ipa-prop.h: Include alloc-pool.h, all sorts of updates to general comments.

2011-07-18  Martin Jambor  <mjambor@suse.cz>

	* ipa-prop.h: Include alloc-pool.h, all sorts of updates to general
	comments.
	(ipcp_values_pool): Declare.
	(ipcp_sources_pool): Likewise.
	(ipcp_lattice): Changed to forward declaration.
	(ipa_param_descriptor): Removed fields ipcp_lattice, types and
	cannot_devirtualize.
	(ipa_node_params): New fields descriptors, lattices, known_vals,
	clone_for_all_contexts and node dead, removed fields params and
	count_scale.
	(ipa_set_param_count): Removed.
	(ipa_get_param_count): Made to work with descriptors vector.
	(ipa_get_param): Updated.
	(ipa_param_cannot_devirtualize_p): Removed.
	(ipa_param_types_vec_empty): Likewise.
	(ipa_set_param_used): New function.
	(ipa_get_param_used): Updated to use descriptors vector.
	(ipa_func_list): Removed.
	(ipa_init_func_list): Removed declaration.
	(ipa_push_func_to_list_1): Likewise.
	(ipa_pop_func_from_list): Likewise.
	(ipa_push_func_to_list): Removed.
	(ipa_lattice_from_jfunc): Remove declaration.
	(ipa_get_jf_pass_through_result): Declare.
	(ipa_get_jf_ancestor_result): Likewise.
	(ipa_value_from_jfunc): Likewise.
	(ipa_get_lattice): Update.
	(ipa_lat_is_single_const): New function.
	* ipa-prop.c (ipa_push_func_to_list_1): Removed.
	(ipa_init_func_list): Likewise.
	(ipa_pop_func_from_list): Likewise.
	(ipa_get_param_decl_index): Fix coding style.
	(count_formal_params): Removed.
	(count_formal_params_1): Renamed to count_formal_params.
	(ipa_populate_param_decls): Update to use descriptors vector.
	(ipa_initialize_node_params): Likewise.
	(visit_ref_for_mod_analysis): Use ipa_set_param_used.
	(ipa_analyze_params_uses): Likewise.
	(ipa_free_node_params_substructures): Likewise and free also lattices
	and known values.
	(duplicate_array): Removed.
	(ipa_edge_duplication_hook): Add the new edge to the list of edge
	clones.
	(ipa_node_duplication_hook): Update to use new lattices.
	(ipa_free_all_structures_after_ipa_cp): Free alloc pools.
	(ipa_free_all_structures_after_iinln): Likewise.
	(ipa_write_node_info): Update to use new lattices.
	(ipa_read_node_info): Likewise.
	(ipa_get_jf_pass_through_result): New function.
	(ipa_get_jf_ancestor_result): Likewise.
	(ipa_value_from_jfunc): Likewise.
	(ipa_cst_from_jfunc): Reimplemented using ipa_value_from_jfunc.
	* ipa-cp.c: Reimplemented.
	* params.def (PARAM_DEVIRT_TYPE_LIST_SIZE): Removed.
	(PARAM_IPA_CP_VALUE_LIST_SIZE): New parameter.
	(PARAM_IPA_CP_EVAL_THRESHOLD): Likewise.
	* Makefile.in (IPA_PROP_H): Added alloc-pool.h to dependencies.

	* doc/invoke.texi (devirt-type-list-size): Removed description.
	(ipa-cp-value-list-size): Added description.

	* testsuite/gcc.dg/ipa/ipa-1.c: Updated testcase dump scan.
	* testsuite/gcc.dg/ipa/ipa-2.c: Likewise.
	* testsuite/gcc.dg/ipa/ipa-3.c: Likewise and made functions static.
	* testsuite/gcc.dg/ipa/ipa-4.c: Updated testcase dump scan.
	* testsuite/gcc.dg/ipa/ipa-5.c: Likewise.
	* testsuite/gcc.dg/ipa/ipa-7.c: Likewise.
	* testsuite/gcc.dg/ipa/ipa-8.c: Updated testcase dump scan.
	* testsuite/gcc.dg/ipa/ipacost-1.c: Likewise.
	* testsuite/gcc.dg/ipa/ipacost-2.c: Likewise and increased sizes
	of some functions.
	* testsuite/gcc.dg/ipa/ipcp-1.c: New test.
	* testsuite/gcc.dg/ipa/ipcp-2.c: Likewise.
	* testsuite/gcc.dg/tree-ssa/ipa-cp-1.c: Updated testcase.

