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* cgraph.h (varpool_node_name): Declare.
[pf3gnuchains/gcc-fork.git] / gcc / ipa.c
index b51c219..bf8faa9 100644 (file)
--- a/gcc/ipa.c
+++ b/gcc/ipa.c
@@ -38,6 +38,7 @@ cgraph_postorder (struct cgraph_node **order)
   int stack_size = 0;
   int order_pos = 0;
   struct cgraph_edge *edge, last;
+  int pass;
 
   struct cgraph_node **stack =
     XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
@@ -48,44 +49,48 @@ cgraph_postorder (struct cgraph_node **order)
      right through inline functions.  */
   for (node = cgraph_nodes; node; node = node->next)
     node->aux = NULL;
-  for (node = cgraph_nodes; node; node = node->next)
-    if (!node->aux)
-      {
-       node2 = node;
-       if (!node->callers)
-         node->aux = &last;
-       else
-         node->aux = node->callers;
-       while (node2)
-         {
-           while (node2->aux != &last)
-             {
-               edge = (struct cgraph_edge *) node2->aux;
-               if (edge->next_caller)
-                 node2->aux = edge->next_caller;
-               else
-                 node2->aux = &last;
-               if (!edge->caller->aux)
-                 {
-                   if (!edge->caller->callers)
-                     edge->caller->aux = &last;
-                   else
-                     edge->caller->aux = edge->caller->callers;
-                   stack[stack_size++] = node2;
-                   node2 = edge->caller;
-                   break;
-                 }
-             }
-           if (node2->aux == &last)
-             {
-               order[order_pos++] = node2;
-               if (stack_size)
-                 node2 = stack[--stack_size];
-               else
-                 node2 = NULL;
-             }
-         }
-      }
+  for (pass = 0; pass < 2; pass++)
+    for (node = cgraph_nodes; node; node = node->next)
+      if (!node->aux
+         && (pass
+             || (!cgraph_only_called_directly_p (node)
+                 && !node->address_taken)))
+       {
+         node2 = node;
+         if (!node->callers)
+           node->aux = &last;
+         else
+           node->aux = node->callers;
+         while (node2)
+           {
+             while (node2->aux != &last)
+               {
+                 edge = (struct cgraph_edge *) node2->aux;
+                 if (edge->next_caller)
+                   node2->aux = edge->next_caller;
+                 else
+                   node2->aux = &last;
+                 if (!edge->caller->aux)
+                   {
+                     if (!edge->caller->callers)
+                       edge->caller->aux = &last;
+                     else
+                       edge->caller->aux = edge->caller->callers;
+                     stack[stack_size++] = node2;
+                     node2 = edge->caller;
+                     break;
+                   }
+               }
+             if (node2->aux == &last)
+               {
+                 order[order_pos++] = node2;
+                 if (stack_size)
+                   node2 = stack[--stack_size];
+                 else
+                   node2 = NULL;
+               }
+           }
+       }
   free (stack);
   for (node = cgraph_nodes; node; node = node->next)
     node->aux = NULL;
@@ -129,11 +134,12 @@ cgraph_remove_unreachable_nodes (bool before_inlining_p, FILE *file)
     gcc_assert (!node->aux);
 #endif
   for (node = cgraph_nodes; node; node = node->next)
-    if (node->needed && !node->global.inlined_to
+    if (!cgraph_can_remove_if_no_direct_calls_p (node)
        && ((!DECL_EXTERNAL (node->decl)) 
             || !node->analyzed
             || before_inlining_p))
       {
+        gcc_assert (!node->global.inlined_to);
        node->aux = first;
        first = node;
       }
@@ -237,9 +243,36 @@ cgraph_remove_unreachable_nodes (bool before_inlining_p, FILE *file)
 #ifdef ENABLE_CHECKING
   verify_cgraph ();
 #endif
+
+  /* Reclaim alias pairs for functions that have disappeared from the
+     call graph.  */
+  remove_unreachable_alias_pairs ();
+
   return changed;
 }
 
