re PR tree-optimization/68559 (Excessive peeling for gaps)

2015-11-27  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68559
	* tree-vect-data-refs.c (vect_analyze_group_access_1): Move
	peeling for gap checks ...
	* tree-vect-stmts.c (vectorizable_load): ... here and relax
	for SLP.
	* tree-vect-loop.c (vect_analyze_loop_2): Re-set
	LOOP_VINFO_PEELING_FOR_GAPS before re-trying without SLP.

	* gcc.dg/vect/slp-perm-4.c: Adjust again.
	* gcc.dg/vect/pr45752.c: Likewise.

From-SVN: r231015

7 files changed, 59 insertions, 62 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ca9635b..505c693 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2015-11-27  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68559
+	* tree-vect-data-refs.c (vect_analyze_group_access_1): Move
+	peeling for gap checks ...
+	* tree-vect-stmts.c (vectorizable_load): ... here and relax
+	for SLP.
+	* tree-vect-loop.c (vect_analyze_loop_2): Re-set
+	LOOP_VINFO_PEELING_FOR_GAPS before re-trying without SLP.
+
 2015-11-27  Nathan Sidwell  <nathan@acm.org>
 
 	* config/nvptx/nvptx-protos.h (nvptx_record_needed_decl): Don't
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b5b837d..d58666e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-11-27  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68559
+	* gcc.dg/vect/slp-perm-4.c: Adjust again.
+	* gcc.dg/vect/pr45752.c: Likewise.
+
 2015-11-27  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/68250
diff --git a/gcc/testsuite/gcc.dg/vect/pr45752.c b/gcc/testsuite/gcc.dg/vect/pr45752.c
index ab95ad6..0736a74 100644
--- a/gcc/testsuite/gcc.dg/vect/pr45752.c
+++ b/gcc/testsuite/gcc.dg/vect/pr45752.c
@@ -33,7 +33,7 @@
 #define M34 7716
 #define M44 16
 
-#define N 40
+#define N 20
 
 void foo (unsigned int *__restrict__ pInput,
           unsigned int *__restrict__ pOutput,
@@ -77,14 +77,10 @@ int main (int argc, const char* argv[])
   unsigned int input[N], output[N], i, input2[N], output2[N];
   unsigned int check_results[N]
     = {3208, 1334, 28764, 35679, 2789, 13028, 4754, 168364, 91254, 12399, 
-    22848, 8174, 307964, 146829, 22009, 32668, 11594, 447564, 202404, 31619, 
-    42488, 15014, 587164, 257979, 41229, 52308, 18434, 726764, 313554, 50839, 
-    62128, 21854, 866364, 369129, 60449, 71948, 25274, 1005964, 424704, 70059};
+    22848, 8174, 307964, 146829, 22009, 32668, 11594, 447564, 202404, 31619 };
   unsigned int check_results2[N]
     = {7136, 2702, 84604, 57909, 6633, 16956, 6122, 224204, 113484, 16243, 
-    26776, 9542, 363804, 169059, 25853, 36596, 12962, 503404, 224634, 35463, 
-    46416, 16382, 643004, 280209, 45073, 56236, 19802, 782604, 335784, 54683, 
-    66056, 23222, 922204, 391359, 64293, 75876, 26642, 1061804, 446934, 73903};
+    26776, 9542, 363804, 169059, 25853, 36596, 12962, 503404, 224634, 35463 };
 
   check_vect ();
 
@@ -108,4 +104,5 @@ int main (int argc, const char* argv[])
 }
 
 /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect"  } } */
+/* { dg-final { scan-tree-dump-times "gaps requires scalar epilogue loop" 0 "vect" } } */
 /* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 2 "vect" { target vect_perm } } } */
diff --git a/gcc/testsuite/gcc.dg/vect/slp-perm-4.c b/gcc/testsuite/gcc.dg/vect/slp-perm-4.c
index 8e1b5d4..80bc58c 100644
--- a/gcc/testsuite/gcc.dg/vect/slp-perm-4.c
+++ b/gcc/testsuite/gcc.dg/vect/slp-perm-4.c
@@ -33,7 +33,7 @@
 #define M34 7716
 #define M44 16
 
-#define N 40
+#define N 20
 
 void foo (unsigned int *__restrict__ pInput, unsigned int *__restrict__ pOutput)
 {
@@ -60,9 +60,7 @@ int main (int argc, const char* argv[])
   unsigned int input[N], output[N], i;
   unsigned int check_results[N]
     = {3208, 1334, 28764, 35679, 2789, 13028, 4754, 168364, 91254, 12399, 
-    22848, 8174, 307964, 146829, 22009, 32668, 11594, 447564, 202404, 31619, 
-    42488, 15014, 587164, 257979, 41229, 52308, 18434, 726764, 313554, 50839, 
-    62128, 21854, 866364, 369129, 60449, 71948, 25274, 1005964, 424704, 70059};
+    22848, 8174, 307964, 146829, 22009, 32668, 11594, 447564, 202404, 31619};
 
   check_vect ();
 
