re PR tree-optimization/41118 (Wrong dependence analysis in graphite for unrestricted pointers)

2009-09-17 Li Feng  <nemokingdom@gmail.com>

	PR middle-end/41118
	* graphite-dependences.c (poly_drs_may_alias_p): Adjust definition.
	(pddr_original_scattering): Make sure 2 pdr2 in the same base object set.
	(graphite_carried_dependence_level_k): Ditto.
	* graphite-poly.c (new_poly_dr): Add init of PDR_BASE_OBJECT_SET.
	* graphite-poly.h (struct poly_dr): Add member dr_base_object_set.
	(new_poly_dr): Adjust declaration.
	* graphite-sese-to-poly.c (free_data_refs_aux): New.
	(free_gimple_bb): Added free_data_refs_aux.
	(build_poly_dr): Add dr_base_object_set.
	(partition_drs_to_sets): New.
	(dr_same_base_object_p): New.
	(build_alias_set_for_drs): New.
	(build_base_object_set_for_drs): New.
	(build_scop_drs): Add build_base_obj_set_for_drs.
	* graphite-sese-to-poly.h: Added #define for alias set number index and
	base object set index.
	* libgomp/testsuite/libgomp.graphite/force-parallel-6.c: Refine tests.
	* libgomp/testsuite/libgomp.graphite/pr4118.c: New.

From-SVN: r154549

gcc/ChangeLog.graphite

+2009-09-17 Li Feng  <nemokingdom@gmail.com>
+
+	PR middle-end/41118
+	* graphite-dependences.c (poly_drs_may_alias_p): Adjust definition.
+	(pddr_original_scattering): Make sure 2 pdr2 in the same base object set.
+	(graphite_carried_dependence_level_k): Ditto.
+	* graphite-poly.c (new_poly_dr): Add init of PDR_BASE_OBJECT_SET.
+	* graphite-poly.h (struct poly_dr): Add member dr_base_object_set.
+	(new_poly_dr): Adjust declaration.
+	* graphite-sese-to-poly.c (free_data_refs_aux): New.
+	(free_gimple_bb): Added free_data_refs_aux.
+	(build_poly_dr): Add dr_base_object_set.
+	(partition_drs_to_sets): New.
+	(dr_same_base_object_p): New.
+	(build_alias_set_for_drs): New.
+	(build_base_object_set_for_drs): New.
+	(build_scop_drs): Add build_base_obj_set_for_drs.
+	* graphite-sese-to-poly.h: Added #define for alias set number index and
+	base object set index.
+	* libgomp/testsuite/libgomp.graphite/force-parallel-6.c: Refine tests.
+	* libgomp/testsuite/libgomp.graphite/pr4118.c: New.
+
 2009-09-16  Alexander Monakov  <amonakov@ispras.ru>
 
 	* graphite-sese-to-poly.c (pdr_add_data_dimensions): Add bounds only

gcc/graphite-dependences.c

@@ -494,8 +494,12 @@ dependence_polyhedron (poly_bb_p pbb1, poly_bb_p pbb2,
   return res;
 }
 
+static bool
+poly_drs_may_alias_p (poly_dr_p pdr1, poly_dr_p pdr2);
+
 /* Returns the PDDR corresponding to the original schedule, or NULL if
-   the dependence relation is empty.  */
+   the dependence relation is empty or unknown (Can't judge dependency
+   under polyhedral model.  */
 
 static poly_ddr_p
 pddr_original_scattering (poly_bb_p pbb1, poly_bb_p pbb2,
@@ -507,8 +511,9 @@ pddr_original_scattering (poly_bb_p pbb1, poly_bb_p pbb2,
   ppl_Polyhedron_t so1 = PBB_ORIGINAL_SCATTERING (pbb1);
   ppl_Polyhedron_t so2 = PBB_ORIGINAL_SCATTERING (pbb2);
 
-  if (PDR_NB_SUBSCRIPTS (pdr1) != PDR_NB_SUBSCRIPTS (pdr2)
-      || (pdr_read_p (pdr1) && pdr_read_p (pdr2)))
+  if ((pdr_read_p (pdr1) && pdr_read_p (pdr2))
+      || PDR_BASE_OBJECT_SET (pdr1) != PDR_BASE_OBJECT_SET (pdr2)
+      || PDR_NB_SUBSCRIPTS (pdr1) != PDR_NB_SUBSCRIPTS (pdr2))
     return NULL;
 
   pddr = dependence_polyhedron (pbb1, pbb2, d1, d2, pdr1, pdr2, so1, so2,
@@ -706,14 +711,19 @@ graphite_carried_dependence_level_k (poly_dr_p pdr1, poly_dr_p pdr2,
   ppl_dimension_type dim;
   bool empty_p;
   poly_ddr_p pddr;
+  int obj_base_set1 = PDR_BASE_OBJECT_SET (pdr1);
+  int obj_base_set2 = PDR_BASE_OBJECT_SET (pdr2);
 
-  if ((PDR_TYPE (pdr1) == PDR_READ && PDR_TYPE (pdr2) == PDR_READ)
+  if ((pdr_read_p (pdr1) && pdr_read_p (pdr2))
       || !poly_drs_may_alias_p (pdr1, pdr2))
     return false;
 
