llvm dev - Jul 2009 - [LLVMdev] Removal of IA-64 target

Hello,

LLVM's IA-64 target has not been maintained for a few years, and it is
currently unable to compile many simple testcases. I'm planning to
remove it from the tree soon, unless someone objects.

Dan

On Jul 16, 2009, at 1:38 PM, Dan Gohman wrote:
> Hello,
>
> LLVM's IA-64 target has not been maintained for a few years, and it is
> currently unable to compile many simple testcases. I'm planning to
> remove it from the tree soon, unless someone objects.
Ouch.

The FreeBSD project is putting serious effort in getting the
OS to compile with LLVM with a future possibility to make it
the default compiler. I'm maintaining FreeBSD/ia64 and while
I was aware that the LLVM/ia64 target had bitrotted, I hoped
to find time to work on that.

I'm still interested in getting it up to par, but know that
it's also a lot of work and maintaining FreeBSD/ia64 already
eats its share of resources. As such, I'm not at all in the
position to object to the removal -- LLVM wasn't built with
(false) promises or (good) intentions.

However ... (didn't we see that coming from afar :-)

What I'll do right now is update, built and run tests. LLVM
built on FreeBSD/ia64 last week, so that much I know. I'll
look into the test results to see how bad it is. In the mean
time I hope that there's a way for me to put my money where
my mouth is and come to some arrangement along the lines of:
test X and Y through Z needs to pass before <event/date> or
else... *axed*

Alternatively (I don't know how bad the target is and thus
how much ramp-up time I need to get anything done), keep it
in the tree for a bit longer, but disconnect it?

BTW: I don't run Linux at all, so no Linux/ia64 support.
I can see how that could be a problem for people.

Anyway: my case is a weak one and I would understand if the
target get axed without considering my email/request...

FYI,

-- 
Marcel Moolenaar
xcllnt at mac.com

On Jul 16, 2009, at 2:30 PM, Marcel Moolenaar wrote:
>
> BTW: I don't run Linux at all, so no Linux/ia64 support.
> I can see how that could be a problem for people.
>
> Anyway: my case is a weak one and I would understand if the
> target get axed without considering my email/request...
Hi Marcel,

There are two levels of problems with the IA64 backend.  On the first  
level, it has not been maintained for a long time, and isn't able to  
compile hello world to a working app.  This is a pretty bad state.  On  
the second level, it will take a significant amount of work to make it  
produce code that is actually *fast* for itanium, because of the  
advanced architectural features of the chip.

For us to keep IA64 around (and for it to be minimally useful for your  
work!), I think that the backend should pass most of the simple  
programs in MultiSource/Benchmarks for example.  It does *not* need to  
produce amazingly fast code, but the code needs to work.  I don't know  
how much performance on IA64 is important to you guys, if GCC is  
currently acceptable, then probably don't have that high of a  
performance bar.

Another question is: who is really interested in FreeBSD/ia64?  Is HP  
(for example) contributing to this work?  If so, perhaps you could  
find help in one of the itanium-friendly companies.

-Chris