@@ -85,5 +83,5 @@ int main (int argc, const char* argv[])
 }
 
 /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
+/* { dg-final { scan-tree-dump-times "gaps requires scalar epilogue loop" 0 "vect" } } */
 /* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect" { target vect_perm } } } */
-
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index 62e61e0..7962e36 100644
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -2166,10 +2166,6 @@ vect_analyze_group_access_1 (struct data_reference *dr)
   HOST_WIDE_INT dr_step = -1;
   HOST_WIDE_INT groupsize, last_accessed_element = 1;
   bool slp_impossible = false;
-  struct loop *loop = NULL;
-
-  if (loop_vinfo)
-    loop = LOOP_VINFO_LOOP (loop_vinfo);
 
   /* For interleaving, GROUPSIZE is STEP counted in elements, i.e., the
      size of the interleaving group (including gaps).  */
@@ -2227,24 +2223,6 @@ vect_analyze_group_access_1 (struct data_reference *dr)
 	      dump_printf (MSG_NOTE, "\n");
 	    }
 
-	  if (loop_vinfo)
-	    {
-	      if (dump_enabled_p ())
-		dump_printf_loc (MSG_NOTE, vect_location,
-		                 "Data access with gaps requires scalar "
-		                 "epilogue loop\n");
-              if (loop->inner)
-                {
-                  if (dump_enabled_p ())
-                    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-                                     "Peeling for outer loop is not"
-                                     " supported\n");
-                  return false;
-                }
-
-              LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
-	    }
-
 	  return true;
 	}
 
@@ -2399,29 +2377,6 @@ vect_analyze_group_access_1 (struct data_reference *dr)
           if (bb_vinfo)
             BB_VINFO_GROUPED_STORES (bb_vinfo).safe_push (stmt);
         }
-
-      /* If there is a gap in the end of the group or the group size cannot
-         be made a multiple of the vector element count then we access excess
-	 elements in the last iteration and thus need to peel that off.  */
-      if (loop_vinfo
-	  && (groupsize - last_accessed_element > 0
-	      || exact_log2 (groupsize) == -1))
-
-	{
-	  if (dump_enabled_p ())
-	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-	                     "Data access with gaps requires scalar "
-	                     "epilogue loop\n");
-          if (loop->inner)
-            {
-              if (dump_enabled_p ())
-                dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-                                 "Peeling for outer loop is not supported\n");
-              return false;
-            }
-
-          LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
-	}
     }
 
   return true;
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 6719c9a..7d1f555 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -2190,6 +2190,7 @@ again:
     = init_cost (LOOP_VINFO_LOOP (loop_vinfo));
   /* Reset assorted flags.  */
   LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo) = false;
+  LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = false;
   LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo) = 0;
 
   goto start_over;
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 687f982..3b078da 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -6246,15 +6246,45 @@ vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt,
          that leaves unused vector loads around punt - we at least create
 	 very sub-optimal code in that case (and blow up memory,
 	 see PR65518).  */
+      bool force_peeling = false;
       if (first_stmt == stmt
-	  && !GROUP_NEXT_ELEMENT (stmt_info)
-	  && GROUP_SIZE (stmt_info) > TYPE_VECTOR_SUBPARTS (vectype))
+	  && !GROUP_NEXT_ELEMENT (stmt_info))
+	{
+	  if (GROUP_SIZE (stmt_info) > TYPE_VECTOR_SUBPARTS (vectype))
+	    {
+	      if (dump_enabled_p ())
+		dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+				 "single-element interleaving not supported "
+				 "for not adjacent vector loads\n");
+	      return false;
+	    }
+
+	  /* Single-element interleaving requires peeling for gaps.  */
+	  force_peeling = true;
+	}
+
+      /* If there is a gap in the end of the group or the group size cannot
+         be made a multiple of the vector element count then we access excess
+	 elements in the last iteration and thus need to peel that off.  */
+      if (loop_vinfo
+	  && ! STMT_VINFO_STRIDED_P (stmt_info)
+	  && (force_peeling
+	      || GROUP_GAP (vinfo_for_stmt (first_stmt)) != 0
+	      || (!slp && vf % GROUP_SIZE (vinfo_for_stmt (first_stmt)) != 0)))
 	{
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-			     "single-element interleaving not supported "
-			     "for not adjacent vector loads\n");
-	  return false;
+			     "Data access with gaps requires scalar "
+			     "epilogue loop\n");
+	  if (loop->inner)
+	    {
+	      if (dump_enabled_p ())
+		dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+				 "Peeling for outer loop is not supported\n");
+	      return false;
+	    }
+
+	  LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
 	}
 
       if (slp && SLP_TREE_LOAD_PERMUTATION (slp_node).exists ())