From-SVN: r176424

gcc/ChangeLog

+2011-07-18  Martin Jambor  <mjambor@suse.cz>
+
+	* ipa-prop.h: Include alloc-pool.h, all sorts of updates to general
+	comments.
+	(ipcp_values_pool): Declare.
+	(ipcp_sources_pool): Likewise.
+	(ipcp_lattice): Changed to forward declaration.
+	(ipa_param_descriptor): Removed fields ipcp_lattice, types and
+	cannot_devirtualize.
+	(ipa_node_params): New fields descriptors, lattices, known_vals,
+	clone_for_all_contexts and node dead, removed fields params and
+	count_scale.
+	(ipa_set_param_count): Removed.
+	(ipa_get_param_count): Made to work with descriptors vector.
+	(ipa_get_param): Updated.
+	(ipa_param_cannot_devirtualize_p): Removed.
+	(ipa_param_types_vec_empty): Likewise.
+	(ipa_set_param_used): New function.
+	(ipa_get_param_used): Updated to use descriptors vector.
+	(ipa_func_list): Removed.
+	(ipa_init_func_list): Removed declaration.
+	(ipa_push_func_to_list_1): Likewise.
+	(ipa_pop_func_from_list): Likewise.
+	(ipa_push_func_to_list): Removed.
+	(ipa_lattice_from_jfunc): Remove declaration.
+	(ipa_get_jf_pass_through_result): Declare.
+	(ipa_get_jf_ancestor_result): Likewise.
+	(ipa_value_from_jfunc): Likewise.
+	(ipa_get_lattice): Update.
+	(ipa_lat_is_single_const): New function.
+	* ipa-prop.c (ipa_push_func_to_list_1): Removed.
+	(ipa_init_func_list): Likewise.
+	(ipa_pop_func_from_list): Likewise.
+	(ipa_get_param_decl_index): Fix coding style.
+	(count_formal_params): Removed.
+	(count_formal_params_1): Renamed to count_formal_params.
+	(ipa_populate_param_decls): Update to use descriptors vector.
+	(ipa_initialize_node_params): Likewise.
+	(visit_ref_for_mod_analysis): Use ipa_set_param_used.
+	(ipa_analyze_params_uses): Likewise.
+	(ipa_free_node_params_substructures): Likewise and free also lattices
+	and known values.
+	(duplicate_array): Removed.
+	(ipa_edge_duplication_hook): Add the new edge to the list of edge
+	clones.
+	(ipa_node_duplication_hook): Update to use new lattices.
+	(ipa_free_all_structures_after_ipa_cp): Free alloc pools.
+	(ipa_free_all_structures_after_iinln): Likewise.
+	(ipa_write_node_info): Update to use new lattices.
+	(ipa_read_node_info): Likewise.
+	(ipa_get_jf_pass_through_result): New function.
+	(ipa_get_jf_ancestor_result): Likewise.
+	(ipa_value_from_jfunc): Likewise.
+	(ipa_cst_from_jfunc): Reimplemented using ipa_value_from_jfunc.
+	* ipa-cp.c: Reimplemented.
+	* params.def (PARAM_DEVIRT_TYPE_LIST_SIZE): Removed.
+	(PARAM_IPA_CP_VALUE_LIST_SIZE): New parameter.
+	(PARAM_IPA_CP_EVAL_THRESHOLD): Likewise.
+	* Makefile.in (IPA_PROP_H): Added alloc-pool.h to dependencies.
+	* doc/invoke.texi (devirt-type-list-size): Removed description.
+	(ipa-cp-value-list-size): Added description.
+
 2011-07-18  Richard Henderson  <rth@redhat.com>
 
