Re: ipa-icf::merge TLC

[Christophe Lyon <christophe.lyon@linaro.org>]

On 3 March 2015 at 13:44, Alex Velenko <Alex.Velenko@arm.com> wrote:
> On 02/03/15 22:04, Christophe Lyon wrote:
>>
>> On 2 March 2015 at 21:21, Jan Hubicka <hubicka@ucw.cz> wrote:
>>>>
>>>>
>>>>
>>>> On 01/03/15 16:47, Christophe Lyon wrote:
>>>>>
>>>>> On 27 February 2015 at 21:49, Jan Hubicka <hubicka@ucw.cz> wrote:
>>>>>>>
>>>>>>>
>>>>>>> ../sysdeps/gnu/siglist.c:72:1: internal compiler error: in
>>>>>>> address_matters_p, at symtab.c:1908
>>>>>>>   versioned_symbol (libc, __new_sys_sigabbrev, sys_sigabbrev,
>>>>>>> GLIBC_2_3_3);
>>>>>>>   ^
>>>>>>> 0x66a080 symtab_node::address_matters_p()
>>>>>>>          /scratch/sellcey/repos/bootstrap/src/gcc/gcc/symtab.c:1908
>>>>>>> 0xe7cbe5 ipa_icf::sem_variable::merge(ipa_icf::sem_item*)
>>>>>>>          /scratch/sellcey/repos/bootstrap/src/gcc/gcc/ipa-icf.c:1443
>>>>>>
>>>>>>
>>>>>> Indeed, the ipa-icf should not try to analyze aliases - just prove
>>>>>> ekvialence of
>>>>>> definitions they are attached to.  It already does that for functions
>>>>>> (bit by accident;
>>>>>> it gives up when there is no gimple body), but it does not do that for
>>>>>> variables because
>>>>>> it gets into ctor_for_folding. For that reason it sometimes decides to
>>>>>> try to make two
>>>>>> variable aliases alias of each other that is not a good idea, because
>>>>>> of possible creation
>>>>>> of loops.
>>>>>>
>>>>>> I am just discussing with Martin the fix.
>>>>>>
>>>>>> Honza
>>>>>
>>>>>
>>>>> For the record, I have noticed similar errors on ARM and AArch64
>>>>> targets, when building glibc.
>>>>>
>>>>> Christophe.
>>>>>
>>>>
>>>> I confirm ARM and AArch64 failing to build with this patch:
>>>> chmod a-w
>>>> /work/build-aarch64-none-linux-gnu/obj/glibc/stdio-common/errlist-compat.cT
>>>> 0x6b9100 symtab_node::address_matters_p()
>>>>        /work/src/gcc/gcc/symtab.c:1908
>>>> 0xedb4e5 ipa_icf::sem_variable::merge(ipa_icf::sem_item*)
>>>>        /work/src/gcc/gcc/ipa-icf.c:1723
>>>> 0xee03f9 ipa_icf::sem_item_optimizer::merge_classes(unsigned int)
>>>>        /work/src/gcc/gcc/ipa-icf.c:2955
>>>> 0xee6d31 ipa_icf::sem_item_optimizer::execute()
>>>>        /work/src/gcc/gcc/ipa-icf.c:2217
>>>> 0xee8df1 ipa_icf_driver
>>>>        /work/src/gcc/gcc/ipa-icf.c:3034
>>>> 0xee8df1 ipa_icf::pass_ipa_icf::execute(function*)
>>>>        /work/src/gcc/gcc/ipa-icf.c:3081
>>>
>>>
>>> I commited patch for the alias merging yesterda night, so it should be
>>> fixed
>>> now.  If it still fails, please fill in a PR with preprocessed testcase
>>> so I
>>> can reproduce it in a cross.
>>>
>>
>> On my side, I saw builds complete again starting with r221090, I guess
>> that's the commit you are referring to?
>
> Hi,
>
> I built with r221117. I see errors while building following targets:
> aarch64_be-none-linux-gnu, aarch64_be-none-linux-gnu,
> arm-none-linux-gnueabihf, arm-none-linux-gnueabi.

Indeed, it's broken again since r221099.

