fix PR68279: bail out when scev gets instantiated to not_known

Co-Authored-By: Sebastian Pop <s.pop@samsung.com>

From-SVN: r230771

9 files changed, 147 insertions, 75 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 53eb8e1571d..76f2474aba3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,29 @@
 2015-11-23  Aditya Kumar  <aditya.k7@samsung.com>
 	    Sebastian Pop  <s.pop@samsung.com>
 
+	PR tree-optimization/68279
+	* graphite-poly.c (new_scop): Remove poly_scop_p.
+	* graphite-poly.h (struct scop): Same.
+	(build_poly_scop): Declare.
+	* graphite-sese-to-poly.c: Do not include graphite-sese-to-poly.h.
+	(cleanup_loop_iter_dom): New.
+	(build_loop_iteration_domains): Early return when scev analysis fails.
+	(create_pw_aff_from_tree): Same.
+	(add_condition_to_pbb): Same.
+	(add_conditions_to_domain): Same.
+	(add_conditions_to_constraints): Same.
+	(build_scop_iteration_domain): Same.
+	(build_poly_scop): Same.  Do not initialize poly_scop_p.
+	* graphite-sese-to-poly.h: Remove.
+	* graphite.c: Do not include graphite-sese-to-poly.h.
+	(graphite_transform_loops): Stop before code generation when
+	build_poly_scop fails.
+	* sese.c (scalar_evolution_in_region): Add fixme note about scev
+	analysis.
+
+2015-11-23  Aditya Kumar  <aditya.k7@samsung.com>
+	    Sebastian Pop  <s.pop@samsung.com>
+
 	* graphite-isl-ast-to-gimple.c (translate_isl_ast_node_user):
 	Remove call to update_ssa.
 	* sese.c (sese_insert_phis_for_liveouts): Same.
diff --git a/gcc/graphite-poly.c b/gcc/graphite-poly.c
index 9137cc43b34..187a3fa2bd4 100644
--- a/gcc/graphite-poly.c
+++ b/gcc/graphite-poly.c
@@ -308,7 +308,6 @@ new_scop (edge entry, edge exit)
   scop_set_region (scop, region);
   scop->original_schedule = NULL;
   scop->pbbs.create (3);
-  scop->poly_scop_p = false;
   scop->drs.create (3);
 
   return scop;
diff --git a/gcc/graphite-poly.h b/gcc/graphite-poly.h
index 3fcbbaf5c38..dec7fd6df8b 100644
--- a/gcc/graphite-poly.h
+++ b/gcc/graphite-poly.h
@@ -420,10 +420,6 @@ struct scop
 
   /* Original schedule of the SCoP.  */
   isl_union_map *original_schedule;
-
-  /* True when the scop has been converted to its polyhedral
-     representation.  */
-  bool poly_scop_p;
 };
 
 extern scop_p new_scop (edge, edge);
@@ -468,4 +464,6 @@ carries_deps (__isl_keep isl_union_map *schedule,
 	      __isl_keep isl_union_map *deps,
 	      int depth);
 
+bool build_poly_scop (scop_p);
+
 #endif
diff --git a/gcc/graphite-sese-to-poly.c b/gcc/graphite-sese-to-poly.c
index 34aa4763c41..65ff4e6111b 100644
--- a/gcc/graphite-sese-to-poly.c
+++ b/gcc/graphite-sese-to-poly.c
@@ -66,7 +66,6 @@ extern "C" {
 #endif
 
 #include "graphite-poly.h"
-#include "graphite-sese-to-poly.h"
 
 /* Assigns to RES the value of the INTEGER_CST T.  */
 
@@ -590,10 +589,20 @@ set_scop_parameter_dim (scop_p scop)
   scop->param_context = isl_set_universe (space);
 }
 
+static inline bool
+cleanup_loop_iter_dom (isl_set *inner, isl_set *outer, isl_space *space, mpz_t g)
+{
+  isl_set_free (inner);
+  isl_set_free (outer);
+  isl_space_free (space);
+  mpz_clear (g);
+  return false;
+}
+
 /* Builds the constraint polyhedra for LOOP in SCOP.  OUTER_PH gives
    the constraints for the surrounding loops.  */
 
-static void
+static bool
 build_loop_iteration_domains (scop_p scop, struct loop *loop,
                               int nb,
 			      isl_set *outer, isl_set **doms)
@@ -638,11 +647,17 @@ build_loop_iteration_domains (scop_p scop, struct loop *loop,
 
       nb_iters = scalar_evolution_in_region (region, loop, nb_iters);
 
