re PR middle-end/52603 (Test failures in gcc.dg/vect: vectorizing unaligned access)

2012-03-16  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/52603
	* tree-vect-data-refs.c (vect_can_force_dr_alignment_p): Clarify
	comment.

	Revert
	2012-03-14  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/52571
	* tree-vect-data-refs.c (vect_compute_data_ref_alignment): Move
	flag_section_anchors check ...
	(vect_can_force_dr_alignment_p): ... here.

From-SVN: r185474

gcc/ChangeLog

+2012-03-16  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/52603
+	* tree-vect-data-refs.c (vect_can_force_dr_alignment_p): Clarify
+	comment.
+
+	Revert
+	2012-03-14  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/52571
+	* tree-vect-data-refs.c (vect_compute_data_ref_alignment): Move
+	flag_section_anchors check ...
+	(vect_can_force_dr_alignment_p): ... here.
+
 2012-03-16  Martin Jambor  <mjambor@suse.cz>
 
 	* expr.c (expand_expr_real_1): handle misaligned scalar reads from

gcc/tree-vect-data-refs.c

@@ -872,7 +872,12 @@ vect_compute_data_ref_alignment (struct data_reference *dr)
 
   if (!base_aligned)
     {
-      if (!vect_can_force_dr_alignment_p (base, TYPE_ALIGN (vectype)))
+      /* Do not change the alignment of global variables here if
+	 flag_section_anchors is enabled as we already generated
+	 RTL for other functions.  Most global variables should
+	 have been aligned during the IPA increase_alignment pass.  */
+      if (!vect_can_force_dr_alignment_p (base, TYPE_ALIGN (vectype))
+	  || (TREE_STATIC (base) && flag_section_anchors))
 	{
 	  if (vect_print_dump_info (REPORT_DETAILS))
 	    {
@@ -4554,11 +4559,6 @@ vect_can_force_dr_alignment_p (const_tree decl, unsigned int alignment)
   if (TREE_ASM_WRITTEN (decl))
     return false;
 
-  /* Do not change the alignment of global variables if flag_section_anchors
-     is enabled.  */
-  if (TREE_STATIC (decl) && flag_section_anchors)
-    return false;
-
   if (TREE_STATIC (decl))
     return (alignment <= MAX_OFILE_ALIGNMENT);
   else