[PATCH] Call flush_ssaname_freelist more often

[PATCH] Call flush_ssaname_freelist more often
       * passes.c (execute_function_todo): Do not call flush_ssaname_freelist
        here.  Instead...
        (execute_todo): Call it here.
        * tree-ssanames.c (make_ssa_name_fn): Unconditionally gather reuse
        statistics
        (pass_release_ssa_names::execute): Do not call flusH_ssaname_freelist.

From-SVN: r229272

gcc/ChangeLog

+2015-10-23  Jeff Law  <law@redhat.com>
+
+	* passes.c (execute_function_todo): Do not call flush_ssaname_freelist
+	here.  Instead...
+	(execute_todo): Call it here.
+	* tree-ssanames.c (make_ssa_name_fn): Unconditionally gather reuse
+	statistics
+	(pass_release_ssa_names::execute): Do not call flusH_ssaname_freelist.
+
 2015-10-23  Gregor Richards  <gregor.richards@uwaterloo.ca>
 	    Szabolcs Nagy  <szabolcs.nagy@arm.com>
 

gcc/passes.c

@@ -1919,14 +1919,6 @@ execute_function_todo (function *fn, void *data)
     {
       cleanup_tree_cfg ();
 
-      /* Once unreachable nodes have been removed from the CFG,
-	 there can't be any lingering references to released
-	 SSA_NAMES (because there is no more unreachable code).
-
-	 Thus, now is the time to flush the SSA_NAMEs freelist.  */
-      if (fn->gimple_df)
-	flush_ssaname_freelist ();
-
       /* When cleanup_tree_cfg merges consecutive blocks, it may
 	 perform some simplistic propagation when removing single
 	 valued PHI nodes.  This propagation may, in turn, cause the
@@ -2032,6 +2024,11 @@ execute_todo (unsigned int flags)
   if (flags)
     do_per_function (execute_function_todo, (void *)(size_t) flags);
 
+  /* At this point we should not have any unreachable code in the
+     CFG, so it is safe to flush the pending freelist for SSA_NAMES.  */
+  if (cfun && cfun->gimple_df)
+    flush_ssaname_freelist ();
+
   /* Always remove functions just as before inlining: IPA passes might be
      interested to see bodies of extern inline functions that are not inlined
      to analyze side effects.  The full removal is done just at the end

gcc/tree-ssanames.c

@@ -151,8 +151,7 @@ make_ssa_name_fn (struct function *fn, tree var, gimple *stmt)
   if (!vec_safe_is_empty (FREE_SSANAMES (fn)))
     {
       t = FREE_SSANAMES (fn)->pop ();
-      if (GATHER_STATISTICS)
-	ssa_name_nodes_reused++;
+      ssa_name_nodes_reused++;
 
       /* The node was cleared out when we put it on the free list, so
 	 there is no need to do so again here.  */
@@ -164,8 +163,7 @@ make_ssa_name_fn (struct function *fn, tree var, gimple *stmt)
       t = make_node (SSA_NAME);
       SSA_NAME_VERSION (t) = SSANAMES (fn)->length ();
       vec_safe_push (SSANAMES (fn), t);
-      if (GATHER_STATISTICS)
-	ssa_name_nodes_created++;
+      ssa_name_nodes_created++;
     }
 
   if (TYPE_P (var))
@@ -646,7 +644,6 @@ unsigned int
 pass_release_ssa_names::execute (function *fun)
 {
   unsigned i, j;
-  flush_ssaname_freelist ();
   int n = vec_safe_length (FREE_SSANAMES (fun));
 
   /* Now release the freelist.  */