[Bug c++/107726] New: Multiple bugs related to __gnu__::__target__

[Bug c++/107726] New: Multiple bugs related to __gnu__::__target__

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107726

            Bug ID: 107726
           Summary: Multiple bugs related to __gnu__::__target__
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: unlvsur at live dot com
  Target Milestone: ---

1. On Linux. the ld linker does not work. Only gold linker would work. (Sounds
like a linker bug) 
./sha512 a_file
./sha512: error while loading shared libraries: unexpected PLT reloc type 0x00


2. On x86_64-w64-mingw32 target.
../../include/fast_io_crypto/hash/sha512_simd16.h:68:13: error: multiversioning
needs 'ifunc' which is not supported on this target

And I tried clang with lld and yes it works even on windows.

[Bug c++/107726] Multiple bugs related to __gnu__::__target__

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107726

--- Comment #1 from cqwrteur <unlvsur at live dot com> ---
#if __has_cpp_attribute(__gnu__::__target__) && defined(__SSE2__) &&
!defined(__AVX2__)
[[__gnu__::__target__("default")]]
#elif __has_cpp_attribute(__gnu__::__flatten__)
[[__gnu__::__flatten__]]
#endif
inline void sha512_runtime_routine(std::uint_least64_t* __restrict
state,std::byte const* __restrict blocks_start,std::byte const* __restrict
blocks_last) noexcept;

#if __has_cpp_attribute(__gnu__::__target__) && defined(__SSE2__) &&
!defined(__AVX2__)
[[__gnu__::__target__("avx2")]]
#elif __has_cpp_attribute(__gnu__::__flatten__)
[[__gnu__::__flatten__]]
#endif
inline void sha512_runtime_routine(std::uint_least64_t* __restrict
state,std::byte const* __restrict blocks_start,std::byte const* __restrict
blocks_last) noexcept;

Something like this.

[Bug c++/107726] Multiple bugs related to __gnu__::__target__

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107726

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2022-11-16

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
We have tests for multiversioning and they are passing with BFD ld.

Also multiversioning requires ifunc support which is not implemented for
Windows (I don't know how clang implements theirs, maybe they do a check at the
beginging of the function to see if a function pointer was assigned).

For 1, can you provide a full testcase which is failing?

[Bug target/107726] Multiple bugs related to __gnu__::__target__

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107726

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|x86_64-w64-mingw32,         |x86_64-linux-gnu
                   |x86_64-linux-gnu            |
          Component|c++                         |target

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Also please file an different issue for the non-ifunc case since it is a new
feature.

[Bug target/107726] Multiple bugs related to __gnu__::__target__

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107726

--- Comment #4 from cqwrteur <unlvsur at live dot com> ---
(In reply to Andrew Pinski from comment #3)
> Also please file an different issue for the non-ifunc case since it is a new
> feature.

https://godbolt.org/z/z5cexGEMK

[Bug target/107726] Multiple bugs related to __gnu__::__target__

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107726

--- Comment #5 from cqwrteur <unlvsur at live dot com> ---
(In reply to Andrew Pinski from comment #2)
> We have tests for multiversioning and they are passing with BFD ld.
> 
> Also multiversioning requires ifunc support which is not implemented for
> Windows (I don't know how clang implements theirs, maybe they do a check at
> the beginging of the function to see if a function pointer was assigned).
> 
> For 1, can you provide a full testcase which is failing?

https://sourceware.org/bugzilla/show_bug.cgi?id=29797(In reply to Andrew Pinski
from comment #3)

> Also please file an different issue for the non-ifunc case since it is a new
> feature.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107727