tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Do not consider…

tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Do not consider dependences between accesses that belong to the same group.

2016-06-15  Richard Biener  <rguenther@suse.de>

	* tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Do
	not consider dependences between accesses that belong to the
	same group.
	(vect_analyze_data_ref_dependences): Do not analyze read-read
	or self-dependences.

	* gcc.dg/vect/bb-slp-pattern-2.c: Disable loop vectorization.

From-SVN: r237473

gcc/ChangeLog

+2016-06-15  Richard Biener  <rguenther@suse.de>
+
+	* tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Do
+	not consider dependences between accesses that belong to the
+	same group.
+	(vect_analyze_data_ref_dependences): Do not analyze read-read
+	or self-dependences.
+
 2016-06-14  David Malcolm  <dmalcolm@redhat.com>
 
 	* spellcheck-tree.c: Include spellcheck-tree.h rather than

gcc/testsuite/ChangeLog

+2016-06-15  Richard Biener  <rguenther@suse.de>
+
+	* gcc.dg/vect/bb-slp-pattern-2.c: Disable loop vectorization.
+
 2016-06-14  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	* gcc.target/powerpc/vsx-elemrev-2.c: Change effective target

gcc/testsuite/gcc.dg/vect/bb-slp-pattern-2.c

 /* { dg-require-effective-target vect_condition } */
+/* { dg-additional-options "-fno-tree-vectorize -ftree-slp-vectorize -ftree-loop-if-convert" } */
 
 #include "tree-vect.h"
 

gcc/tree-vect-data-refs.c

@@ -227,6 +227,12 @@ vect_analyze_data_ref_dependence (struct data_dependence_relation *ddr,
       || (DR_IS_READ (dra) && DR_IS_READ (drb)))
     return false;
 
+  /* We do not have to consider dependences between accesses that belong
+     to the same group.  */
+  if (GROUP_FIRST_ELEMENT (stmtinfo_a)
+      && GROUP_FIRST_ELEMENT (stmtinfo_a) == GROUP_FIRST_ELEMENT (stmtinfo_b))
+    return false;
+
   /* Even if we have an anti-dependence then, as the vectorized loop covers at
      least two scalar iterations, there is always also a true dependence.
      As the vectorizer does not re-order loads and stores we can ignore
@@ -469,7 +475,7 @@ vect_analyze_data_ref_dependences (loop_vec_info loop_vinfo, int *max_vf)
   LOOP_VINFO_NO_DATA_DEPENDENCIES (loop_vinfo) = true;
   if (!compute_all_dependences (LOOP_VINFO_DATAREFS (loop_vinfo),
 				&LOOP_VINFO_DDRS (loop_vinfo),
-				LOOP_VINFO_LOOP_NEST (loop_vinfo), true))
+				LOOP_VINFO_LOOP_NEST (loop_vinfo), false))
     return false;
 
   FOR_EACH_VEC_ELT (LOOP_VINFO_DDRS (loop_vinfo), i, ddr)