2014-01-10 Richard Biener <rguenther@suse.de>

	PR tree-optimization/59374
	* tree-vect-slp.c (vect_slp_analyze_bb_1): Move dependence
	checking after SLP discovery.  Mark stmts not participating
	in any SLP instance properly.

	* gcc.dg/torture/pr59374-3.c: New testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@206523 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 56 insertions, 11 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b6f808903ff..7b5229136a7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2014-01-10  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/59374
+	* tree-vect-slp.c (vect_slp_analyze_bb_1): Move dependence
+	checking after SLP discovery.  Mark stmts not participating
+	in any SLP instance properly.
+
 2014-01-10  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/arm/arm.c (arm_new_rtx_costs): Use destination mode
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2e3b11d9e6a..a5738130f44 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-01-10  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/59374
+	* gcc.dg/torture/pr59374-3.c: New testcase.
+
 2014-01-10  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* lib/target-supports.exp
diff --git a/gcc/testsuite/gcc.dg/torture/pr59374-3.c b/gcc/testsuite/gcc.dg/torture/pr59374-3.c
new file mode 100644
index 00000000000..ab0014d8f13
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr59374-3.c
@@ -0,0 +1,21 @@
+extern void abort (void);
+
+static struct X { void *a; void *b; } a, b;
+
+void __attribute__((noinline)) foo (void)
+{
+  void *tem = a.b;
+  a.b = (void *)0;
+  b.b = tem;
+  b.a = a.a;
+  a.a = tem;
+}
+
+int main()
+{
+  a.b = &a;
+  foo ();
+  if (b.b != &a)
+    abort ();
+  return 0;
+}
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 2b075dfea96..372d7db3e70 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -2110,17 +2110,6 @@ vect_slp_analyze_bb_1 (basic_block bb)
 
   vect_pattern_recog (NULL, bb_vinfo);
 
-  if (!vect_slp_analyze_data_ref_dependences (bb_vinfo))
-     {
-       if (dump_enabled_p ())
-	 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-			  "not vectorized: unhandled data dependence "
-			  "in basic block.\n");
-
-       destroy_bb_vec_info (bb_vinfo);
-       return NULL;
-     }
-
   if (!vect_analyze_data_refs_alignment (NULL, bb_vinfo))
     {
       if (dump_enabled_p ())
@@ -2155,6 +2144,29 @@ vect_slp_analyze_bb_1 (basic_block bb)
       vect_mark_slp_stmts_relevant (SLP_INSTANCE_TREE (instance));
     }
 
+  /* Mark all the statements that we do not want to vectorize.  */
+  for (gimple_stmt_iterator gsi = gsi_start_bb (BB_VINFO_BB (bb_vinfo));
+       !gsi_end_p (gsi); gsi_next (&gsi))
+    {
+      stmt_vec_info vinfo = vinfo_for_stmt (gsi_stmt (gsi));
+      if (STMT_SLP_TYPE (vinfo) != pure_slp)
+	STMT_VINFO_VECTORIZABLE (vinfo) = false;
+    }
+
+  /* Analyze dependences.  At this point all stmts not participating in
+     vectorization have to be marked.  Dependence analysis assumes
+     that we either vectorize all SLP instances or none at all.  */
+  if (!vect_slp_analyze_data_ref_dependences (bb_vinfo))
+     {
+       if (dump_enabled_p ())
+	 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			  "not vectorized: unhandled data dependence "
+			  "in basic block.\n");
+
+       destroy_bb_vec_info (bb_vinfo);
+       return NULL;
+     }
+
   if (!vect_verify_datarefs_alignment (NULL, bb_vinfo))
     {
       if (dump_enabled_p ())