+static bool
+cgraph_externally_visible_p (struct cgraph_node *node, bool whole_program)
+{
+  if (!node->local.finalized)
+    return false;
+  if (!DECL_COMDAT (node->decl)
+      && (!TREE_PUBLIC (node->decl) || DECL_EXTERNAL (node->decl)))
+    return false;
+  if (!whole_program)
+    return true;
+  /* COMDAT functions must be shared only if they have address taken,
+     otherwise we can produce our own private implementation with
+     -fwhole-program.  */
+  if (DECL_COMDAT (node->decl) && (node->address_taken || !node->analyzed))
+    return true;
+  if (MAIN_NAME_P (DECL_NAME (node->decl)))
+    return true;
+  if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (node->decl)))
+    return true;
+  return false;
+}
+
 /* Mark visibility of all functions.
 
    A local function is one whose calls can occur only in the current
@@ -252,38 +285,57 @@ cgraph_remove_unreachable_nodes (bool before_inlining_p, FILE *file)
    via visibilities for the backend point of view.  */
 
 static unsigned int
-function_and_variable_visibility (void)
+function_and_variable_visibility (bool whole_program)
 {
   struct cgraph_node *node;
   struct varpool_node *vnode;
 
   for (node = cgraph_nodes; node; node = node->next)
     {
-      if (node->reachable
-         && (DECL_COMDAT (node->decl)
-             || (!flag_whole_program
-                 && TREE_PUBLIC (node->decl) && !DECL_EXTERNAL (node->decl))))
-       node->local.externally_visible = true;
+      gcc_assert ((!DECL_WEAK (node->decl) && !DECL_COMDAT (node->decl))
+                 || TREE_PUBLIC (node->decl) || DECL_EXTERNAL (node->decl));
+      if (cgraph_externally_visible_p (node, whole_program))
+        {
+         gcc_assert (!node->global.inlined_to);
+         node->local.externally_visible = true;
+       }
+      else
+       node->local.externally_visible = false;
       if (!node->local.externally_visible && node->analyzed
          && !DECL_EXTERNAL (node->decl))
        {
-         gcc_assert (flag_whole_program || !TREE_PUBLIC (node->decl));
+         gcc_assert (whole_program || !TREE_PUBLIC (node->decl));
          TREE_PUBLIC (node->decl) = 0;
+         DECL_COMDAT (node->decl) = 0;
+         DECL_WEAK (node->decl) = 0;
        }
-      node->local.local = (!node->needed
+      node->local.local = (cgraph_only_called_directly_p (node)
                           && node->analyzed
                           && !DECL_EXTERNAL (node->decl)
                           && !node->local.externally_visible);
     }
   for (vnode = varpool_nodes_queue; vnode; vnode = vnode->next_needed)
     {
+      if (!vnode->finalized)
+        continue;
+      gcc_assert ((!DECL_WEAK (vnode->decl) && !DECL_COMMON (vnode->decl) && !DECL_COMDAT (vnode->decl))
+                 || TREE_PUBLIC (vnode->decl) || DECL_EXTERNAL (node->decl));
       if (vnode->needed
-         && !flag_whole_program
-         && (DECL_COMDAT (vnode->decl) || TREE_PUBLIC (vnode->decl)))
-       vnode->externally_visible = 1;
+         && (DECL_COMDAT (vnode->decl) || TREE_PUBLIC (vnode->decl))
+         && (!whole_program
+             /* We can privatize comdat readonly variables whose address is not taken,
+                but doing so is not going to bring us optimization oppurtunities until
+                we start reordering datastructures.  */
+             || DECL_COMDAT (vnode->decl)
+             || DECL_WEAK (vnode->decl)
+             || lookup_attribute ("externally_visible",
+                                  DECL_ATTRIBUTES (vnode->decl))))
+       vnode->externally_visible = true;
+      else
+        vnode->externally_visible = false;
       if (!vnode->externally_visible)
        {
-         gcc_assert (flag_whole_program || !TREE_PUBLIC (vnode->decl));
+         gcc_assert (whole_program || !TREE_PUBLIC (vnode->decl));
          TREE_PUBLIC (vnode->decl) = 0;
        }
      gcc_assert (TREE_STATIC (vnode->decl));
@@ -301,18 +353,32 @@ function_and_variable_visibility (void)
        if (node->local.externally_visible)
          fprintf (dump_file, " %s", cgraph_node_name (node));
       fprintf (dump_file, "\n\n");
+      fprintf (dump_file, "\nMarking externally visible variables:");
+      for (vnode = varpool_nodes_queue; vnode; vnode = vnode->next_needed)
+       if (vnode->externally_visible)
+         fprintf (dump_file, " %s", varpool_node_name (vnode));
+      fprintf (dump_file, "\n\n");
     }
   cgraph_function_flags_ready = true;
   return 0;
 }
 