-  if (PDR_NB_SUBSCRIPTS (pdr1) != PDR_NB_SUBSCRIPTS (pdr2))
+  if (obj_base_set1 != obj_base_set2)
     return true;
 
+  if (PDR_NB_SUBSCRIPTS (pdr1) != PDR_NB_SUBSCRIPTS (pdr2))
+    return false;
+
   pddr = dependence_polyhedron (pbb1, pbb2, d1, d2, pdr1, pdr2, so1, so2,
 				true, false);
 

gcc/graphite-poly.c

@@ -307,7 +307,7 @@ pbb_remove_duplicate_pdrs (poly_bb_p pbb)
    NB_SUBSCRIPTS.  */
 
 void
-new_poly_dr (poly_bb_p pbb,
+new_poly_dr (poly_bb_p pbb, int dr_base_object_set,
 	     ppl_Pointset_Powerset_C_Polyhedron_t accesses,
 	     enum poly_dr_type type, void *cdr, graphite_dim_t nb_subscripts)
 {
@@ -315,6 +315,7 @@ new_poly_dr (poly_bb_p pbb,
   poly_dr_p pdr = XNEW (struct poly_dr);
 
   PDR_ID (pdr) = id++;
+  PDR_BASE_OBJECT_SET (pdr) = dr_base_object_set;
   PDR_NB_REFS (pdr) = 1;
   PDR_PBB (pdr) = pbb;
   PDR_ACCESSES (pdr) = accesses;

gcc/graphite-poly.h

@@ -72,13 +72,13 @@ struct poly_dr
 
      The polyhedron contains these dimensions:
 
-      - The alias set (a):
-      Every memory access is classified in at least one alias set.
+     - The alias set (a):
+     Every memory access is classified in at least one alias set.
 
-      - The subscripts (s_0, ..., s_n):
-      The memory is accessed using zero or more subscript dimensions.
+     - The subscripts (s_0, ..., s_n):
+     The memory is accessed using zero or more subscript dimensions.
 
-      - The iteration domain (variables and parameters)
+     - The iteration domain (variables and parameters)
 
      Do not hardcode the dimensions.  Use the following accessor functions:
      - pdr_alias_set_dim
@@ -135,6 +135,10 @@ struct poly_dr
      | 0   0   0  -1   15  = 0 */
   ppl_Pointset_Powerset_C_Polyhedron_t accesses;
 
+  /* Data reference's base object set number, we must assure 2 pdrs are in the
+     same base object set before dependency checking.  */
+  int dr_base_object_set;
+
   /* The number of subscripts.  */
   graphite_dim_t nb_subscripts;
 };
@@ -145,9 +149,10 @@ struct poly_dr
 #define PDR_PBB(PDR) (PDR->pbb)
 #define PDR_TYPE(PDR) (PDR->type)
 #define PDR_ACCESSES(PDR) (PDR->accesses)
+#define PDR_BASE_OBJECT_SET(PDR) (PDR->dr_base_object_set)
 #define PDR_NB_SUBSCRIPTS(PDR) (PDR->nb_subscripts)
 
-void new_poly_dr (poly_bb_p, ppl_Pointset_Powerset_C_Polyhedron_t,
+void new_poly_dr (poly_bb_p, int, ppl_Pointset_Powerset_C_Polyhedron_t,
 		  enum poly_dr_type, void *, graphite_dim_t);
 void free_poly_dr (poly_dr_p);
 void debug_pdr (poly_dr_p);

gcc/graphite-sese-to-poly.c

@@ -282,6 +282,20 @@ new_gimple_bb (basic_block bb, VEC (data_reference_p, heap) *drs)
   return gbb;
 }
 
+static void
+free_data_refs_aux (VEC (data_reference_p, heap) *datarefs)
+{
+  unsigned int i;
+  struct data_reference *dr;
+
+  for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
+    if (!dr->aux)
+      {
+	free (dr->aux);
+	dr->aux = NULL;
+      }
+}
+
 /* Frees GBB.  */
 
 static void
@@ -290,6 +304,7 @@ free_gimple_bb (struct gimple_bb *gbb)
   if (GBB_CLOOG_IV_TYPES (gbb))
     htab_delete (GBB_CLOOG_IV_TYPES (gbb));
 
+  free_data_refs_aux (GBB_DATA_REFS (gbb));
   free_data_refs (GBB_DATA_REFS (gbb));
 
   VEC_free (gimple, heap, GBB_CONDITIONS (gbb));
@@ -1546,11 +1561,7 @@ pdr_add_alias_set (ppl_Polyhedron_t accesses, data_reference_p dr,
   int alias_set_num = 0;
 
   if (dr->aux != NULL)
-    {
-      alias_set_num = *((int *)(dr->aux));
-      free (dr->aux);
-      dr->aux = NULL;
-    }
+    alias_set_num = ((int *)(dr->aux))[ALIAS_SET_INDEX];
 
   ppl_new_Linear_Expression_with_dimension (&alias, accessp_nb_dims);
 
