[Bug tree-optimization/52686] New: SLP crashes with WIDEN_LSHIFT_EXPR

["uweigand at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52686

             Bug #: 52686
           Summary: SLP crashes with WIDEN_LSHIFT_EXPR
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: uweigand@gcc.gnu.org


When building the following test case:

unsigned int output[4];

void test (unsigned short *p)
{
  unsigned int x = *p;
  if (x)
    {
      output[0] = x << 1;
      output[1] = x << 1;
      output[2] = x << 1;
      output[3] = x << 1;
    }
}

GCC crashes with various symptoms (segmentation fault if checking is disabled;
assertion failures along the lines of "vector VEC(tree,base) index domain
error, in vect_create_vectorized_promotion_stmts at tree-vect-stmts.c:2130" if
checking is enabled) when building on ARM with -O1 -ftree-vectorize -mfpu=neon
-mfloat-abi=softfp.