[Bug middle-end/49536] latent bug with creation of vector of arrays

["howarth at nitro dot med.uc.edu" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49536

--- Comment #7 from Jack Howarth <howarth at nitro dot med.uc.edu> 2011-06-27 16:46:17 UTC ---
I can confirm that the adjusted backport of...

Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c    (revision 175535)
+++ gcc/tree-vect-stmts.c    (working copy)
@@ -4660,6 +4660,15 @@ get_vectype_for_scalar_type (tree scalar
       && GET_MODE_BITSIZE (inner_mode) != TYPE_PRECISION (scalar_type))
     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);
+
   /* FORNOW: Only a single vector size per mode (UNITS_PER_SIMD_WORD)
      is expected.  */
   nunits = UNITS_PER_SIMD_WORD (inner_mode) / nbytes;

on current gcc-4_5-branch solves the ICE under dragonegg in the original
testcase from  http://llvm.org/bugs/show_bug.cgi?id=10042.