+      /* Bail out as we do not know the scev.  */
+      if (chrec_contains_undetermined (nb_iters))
+	return cleanup_loop_iter_dom (inner, outer, space, g);
+
       aff = extract_affine (scop, nb_iters, isl_set_get_space (inner));
       isl_set *valid = isl_pw_aff_nonneg_set (isl_pw_aff_copy (aff));
       valid = isl_set_project_out (valid, isl_dim_set, 0,
 				   isl_set_dim (valid, isl_dim_set));
-      scop->param_context = isl_set_intersect (scop->param_context, valid);
+
+      if (valid)
+	scop->param_context = isl_set_intersect (scop->param_context, valid);
 
       isl_local_space *ls = isl_local_space_from_space (isl_space_copy (space));
       isl_aff *al = isl_aff_set_coefficient_si (isl_aff_zero_on_domain (ls),
@@ -686,21 +701,24 @@ build_loop_iteration_domains (scop_p scop, struct loop *loop,
   else
     gcc_unreachable ();
 
-  if (loop->inner)
-    build_loop_iteration_domains (scop, loop->inner, nb + 1,
-				  isl_set_copy (inner), doms);
+  if (loop->inner
+      && !build_loop_iteration_domains (scop, loop->inner, nb + 1,
+					isl_set_copy (inner), doms))
+    return cleanup_loop_iter_dom (inner, outer, space, g);
 
   if (nb != 0
       && loop->next
-      && loop_in_sese_p (loop->next, region))
-    build_loop_iteration_domains (scop, loop->next, nb,
-				  isl_set_copy (outer), doms);
+      && loop_in_sese_p (loop->next, region)
+      && !build_loop_iteration_domains (scop, loop->next, nb,
+					isl_set_copy (outer), doms))
+    return cleanup_loop_iter_dom (inner, outer, space, g);
 
   doms[loop->num] = inner;
 
   isl_set_free (outer);
   isl_space_free (space);
   mpz_clear (g);
+  return true;
 }
 
 /* Returns a linear expression for tree T evaluated in PBB.  */
@@ -711,6 +729,11 @@ create_pw_aff_from_tree (poly_bb_p pbb, tree t)
   scop_p scop = PBB_SCOP (pbb);
 
   t = scalar_evolution_in_region (scop->scop_info->region, pbb_loop (pbb), t);
+
+  /* Bail out as we do not know the scev.  */
+  if (chrec_contains_undetermined (t))
+    return NULL;
+
   gcc_assert (!automatically_generated_chrec_p (t));
 
   return extract_affine (scop, t, isl_set_get_space (pbb->domain));
@@ -720,13 +743,21 @@ create_pw_aff_from_tree (poly_bb_p pbb, tree t)
    operator.  This allows us to invert the condition or to handle
    inequalities.  */
 
-static void
+static bool
 add_condition_to_pbb (poly_bb_p pbb, gcond *stmt, enum tree_code code)
 {
   isl_pw_aff *lhs = create_pw_aff_from_tree (pbb, gimple_cond_lhs (stmt));
+  if (!lhs)
+    return false;
+
   isl_pw_aff *rhs = create_pw_aff_from_tree (pbb, gimple_cond_rhs (stmt));
-  isl_set *cond;
+  if (!rhs)
+    {
+      isl_pw_aff_free (lhs);
+      return false;
+    }
 
+  isl_set *cond;
   switch (code)
     {
       case LT_EXPR:
@@ -756,17 +787,18 @@ add_condition_to_pbb (poly_bb_p pbb, gcond *stmt, enum tree_code code)
       default:
 	isl_pw_aff_free (lhs);
 	isl_pw_aff_free (rhs);
-	return;
+	return true;
     }
 
   cond = isl_set_coalesce (cond);
   cond = isl_set_set_tuple_id (cond, isl_set_get_tuple_id (pbb->domain));
   pbb->domain = isl_set_intersect (pbb->domain, cond);
+  return true;
 }
 
 /* Add conditions to the domain of PBB.  */
 
-static void
+static bool
 add_conditions_to_domain (poly_bb_p pbb)
 {
   unsigned int i;
@@ -774,7 +806,7 @@ add_conditions_to_domain (poly_bb_p pbb)
   gimple_poly_bb_p gbb = PBB_BLACK_BOX (pbb);
 
   if (GBB_CONDITIONS (gbb).is_empty ())
-    return;
+    return true;
 