>
> For aarch64_be-none-linux-gnu I reproduce the error like this:
>
> /work/build-aarch64-none-linux-gnu/install//bin/aarch64-none-linux-gnu-gcc
> /work/src/glibc/sysdeps/gnu/siglist.c -c -std=gnu99 -fgnu89-inline  -O2
> -Wall -Winline -Wundef -Wwrite-strings -fmerge-all-constants -frounding-math
> -g -Wstrict-prototypes   -fno-toplevel-reorder -fno-section-anchors
> -I/work/src/glibc/include
> -I/work/build-aarch64-none-linux-gnu/obj/glibc/stdio-common
> -I/work/build-aarch64-none-linux-gnu/obj/glibc
> -I/work/src/glibc/sysdeps/unix/sysv/linux/aarch64
> -I/work/src/glibc/sysdeps/aarch64/nptl
> -I/work/src/glibc/sysdeps/unix/sysv/linux/generic
> -I/work/src/glibc/sysdeps/unix/sysv/linux/wordsize-64
> -I/work/src/glibc/sysdeps/unix/sysv/linux/include
> -I/work/src/glibc/sysdeps/unix/sysv/linux -I/work/src/glibc/sysdeps/nptl
> -I/work/src/glibc/sysdeps/pthread -I/work/src/glibc/sysdeps/gnu
> -I/work/src/glibc/sysdeps/unix/inet -I/work/src/glibc/sysdeps/unix/sysv
> -I/work/src/glibc/sysdeps/unix -I/work/src/glibc/sysdeps/posix
> -I/work/src/glibc/sysdeps/aarch64/fpu -I/work/src/glibc/sysdeps/aarch64
> -I/work/src/glibc/sysdeps/wordsize-64
> -I/work/src/glibc/sysdeps/ieee754/ldbl-128
> -I/work/src/glibc/sysdeps/ieee754/dbl-64/wordsize-64
> -I/work/src/glibc/sysdeps/ieee754/dbl-64
> -I/work/src/glibc/sysdeps/ieee754/flt-32
> -I/work/src/glibc/sysdeps/aarch64/soft-fp -I/work/src/glibc/sysdeps/ieee754
> -I/work/src/glibc/sysdeps/generic -I/work/src/glibc -I/work/src/glibc/libio
> -I. -nostdinc -isystem
> /work/build-aarch64-none-linux-gnu/install/bin/../lib/gcc/aarch64-none-linux-gnu/5.0.0/include
> -isystem
> /work/build-aarch64-none-linux-gnu/install/bin/../lib/gcc/aarch64-none-linux-gnu/5.0.0/include-fixed
> -isystem
> /work/build-aarch64-none-linux-gnu/install//aarch64-none-linux-gnu/libc/usr/include
> -D_LIBC_REENTRANT -include
> /work/build-aarch64-none-linux-gnu/obj/glibc/libc-modules.h
> -DMODULE_NAME=libc -include /work/src/glibc/include/libc-symbols.h
> -D_IO_MTSAFE_IO -o
> /work/build-aarch64-none-linux-gnu/obj/glibc/stdio-common/siglist.o -MD -MP
> -MF /work/build-aarch64-none-linux-gnu/obj/glibc/stdio-common/siglist.o.dt
> -MT /work/build-aarch64-none-linux-gnu/obj/glibc/stdio-common/siglist.o
> /work/src/glibc/sysdeps/gnu/siglist.c:77:1: internal compiler error: in
> address_matters_p, at symtab.c:1908
>  versioned_symbol (libc, __new_sys_sigabbrev, sys_sigabbrev, GLIBC_2_1);
>  ^
> 0x6b9140 symtab_node::address_matters_p()
>         /work/src/gcc/gcc/symtab.c:1908
> 0xedb685 ipa_icf::sem_variable::merge(ipa_icf::sem_item*)
>         /work/src/gcc/gcc/ipa-icf.c:1740
> 0xee05b1 ipa_icf::sem_item_optimizer::merge_classes(unsigned int)
>         /work/src/gcc/gcc/ipa-icf.c:2979
> 0xee6f11 ipa_icf::sem_item_optimizer::execute()
>         /work/src/gcc/gcc/ipa-icf.c:2236
> 0xee902e ipa_icf_driver
>         /work/src/gcc/gcc/ipa-icf.c:3061
> 0xee902e ipa_icf::pass_ipa_icf::execute(function*)
>         /work/src/gcc/gcc/ipa-icf.c:3108
> Please submit a full bug report,
> with preprocessed source if appropriate.
> Please include the complete backtrace with any bug report.
> See <http://gcc.gnu.org/bugs.html> for instructions.
>
>
> I see a related ticket opened recently:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65287
>
> Kind regards,
> Alex
>
>>
>> Thanks,
>>
>> Christophe.
>>
>>> Honza
>>>>
>>>> Please submit a full bug report,
>>>> with preprocessed source if appropriate.
>>>> Please include the complete backtrace with any bug report.
>>>> See <http://gcc.gnu.org/bugs.html> for instructions.
>>>> make[2]: ***
>>>> [/work/build-aarch64-none-linux-gnu/obj/glibc/stdio-common/siglist.o]
>>>> Error 1
>>>> make[2]: *** Waiting for unfinished jobs....
>>>> mv -f
>>>> /work/build-aarch64-none-linux-gnu/obj/glibc/stdio-common/errlist-compat.cT
>>>> /work/build-aarch64-none-linux-gnu/obj/glibc/stdio-common/errlist-compat.c
>>>>
>>>> Regards,
>>>> Alex
>>
>>
>