From: Richard Biener <rguenther@suse.de>
Date: Thu, 10 Dec 2015 09:00:58 +0000 (+0000)
Subject: re PR tree-optimization/68806 (internal compiler error: Segmentation fault)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=77ad31753c0440c4141e957edee243f739570587;p=gcc.git

re PR tree-optimization/68806 (internal compiler error: Segmentation fault)

2015-12-10  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68806
	* tree-vect-loop.c (vect_analyze_loop_2): Properly detect
	reduction chains and ignore SLP reductions.

	* gcc.dg/torture/pr68806.c: New testcase.

From-SVN: r231493
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 856a88f5314..c990fc3fc66 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-12-10  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68806
+	* tree-vect-loop.c (vect_analyze_loop_2): Properly detect
+	reduction chains and ignore SLP reductions.
+
 2015-12-10  Richard Biener  <rguenther@suse.de>
 
 	* tree-if-conv.c (if_convertible_loop_p_1): Do not compute
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ef7857a3935..a24de4266cd 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-12-10  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68806
+	* gcc.dg/torture/pr68806.c: New testcase.
+
 2015-12-08  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR ipa/61886
diff --git a/gcc/testsuite/gcc.dg/torture/pr68806.c b/gcc/testsuite/gcc.dg/torture/pr68806.c
new file mode 100644
index 00000000000..dbb743b8033
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr68806.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+int sad(const unsigned char *p1, long p2)
+{
+  int a = 0;
+  for (int y = 0; y < 16; y++)
+    {
+      for (int x = 0; x < 12; x++)
+	a += p1[x];
+      p1 += p2;
+    }
+  return a;
+}
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index ee321667a86..77ad76091c1 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -2123,9 +2123,12 @@ again:
   if (!slp)
     return false;
 
+  /* If there are reduction chains re-trying will fail anyway.  */
+  if (! LOOP_VINFO_REDUCTION_CHAINS (loop_vinfo).is_empty ())
+    return false;
+
   /* Likewise if the grouped loads or stores in the SLP cannot be handled
-     via interleaving or lane instructions or if there were any SLP
-     reductions.  */
+     via interleaving or lane instructions.  */
   slp_instance instance;
   slp_tree node;
   unsigned i, j;
@@ -2135,7 +2138,7 @@ again:
       vinfo = vinfo_for_stmt
 	  (SLP_TREE_SCALAR_STMTS (SLP_INSTANCE_TREE (instance))[0]);
       if (! STMT_VINFO_GROUPED_ACCESS (vinfo))
-	return false;
+	continue;
       vinfo = vinfo_for_stmt (STMT_VINFO_GROUP_FIRST_ELEMENT (vinfo));
       unsigned int size = STMT_VINFO_GROUP_SIZE (vinfo);
       tree vectype = STMT_VINFO_VECTYPE (vinfo);