revert: re PR middle-end/63155 (memory hog)

2015-03-19  Richard Biener  <rguenther@suse.de>

	Revert
	2015-03-10  Richard Biener  <rguenther@suse.de>

	PR middle-end/63155
	* tree-ssa-coalesce.h (verify_ssa_coalescing): Declare.
	* tree-ssa-coalesce.c: Include timevar.h.
	(attempt_coalesce): Handle graph being NULL.
	(coalesce_partitions): Call verify_ssa_coalescing if ENABLE_CHECKING.
	Split out abnormal coalescing to ...
	(perform_abnormal_coalescing): ... this function.
	(coalesce_ssa_name): Perform abnormal coalescing without computing
	live/conflict.
	(verify_ssa_coalescing_worker): New function.
	(verify_ssa_coalescing): Likewise.

From-SVN: r221515

3 files changed, 38 insertions, 134 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 467b445..902de05 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,20 @@
+2015-03-19  Richard Biener  <rguenther@suse.de>
+
+	Revert
+	2015-03-10  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/63155
+	* tree-ssa-coalesce.h (verify_ssa_coalescing): Declare.
+	* tree-ssa-coalesce.c: Include timevar.h.
+	(attempt_coalesce): Handle graph being NULL.
+	(coalesce_partitions): Call verify_ssa_coalescing if ENABLE_CHECKING.
+	Split out abnormal coalescing to ...
+	(perform_abnormal_coalescing): ... this function.
+	(coalesce_ssa_name): Perform abnormal coalescing without computing
+	live/conflict.
+	(verify_ssa_coalescing_worker): New function.
+	(verify_ssa_coalescing): Likewise.
+
 2015-03-19  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 	    Jakub Jelinek  <jakub@redhat.com>
 
diff --git a/gcc/tree-ssa-coalesce.c b/gcc/tree-ssa-coalesce.c
index dd6b9c0..1afeefe 100644
--- a/gcc/tree-ssa-coalesce.c
+++ b/gcc/tree-ssa-coalesce.c
@@ -59,7 +59,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-live.h"
 #include "tree-ssa-coalesce.h"
 #include "diagnostic-core.h"
-#include "timevar.h"
 
 
 /* This set of routines implements a coalesce_list.  This is an object which
@@ -1122,8 +1121,8 @@ create_outofssa_var_map (coalesce_list_p cl, bitmap used_in_copy)
 
 
 /* Attempt to coalesce ssa versions X and Y together using the partition
-   mapping in MAP and checking conflicts in GRAPH if not NULL.
-   Output any debug info to DEBUG, if it is nun-NULL.  */
+   mapping in MAP and checking conflicts in GRAPH.  Output any debug info to
+   DEBUG, if it is nun-NULL.  */
 
 static inline bool
 attempt_coalesce (var_map map, ssa_conflicts_p graph, int x, int y,
@@ -1155,8 +1154,7 @@ attempt_coalesce (var_map map, ssa_conflicts_p graph, int x, int y,
     fprintf (debug, " [map: %d, %d] ", p1, p2);
 
 
-  if (!graph
-      || !ssa_conflicts_test_p (graph, p1, p2))
+  if (!ssa_conflicts_test_p (graph, p1, p2))
     {
       var1 = partition_to_var (map, p1);
       var2 = partition_to_var (map, p2);
@@ -1170,13 +1168,10 @@ attempt_coalesce (var_map map, ssa_conflicts_p graph, int x, int y,
 
       /* z is the new combined partition.  Remove the other partition from
 	 the list, and merge the conflicts.  */
-      if (graph)
-	{
-	  if (z == p1)
-	    ssa_conflicts_merge (graph, p1, p2);
-	  else
-	    ssa_conflicts_merge (graph, p2, p1);
-	}
+      if (z == p1)
+	ssa_conflicts_merge (graph, p1, p2);
+      else
+	ssa_conflicts_merge (graph, p2, p1);
 
       if (debug)
 	fprintf (debug, ": Success -> %d\n", z);
@@ -1190,16 +1185,24 @@ attempt_coalesce (var_map map, ssa_conflicts_p graph, int x, int y,
 }
 
