[Bug rtl-optimization/16669] New: ICE with union { long double l; }

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

union U { long double l; };
extern union U foo (void);
void baz (void)
{
  union U u = foo ();
}

ICEs at -O0 in:
S.c: In function `baz':
S.c:6: internal compiler error: in ix86_secondary_memory_needed, at
config/i386/i386.c:14708
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

This is why reloading
(insn 12 11 13 1 (set (mem/s:DI (plus:DI (reg/f:DI 20 frame)
                (const_int -24 [0xffffffffffffffe8])) [0 S8 A64])
        (subreg:DI (reg:XF 8 st) 8)) 83 {*movdi_1_rex64_nointerunit} (nil)
    (expr_list:REG_DEAD (reg:XF 8 st)
        (nil)))

-- 
           Summary: ICE with union { long double l; }
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: x86_64-*-linux*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16669