Hi,
Please have a look at upstream bug report:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61799
I was asked to test GCC 4.8 and found this issue go away with
locally-recompiled GCC 4.8.2 (upstream source, as ia64 is no more
supported by Debian).
Whether this was expected or not, I don't know.
Feel free to discuss more in details with ia64/GCC gurus in upstream bug.
Thanks,
Émeric