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Re: PATCH: PR target/47715: [x32] Use SImode for thread pointer
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.
--
H.J.