On Thu, Jul 28, 2011 at 4:25 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
> On Thu, Jul 28, 2011 at 3:46 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
>> On Thu, Jul 28, 2011 at 3:40 PM, Uros Bizjak <ubiz...@gmail.com> wrote:
>>> On Fri, Jul 29, 2011 at 12:28 AM, H.J. Lu <hjl.to...@gmail.com> 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?
>>>>>
>>>>
>>>> We start with
>>>
>>> Uh, we didn't understand each other... can you please debug what goes
>>> wrong with glibc runtime test?
>>>
>>
>> I haven't be able to reproduce it. I may have a typo when I fixed the
>> pattern. I will try again.
>>
>
> I can't reproduce it any more.
>
I know why. I also have
(*load_tp_<mode>): Disabled for TARGET_X32.
(*add_tp_<mode>): Likewise.
since the SImode version is wrong for x32 due to
(define_mode_attr tp_seg [(SI "gs") (DI "fs")])
x32 uses fs even if it is 32bit.
--
H.J.
