Another inline heuristic tweak

Index: lto-cgraph.c
===================================================================
--- lto-cgraph.c	(revision 221777)
+++ lto-cgraph.c	(working copy)
@@ -578,6 +578,7 @@  lto_output_node (struct lto_simple_outpu
   bp_pack_enum (&bp, ld_plugin_symbol_resolution,
 	        LDPR_NUM_KNOWN, node->resolution);
   bp_pack_value (&bp, node->instrumentation_clone, 1);
+  bp_pack_value (&bp, node->split_part, 1);
   streamer_write_bitpack (&bp);
   streamer_write_data_stream (ob->main_stream, section, strlen (section) + 1);
 
@@ -1214,6 +1216,7 @@  input_overwrite_node (struct lto_file_de
   node->resolution = bp_unpack_enum (bp, ld_plugin_symbol_resolution,
 				     LDPR_NUM_KNOWN);
   node->instrumentation_clone = bp_unpack_value (bp, 1);
+  node->split_part = bp_unpack_value (bp, 1);
   gcc_assert (flag_ltrans
 	      || (!node->in_other_partition
 		  && !node->used_from_other_partition));
Index: ipa-inline.c
===================================================================
--- ipa-inline.c	(revision 221777)
+++ ipa-inline.c	(working copy)
@@ -1088,6 +1088,7 @@  edge_badness (struct cgraph_edge *edge,
   else if (opt_for_fn (caller->decl, flag_guess_branch_prob) || caller->count)
     {
       sreal numerator, denominator;
+      int overall_growth;
 
       numerator = (compute_uninlined_call_time (callee_info, edge)
 		   - compute_inlined_call_time (edge, edge_time));
@@ -1098,8 +1099,74 @@  edge_badness (struct cgraph_edge *edge,
       else if (opt_for_fn (caller->decl, flag_branch_probabilities))
 	numerator = numerator >> 11;
       denominator = growth;
-      if (callee_info->growth > 0)
-	denominator *= callee_info->growth * callee_info->growth;
+
+      overall_growth = callee_info->growth;
+
+      /* Look for inliner wrappers of the form:
+
+	 inline_caller ()
+	   {
+	     do_fast_job...
+	     if (need_more_work)
+	       noninline_callee ();
+	   }
+	 Withhout panilizing this case, we usually inline noninline_callee
+	 into the inline_caller because overall_growth is small preventing
+	 further inlining of inline_caller.
+
+	 Penalize only callgraph edges to functions with small overall
+	 growth ...
+	*/
+      if (growth > overall_growth
+	  /* ... and having only one caller which is not inlined ... */
+	  && callee_info->single_caller
+	  && !edge->caller->global.inlined_to
+	  /* ... and edges executed only conditionally ... */
+	  && edge->frequency < CGRAPH_FREQ_BASE
+	  /* ... consider case where callee is not inline but caller is ... */
+	  && ((!DECL_DECLARED_INLINE_P (edge->callee->decl)
+	       && DECL_DECLARED_INLINE_P (caller->decl))
+	      /* ... or when early optimizers decided to split and edge
+		 frequency still indicates splitting is a win ... */
+	      || (callee->split_part && !caller->split_part
+		  && edge->frequency
+		     < CGRAPH_FREQ_BASE
+		       * PARAM_VALUE
+			  (PARAM_PARTIAL_INLINING_ENTRY_PROBABILITY) / 100
+		  /* ... and do not overwrite user specified hints.   */
+		  && (!DECL_DECLARED_INLINE_P (edge->callee->decl)
+		      || DECL_DECLARED_INLINE_P (caller->decl)))))
+	{
+	  struct inline_summary *caller_info = inline_summaries->get (caller);
+	  int caller_growth = caller_info->growth;
+
+	  /* Only apply the penalty when caller looks like inline candidate,
+	     and it is not called once and.  */
+	  if (!caller_info->single_caller && overall_growth < caller_growth
+	      && caller_info->inlinable
+	      && caller_info->size
+		 < (DECL_DECLARED_INLINE_P (caller->decl)
+		    ? MAX_INLINE_INSNS_SINGLE : MAX_INLINE_INSNS_AUTO))
+	    {
+	      if (dump)
+		fprintf (dump_file,
+			 "     Wrapper penalty. Increasing growth %i to %i\n",
+			 overall_growth, caller_growth);
+	      overall_growth = caller_growth;
+	    }
+	}
+      if (overall_growth > 0)
+        {
+	  /* Strongly preffer functions with few callers that can be inlined
+	     fully.  The square root here leads to smaller binaries at average.
+	     Watch however for extreme cases and return to linear function
+	     when growth is large.  */
+	  if (overall_growth < 64)
+	    overall_growth *= overall_growth;
+	  else
+	    overall_growth += 64 * 64 - 64;
+	  denominator *= overall_growth;
+        }
 
