re PR tree-optimization/53185 (segmentation fault in vectorizable_load)

	PR tree-optimization/53185
	* tree-vect-data-refs.c (vect_enhance_data_refs_alignment): Disable
	peeling when we see strided loads.

testsuite/
	* gcc.dg/vect/pr53185.c: New test.

From-SVN: r187340

gcc/ChangeLog

+2012-05-09  Michael Matz  <matz@suse.de>
+
+	PR tree-optimization/53185
+	* tree-vect-data-refs.c (vect_enhance_data_refs_alignment): Disable
+	peeling when we see strided loads.
+
 2012-05-09  Matthias Klose  <doko@ubuntu.com>
 
 	* gcc-ar.c (main): Don't check for execute bits for the plugin.

gcc/testsuite/ChangeLog

+2012-05-09  Michael Matz  <matz@suse.de>
+
+	PR tree-optimization/53185
+	* gcc.dg/vect/pr53185.c: New test.
+
 2012-05-09  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR middle-end/53249

gcc/testsuite/gcc.dg/vect/pr53185.c

+/* { dg-do compile } */
+/* { dg-options "-O3 -ftree-vectorize" } */
+unsigned short a, e;
+int *b, *d;
+int c;
+extern int fn2();
+void fn1 () {
+  void *f;
+  for (;;) {
+    fn2 ();
+    b = f;
+    e = 0;
+    for (; e < a; ++e)
+      b[e] = d[e * c];
+  }
+}

gcc/tree-vect-data-refs.c

@@ -1507,6 +1507,17 @@ vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo)
           && GROUP_FIRST_ELEMENT (stmt_info) != stmt)
         continue;
 
+      /* FORNOW: Any strided load prevents peeling.  The induction
+         variable analysis will fail when the prologue loop is generated,
+	 and so we can't generate the new base for the pointer.  */
+      if (STMT_VINFO_STRIDE_LOAD_P (stmt_info))
+	{
+	  if (vect_print_dump_info (REPORT_DETAILS))
+	    fprintf (vect_dump, "strided load prevents peeling");
+	  do_peeling = false;
+	  break;
+	}
+
       /* For invariant accesses there is nothing to enhance.  */
       if (integer_zerop (DR_STEP (dr)))
 	continue;