   FOR_EACH_VEC_ELT (GBB_CONDITIONS (gbb), i, stmt)
     switch (gimple_code (stmt))
@@ -792,7 +824,8 @@ add_conditions_to_domain (poly_bb_p pbb)
 	    if (!GBB_CONDITION_CASES (gbb)[i])
 	      code = invert_tree_comparison (code, false);
 
-	    add_condition_to_pbb (pbb, cond_stmt, code);
+	    if (!add_condition_to_pbb (pbb, cond_stmt, code))
+	      return false;
 	    break;
 	  }
 
@@ -803,19 +836,24 @@ add_conditions_to_domain (poly_bb_p pbb)
 	gcc_unreachable ();
 	break;
       }
+
+  return true;
 }
 
 /* Traverses all the GBBs of the SCOP and add their constraints to the
    iteration domains.  */
 
-static void
+static bool
 add_conditions_to_constraints (scop_p scop)
 {
   int i;
   poly_bb_p pbb;
 
   FOR_EACH_VEC_ELT (scop->pbbs, i, pbb)
-    add_conditions_to_domain (pbb);
+    if (!add_conditions_to_domain (pbb))
+      return false;
+
+  return true;
 }
 
 /* Add constraints on the possible values of parameter P from the type
@@ -895,19 +933,23 @@ build_scop_context (scop_p scop)
    SCOP, and that vary for the execution of the current basic block.
    Returns false if there is no loop in SCOP.  */
 
-static void
+static bool
 build_scop_iteration_domain (scop_p scop)
 {
   sese_info_p region = scop->scop_info;
   int nb_loops = number_of_loops (cfun);
   isl_set **doms = XCNEWVEC (isl_set *, nb_loops);
-
+  bool res = true;
   int i;
   struct loop *loop;
   FOR_EACH_VEC_ELT (region->loop_nest, i, loop)
-    if (!loop_in_sese_p (loop_outer (loop), region->region))
-      build_loop_iteration_domains (scop, loop, 0,
-				    isl_set_copy (scop->param_context), doms);
+    if (!loop_in_sese_p (loop_outer (loop), region->region)
+	&& !build_loop_iteration_domains (scop, loop, 0,
+					  isl_set_copy (scop->param_context), doms))
+      {
+	res = false;
+	goto cleanup;
+      }
 
   poly_bb_p pbb;
   FOR_EACH_VEC_ELT (scop->pbbs, i, pbb)
@@ -923,11 +965,13 @@ build_scop_iteration_domain (scop_p scop)
 					  isl_id_for_pbb (scop, pbb));
     }
 
+ cleanup:
   for (int i = 0; i < nb_loops; i++)
     if (doms[i])
       isl_set_free (doms[i]);
 
   free (doms);
+  return res;
 }
 
 /* Add a constrain to the ACCESSES polyhedron for the alias set of
@@ -1187,20 +1231,21 @@ build_scop_drs (scop_p scop)
 
 /* Builds the polyhedral representation for a SESE region.  */
 
-void
+bool
 build_poly_scop (scop_p scop)
 {
   set_scop_parameter_dim (scop);
-  build_scop_iteration_domain (scop);
+  if (!build_scop_iteration_domain (scop))
+    return false;
+
   build_scop_context (scop);
-  add_conditions_to_constraints (scop);
+
+  if (!add_conditions_to_constraints (scop))
+    return false;
 
   build_scop_drs (scop);
   build_scop_minimal_scattering (scop);
   build_scop_original_schedule (scop);
-
-  /* This SCoP has been translated to the polyhedral
-     representation.  */
-  scop->poly_scop_p = true;
+  return true;
 }
 #endif  /* HAVE_isl */
diff --git a/gcc/graphite-sese-to-poly.h b/gcc/graphite-sese-to-poly.h
deleted file mode 100644
index 48f0d56acff..00000000000
--- a/gcc/graphite-sese-to-poly.h
+++ /dev/null
@@ -1,26 +0,0 @@
-/* Conversion of SESE regions to Polyhedra.
-   Copyright (C) 2009-2015 Free Software Foundation, Inc.
-   Contributed by Sebastian Pop <sebastian.pop@amd.com>.
-
-This file is part of GCC.
-
-GCC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 3, or (at your option)
-any later version.
-
-GCC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING3.  If not see
-<http://www.gnu.org/licenses/>.  */
-
-#ifndef GCC_GRAPHITE_SESE_TO_POLY_H
-#define GCC_GRAPHITE_SESE_TO_POLY_H
-
-void build_poly_scop (scop_p);
-
-#endif
diff --git a/gcc/graphite.c b/gcc/graphite.c
index c2efdc95925..ef7e64daf2f 100644
--- a/gcc/graphite.c
+++ b/gcc/graphite.c
@@ -62,7 +62,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "graphite-poly.h"
 #include "graphite-scop-detection.h"
 #include "graphite-isl-ast-to-gimple.h"
-#include "graphite-sese-to-poly.h"
 
