Zero local estimated benefit for cloning extern inline function

2019-03-07  Martin Jambor  <mjambor@suse.cz>

	PR lto/87525
	* ipa-cp.c (perform_estimation_of_a_value): Account zero time benefit
	for extern inline functions.

	testsuite/
	* gcc.dg/ipa/ipcp-5.c: New test.

From-SVN: r269464

gcc/ChangeLog

 2019-03-07  Martin Jambor  <mjambor@suse.cz>
 
+	PR lto/87525
+	* ipa-cp.c (perform_estimation_of_a_value): Account zero time benefit
+	for extern inline functions.
+
+2019-03-07  Martin Jambor  <mjambor@suse.cz>
+
 	PR ipa/88235
 	* cgraph.h (cgraph_node): New inline method former_thunk_p.
 	* cgraph.c (cgraph_node::dump): Dump a note if node is a former thunk.

gcc/ipa-cp.c

@@ -2818,11 +2818,18 @@ perform_estimation_of_a_value (cgraph_node *node, vec<tree> known_csts,
   base_time -= time;
   if (base_time > 65535)
     base_time = 65535;
-  time_benefit = base_time.to_int ()
-    + devirtualization_time_bonus (node, known_csts, known_contexts,
-				   known_aggs_ptrs)
-    + hint_time_bonus (hints)
-    + removable_params_cost + est_move_cost;
+
+  /* Extern inline functions have no cloning local time benefits because they
+     will be inlined anyway.  The only reason to clone them is if it enables
+     optimization in any of the functions they call.  */
+  if (DECL_EXTERNAL (node->decl) && DECL_DECLARED_INLINE_P (node->decl))
+    time_benefit = 0;
+  else
+    time_benefit = base_time.to_int ()
+      + devirtualization_time_bonus (node, known_csts, known_contexts,
+				     known_aggs_ptrs)
+      + hint_time_bonus (hints)
+      + removable_params_cost + est_move_cost;
 
   gcc_checking_assert (size >=0);
   /* The inliner-heuristics based estimates may think that in certain

gcc/testsuite/ChangeLog

 2019-03-07  Martin Jambor  <mjambor@suse.cz>
 
+	PR lto/87525
+	* gcc.dg/ipa/ipcp-5.c: New test.
+
+2019-03-07  Martin Jambor  <mjambor@suse.cz>
+
 	PR ipa/88235
 	* g++.dg/ipa/pr88235.C: New test.
 

gcc/testsuite/gcc.dg/ipa/ipcp-5.c

+/* Test that estimated local cloning time benefit of extern inline functions is
+   zero.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O3 -fdump-ipa-cp -fno-early-inlining"  } */
+/* { dg-add-options bind_pic_locally } */
+
+extern int get_int (void);
+extern void use_stuff (int);
+
+int arr[10];
+
+inline void
+f (int a)
+{
+  arr[0] += a + 5;
+  arr[1] += a + 50;
+  arr[2] += a - 3;
+  arr[3] += a;
+  arr[4] += a + 21;
+  arr[5] += a + 900;
+  arr[6] += a + 2;
+  arr[7] += a + 3456;
+  arr[8] += a + 3;
+  arr[9] += a + 32;
+  use_stuff (a);
+}
+
+
+int
+entry (void)
+{
+  int i;
+  for (i = 0; i < 100; i++)
+    f (7);
+  for (i = 0; i < 100; i++)
+    f (get_int ());
+  return 0;
+}
+
+
+/* { dg-final { scan-ipa-dump "loc_time: 0" "cp" } } */
+/* { dg-final { scan-ipa-dump-not "replacing param.*with const" "cp"  } } */
+
+