How to avoid unnecessary R_IA64_FPTR64LSB in executable?

[H. J. Lu]

The ia64 linker creates unnecessary R_IA64_FPTR64LSB relocations:

http://sources.redhat.com/bugzilla/show_bug.cgi?id=883

Basically, the ia64 linker creates R_IA64_FPTR64LSB relocations in
executable when there is any reference in DSO even though it is only
needed for dynamic R_IA64_FPTR64LSB relocations. I have 2 questions:

1. When we export a function in executable, whose function pointer is
used in executable and which is referenced by a DSO, can we create a
R_IA64_FPTR64LSB in executable only when there is a dynamic
R_IA64_FPTR64LSB reference? The only problem I can see is the different
version of the DSO may have dynamic R_IA64_FPTR64LSB reference. But
I think it is the same problem that the different version of the DSO 
may reference functions in executable which weren't referenced and
weren't exported before.
2. Assuming, we create a R_IA64_FPTR64LSB in executable only when
there is a dynamic R_IA64_FPTR64LSB relocation, how does linker
know there is a dynamic R_IA64_FPTR64LSB relocation? I am thinking to
allow the backend to read dynamic relocations after all input files
have been opened. The ia64 backend will have enough information to
decide what to do.


H.J.