 /* Print global statistics to FILE.  */
 
@@ -326,20 +325,18 @@ graphite_transform_loops (void)
     if (dbg_cnt (graphite_scop))
       {
 	scop->isl_context = ctx;
-	build_poly_scop (scop);
-
-	if (dump_file && dump_flags)
-	  print_scop (dump_file, scop);
-	if (scop->poly_scop_p
-	    && apply_poly_transforms (scop))
-	  {
-	    need_cfg_cleanup_p = true;
-	    /* When code generation is not successful, do not continue
-	       generating code for the next scops: the IR has to be cleaned up
-	       and could be in an inconsistent state.  */
-	    if (!graphite_regenerate_ast_isl (scop))
-	      break;
-	  }
+	if (!build_poly_scop (scop))
+	  continue;
+
+	if (!apply_poly_transforms (scop))
+	  continue;
+
+	need_cfg_cleanup_p = true;
+	/* When code generation is not successful, do not continue
+	   generating code for the next scops: the IR has to be cleaned up
+	   and could be in an inconsistent state.  */
+	if (!graphite_regenerate_ast_isl (scop))
+	  break;
       }
 
   free_scops (scops);
diff --git a/gcc/sese.c b/gcc/sese.c
index 9b932ce77fd..74dc4ac7b86 100644
--- a/gcc/sese.c
+++ b/gcc/sese.c
@@ -609,6 +609,8 @@ scalar_evolution_in_region (sese_l &region, loop_p loop, tree t)
 
   if (TREE_CODE (t) != SSA_NAME
       || loop_in_sese_p (loop, region))
+    /* FIXME: we would need instantiate SCEV to work on a region, and be more
+       flexible wrt. memory loads that may be invariant in the region.  */
     return instantiate_scev (before, loop,
 			     analyze_scalar_evolution (loop, t));
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d65527fbdad..19fa7024246 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-11-23  Aditya Kumar  <aditya.k7@samsung.com>
+	    Sebastian Pop  <s.pop@samsung.com>
+
+	PR tree-optimization/68279
+	* testsuite/gfortran.dg/graphite/pr68279.f90: New.
+
 2015-11-23  Marek Polacek  <polacek@redhat.com>
 
 	PR tree-optimization/68455
diff --git a/gcc/testsuite/gfortran.dg/graphite/pr68279.f90 b/gcc/testsuite/gfortran.dg/graphite/pr68279.f90
new file mode 100644
index 00000000000..e68d6e71118
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/graphite/pr68279.f90
@@ -0,0 +1,28 @@
+! { dg-options "-std=legacy -floop-nest-optimize -O2" }
+
+MODULE dbcsr_mm_accdrv
+  INTEGER, SAVE :: accdrv_binning_nbins = 4096
+  INTEGER, SAVE :: accdrv_binning_binsize = 16
+  INTEGER, PARAMETER, PUBLIC :: dbcsr_ps_width = 7
+  CONTAINS
+  SUBROUTINE stack_binning(params_in, params_out, stack_size)
+    INTEGER, INTENT(IN)                      :: stack_size
+    INTEGER, DIMENSION(dbcsr_ps_width, &
+      stack_size), INTENT(OUT)               :: params_out
+    INTEGER, DIMENSION(dbcsr_ps_width, &
+      stack_size), INTENT(IN)                :: params_in
+    INTEGER, DIMENSION(accdrv_binning_nbins) :: bin_top
+    INTEGER, DIMENSION(dbcsr_ps_width)       :: val
+    INTEGER, DIMENSION(dbcsr_ps_width, &
+      accdrv_binning_binsize, &
+      accdrv_binning_nbins)                  :: bin_arr
+     DO i=1,stack_size
+        val(:) = params_in(:,i)
+        IF(bin_top(bin_id) > accdrv_binning_binsize) THEN
+           params_out(:, top:top+bin_top(bin_id)-2) = bin_arr(:, 1:bin_top(bin_id)-1, bin_id)
+        ENDIF
+        bin_arr(:, bin_top(bin_id), bin_id) =  val(:)
+        bin_top(bin_id) = bin_top(bin_id) + 1
+     END DO
+  END SUBROUTINE  stack_binning
+END MODULE