Speed up inliner

[Jan Hubicka]

Hi,
this patch cuts 10 minutes of Mozilla compilation time that is spent by updating keys.
After Richi's removal of overall growth from the cost functions, we no longer need to
update that much.

Bootstrapped/regtested x86_64-linux and tested on Mozilla build. Comitted.

Honza

	* ipa-inline.c (update_all_callee_keys): Remove.
	(inline_small_functions): Simplify priority updating.
Index: ipa-inline.c
===================================================================
--- ipa-inline.c	(revision 187375)
+++ ipa-inline.c	(working copy)
@@ -1097,45 +1097,6 @@ update_callee_keys (fibheap_t heap, stru
       }
 }
 
-/* Recompute heap nodes for each of caller edges of each of callees.
-   Walk recursively into all inline clones.  */
-
-static void
-update_all_callee_keys (fibheap_t heap, struct cgraph_node *node,
-			bitmap updated_nodes)
-{
-  struct cgraph_edge *e = node->callees;
-  if (!e)
-    return;
-  while (true)
-    if (!e->inline_failed && e->callee->callees)
-      e = e->callee->callees;
-    else
-      {
-	struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee,
-								    NULL);
-
-	/* We inlined and thus callees might have different number of calls.
-	   Reset their caches  */
-        reset_node_growth_cache (callee);
-	if (e->inline_failed)
-	  update_caller_keys (heap, callee, updated_nodes, e);
-	if (e->next_callee)
-	  e = e->next_callee;
-	else
-	  {
-	    do
-	      {
-		if (e->caller == node)
-		  return;
-		e = e->caller->callers;
-	      }
-	    while (!e->next_callee);
-	    e = e->next_callee;
-	  }
-      }
-}
-
 /* Enqueue all recursive calls from NODE into priority queue depending on
    how likely we want to recursively inline the call.  */
 
@@ -1488,7 +1449,7 @@ inline_small_functions (void)
 	     at once. Consequently we need to update all callee keys.  */
 	  if (flag_indirect_inlining)
 	    add_new_edges_to_heap (heap, new_indirect_edges);
-          update_all_callee_keys (heap, where, updated_nodes);
+          update_callee_keys (heap, where, updated_nodes);
 	}
       else
 	{
@@ -1527,18 +1488,7 @@ inline_small_functions (void)
 	  reset_edge_caches (edge->callee);
           reset_node_growth_cache (callee);
 
-	  /* We inlined last offline copy to the body.  This might lead
-	     to callees of function having fewer call sites and thus they
-	     may need updating. 
-
-	     FIXME: the callee size could also shrink because more information
-	     is propagated from caller.  We don't track when this happen and
-	     thus we need to recompute everything all the time.  Once this is
-	     solved, "|| 1" should go away.  */
-	  if (callee->global.inlined_to || 1)
-	    update_all_callee_keys (heap, callee, updated_nodes);
-	  else
-	    update_callee_keys (heap, edge->callee, updated_nodes);
+	  update_callee_keys (heap, edge->callee, updated_nodes);
 	}
       where = edge->caller;
       if (where->global.inlined_to)
@@ -1551,11 +1501,6 @@ inline_small_functions (void)
 	 called by function we inlined (since number of it inlinable callers
 	 might change).  */
       update_caller_keys (heap, where, updated_nodes, NULL);
-
-      /* We removed one call of the function we just inlined.  If offline
-	 copy is still needed, be sure to update the keys.  */
-      if (callee != where && !callee->global.inlined_to)
-        update_caller_keys (heap, callee, updated_nodes, NULL);
       bitmap_clear (updated_nodes);
 
       if (dump_file)