 
-/* Perform all abnormal coalescing on MAP.
-   Debug output is sent to DEBUG if it is non-NULL.  */
+/* Attempt to Coalesce partitions in MAP which occur in the list CL using
+   GRAPH.  Debug output is sent to DEBUG if it is non-NULL.  */
 
 static void
-perform_abnormal_coalescing (var_map map, FILE *debug)
+coalesce_partitions (var_map map, ssa_conflicts_p graph, coalesce_list_p cl,
+		     FILE *debug)
 {
+  int x = 0, y = 0;
+  tree var1, var2;
+  int cost;
   basic_block bb;
   edge e;
   edge_iterator ei;
 
+  /* First, coalesce all the copies across abnormal edges.  These are not placed
+     in the coalesce list because they do not need to be sorted, and simply
+     consume extra memory/compilation time in large programs.  */
+
   FOR_EACH_BB_FN (bb, cfun)
     {
       FOR_EACH_EDGE (e, ei, bb->preds)
@@ -1223,23 +1226,11 @@ perform_abnormal_coalescing (var_map map, FILE *debug)
 		if (debug)
 		  fprintf (debug, "Abnormal coalesce: ");
 
-		if (!attempt_coalesce (map, NULL, v1, v2, debug))
+		if (!attempt_coalesce (map, graph, v1, v2, debug))
 		  fail_abnormal_edge_coalesce (v1, v2);
 	      }
 	  }
     }
-}
-
-/* Attempt to Coalesce partitions in MAP which occur in the list CL using
-   GRAPH.  Debug output is sent to DEBUG if it is non-NULL.  */
-
-static void
-coalesce_partitions (var_map map, ssa_conflicts_p graph, coalesce_list_p cl,
-		     FILE *debug)
-{
-  int x = 0, y = 0;
-  tree var1, var2;
-  int cost;
 
   /* Now process the items in the coalesce list.  */
 
@@ -1294,11 +1285,6 @@ coalesce_ssa_name (void)
   var_map map;
   unsigned int i;
 
-#ifdef ENABLE_CHECKING
-  /* Verify we can perform all must coalesces.  */
-  verify_ssa_coalescing ();
-#endif
-
   cl = create_coalesce_list ();
   map = create_outofssa_var_map (cl, used_in_copies);
 
@@ -1355,15 +1341,6 @@ coalesce_ssa_name (void)
       return map;
     }
 
-  /* First, coalesce all the copies across abnormal edges.  These are not placed
-     in the coalesce list because they do not need to be sorted, and simply
-     consume extra memory/compilation time in large programs.
-     Performing abnormal coalescing also needs no live/conflict computation
-     because it must succeed (but we lose checking that it indeed does).
-     Still for PR63155 this reduces memory usage from 10GB to zero.  */
-  perform_abnormal_coalescing (map,
-			       ((dump_flags & TDF_DETAILS) ? dump_file : NULL));
-
   if (dump_file && (dump_flags & TDF_DETAILS))
     dump_var_map (dump_file, map);
 
@@ -1394,100 +1371,11 @@ coalesce_ssa_name (void)
 
