PATCH: PR target/47715: [x32] Use SImode for thread pointer

[H.J. Lu]

On Thu, Jul 28, 2011 at 8:59 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Thu, Jul 28, 2011 at 7:59 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
>> On Thu, Jul 28, 2011 at 4:47 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>
>>>>>>>> In x32, thread pointer is 32bit and choice of segment register for the
>>>>>>>> thread base ptr load should be based on TARGET_64BIT.  This patch
>>>>>>>> implements it.  OK for trunk?
>>>>>>>
>>>>>>> -ENOTESTCASE.
>>>>>>>
>>>>>>
>>>>>> There is no standalone testcase.  The symptom is in glibc build, I
>>>>>> got
>>>>>>
>>>>>> CPP='/export/build/gnu/gcc-x32/release/usr/gcc-4.7.0-x32/bin/gcc -mx32
>>>>>>  -E -x c-header'
>>>>>> /export/build/gnu/glibc-x32/build-x86_64-linux/elf/ld-linux-x32.so.2
>>>>>> --library-path /export/build/gnu/glibc-x32/build-x86_64-linux:/export/build/gnu/glibc-x32/build-x86_64-linux/math:/export/build/gnu/glibc-x32/build-x86_64-linux/elf:/export/build/gnu/glibc-x32/build-x86_64-linux/dlfcn:/export/build/gnu/glibc-x32/build-x86_64-linux/nss:/export/build/gnu/glibc-x32/build-x86_64-linux/nis:/export/build/gnu/glibc-x32/build-x86_64-linux/rt:/export/build/gnu/glibc-x32/build-x86_64-linux/resolv:/export/build/gnu/glibc-x32/build-x86_64-linux/crypt:/export/build/gnu/glibc-x32/build-x86_64-linux/nptl
>>>>>> /export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/rpcgen -Y
>>>>>> ../scripts -h rpcsvc/yppasswd.x -o
>>>>>> /export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/rpcsvc/yppasswd.T
>>>>>> make[5]: *** [/export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/xbootparam_prot.stmp]
>>>>>> Segmentation fault
>>>>>> make[5]: *** Waiting for unfinished jobs....
>>>>>> make[5]: *** [/export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/xrstat.stmp]
>>>>>> Segmentation fault
>>>>>> make[5]: *** [/export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/xyppasswd.stmp]
>>>>>> Segmentation fault
>>>>>>
>>>>>> since thread pointer is 32bit in x32.
>>>>>>
>>>>>
>>>>> If we load thread pointer (fs segment register) in x32 with 64bit
>>>>> load, the upper 32bits are garbage.
>>>>> We must load 32bit
>>>>
>>>> So, instead of huge complications with new mode iterator, just
>>>> introduce two new patterns that will shadow existing ones for
>>>> TARGET_X32.
>>>>
>>>> Like in attached (untested) patch.
>>>>
>>>
>>> I tried the following patch with typos fixed.  It almost worked,
>>> except for this failure in glibc testsuite:
>>>
>>> gen-locale.sh: line 27: 14755 Aborted                 (core dumped)
>>> I18NPATH=. GCONV_PATH=${common_objpfx}iconvdata ${localedef} --quiet
>>> -c -f $charmap -i $input ${common_objpfx}localedata/$out
>>> Charmap: "ISO-8859-1" Inputfile: "nb_NO" Outputdir: "nb_NO.ISO-8859-1" failed
>>> make[4]: *** [/export/build/gnu/glibc-x32/build-x86_64-linux/localedata/nb_NO.ISO-8859-1/LC_CTYPE]
>>> Error 1
>>>
>>> I will add:
>>>
>>> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>>> index 8723dc5..d32d64d 100644
>>> --- a/gcc/config/i386/i386.c
>>> +++ b/gcc/config/i386/i386.c
>>> @@ -12120,7 +12120,9 @@ get_thread_pointer (bool to_reg)
>>>  {
>>>   rtx tp, reg, insn;
>>>
>>> -  tp = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, const0_rtx), UNSPEC_TP);
>>> +  tp = gen_rtx_UNSPEC (ptr_mode, gen_rtvec (1, const0_rtx), UNSPEC_TP);
>>> +  if (ptr_mode != Pmode)
>>> +    tp = convert_to_mode (Pmode, tp, 1);
>>>   if (!to_reg)
>>>     return tp;
>>>
>>> since TP must be 32bit.
>>
>> No, this won't have the desired effect. It will change the UNSPEC, so
>> it won't match patterns in i386.md.
>>
>> Can you debug the failure a bit more? With my patterns, add{l} and
>> mov{l} should clear top 32bits.
>>
>
> 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.
>

I will see what I can do.


-- 
H.J.