Hi Claudiu,
Thanks for the tip, I've since looked at and drawn inspiration from arc.cc.
The main issue I have now is how to implement the code in
legitimize_tls_address under i386.cc and the corresponding i386.md machine
description file to get the following assembly for a TLS read (Assuming
that local is the name of the thread local variable, that the last mov
depends on the size of the variable, since it would be movq if it was an 8
byte variable, that rscratch refers to scratch registers, and that
rscratch1 holds the read TLS value at the end of the operation):
movl _tls_index(%rip), %rscratch1
movq %gs:88, %rscratch2
movq (%rscratch2, %rscratch1, 8), %rscratch1
movl local@SECREL32(%rscratch1), %rscratch1
With some reference from the arc.cc code and another (unofficial) patch for
the platform that I want to implement TLS for, I've managed a half finished
implementation of TLS, but the final blocker so to speak is my lack of
understanding on how the RTL manipulating code in legitimize_tls_address
works. If you have any pointers on how to manipulate RTL to get the
assembly required as seen above, I would be very much grateful :)
best regards,
Julian
On Tue, Jul 16, 2024 at 8:16 PM Claudiu Zissulescu Ianculescu <
claz...@gmail.com> wrote:
> Hi Julian,
>
> You can check how we did it for ARC. In a nutshell, you need to define
> HAVS_AS_TLS macro, you need to legitimize the new TLS address and
> calls. Please have a look in arc.cc and search for TLS, also use git
> blame to see the original patches. Of course, there are different ways
> to implement TLS, in ARC is the simplest solution. Also, u need to
> hack the assembler, linker and the OS for a full implementation.
>
> Cheers,
> Claudiu
>
> On Tue, Jul 9, 2024 at 7:14 PM Julian Waters via Gcc <gcc@gcc.gnu.org>
> wrote:
> >
> > Hi all,
> >
> > I'm currently trying to implement Native TLS on a platform that gcc uses
> > emutls for at the moment, but I can't seem to figure out where and how to
> > implement it. I have a rough idea of the assembly required for TLS on
> this
> > platform, but I don't know where to plug it in to the compiler to make it
> > work. Could someone point me in the right direction for implementing TLS
> > for a platform that doesn't have it implemented at the moment?
> >
> > I'm aware that I am being vague as to which platform I want to implement
> it
> > for. It's a platform that is likely low priority in the eyes of most gcc
> > maintainers, so I'm deliberately avoiding mentioning what platform it is
> so
> > I don't get crickets for a reply :)
> >
> > best regards,
> > Julian
>
