Fix PR47654: Loop blocking should strip-mine at least two loops.

	PR tree-optimization/47654
	* graphite-blocking.c (pbb_strip_mine_time_depth): Do not return bool.
	(lst_do_strip_mine_loop): Return an int.
	(lst_do_strip_mine): Same.
	(scop_do_strip_mine): Same.
	(scop_do_block): Loop blocking should strip-mine at least two loops.
	* graphite-interchange.c (lst_interchange_select_outer): Return an int.
	(scop_do_interchange): Same.
	* graphite-poly.h (scop_do_interchange): Update declaration.
	(scop_do_strip_mine): Same.

	* gcc.dg/graphite/block-pr47654.c: New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@175861 138bc75d-0d04-0410-961f-82ee72b054a4

6 files changed, 83 insertions, 46 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d08e4a3cb75..418f5dce6a7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,18 @@
 2011-07-05  Sebastian Pop  <sebastian.pop@amd.com>
 
+	PR tree-optimization/47654
+	* graphite-blocking.c (pbb_strip_mine_time_depth): Do not return bool.
+	(lst_do_strip_mine_loop): Return an int.
+	(lst_do_strip_mine): Same.
+	(scop_do_strip_mine): Same.
+	(scop_do_block): Loop blocking should strip-mine at least two loops.
+	* graphite-interchange.c (lst_interchange_select_outer): Return an int.
+	(scop_do_interchange): Same.
+	* graphite-poly.h (scop_do_interchange): Update declaration.
+	(scop_do_strip_mine): Same.
+
+2011-07-05  Sebastian Pop  <sebastian.pop@amd.com>
+
 	* graphite-clast-to-gimple.c (precision_for_value): Removed.
 	(precision_for_interval): Removed.
 	(gcc_type_for_interval): Use mpz_sizeinbase.
diff --git a/gcc/graphite-blocking.c b/gcc/graphite-blocking.c
index bcd077a8310..967de9d9462 100644
--- a/gcc/graphite-blocking.c
+++ b/gcc/graphite-blocking.c
@@ -89,7 +89,7 @@ along with GCC; see the file COPYING3.  If not see
    # }
 */
 
-static bool
+static void
 pbb_strip_mine_time_depth (poly_bb_p pbb, int time_depth, int stride)
 {
   ppl_dimension_type iter, dim, strip;
@@ -151,8 +151,6 @@ pbb_strip_mine_time_depth (poly_bb_p pbb, int time_depth, int stride)
     ppl_Polyhedron_add_constraint (res, new_cstr);
     ppl_delete_Constraint (new_cstr);
   }
-
-  return true;
 }
 
 /* Returns true when strip mining with STRIDE of the loop LST is
@@ -177,10 +175,10 @@ lst_strip_mine_profitable_p (lst_p lst, int stride)
   return res;
 }
 
-/* Strip-mines all the loops of LST with STRIDE.  Return true if it
-   did strip-mined some loops.  */
+/* Strip-mines all the loops of LST with STRIDE.  Return the number of
+   loops strip-mined.  */
 
-static bool
+static int
 lst_do_strip_mine_loop (lst_p lst, int depth, int stride)
 {
   int i;
@@ -188,26 +186,26 @@ lst_do_strip_mine_loop (lst_p lst, int depth, int stride)
   poly_bb_p pbb;
 
   if (!lst)
-    return false;
+    return 0;
 
   if (LST_LOOP_P (lst))
     {
-      bool res = false;
+      int res = 0;
 
       FOR_EACH_VEC_ELT (lst_p, LST_SEQ (lst), i, l)
-	res |= lst_do_strip_mine_loop (l, depth, stride);
+	res += lst_do_strip_mine_loop (l, depth, stride);
 
       return res;
     }
 
   pbb = LST_PBB (lst);
-  return pbb_strip_mine_time_depth (pbb, psct_dynamic_dim (pbb, depth),
-				    stride);
+  pbb_strip_mine_time_depth (pbb, psct_dynamic_dim (pbb, depth), stride);
+  return 1;
 }
 
 /* Strip-mines all the loops of LST with STRIDE.  When STRIDE is zero,
-   read the stride from the PARAM_LOOP_BLOCK_TILE_SIZE.  Return true
-   if it did strip-mined some loops.
+   read the stride from the PARAM_LOOP_BLOCK_TILE_SIZE.  Return the
+   number of strip-mined loops.
 
