* tree-ssanames.c (make_ssa_name): No longer need to clear, then

	initialize key elements here.
	(release_ssa_name): Zero the released SSA_NAME here.
	* tree.h (SSA_NAME_EQUIV, SET_SSA_NAME_EQUIV): New macros.
	(struct tree_ssa_name): Add new "equiv" field.
	* tree-ssa-dom.c (const_and_copies): Kill the global varray.
	(tree_ssa_dominator_optimize): No longer allocate, resize or
	clear CONST_AND_COPIES.
	(get_value_for, set_value_for): Kill.
	(thread_across_edge): Get/set the equivalency using
	SSA_NAME_EQUIV and SET_SSA_NAME_EQUIV.
	(restore_vars_to_original_value): Likewise.
	(record_equivalences_from_phis): Likewise.
	(record_dominating_conditions): Likewise.
	(record_const_or_copy, record_equality): Likewise.
	(lookup_avail_expr): Likewise.
	(record_equivalences_from_stmt, cprop_operand): Likewise.
	(cprop_into_successor_phis): No longer need to pass around
	CONST_AND_COPIES.  Callers updated. Get equivalences via
	SSA_NAME_EQUIV.
	(cprop_into_phis): Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@87787 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 24 insertions, 13 deletions

diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c
index cc12f28d7d4..0d8ccf81b16 100644
--- a/gcc/tree-ssanames.c
+++ b/gcc/tree-ssanames.c
@@ -186,27 +186,19 @@ make_ssa_name (tree var, tree stmt)
 
   gcc_assert (!stmt || EXPR_P (stmt) || TREE_CODE (stmt) == PHI_NODE);
 
-  /* If our free list has an element, then use it.  Also reuse the
-     SSA version number of the element on the free list which helps
-     keep sbitmaps and arrays sized HIGHEST_SSA_VERSION smaller.  */
+  /* If our free list has an element, then use it.  */
   if (free_ssanames)
     {
-      unsigned int save_version;
-
       t = free_ssanames;
       free_ssanames = TREE_CHAIN (free_ssanames);
 #ifdef GATHER_STATISTICS
       ssa_name_nodes_reused++;
 #endif
 
-      /* Clear the node so that it looks just like one we would have
-	 received from make_node.  */
-      save_version = SSA_NAME_VERSION (t);
-      memset (t, 0, tree_size (t));
-      TREE_SET_CODE (t, SSA_NAME);
-      SSA_NAME_VERSION (t) = save_version;
-      gcc_assert (ssa_name (save_version) == NULL);
-      VARRAY_TREE (ssa_names, save_version) = t;
+      /* The node was cleared out when we put it on the free list, so
+	 there is no need to do so again here.  */
+      gcc_assert (ssa_name (SSA_NAME_VERSION (t)) == NULL);
+      VARRAY_TREE (ssa_names, SSA_NAME_VERSION (t)) = t;
     }
   else
     {
@@ -262,8 +254,27 @@ release_ssa_name (tree var)
      defining statement.  */
   if (! SSA_NAME_IN_FREE_LIST (var))
     {
+      tree saved_ssa_name_var = SSA_NAME_VAR (var);
+      int saved_ssa_name_version = SSA_NAME_VERSION (var);
+
       VARRAY_TREE (ssa_names, SSA_NAME_VERSION (var)) = NULL;
+      memset (var, 0, tree_size (var));
+
+      /* First put back the right tree node so that the tree checking
+	 macros do not complain.  */
+      TREE_SET_CODE (var, SSA_NAME);
+
+      /* Restore the version number.  */
+      SSA_NAME_VERSION (var) = saved_ssa_name_version;
+
+      /* Hopefully this can go away once we have the new incremental
+         SSA updating code installed.  */
+      SSA_NAME_VAR (var) = saved_ssa_name_var;
+
+      /* Note this SSA_NAME is now in the first list.  */
       SSA_NAME_IN_FREE_LIST (var) = 1;
+
+      /* And finally link it into the free list.  */
       TREE_CHAIN (var) = free_ssanames;
       free_ssanames = var;
     }