[Bug driver/46760] LTO doesn't work with FDO

[davek at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46760

Dave Korn <davek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Depends on|                            |42690
         AssignedTo|davek at gcc dot gnu.org    |unassigned at gcc dot
                   |                            |gnu.org

--- Comment #7 from Dave Korn <davek at gcc dot gnu.org> 2010-12-02 09:08:42 UTC ---
(In reply to comment #6)
> Hi,
> at one point I tried profiledbootstrap and problem is that we can not merge
> multiple LTO files
> that has been profiled different amount of times.  This happens during our
> build because lto1
> and cc1 share libbackend.  We probably need to add code rescaling corresponding
> events...
> 
> Honza

  Rather than open a second bug for this part of the problem, let's leave this
PR to handle it; the first part of the problem that HJ originally reported can
be considered a part of bug 42690, which I'm in the course of testing the
attached patch as part of.

  So, de-assigning myself from this PR.  Possibly we should consider this a
build system bug and the makefile should be responsible for swapping sets of
gcda files in and out?  Otherwise the component should be changed to lto.