https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85052
--- Comment #5 from Matthias Kretz <kretz at kde dot org> --- Thank you Jakub! Here's a tested x86 library implementation for all conversions and different ISA extension support for reference: https://github.com/mattkretz/gcc/blob/mkretz/simd/libstdc%2B%2B-v3/include/experimental/bits/simd_x86_conversions.h (I have not looked at the patch yet to see whether I understand enough of the implementation to optimize conversions myself.)