    Strip mining transforms a loop
 
@@ -221,12 +219,12 @@ lst_do_strip_mine_loop (lst_p lst, int depth, int stride)
    |     S (i = k + j);
 */
 
-static bool
+static int
 lst_do_strip_mine (lst_p lst, int stride)
 {
   int i;
   lst_p l;
-  bool res = false;
+  int res = 0;
   int depth;
 
   if (!stride)
@@ -237,23 +235,23 @@ lst_do_strip_mine (lst_p lst, int stride)
     return false;
 
   FOR_EACH_VEC_ELT (lst_p, LST_SEQ (lst), i, l)
-    res |= lst_do_strip_mine (l, stride);
+    res += lst_do_strip_mine (l, stride);
 
   depth = lst_depth (lst);
   if (depth >= 0
       && lst_strip_mine_profitable_p (lst, stride))
     {
-      res |= lst_do_strip_mine_loop (lst, lst_depth (lst), stride);
+      res += lst_do_strip_mine_loop (lst, lst_depth (lst), stride);
       lst_add_loop_under_loop (lst);
     }
 
   return res;
 }
 
-/* Strip mines all the loops in SCOP.  Returns true when some loops
-   have been strip-mined.  */
+/* Strip mines all the loops in SCOP.  Returns the number of
+   strip-mined loops.  */
 
-bool
+int
 scop_do_strip_mine (scop_p scop, int stride)
 {
   return lst_do_strip_mine (SCOP_TRANSFORMED_SCHEDULE (scop), stride);
@@ -265,27 +263,22 @@ scop_do_strip_mine (scop_p scop, int stride)
 bool
 scop_do_block (scop_p scop)
 {
-  bool strip_mined = false;
-  bool interchanged = false;
-
   store_scattering (scop);
 
-  strip_mined = lst_do_strip_mine (SCOP_TRANSFORMED_SCHEDULE (scop), 0);
-  interchanged = scop_do_interchange (scop);
-
-  /* If we don't interchange loops, the strip mine alone will not be
-     profitable, and the transform is not a loop blocking: so revert
-     the transform.  */
-  if (!interchanged)
+  /* If we don't strip mine at least two loops, or not interchange
+     loops, the strip mine alone will not be profitable, and the
+     transform is not a loop blocking: so revert the transform.  */
+  if (lst_do_strip_mine (SCOP_TRANSFORMED_SCHEDULE (scop), 0) < 2
+      || scop_do_interchange (scop) == 0)
     {
       restore_scattering (scop);
       return false;
     }
-  else if (strip_mined && interchanged
-	   && dump_file && (dump_flags & TDF_DETAILS))
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "SCoP will be loop blocked.\n");
 
-  return strip_mined || interchanged;
+  return true;
 }
 
 #endif
diff --git a/gcc/graphite-interchange.c b/gcc/graphite-interchange.c
index 934839aace0..cb4d32cc0d2 100644
--- a/gcc/graphite-interchange.c
+++ b/gcc/graphite-interchange.c
@@ -664,27 +664,27 @@ lst_interchange_select_inner (scop_p scop, lst_p outer_father, int outer,
 }
 
 /* Interchanges all the loops of LOOP and the loops of its body that
-   are considered profitable to interchange.  Return true if it did
-   interchanged some loops.  OUTER is the index in LST_SEQ (LOOP) that
+   are considered profitable to interchange.  Return the number of
+   interchanged loops.  OUTER is the index in LST_SEQ (LOOP) that
    points to the next outer loop to be considered for interchange.  */
 
