[Bug target/48213] New: [4.6/4.7 Regression] ICE in simplify_subreg called from s390_delegitimize_address

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48213

           Summary: [4.6/4.7 Regression] ICE in simplify_subreg called
                    from s390_delegitimize_address
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: jakub@gcc.gnu.org
        ReportedBy: jakub@gcc.gnu.org


Since my PR48043 patch the following testcase ICEs on s390:

/* { dg-do compile } */
/* { dg-options "-g -O2" } */
/* { dg-options "-g -O2 -fpic" { target fpic } } */

struct S { int (*s) (void); };
int bar (void);

void
foo (struct S *x)
{
  if (x->s != bar)
    bar ();
}

clc uses BLKmode for the UNSPEC MEM, and lowpart_subreg doesn't allow that.