   /* Now coalesce everything in the list.  */
   coalesce_partitions (map, graph, cl,
-		       ((dump_flags & TDF_DETAILS) ? dump_file : NULL));
+		       ((dump_flags & TDF_DETAILS) ? dump_file
+						   : NULL));
 
   delete_coalesce_list (cl);
   ssa_conflicts_delete (graph);
 
   return map;
 }
-
-
-/* Helper for verify_ssa_coalescing.  Operates in two modes:
-   1) scan the function for coalesces we must perform and store the
-      SSA names participating in USED_IN_COPIES
-   2) scan the function for coalesces and verify they can be performed
-      under the constraints of GRAPH updating MAP in the process
-   FIXME:  This can be extended to verify that the virtual operands
-   form a factored use-def chain (coalescing the active virtual use
-   with the virtual def at virtual def point).  */
-
-static void
-verify_ssa_coalescing_worker (bitmap used_in_copies,
-			      var_map map, ssa_conflicts_p graph)
-{
-  basic_block bb;
-
-  FOR_EACH_BB_FN (bb, cfun)
-    {
-      edge e;
-      edge_iterator ei;
-
-      FOR_EACH_EDGE (e, ei, bb->preds)
-	if (e->flags & EDGE_ABNORMAL)
-	  {
-	    gphi_iterator gsi;
-	    for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
-		 gsi_next (&gsi))
-	      {
-		gphi *phi = gsi.phi ();
-		tree arg = PHI_ARG_DEF (phi, e->dest_idx);
-		if (SSA_NAME_IS_DEFAULT_DEF (arg)
-		    && (!SSA_NAME_VAR (arg)
-			|| TREE_CODE (SSA_NAME_VAR (arg)) != PARM_DECL))
-		  continue;
-
-		tree res = PHI_RESULT (phi);
-
-		int v1 = SSA_NAME_VERSION (res);
-		int v2 = SSA_NAME_VERSION (arg);
-		if (used_in_copies)
-		  {
-		    bitmap_set_bit (used_in_copies, v1);
-		    bitmap_set_bit (used_in_copies, v2);
-		  }
-		else
-		  {
-		    int p1 = var_to_partition (map, res);
-		    int p2 = var_to_partition (map, arg);
-		    if (p1 != p2)
-		      {
-			if (ssa_conflicts_test_p (graph, p1, p2))
-			  fail_abnormal_edge_coalesce (v1, v2);
-			int z = var_union (map,
-					   partition_to_var (map, p1),
-					   partition_to_var (map, p2));
-			if (z == p1)
-			  ssa_conflicts_merge (graph, p1, p2);
-			else
-			  ssa_conflicts_merge (graph, p2, p1);
-		      }
-		  }
-	      }
-	  }
-    }
-}
-
-/* Verify that we can coalesce SSA names we must coalesce.  */
-
-DEBUG_FUNCTION void
-verify_ssa_coalescing (void)
-{
-  auto_timevar tv (TV_TREE_SSA_VERIFY);
-  bitmap used_in_copies = BITMAP_ALLOC (NULL);
-  verify_ssa_coalescing_worker (used_in_copies, NULL, NULL);
-  if (bitmap_empty_p (used_in_copies))
-    {
-      BITMAP_FREE (used_in_copies);
-      return;
-    }
-  var_map map = init_var_map (num_ssa_names);
-  partition_view_bitmap (map, used_in_copies, true);
-  BITMAP_FREE (used_in_copies);
-  tree_live_info_p liveinfo = calculate_live_ranges (map, false);
-  ssa_conflicts_p graph = build_ssa_conflict_graph (liveinfo);
-  delete_tree_live_info (liveinfo);
-  verify_ssa_coalescing_worker (NULL, map, graph);
-  ssa_conflicts_delete (graph);
-  delete_var_map (map);
-}
diff --git a/gcc/tree-ssa-coalesce.h b/gcc/tree-ssa-coalesce.h
index 06c33bf..99b188a 100644
--- a/gcc/tree-ssa-coalesce.h
+++ b/gcc/tree-ssa-coalesce.h
@@ -21,6 +21,5 @@ along with GCC; see the file COPYING3.  If not see
 #define GCC_TREE_SSA_COALESCE_H
 
 extern var_map coalesce_ssa_name (void);
-extern void verify_ssa_coalescing (void);
 
 #endif /* GCC_TREE_SSA_COALESCE_H */