, num_ssa_names);
 
   /* Find the uses outside loops.  */
   find_uses_to_rename (changed_bbs, use_blocks, names_to_rename);
@@ -389,11 +401,8 @@ rewrite_into_loop_closed_ssa (bitmap changed_bbs, unsigned update_flag)
      rewrite.  */
   add_exit_phis (names_to_rename, use_blocks, loop_exits);
 
-  for (i = 0; i < old_num_ssa_names; i++)
-    BITMAP_FREE (use_blocks[i]);
+  bitmap_obstack_release (&loop_renamer_obstack);
   free (use_blocks);
-  BITMAP_FREE (loop_exits);
-  BITMAP_FREE (names_to_rename);
 
   /* Fix up all the names found to be used outside their original
      loops.  */
@@ -428,7 +437,7 @@ check_loop_closed_ssa_stmt (basic_block bb, gimple stmt)
   if (is_gimple_debug (stmt))
     return;
 
-  FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES)
+  FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE)
     check_loop_closed_ssa_use (bb, var);
 }
 

gcc/tree-ssa-pre.c

@@ -3442,6 +3442,9 @@ do_regular_insertion (basic_block block, basic_block dom)
 	      continue;
 	    }
 
+	  /* FIXME: This costs N_EXPR*N_BASIC_BLOCKS.  Should use
+	     a less costly data structure for avail (e.g. a VEC
+	     indexed by edge index).  */
 	  avail = XCNEWVEC (pre_expr, last_basic_block);
 	  FOR_EACH_EDGE (pred, ei, block->preds)
 	    {
@@ -3602,6 +3605,9 @@ do_partial_partial_insertion (basic_block block, basic_block dom)
 	  if (bitmap_set_contains_value (AVAIL_OUT (dom), val))
 	    continue;
 
+	  /* FIXME: This costs N_EXPR*N_BASIC_BLOCKS.  Should use
+	     a less costly data structure for avail (e.g. a VEC
+	     indexed by edge index).  */
 	  avail = XCNEWVEC (pre_expr, last_basic_block);
 	  FOR_EACH_EDGE (pred, ei, block->preds)
 	    {

gcc/tree-ssa-reassoc.c

@@ -3613,7 +3613,7 @@ init_reassoc (void)
 {
   int i;
   long rank = 2;
-  int *bbs = XNEWVEC (int, last_basic_block + 1);
+  int *bbs = XNEWVEC (int, n_basic_blocks - NUM_FIXED_BLOCKS);
 
   /* Find the loops, so that we can prevent moving calculations in
      them.  */
@@ -3628,7 +3628,7 @@ init_reassoc (void)
   /* Reverse RPO (Reverse Post Order) will give us something where
      deeper loops come later.  */
   pre_and_rev_post_order_compute (NULL, bbs, false);
-  bb_rank = XCNEWVEC (long, last_basic_block + 1);
+  bb_rank = XCNEWVEC (long, last_basic_block);
   operand_rank = pointer_map_create ();
 
   /* Give each default definition a distinct rank.  This includes

gcc/tree-ssa-sccvn.c

@@ -3835,13 +3835,14 @@ init_scc_vn (void)
   vn_ssa_aux_table = VEC_alloc (vn_ssa_aux_t, heap, num_ssa_names + 1);
   /* VEC_alloc doesn't actually grow it to the right size, it just
      preallocates the space to do so.  */
-  VEC_safe_grow_cleared (vn_ssa_aux_t, heap, vn_ssa_aux_table, num_ssa_names + 1);
+  VEC_safe_grow_cleared (vn_ssa_aux_t, heap, vn_ssa_aux_table,
+			 num_ssa_names + 1);
   gcc_obstack_init (&vn_ssa_aux_obstack);
 
   shared_lookup_phiargs = NULL;
   shared_lookup_references = NULL;
-  rpo_numbers = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
-  rpo_numbers_temp = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
+  rpo_numbers = XNEWVEC (int, last_basic_block);
+  rpo_numbers_temp = XNEWVEC (int, n_basic_blocks - NUM_FIXED_BLOCKS);
   pre_and_rev_post_order_compute (NULL, rpo_numbers_temp, false);
 
   /* RPO numbers is an array of rpo ordering, rpo[i] = bb means that

gcc/tree-vrp.c

@@ -5574,19 +5574,19 @@ find_assert_locations_1 (basic_block bb, sbitmap live)
 static bool
 find_assert_locations (void)
 {
-  int *rpo = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
-  int *bb_rpo = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
-  int *last_rpo = XCNEWVEC (int, last_basic_block + NUM_FIXED_BLOCKS);
+  int *rpo = XNEWVEC (int, last_basic_block);
+  int *bb_rpo = XNEWVEC (int, last_basic_block);
+  int *last_rpo = XCNEWVEC (int, last_basic_block);
   int rpo_cnt, i;
   bool need_asserts;
 
-  live = XCNEWVEC (sbitmap, last_basic_block + NUM_FIXED_BLOCKS);
+  live = XCNEWVEC (sbitmap, last_basic_block);
   rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false);
   for (i = 0; i < rpo_cnt; ++i)
     bb_rpo[rpo[i]] = i;
 
   need_asserts = false;
-  for (i = rpo_cnt-1; i >= 0; --i)
+  for (i = rpo_cnt - 1; i >= 0; --i)
     {
       basic_block bb = BASIC_BLOCK (rpo[i]);
       edge e;
@@ -5647,7 +5647,7 @@ find_assert_locations (void)
   XDELETEVEC (rpo);
   XDELETEVEC (bb_rpo);
   XDELETEVEC (last_rpo);
-  for (i = 0; i < last_basic_block + NUM_FIXED_BLOCKS; ++i)
+  for (i = 0; i < last_basic_block; ++i)
     if (live[i])
       sbitmap_free (live[i]);
   XDELETEVEC (live);