Re: [PATCH,IA64] Fix bug in double slot instruction reloc

[Jim Wilson <jimwilso at cisco dot com>]

On 02/21/2013 01:15 PM, Douglas B Rupp wrote:
> Please find attached my proposed fix to a bug which shows up on ia64 vms
> with the "brl" instruction. It needs both approval and commit.

I unfortunately don't have a working ia64-linux machine at the moment so 
I can't easily test this with a build.  I looked at bfd sources though, 
as I was wondering how this would affect ld.  It appears that when we 
have a 60- or 64-bit relocation type we never look at the slot number, 
so it doesn't matter whether this is 1 or 2.  Furthermore, in the code 
that relaxes br to brl and vice versa, it assumes that the slot number 
for brl is 1.  So for linux the patch appears to be harmless, and is 
fixing a minor inconsistency between gas and bfd.

I also looked at the Itanium ABI, and didn't see any clear indication of 
whether relocs for a long instruction should be marked as slot 1 or slot 
2.  So it appears that we can use whatever is convenient which appears 
to be 1 since VMS requires that.

The patch looks OK to me.

A small testcase for the gas testsuite might be useful to ensure that 
the slot number remains 1.

Jim