https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107563
--- Comment #2 from cqwrteur <unlvsur at live dot com> ---
(In reply to cqwrteur from comment #0)
> #if defined(__SSE2__)
>
> using temp_vec_type [[__gnu__::__vector_size__ (16)]] = char;
> void foo(temp_vec_type& v) noexcept
> {
> v=__builtin_shufflevector(v,v,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0);
> }
>
> #endif
>
> g++ -S pq.cc -Ofast
> proves sse2 is enabled by default, but it does not call
> https://www.felixcloutier.com/x86/pshufb
> neither
> https://www.felixcloutier.com/x86/pshufd
>
> while g++ -S pq.cc -Ofast -msse4.2 will generate them correctly. Which is
> buggy
pshufb is sse3 sorry. but pshufd is sse2. It can be used for generating the
right instruction.