-static bool
+static int
 lst_interchange_select_outer (scop_p scop, lst_p loop, int outer)
 {
   lst_p l;
-  bool res = false;
+  int res = 0;
   int i = 0;
   lst_p father;
 
   if (!loop || !LST_LOOP_P (loop))
-    return false;
+    return 0;
 
   father = LST_LOOP_FATHER (loop);
   if (father)
     {
       while (lst_interchange_select_inner (scop, father, outer, loop))
 	{
-	  res = true;
+	  res++;
 	  loop = VEC_index (lst_p, LST_SEQ (father), outer);
 	}
     }
@@ -692,17 +692,18 @@ lst_interchange_select_outer (scop_p scop, lst_p loop, int outer)
   if (LST_LOOP_P (loop))
     FOR_EACH_VEC_ELT (lst_p, LST_SEQ (loop), i, l)
       if (LST_LOOP_P (l))
-	res |= lst_interchange_select_outer (scop, l, i);
+	res += lst_interchange_select_outer (scop, l, i);
 
   return res;
 }
 
-/* Interchanges all the loop depths that are considered profitable for SCOP.  */
+/* Interchanges all the loop depths that are considered profitable for
+   SCOP.  Return the number of interchanged loops.  */
 
-bool
+int
 scop_do_interchange (scop_p scop)
 {
-  bool res = lst_interchange_select_outer
+  int res = lst_interchange_select_outer
     (scop, SCOP_TRANSFORMED_SCHEDULE (scop), 0);
 
   lst_update_scattering (SCOP_TRANSFORMED_SCHEDULE (scop));
diff --git a/gcc/graphite-poly.h b/gcc/graphite-poly.h
index 3bf87b088c9..417e99eef25 100644
--- a/gcc/graphite-poly.h
+++ b/gcc/graphite-poly.h
@@ -410,8 +410,8 @@ extern void print_iteration_domain (FILE *, poly_bb_p, int);
 extern void print_iteration_domains (FILE *, scop_p, int);
 extern void debug_iteration_domain (poly_bb_p, int);
 extern void debug_iteration_domains (scop_p, int);
-extern bool scop_do_interchange (scop_p);
-extern bool scop_do_strip_mine (scop_p, int);
+extern int scop_do_interchange (scop_p);
+extern int scop_do_strip_mine (scop_p, int);
 extern bool scop_do_block (scop_p);
 extern bool flatten_all_loops (scop_p);
 extern void pbb_number_of_iterations_at_time (poly_bb_p, graphite_dim_t, mpz_t);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 891763504d3..282990f311d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-07-05  Sebastian Pop  <sebastian.pop@amd.com>
+
+	PR tree-optimization/47654
+	* gcc.dg/graphite/block-pr47654.c: New.
+
 2011-07-05  Jason Merrill  <jason@redhat.com>
 
 	* g++.dg/cpp0x/lambda/lambda-ref2.C: New.
@@ -39,7 +44,7 @@
 	* gcc.dg/pr49602.c: New test.
 
 2011-07-04  Georg-Johann Lay  <avr@gjlay.de>
-	
+
 	PR target/34734
 	PR target/44643
 	* gcc.target/avr/avr.exp: Run over cpp files, too.
diff --git a/gcc/testsuite/gcc.dg/graphite/block-pr47654.c b/gcc/testsuite/gcc.dg/graphite/block-pr47654.c
new file mode 100644
index 00000000000..9cdeb0c3579
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/graphite/block-pr47654.c
@@ -0,0 +1,25 @@
+int a[128][40];
+
+void __attribute__ ((noinline, noclone))
+foo (void)
+{
+  int i, j;
+  for (i = 0; i < 40; i++)
+    for (j = 0; j < 128; j++)
+      a[j][i] = 4;
+}
+
+int
+main ()
+{
+  int i, j;
+  foo ();
+  for (i = 0; i < 40; i++)
+    for (j = 0; j < 128; j++)
+      if (a[j][i] != 4)
+	__builtin_abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-not "will be loop blocked" "graphite" } } */
+/* { dg-final { cleanup-tree-dump "graphite" } } */