On Thu, Jul 28, 2011 at 10:15 PM, H.J. Lu <[email protected]> wrote:
>>>>>>> TP is 32bit in x32 For load_tp_x32, we load SImode value and
>>>>>>> zero-extend to DImode. For add_tp_x32, we are adding SImode
>>>>>>> value. We can't pretend TP is 64bit. load_tp_x32 and add_tp_x32
>>>>>>> must take SImode TP.
> Here is the revised patch. The difference is I changed *add_tp_x32 to SImode.
> For
>
> ---
> extern __thread int __libc_errno __attribute__ ((tls_model ("initial-exec")));
>
> int *
> __errno_location (void)
> {
> return &__libc_errno;
> }
> ---
>
> compiled with -mx32 -O2 -fPIC DImode *add_tp_x32 generates:
>
> movq __libc_errno@gottpoff(%rip), %rax
> addl %fs:0, %eax
> mov %eax, %eax
> ret
>
> SImode *add_tp_x32 generates:
>
> movl %fs:0, %eax
> addl __libc_errno@gottpoff(%rip), %eax
> ret
This happens because combine can't combine DImode load and SImode plus
RTXes. These RTXes have to be in Pmode, see the intention in
legitimize_tls_address, also for TARGET_GNU2_TLS.
Can you please debug what goes wrong with tp_add_x32 in DImode?
Uros.