 	* bb-reorder.c (fix_crossing_conditional_branches): Emit all insns

gcc/Makefile.in

@@ -1006,7 +1006,7 @@ LTO_STREAMER_H = lto-streamer.h $(LINKER_PLUGIN_API_H) $(TARGET_H) \
 		$(CGRAPH_H) $(VEC_H) vecprim.h $(TREE_H) $(GIMPLE_H) \
 		$(GCOV_IO_H)
 TREE_VECTORIZER_H = tree-vectorizer.h $(TREE_DATA_REF_H)
-IPA_PROP_H = ipa-prop.h $(TREE_H) $(VEC_H) $(CGRAPH_H) $(GIMPLE_H)
+IPA_PROP_H = ipa-prop.h $(TREE_H) $(VEC_H) $(CGRAPH_H) $(GIMPLE_H) alloc-pool.h
 GSTAB_H = gstab.h stab.def
 BITMAP_H = bitmap.h $(HASHTAB_H) statistics.h
 GCC_PLUGIN_H = gcc-plugin.h highlev-plugin-common.h $(CONFIG_H) $(SYSTEM_H) \

gcc/doc/invoke.texi

@@ -9006,11 +9006,11 @@ loop in the loop nest by a given number of iterations.  The strip
 length can be changed using the @option{loop-block-tile-size}
 parameter.  The default value is 51 iterations.
 
-@item devirt-type-list-size
-IPA-CP attempts to track all possible types passed to a function's
-parameter in order to perform devirtualization.
-@option{devirt-type-list-size} is the maximum number of types it
-stores per a single formal parameter of a function.
+@item ipa-cp-value-list-size
+IPA-CP attempts to track all possible values and types passed to a function's
+parameter in order to propagate them and perform devirtualization.
+@option{ipa-cp-value-list-size} is the maximum number of values and types it
+stores per one formal parameter of a function.
 
 @item lto-partitions
 Specify desired number of partitions produced during WHOPR compilation.

gcc/params.def

@@ -860,12 +860,18 @@ DEFPARAM (PARAM_IPA_SRA_PTR_GROWTH_FACTOR,
 	  "a pointer to an aggregate with",
 	  2, 0, 0)
 
-DEFPARAM (PARAM_DEVIRT_TYPE_LIST_SIZE,
-	  "devirt-type-list-size",
-	  "Maximum size of a type list associated with each parameter for "
-	  "devirtualization",
+DEFPARAM (PARAM_IPA_CP_VALUE_LIST_SIZE,
+	  "ipa-cp-value-list-size",
+	  "Maximum size of a list of values associated with each parameter for "
+	  "interprocedural constant propagation",
 	  8, 0, 0)
 
+DEFPARAM (PARAM_IPA_CP_EVAL_THRESHOLD,
+	  "ipa-cp-eval-threshold",
+	  "Threshold ipa-cp opportunity evaluation that is still considered "
+	  "beneficial to clone.",
+	  500, 0, 0)
+
 /* WHOPR partitioning configuration.  */
 
 DEFPARAM (PARAM_LTO_PARTITIONS,

gcc/testsuite/ChangeLog

+2011-07-18  Martin Jambor  <mjambor@suse.cz>
+
+	* gcc.dg/ipa/ipa-1.c: Updated testcase dump scan.
+	* gcc.dg/ipa/ipa-2.c: Likewise.
+	* gcc.dg/ipa/ipa-3.c: Likewise and made functions static.
+	* gcc.dg/ipa/ipa-4.c: Updated testcase dump scan.
+	* gcc.dg/ipa/ipa-5.c: Likewise.
+	* gcc.dg/ipa/ipa-7.c: Likewise.
+	* gcc.dg/ipa/ipa-8.c: Updated testcase dump scan.
+	* gcc.dg/ipa/ipacost-1.c: Likewise.
+	* gcc.dg/ipa/ipacost-2.c: Likewise and increased sizes of some
+	functions.
+	* gcc.dg/ipa/ipcp-1.c: New test.
+	* gcc.dg/ipa/ipcp-2.c: Likewise.
+	* gcc.dg/tree-ssa/ipa-cp-1.c: Updated testcase.
+
 2011-07-18  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/49675

gcc/testsuite/gcc.dg/ipa/ipa-1.c

@@ -24,9 +24,8 @@ int main ()
 }
 
 
-/* { dg-final { scan-ipa-dump-times "versioned function" 2 "cp"  } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of f" "cp" } } */
 /* { dg-final { scan-ipa-dump "replacing param a with const 7" "cp"  } } */
-/* { dg-final { scan-ipa-dump "replacing param b with const 7" "cp"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */
 
