I think I found the problem. tcltk is not 64bit clean. That is why it
fails under ia64. There are tens of warnings like

./../generic/tclIndexObj.c:97: warning: passing arg 4 of
`Tcl_GetIndexFromObjStruct' with different width due to prototype
./../generic/tclIndexObj.c: In function `Tcl_GetIndexFromObjStruct':
./../generic/tclIndexObj.c:154: warning: cast from pointer to integer of
different size
./../generic/tclIndexObj.c: In function `Tcl_WrongNumArgs':
./../generic/tclIndexObj.c:331: warning: cast from pointer to integer of
different size

I believe if all those warnings are fixed, the ia64 problem will
go away.

autoconf 64 bit doesn't seem to work. The above bugs are failing because
routines are using unions to access the same data different ways.

will defer and try to get it for gold.

I have a kludge at

http://ftp.valinux.com/pub/support/hjl/ia64/

It has both srpms and rpms. It is a kludge, not
a real fix, although it works for me and
Jakub.

Thanks for the patch. Need to test on the other architectures before I go with
it. Last version had problems on IA-32 and other architectures (make clean
failed on some tests-- some font related, others more serious and pointing to
something deeper)

I'm taking a look at it.

Is this still a problem?

Closing this for now, since it is no longer clear what
the problem was.