Deprecating Itanium1 for GCC 4.4

[Steven Bosscher <stevenb dot gcc at gmail dot com>]

Hello,

I would like to propose that support for Itanium1 be deprecated for
GCC 4.4 and removed for GCC 4.5.

I doubt there are many Itanium 1 machines left in use (production or
even for hobbyists). The only Itanium1 that reached the market was the
Merced, AFAIK. But only a few 1000s of these were sold, in 2000/2001.
Most of them are probably not running anymore, and the ones still
working probably don't run ia64-linux so they don't need GCC.

On the other side of the equation: The Itanium1 machine description
accounts for ~15% of the total ia64 back-end code, and it's probably
not very well tested. Both GCC and binutils are defaulted to tune for
Itanium 2 processors, so generating code for Itanium1 requires the
-mtune=itanium1 option. I can't find any test results in
gcc-testresults reported with -mtune=itanium1 [1]. Those people who
still use Itanium1 are probably better off if they  stick with the
older GCC releases (pre-gcc-3.4) because at least back then, Itanium1
received maybe some testing (there were regressions reported against
gcc 3.4, for example, by H.J. Lu).

I understand that removing the back end is a big hammer.  On the other
hand, this discussion has come up before, ~5 years ago (see e.g.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15653#c18) and basically
nothing has happened since then.

It seems to me that removing obviously-unused code from a back end
that already perhaps doesn't get as much attention as it needs, is a
good idea...
Thoughts?

Ciao!
Steven


[1] http://gcc.gnu.org/cgi-bin/search.cgi?wm=wrd&form=extended&m=all&s=D&q=itanium1&ul=%2Fml%2Fgcc-testresults%2F%25