       badness = - numerator / denominator;
 
@@ -1109,13 +1176,15 @@  edge_badness (struct cgraph_edge *edge,
 		   "      %f: guessed profile. frequency %f, count %"PRId64
 		   " caller count %"PRId64
 		   " time w/o inlining %f, time w inlining %f"
-		   " overall growth %i (current) %i (original)\n",
-		   badness.to_double (), (double)edge->frequency / CGRAPH_FREQ_BASE,
+		   " overall growth %i (current) %i (original)"
+		   " %i (compensated)\n",
+		   badness.to_double (),
+		  (double)edge->frequency / CGRAPH_FREQ_BASE,
 		   edge->count, caller->count,
 		   compute_uninlined_call_time (callee_info, edge).to_double (),
 		   compute_inlined_call_time (edge, edge_time).to_double (),
 		   estimate_growth (callee),
-		   callee_info->growth);
+		   callee_info->growth, overall_growth);
 	}
     }
   /* When function local profile is not available or it does not give
@@ -1133,8 +1202,8 @@  edge_badness (struct cgraph_edge *edge,
       else
 	badness = badness << nest;
       if (dump)
-	fprintf (dump_file, "      %f: no profile. nest %i\n", badness.to_double (),
-		 nest);
+	fprintf (dump_file, "      %f: no profile. nest %i\n",
+		 badness.to_double (), nest);
     }
   gcc_checking_assert (badness != 0);
 
@@ -1649,6 +1718,20 @@  inline_account_function_p (struct cgraph
 	   && node->frequency != NODE_FREQUENCY_UNLIKELY_EXECUTED);
 }
 
+/* Count number of callers of NODE and store it into DATA (that
+   points to int.  Worker for cgraph_for_node_and_aliases.  */
+
+static bool
+sum_callers (struct cgraph_node *node, void *data)
+{
+  struct cgraph_edge *e;
+  int *num_calls = (int *)data;
+
+  for (e = node->callers; e; e = e->next_caller)
+    (*num_calls)++;
+  return false;
+}
+
 /* We use greedy algorithm for inlining of small functions:
    All inline candidates are put into prioritized heap ordered in
    increasing badness.
@@ -1693,6 +1776,12 @@  inline_small_functions (void)
 	    if (inline_account_function_p (node))
 	      initial_size += info->size;
 	    info->growth = estimate_growth (node);
+
+	    int num_calls = 0;
+	    node->call_for_symbol_and_aliases (sum_callers, &num_calls,
+					       true);
+	    if (num_calls == 1)
+	      info->single_caller = true;
 	    if (dfs && dfs->next_cycle)
 	      {
 		struct cgraph_node *n2;
@@ -2085,20 +2174,6 @@  flatten_function (struct cgraph_node *no
     inline_update_overall_summary (node);
 }
 
-/* Count number of callers of NODE and store it into DATA (that
-   points to int.  Worker for cgraph_for_node_and_aliases.  */
-
-static bool
-sum_callers (struct cgraph_node *node, void *data)
-{
-  struct cgraph_edge *e;
-  int *num_calls = (int *)data;
-
-  for (e = node->callers; e; e = e->next_caller)
-    (*num_calls)++;
-  return false;
-}
-
 /* Inline NODE to all callers.  Worker for cgraph_for_node_and_aliases.
    DATA points to number of calls originally found so we avoid infinite
    recursion.  */
Index: ipa-inline.h
===================================================================
--- ipa-inline.h	(revision 221777)
+++ ipa-inline.h	(working copy)
@@ -129,6 +129,9 @@  struct GTY(()) inline_summary
   /* True when function contains cilk spawn (and thus we can not inline
      into it).  */
   unsigned contains_cilk_spawn : 1;
+  /* True wen there is only one caller of the function before small function
+     inlining.  */
+  unsigned int single_caller : 1;
 