 

gcc/testsuite/gcc.dg/ipa/ipa-2.c

@@ -22,7 +22,6 @@ int main ()
 }
 
 
-/* { dg-final { scan-ipa-dump-times "versioned function" 2 "cp"  } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of f" "cp" } } */
 /* { dg-final { scan-ipa-dump "replacing param a with const 7" "cp"  } } */
-/* { dg-final { scan-ipa-dump "replacing param c with const 3" "cp"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */

gcc/testsuite/gcc.dg/ipa/ipa-3.c

@@ -7,12 +7,12 @@
 
 #include <stdio.h>
 void t(void);
-int g (double b, double c)
+static int g (double b, double c)
 {
   t();
   return (int)(b+c);
 }
-int f (double a)
+static int f (double a)
 {
   if (a > 0)
     g (a, 3.1);
@@ -28,8 +28,9 @@ int main ()
 }
 
 
-/* { dg-final { scan-ipa-dump-times "versioned function" 2 "cp"  } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of f" "cp" } } */
 /* { dg-final { scan-ipa-dump "replacing param a with const 7" "cp"  } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of g" "cp" } } */
 /* { dg-final { scan-ipa-dump "replacing param b with const 7" "cp"  } } */
 /* { dg-final { scan-ipa-dump "replacing param c with const 3" "cp"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */

gcc/testsuite/gcc.dg/ipa/ipa-4.c

@@ -25,6 +25,6 @@ int main ()
 }
 
 
-/* { dg-final { scan-ipa-dump-times "versioned function" 1 "cp"  } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of f" "cp"  } } */
 /* { dg-final { scan-ipa-dump-times "replacing param a with const 7" 1 "cp"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */

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

@@ -26,8 +26,7 @@ int main ()
   return 0;
 }
 
-
-/* { dg-final { scan-ipa-dump-times "versioned function" 2 "cp"  } } */
+/* { dg-final { scan-ipa-dump-times "Creating a specialized node" 2 "cp"  } } */
 /* { dg-final { scan-ipa-dump "replacing param c with const 3" "cp"  } } */
 /* { dg-final { scan-ipa-dump "replacing param a with const 7" "cp"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */

gcc/testsuite/gcc.dg/ipa/ipa-7.c

@@ -26,8 +26,8 @@ int main ()
 }
 
 
-/* { dg-final { scan-ipa-dump-times "versioned function" 1 "cp"  } } */
-/* { dg-final { scan-ipa-dump-times "replacing param a with const 7" 1 "cp"  } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of f" "cp" } } */
+/* { dg-final { scan-ipa-dump-times "replacing param . with const 7" 1 "cp" } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */
 
 

gcc/testsuite/gcc.dg/ipa/ipa-8.c

@@ -22,8 +22,9 @@ int main ()
 }
 
 
-/* { dg-final { scan-ipa-dump-times "versioned function" 2 "cp"  } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of f" "cp" } } */
 /* { dg-final { scan-ipa-dump "replacing param a with const 7" "cp"  } } */
+/* { dg-final { scan-ipa-dump "Creating a specialized node of g" "cp" } } */
 /* { dg-final { scan-ipa-dump "replacing param b with const 7" "cp"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */
 

