[PATCH} backport r175475 to gcc-4_6-branch

[Jack Howarth]

   Currently PR49536 still exists in gcc-4_6-branch. The following
patch backports r175475 for the gcc 4.6.3 release. This will be helpful
to dragonegg users (http://llvm.org/bugs/show_bug.cgi?id=10042) as
dragonegg currently doesn't build against FSF gcc trunk yet. Regression
tested on x86_64-apple-darwin11...

http://gcc.gnu.org/ml/gcc-testresults/2012-02/msg00599.html

Okay for gcc-4_6-branch and thus gcc 4.6.3?
                Jack

2012-02-08  Jack Howarth  <howarth@bromo.med.uc.edu>

	Backport from mainline
	2011-06-27  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/49536
	* tree-vect-stmts.c (get_vectype_for_scalar_type_and_size):
	For non-scalar inner types use a scalar type according to
	the scalar inner mode.

Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c	(revision 183938)
+++ gcc/tree-vect-stmts.c	(working copy)
@@ -5117,6 +5117,15 @@ get_vectype_for_scalar_type_and_size (tr
       && GET_MODE_CLASS (inner_mode) != MODE_FLOAT)
     return NULL_TREE;
 
+  /* We shouldn't end up building VECTOR_TYPEs of non-scalar components.
+     When the component mode passes the above test simply use a type
+     corresponding to that mode.  The theory is that any use that
+     would cause problems with this will disable vectorization anyway.  */
+  if (!SCALAR_FLOAT_TYPE_P (scalar_type)
+      && !INTEGRAL_TYPE_P (scalar_type)
+      && !POINTER_TYPE_P (scalar_type))
+    scalar_type = lang_hooks.types.type_for_mode (inner_mode, 1);
+
   /* If no size was supplied use the mode the target prefers.   Otherwise
      lookup a vector mode of the specified size.  */
   if (size == 0)