tree-vect-data-refs.c (vect_analyze_group_access): Properly compute GROUP_GAP for the first element.

2015-06-03  Richard Biener  <rguenther@suse.de>

	* tree-vect-data-refs.c (vect_analyze_group_access): Properly
	compute GROUP_GAP for the first element.
	* tree-vect-slp.c (vect_build_slp_tree_1): Remove restriction
	on in-group gaps.

	* gcc.dg/vect/bb-slp-36.c: New testcase.

From-SVN: r224077

5 files changed, 76 insertions, 30 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cab2f38..f4d83db 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2015-06-03  Richard Biener  <rguenther@suse.de>
+
+	* tree-vect-data-refs.c (vect_analyze_group_access): Properly
+	compute GROUP_GAP for the first element.
+	* tree-vect-slp.c (vect_build_slp_tree_1): Remove restriction
+	on in-group gaps.
+
 2015-06-03  Nick Clifton  <nickc@redhat.com>
 
 	* config/rl78/rl78-real.md: Add peepholes to avoid a register
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5567282..43604b7 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2015-06-03  Richard Biener  <rguenther@suse.de>
+
+	* gcc.dg/vect/bb-slp-36.c: New testcase.
+
 2015-06-03  Ilya Enkovich  <ilya.enkovich@intel.com>
 
 	* gcc.dg/lto/chkp-removed-alias_0.c: New.
diff --git a/gcc/testsuite/gcc.dg/vect/bb-slp-36.c b/gcc/testsuite/gcc.dg/vect/bb-slp-36.c
new file mode 100644
index 0000000..f424d12
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/bb-slp-36.c
@@ -0,0 +1,35 @@
+/* { dg-require-effective-target vect_int } */
+
+#include "tree-vect.h"
+
+extern void abort (void);
+
+int a[8], b[8];
+
+void __attribute__((noinline,noclone))
+foo(void)
+{
+  a[0] = b[0];
+  a[1] = b[0];
+  a[2] = b[3];
+  a[3] = b[3];
+  a[4] = b[4];
+  a[5] = b[7];
+  a[6] = b[4];
+  a[7] = b[7];
+}
+
+int main()
+{
+  int i;
+  check_vect ();
+  for (i = 0; i < 8; ++i)
+    b[i] = i;
+  foo ();
+  if (a[0] != 0 || a[1] != 0 || a[2] != 3 || a[3] != 3
+      || a[4] != 4 || a[5] != 7 || a[6] != 4 || a[7] != 7)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump "basic block vectorized" "slp2" { target vect_perm } } } */
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index 5c3fa3d..a019dba 100644
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -2205,29 +2205,33 @@ vect_analyze_group_access (struct data_reference *dr)
 
       /* Check that the size of the interleaving is equal to count for stores,
          i.e., that there are no gaps.  */
-      if (groupsize != count)
+      if (groupsize != count
+	  && !DR_IS_READ (dr))
         {
-          if (DR_IS_READ (dr))
-            {
-              slp_impossible = true;
-              /* There is a gap after the last load in the group. This gap is a
-                 difference between the groupsize and the number of elements.
-		 When there is no gap, this difference should be 0.  */
-              GROUP_GAP (vinfo_for_stmt (stmt)) = groupsize - count;
-            }
-          else
-            {
-              if (dump_enabled_p ())
-                dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-                                 "interleaved store with gaps\n");
-              return false;
-            }
-        }
+	  if (dump_enabled_p ())
+	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			     "interleaved store with gaps\n");
+	  return false;
+	}
+
+      /* If there is a gap after the last load in the group it is the
+	 difference between the groupsize and the last accessed
+	 element.
+	 When there is no gap, this difference should be 0.  */
+      GROUP_GAP (vinfo_for_stmt (stmt)) = groupsize - last_accessed_element;
 
       GROUP_SIZE (vinfo_for_stmt (stmt)) = groupsize;
       if (dump_enabled_p ())
-        dump_printf_loc (MSG_NOTE, vect_location,
-                         "Detected interleaving of size %d\n", (int)groupsize);
+	{
+	  dump_printf_loc (MSG_NOTE, vect_location,
+			   "Detected interleaving of size %d starting with ",
+			   (int)groupsize);
+	  dump_gimple_stmt (MSG_NOTE, TDF_SLIM, stmt, 0);
+	  if (GROUP_GAP (vinfo_for_stmt (stmt)) != 0)
+	    dump_printf_loc (MSG_NOTE, vect_location,
+			     "There is a gap of %d elements after the group\n",
+			     (int)GROUP_GAP (vinfo_for_stmt (stmt)));
+	}
 
       /* SLP: create an SLP data structure for every interleaving group of
 	 stores for further analysis in vect_analyse_slp.  */
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 9e36d9c..5fd1635 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -777,17 +777,13 @@ vect_build_slp_tree_1 (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo,
 		    (*max_nunits, group_size) / group_size;
               /* FORNOW: Check that there is no gap between the loads
 		 and no gap between the groups when we need to load
-		 multiple groups at once.
-		 ???  We should enhance this to only disallow gaps
-		 inside vectors.  */
-              if ((unrolling_factor > 1
-		   && ((GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) == stmt
-			&& GROUP_GAP (vinfo_for_stmt (stmt)) != 0)
-		       /* If the group is split up then GROUP_GAP
-			  isn't correct here, nor is GROUP_FIRST_ELEMENT.  */
-		       || GROUP_SIZE (vinfo_for_stmt (stmt)) > group_size))
-		  || (GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) != stmt
-		      && GROUP_GAP (vinfo_for_stmt (stmt)) != 1))
+		 multiple groups at once.  */
+              if (unrolling_factor > 1
+		  && ((GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) == stmt
+		       && GROUP_GAP (vinfo_for_stmt (stmt)) != 0)
+		      /* If the group is split up then GROUP_GAP
+			 isn't correct here, nor is GROUP_FIRST_ELEMENT.  */
+		      || GROUP_SIZE (vinfo_for_stmt (stmt)) > group_size))
                 {
                   if (dump_enabled_p ())
                     {