gcc/testsuite/gcc.dg/ipa/ipacost-1.c

@@ -51,10 +51,10 @@ main()
   i_can_not_be_propagated_fully2 (array);
 }
 
-/* { dg-final { scan-ipa-dump-times "versioned function i_can_be_propagated_fully2" 1 "cp"  } } */
-/* { dg-final { scan-ipa-dump-times "versioned function i_can_be_propagated_fully " 1 "cp"  } } */
-/* { dg-final { scan-ipa-dump-not "versioned function i_can_not_be_propagated_fully2" "cp"  } } */
-/* { dg-final { scan-ipa-dump-not "versioned function i_can_not_be_propagated_fully " "cp"  } } */
+/* { dg-final { scan-ipa-dump-times "Creating a specialized node of i_can_be_propagated_fully2" 1 "cp"  } } */
+/* { dg-final { scan-ipa-dump-times "Creating a specialized node of i_can_be_propagated_fully/" 1 "cp"  } } */
+/* { dg-final { scan-ipa-dump-not "Creating a specialized node of i_can_not_be_propagated_fully2" "cp"  } } */
+/* { dg-final { scan-ipa-dump-not "Creating a specialized node of i_can_not_be_propagated_fully/" "cp"  } } */
 /* { dg-final { scan-tree-dump-not "i_can_be_propagated_fully " "optimized"  } } */
 /* { dg-final { scan-tree-dump-not "i_can_be_propagated_fully2 " "optimized"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */

gcc/testsuite/gcc.dg/ipa/ipacost-2.c

@@ -40,8 +40,23 @@ i_can_not_be_propagated_fully (int *a)
 int
 i_can_not_be_propagated_fully2 (int *a)
 {
+  int i;
   i_can_not_be_propagated_fully (a);
+  for (i=0;i<50;i++)
+  {
+    t(a[i] + 1);
+    t(a[i+1] + 1);
+    t(a[i+2] + 1);
+    t(a[i+3] + 1);
+  }
   i_can_not_be_propagated_fully (a);
+  for (i=0;i<50;i++)
+  {
+    t(a[i] + 2);
+    t(a[i+1] + 2);
+    t(a[i+2] + 2);
+    t(a[i+3] + 2);
+  }
   i_can_not_be_propagated_fully (a);
 }
 main()
@@ -50,15 +65,15 @@ main()
   i_can_be_propagated_fully2 (array);
   i_can_be_propagated_fully2 (array);
 
-  for (i = 0; i < 100; i++)
+  for (i = 0; i < 7; i++)
     i_can_not_be_propagated_fully2 (array);
   i_can_not_be_propagated_fully2 (array);
 }
 
-/* { dg-final { scan-ipa-dump-times "versioned function i_can_be_propagated_fully2" 1 "cp"  } } */
-/* { dg-final { scan-ipa-dump-times "versioned function i_can_be_propagated_fully " 1 "cp"  } } */
-/* { dg-final { scan-ipa-dump-times "versioned function i_can_not_be_propagated_fully2" 1 "cp"  } } */
-/* { dg-final { scan-ipa-dump-times "versioned function i_can_not_be_propagated_fully " 1 "cp"  } } */
+/* { dg-final { scan-ipa-dump-times "Creating a specialized node of i_can_be_propagated_fully2" 1 "cp"  } } */
+/* { dg-final { scan-ipa-dump-times "Creating a specialized node of i_can_be_propagated_fully/" 1 "cp"  } } */
+/* { dg-final { scan-ipa-dump-not "Creating a specialized node of i_can_not_be_propagated_fully2" "cp"  } } */
+/* { dg-final { scan-ipa-dump-not "Creating a specialized node of i_can_not_be_propagated_fully/" "cp"  } } */
 /* { dg-final { scan-tree-dump-not "i_can_be_propagated_fully \\(" "optimized"  } } */
 /* { dg-final { scan-tree-dump-not "i_can_be_propagated_fully2 \\(" "optimized"  } } */
 /* { dg-final { cleanup-ipa-dump "cp" } } */

