The attach file passes with -O1 and lower but fails at this level. The code is
part of RTEMS.

$ m68k-rtems-gcc -m5200 -O2 -c ata.i
ata.i: In function 'ata_initialize':
ata.i:190: error: insn does not satisfy its constraints:
(insn 353 198 200 13 (set (reg:QI 8 %a0)
        (mem:QI (plus:SI (reg/f:SI 14 %a6)
                (const_int -71 [0xffffffb9])) [29 D.1229+0 S1 A8])) 34
{*m68k.md:752} (nil)
    (nil))
ata.i:190: internal compiler error: in reload_cse_simplify_operands, at
postreload.c:391
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

Compiler version is:
$ m68k-rtems-gcc -v
Using built-in specs.
Configured with: ../cvs/head/configure --target=m68k-rtems
--prefix=/local/tools/head --with-gnu-as --with-gnu-ld --with-newlib
--disable-nls --with-system-zlib --enable-version-specific-runtime-libs
--enable-languages=c,c++ --enable-threads=rtems
Thread model: rtems
gcc version 4.0.0 20050131 (experimental)