re PR tree-optimization/82473 (ICE in vect_get_vec_def_for_stmt_copy, at tree-vect-stmts.c:1524)

2017-10-20  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/82473
	* tree-vect-loop.c (vectorizable_reduction): Properly get at
	the largest input type.

	* gcc.dg/torture/pr82473.c: New testcase.

From-SVN: r253937

gcc/ChangeLog

+2017-10-20  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/82473
+	* tree-vect-loop.c (vectorizable_reduction): Properly get at
+	the largest input type.
+
 2017-10-20  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
 
 	* c-attribs.c (handle_nocf_check_attribute): New function.

gcc/testsuite/ChangeLog

 2017-10-20  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/82473
+	* gcc.dg/torture/pr82473.c: New testcase.
+
+2017-10-20  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/82603
 	* gcc.dg/torture/pr82603.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr82473.c

+/* { dg-do compile } */
+/* { dg-additional-options "-ftree-vectorize" } */
+
+void
+zz (int x9, short int gt)
+{
+  if (0)
+    {
+      while (gt < 1)
+	{
+	  int pz;
+
+k6:
+	  for (pz = 0; pz < 3; ++pz)
+	    x9 += gt;
+	  ++gt;
+	}
+    }
+
+  if (x9 != 0)
+    goto k6;
+}

gcc/tree-vect-loop.c

@@ -5836,9 +5836,12 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi,
 	  reduc_index = i;
 	  continue;
 	}
-      else
+      else if (tem)
 	{
-	  if (!vectype_in)
+	  /* To properly compute ncopies we are interested in the widest
+	     input type in case we're looking at a widening accumulation.  */
+	  if (!vectype_in
+	      || TYPE_VECTOR_SUBPARTS (vectype_in) > TYPE_VECTOR_SUBPARTS (tem))
 	    vectype_in = tem;
 	}