https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86547
--- Comment #2 from Ilya Leoshkevich <iii at linux dot ibm.com> ---
I dug a bit deeper and found that this used to compile without errors on
gcc-4_8_5-release.
Bisect points to s390-specific commit 7b1bda1c, which first appeared in
gcc-4_9_0-release:
2013-06-06 Vladimir Makarov <vmaka...@redhat.com>
* config/s390/s390.opt (mlra): New option.
* config/s390/s390.c (s390_decompose_address): Check displacement
for all registers for LRA.
(s390_secondary_reload): Don't used secondary reloads for LRA.
(s390_lra_p): New function.
(TARGET_LRA_P): Define.
* config/s390/s390.md (*movmem_short, *clrmem_short): Change value
of attribute cpu_facility to zarch for the last alternative.
(*cmpmem_short): Ditto.
This commit appears to have introduced LRA for s390x.
