PR c/17424

[pf3gnuchains/gcc-fork.git] / gcc / tree-ssanames.c

diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c
index d498270..cc12f28 100644 (file)
--- a/gcc/tree-ssanames.c
+++ b/gcc/tree-ssanames.c
@@ -1,5 +1,5 @@
 /* Generic routines for manipulating SSA_NAME expressions
-   Copyright (C) 2003 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
                                                                                 
 This file is part of GCC.
                                                                                 
@@ -60,7 +60,10 @@ 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.  */
+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;
@@ -74,6 +77,64 @@ 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)
+{
+  if (ssa_names_to_rewrite
+      && bitmap_bit_p (ssa_names_to_rewrite, SSA_NAME_VERSION (var)))
+    return true;
+
+  return false;
+}
+
+/* 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_first_set_bit (ssa_names_to_rewrite) != -1;
+}
+
+/* Mark ssa name VAR for rewriting.  */
+
+void
+mark_for_rewrite (tree var)
+{
+  if (!ssa_names_to_rewrite)
+    ssa_names_to_rewrite = BITMAP_XMALLOC ();
+
+  bitmap_set_bit (ssa_names_to_rewrite, SSA_NAME_VERSION (var));
+}
+
+/* Unmark all ssa names marked for rewrite.  */
+
+void
+unmark_all_for_rewrite (void)
+{
+  if (!ssa_names_to_rewrite)
+    return;
+
+  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_XMALLOC ();
+  if (ssa_names_to_rewrite)
+    bitmap_copy (ret, ssa_names_to_rewrite);
+
+  return ret;
+}
+
 /* Initialize management of SSA_NAMEs.  */
 
 void
@@ -94,6 +155,8 @@ init_ssanames (void)
 void
 fini_ssanames (void)
 {
+  ggc_free (ssa_names);
+  ssa_names = NULL;
   free_ssanames = NULL;
 }
 
@@ -118,13 +181,10 @@ make_ssa_name (tree var, tree stmt)
 {
   tree t;
 
-#if defined ENABLE_CHECKING
-  if ((!DECL_P (var)
-       && TREE_CODE (var) != INDIRECT_REF)
-      || (!IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (stmt)))
-         && TREE_CODE (stmt) != PHI_NODE))
-    abort ();
-#endif
+  gcc_assert (DECL_P (var)
+             || TREE_CODE (var) == INDIRECT_REF);
+
+  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
@@ -145,6 +205,8 @@ make_ssa_name (tree var, tree stmt)
       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;
     }
   else
     {
@@ -160,6 +222,7 @@ make_ssa_name (tree var, tree stmt)
   SSA_NAME_VAR (t) = var;
   SSA_NAME_DEF_STMT (t) = stmt;
   SSA_NAME_PTR_INFO (t) = NULL;
+  SSA_NAME_IN_FREE_LIST (t) = 0;
 
   return t;
 }
@@ -176,6 +239,20 @@ make_ssa_name (tree var, tree stmt)
 void
 release_ssa_name (tree var)
 {
+  if (!var)
+    return;
+
+  /* Never release the default definition for a symbol.  It's a
+     special SSA name that should always exist once it's created.  */
+  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;
+
   /* 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
      keep a status bit in the SSA_NAME node itself to indicate it has
@@ -185,6 +262,7 @@ release_ssa_name (tree var)
      defining statement.  */
   if (! SSA_NAME_IN_FREE_LIST (var))
     {
+      VARRAY_TREE (ssa_names, SSA_NAME_VERSION (var)) = NULL;
       SSA_NAME_IN_FREE_LIST (var) = 1;
       TREE_CHAIN (var) = free_ssanames;
       free_ssanames = var;
@@ -216,4 +294,28 @@ duplicate_ssa_name (tree name, tree stmt)
   return new_name;
 }
 
+
+/* Release all the SSA_NAMEs created by STMT.  */
+
+void
+release_defs (tree stmt)
+{
+  tree def;
+  ssa_op_iter iter;
+
+  FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS)
+    if (TREE_CODE (def) == SSA_NAME)
+      release_ssa_name (def);
+}
+
+
+/* Replace the symbol associated with SSA_NAME with SYM.  */
+
+void
+replace_ssa_name_symbol (tree ssa_name, tree sym)
+{
+  SSA_NAME_VAR (ssa_name) = sym;
+  TREE_TYPE (ssa_name) = TREE_TYPE (sym);
+}
+
 #include "gt-tree-ssanames.h"