+/* Local function pass handling visibilities.  This happens before LTO streaming
+   so in particular -fwhole-program should be ignored at this level.  */
+
+static unsigned int
+local_function_and_variable_visibility (void)
+{
+  return function_and_variable_visibility (flag_whole_program && !flag_lto && !flag_whopr);
+}
+
 struct simple_ipa_opt_pass pass_ipa_function_and_variable_visibility = 
 {
  {
   SIMPLE_IPA_PASS,
   "visibility",                                /* name */
   NULL,                                        /* gate */
-  function_and_variable_visibility,    /* execute */
+  local_function_and_variable_visibility,/* execute */
   NULL,                                        /* sub */
   NULL,                                        /* next */
   0,                                   /* static_pass_number */
@@ -325,6 +391,68 @@ struct simple_ipa_opt_pass pass_ipa_function_and_variable_visibility =
  }
 };
 
+/* Do not re-run on ltrans stage.  */
+
+static bool
+gate_whole_program_function_and_variable_visibility (void)
+{
+  return !flag_ltrans;
+}
+
+/* Bring functionss local at LTO time whith -fwhole-program.  */
+
+static unsigned int
+whole_program_function_and_variable_visibility (void)
+{
+  struct cgraph_node *node;
+  struct varpool_node *vnode;
+
+  function_and_variable_visibility (flag_whole_program);
+
+  for (node = cgraph_nodes; node; node = node->next)
+    if ((node->local.externally_visible && !DECL_COMDAT (node->decl))
+        && node->local.finalized)
+      cgraph_mark_needed_node (node);
+  for (vnode = varpool_nodes_queue; vnode; vnode = vnode->next_needed)
+    if (vnode->externally_visible && !DECL_COMDAT (vnode->decl))
+      varpool_mark_needed_node (vnode);
+  if (dump_file)
+    {
+      fprintf (dump_file, "\nNeeded variables:");
+      for (vnode = varpool_nodes_queue; vnode; vnode = vnode->next_needed)
+       if (vnode->needed)
+         fprintf (dump_file, " %s", varpool_node_name (vnode));
+      fprintf (dump_file, "\n\n");
+    }
+  return 0;
+}
+
+struct ipa_opt_pass_d pass_ipa_whole_program_visibility =
+{
+ {
+  IPA_PASS,
+  "whole-program",                     /* name */
+  gate_whole_program_function_and_variable_visibility,/* gate */
+  whole_program_function_and_variable_visibility,/* execute */
+  NULL,                                        /* sub */
+  NULL,                                        /* next */
+  0,                                   /* static_pass_number */
+  TV_CGRAPHOPT,                                /* tv_id */
+  0,                                   /* properties_required */
+  0,                                   /* properties_provided */
+  0,                                   /* properties_destroyed */
+  0,                                   /* todo_flags_start */
+  TODO_dump_cgraph | TODO_remove_functions/* todo_flags_finish */
+ },
+ NULL,                                 /* generate_summary */
+ NULL,                                 /* write_summary */
+ NULL,                                 /* read_summary */
+ NULL,                                 /* function_read_summary */
+ NULL,                                 /* stmt_fixup */
+ 0,                                    /* TODOs */
+ NULL,                                 /* function_transform */
+ NULL,                                 /* variable_transform */
+};
 
 /* Hash a cgraph node set element.  */