   /* Information about function that will result after applying all the
      inline decisions present in the callgraph.  Generally kept up to
Index: ipa-split.c
===================================================================
--- ipa-split.c	(revision 221777)
+++ ipa-split.c	(working copy)
@@ -1402,6 +1402,8 @@  split_function (basic_block return_bb, s
     (vNULL, NULL, args_to_skip, !split_part_return_p, split_point->split_bbs,
      split_point->entry_bb, "part");
 
+  node->split_part = true;
+
   /* Let's take a time profile for splitted function.  */
   node->tp_first_run = cur_node->tp_first_run + 1;
 
Index: cgraphclones.c
===================================================================
--- cgraphclones.c	(revision 221777)
+++ cgraphclones.c	(working copy)
@@ -437,7 +437,7 @@  cgraph_node::expand_all_artificial_thunk
    node is not inlined.  */
 
 cgraph_node *
-cgraph_node::create_clone (tree decl, gcov_type gcov_count, int freq,
+cgraph_node::create_clone (tree new_decl, gcov_type gcov_count, int freq,
 			   bool update_original,
 			   vec<cgraph_edge *> redirect_callers,
 			   bool call_duplication_hook,
@@ -449,7 +449,7 @@  cgraph_node::create_clone (tree decl, gc
   gcov_type count_scale;
   unsigned i;
 
-  new_node->decl = decl;
+  new_node->decl = new_decl;
   new_node->register_symbol ();
   new_node->origin = origin;
   new_node->lto_file_data = lto_file_data;
@@ -476,6 +476,7 @@  cgraph_node::create_clone (tree decl, gc
 
   new_node->clone.tree_map = NULL;
   new_node->clone.args_to_skip = args_to_skip;
+  new_node->split_part = split_part;
   if (!args_to_skip)
     new_node->clone.combined_args_to_skip = clone.combined_args_to_skip;
   else if (clone.combined_args_to_skip)
Index: testsuite/gcc.dg/ipa/inlinehint-4.c
===================================================================
--- testsuite/gcc.dg/ipa/inlinehint-4.c	(revision 0)
+++ testsuite/gcc.dg/ipa/inlinehint-4.c	(revision 0)
@@ -0,0 +1,40 @@ 
+/* { dg-options "-O3 -fdump-ipa-inline-details -fno-early-inlining --param large-unit-insns=1"  } */
+/* { dg-add-options bind_pic_locally } */
+int *hashval;
+int *hash;
+int hash_size;
+
+static int
+lookup_slow (int val)
+{
+  int i = val % hash_size;
+  while (hashval[i] && hashval[i] != val)
+    i++;
+  return hash[i];
+}
+
+static inline int
+lookup (int val)
+{
+  static int cache, cache_val;
+  if (val == cache_val)
+    return cache;
+  else
+    {
+      cache_val = val;
+      cache = lookup_slow (val);
+      return cache;
+    }
+}
+
+int
+test (int i)
+{
+  return lookup (i) + lookup (2 * i) + lookup (3 * i) + lookup (4 * i) +
+    lookup (5 * i) + lookup (6 * i) + lookup (7 * i) + lookup (8 * i) +
+    lookup (9 * i);
+}
+/* { dg-final { scan-ipa-dump "Wrapper penalty"  "inline"  } } */
+/* { dg-final { scan-ipa-dump-not "Inlining lookup_slow to lookup"  "inline"  } } */
+/* { dg-final { scan-ipa-dump "Inlining lookup to test"  "inline"  } } */
+/* { dg-final { cleanup-ipa-dump "inline" } } */
Index: cgraph.h
===================================================================
--- cgraph.h	(revision 221777)
+++ cgraph.h	(working copy)
@@ -1319,6 +1319,8 @@  public:
   unsigned merged : 1;
   /* True if function was created to be executed in parallel.  */
   unsigned parallelized_function : 1;
+  /* True if function is part split out by ipa-split.  */
+  unsigned split_part : 1;
 
 private:
   /* Worker for call_for_symbol_and_aliases.  */