gcc/testsuite/gcc.dg/ipa/ipcp-1.c

+/* Test that IPA-CP is able to figure out that poth parameters a are constant 7
+   even though f and h recursively call each other and specialize them
+   accordinly.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O3 -fipa-cp -fipa-cp-clone -fdump-ipa-cp -fno-early-inlining"  } */
+/* { dg-add-options bind_pic_locally } */
+
+extern void use_stuff (int);
+
+static
+int g (int b, int c)
+{
+  int i;
+
+  for (i = 0; i < b; i++)
+    use_stuff (c);
+}
+
+static void f (int a, int x, int z);
+
+static void h (int z, int a)
+{
+  use_stuff (z);
+  f (a, 9, 10);
+
+}
+
+static void
+f (int a, int x, int z)
+{
+  if (z > 1)
+    g (a, x);
+  else
+    h (5, a);
+}
+
+int
+main (int argc, char *argv[])
+{
+  int i;
+  for (i = 0; i < 100; i++)
+    f (7, 8, argc);
+  return 0;
+}
+
+
+/* { dg-final { scan-ipa-dump "Creating a specialized node of f.*for all known contexts" "cp" } } */
+/* { dg-final { scan-ipa-dump "replacing param a with const 7" "cp"  } } */
+/* { dg-final { cleanup-ipa-dump "cp" } } */
+
+

gcc/testsuite/gcc.dg/ipa/ipcp-2.c

+/* { dg-do compile } */
+/* { dg-options "-O3 -fipa-cp -fipa-cp-clone -fdump-ipa-cp -fno-early-inlining"  } */
+/* { dg-add-options bind_pic_locally } */
+
+extern int get_stuff (int);
+extern void do_stuff (int);
+extern void do_stuff2 (int);
+extern void do_other_stuff (void);
+extern int get_element (int, int, int);
+extern int adjust (int, int, int, int);
+
+extern int count;
+
+int
+foo (int s, int p)
+{
+  int c, r = 0;
+
+  for (c = 0 ; c < count; c++)
+    {
+      r += get_stuff (s);
+      /* The following is just something big that can go away.  */
+      if (p != 0)
+	{
+	  int a[64][64];
+	  int i, j, k;
+
+	  for (i = 0; i < 64; i++)
+	    for (j = 0; j < 64; j++)
+	      a[i][j] = get_element (p + c, i, j);
+
+	  for (k = 0; k < 4; k++)
+	    {
+	      r = r / 2;
+
+	      for (i = 1; i < 63; i++)
+		for (j = 62; j > 0; j--)
+		  a[i][j] += adjust (a[i-1][j], a[i][j-1],
+				     a[i+1][j], a[i][j+1]);
+
+	      for (i = 4; i < 64; i += 4)
+		for (j = 4; j < 64; j += 4)
+		  r += a[i][j] / 4;
+	    }
+	}
+    }
+  return r;
+}
+
+int
+bar (int p, int q)
+{
+  if (q > 0)
+    do_stuff (q);
+  else
+    do_stuff (-q);
+
+  if (q % 2)
+    do_stuff2 (2 * q);
+  else
+    do_stuff2 (2 * (q + 1));
+
+  return foo (4, p);
+}
+
+int
+bah (int p, int q)
+{
+  int i, j;
+
+  while (q < -20)
+    q += get_stuff (-q);
+
+  for (i = 0; i < 36; i++)
+    for (j = 0; j < 36; j++)
+      do_stuff (get_stuff (q * i + 2));
+
+  bar (p, q);
+}
+
+int
+top1 (int q)
+{
+  do_other_stuff ();
+  return bah (0, q);
+}
+
+int
+top2 (int q)
+{
+  do_stuff (200);
+  do_other_stuff ();
+  return bah (16, q);
+}
+
+/* { dg-final { scan-ipa-dump-times "Creating a specialized node of foo" 1 "cp" } } */
+/* { dg-final { scan-ipa-dump-times "replacing param p with const 0" 3 "cp"  } } */
+/* { dg-final { scan-ipa-dump "replacing param s with const 4" "cp"  } } */
+/* { dg-final { cleanup-ipa-dump "cp" } } */

gcc/testsuite/gcc.dg/tree-ssa/ipa-cp-1.c

@@ -5,9 +5,13 @@
 int
 very_long_function(int a)
 {
-  return very_long_function (a)/4;
+  if (a > 0)
+    return 2 * a + very_long_function (a)/4;
+  else
+    return 2 * -a + very_long_function (a)/4;
 }
-main()
+
+blah ()
 {
   very_long_function (1);
 }