Assorted fixes:
  * Stop being pessimistic about output register allocation
  * Start to handle function descriptors: compute target GPs and so on
  when doing indirect calls etc. Not there yet, though. For the moment,
  we try to use _indirect_ branches wherever possible, to stress test
  function descriptors.
  * FP divide-by-zero should work now
  * add varargs (it doesn't work, though)

At this point, all of SingleSource passes (modulo C++ tests that are due
to issues with the CFE, see note in the README.) Much of MultiSource also
passes although there's still a ton of bugs around. Something for me to
work on tomorrow, then. :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20960 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/IA64/README b/lib/Target/IA64/README
index 86606dd..ec94299 100644
--- a/lib/Target/IA64/README
+++ b/lib/Target/IA64/README
@@ -77,7 +77,9 @@
 
 KNOWN DEFECTS AT THE CURRENT TIME:
 
-  - no varargs
+  - C++ vtables contain naked function pointers, not function descriptors,
+  which is bad. see http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=406
+  - varargs are broken
   - alloca doesn't work (indeed, stack frame layout is bogus)
   - no support for big-endian environments
   - (not really the backend, but...) the CFE has some issues on IA64.