@@ -1675,6 +1686,7 @@ build_poly_dr (data_reference_p dr, poly_bb_p pbb)
   ppl_Pointset_Powerset_C_Polyhedron_t accesses_ps;
   ppl_dimension_type dom_nb_dims;
   ppl_dimension_type accessp_nb_dims;
+  int dr_base_object_set;
 
   ppl_Pointset_Powerset_C_Polyhedron_space_dimension (PBB_DOMAIN (pbb),
 						      &dom_nb_dims);
@@ -1689,14 +1701,17 @@ build_poly_dr (data_reference_p dr, poly_bb_p pbb)
   ppl_new_Pointset_Powerset_C_Polyhedron_from_C_Polyhedron (&accesses_ps,
 							    accesses);
   ppl_delete_Polyhedron (accesses);
-  new_poly_dr (pbb, accesses_ps, DR_IS_READ (dr) ? PDR_READ : PDR_WRITE, dr,
-	       DR_NUM_DIMENSIONS (dr));
-}
 
-/* Group each data reference in DRS with it's alias set num.  */
+  dr_base_object_set = ((int *)(dr->aux))[BASE_OBJECT_SET_INDEX];
+
+  new_poly_dr (pbb, dr_base_object_set, accesses_ps, DR_IS_READ (dr) ? PDR_READ : PDR_WRITE,
+	       dr, DR_NUM_DIMENSIONS (dr));
+}
 
 static void
-build_alias_set_for_drs (VEC (data_reference_p, heap) **drs)
+partition_drs_to_sets (VEC (data_reference_p, heap) **drs, int choice,
+			 bool (* edge_exist_p) (const struct data_reference *,
+						const struct data_reference *))
 {
   int num_vertex = VEC_length (data_reference_p, *drs);
   struct graph *g = new_graph (num_vertex);
@@ -1707,7 +1722,7 @@ build_alias_set_for_drs (VEC (data_reference_p, heap) **drs)
 
   for (i = 0; VEC_iterate (data_reference_p, *drs, i, dr1); i++)
     for (j = i+1; VEC_iterate (data_reference_p, *drs, j, dr2); j++)
-      if (dr_may_alias_p (dr1, dr2))
+      if ((*edge_exist_p) (dr1, dr2))
 	{
 	  add_edge (g, i, j);
 	  add_edge (g, j, i);
@@ -1722,14 +1737,38 @@ build_alias_set_for_drs (VEC (data_reference_p, heap) **drs)
   for (i = 0; i < g->n_vertices; i++)
     {
       data_reference_p dr = VEC_index (data_reference_p, *drs, i);
-      dr->aux = XNEW (int);
-      *((int *)(dr->aux)) = g->vertices[i].component + 1;
+      if (!dr->aux)
+	dr->aux = XNEWVEC (int, 2);
+      ((int *)(dr->aux))[choice] = g->vertices[i].component + 1;
     }
 
   free (queue);
   free_graph (g);
 }
 
+static bool
+dr_same_base_object_p (const struct data_reference *dr1,
+		       const struct data_reference *dr2)
+{
+  return operand_equal_p (DR_BASE_OBJECT (dr1), DR_BASE_OBJECT (dr2), 0);
+}
+
+/* Group each data reference in DRS with it's alias set num.  */
+
+static void
+build_alias_set_for_drs (VEC (data_reference_p, heap) **drs)
+{
+  partition_drs_to_sets (drs, ALIAS_SET_INDEX, dr_may_alias_p);
+}
+
+/* Group each data reference in DRS with it's base object set num.  */
+
+static void
+build_base_obj_set_for_drs (VEC (data_reference_p, heap) **drs)
+{
+  partition_drs_to_sets (drs, BASE_OBJECT_SET_INDEX, dr_same_base_object_p);
+}
+
 /* Build the data references for PBB.  */
 
 static void
@@ -1761,6 +1800,8 @@ build_scop_drs (scop_p scop)
     }
 
   build_alias_set_for_drs (&drs);
+  build_base_obj_set_for_drs (&drs);
+
   VEC_free (data_reference_p, heap, drs);
 
   for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)

gcc/graphite-sese-to-poly.h

@@ -21,6 +21,9 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef GCC_GRAPHITE_SESE_TO_POLY_H
 #define GCC_GRAPHITE_SESE_TO_POLY_H
 
+#define ALIAS_SET_INDEX 0
+#define BASE_OBJECT_SET_INDEX 1
+
 bool build_poly_scop (scop_p);
 void check_poly_representation (scop_p);
 

libgomp/testsuite/libgomp.graphite/force-parallel-6.c

@@ -31,7 +31,7 @@ int main(void)
 }
 
 /* Check that parallel code generation part make the right answer.  */
-/* { dg-final { scan-tree-dump-times "1 loops carried no dependency" 2 "graphite" } } */
+/* { dg-final { scan-tree-dump-times "1 loops carried no dependency" 1 "graphite" } } */
 /* { dg-final { cleanup-tree-dump "graphite" } } */
 /* { dg-final { scan-tree-dump-times "loopfn.0" 5 "optimized" } } */
 /* { dg-final { cleanup-tree-dump "parloops" } } */