https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107929
--- Comment #4 from Matthias Kretz (Vir) <mkretz at gcc dot gnu.org> --- I agree that compilation speed is a problem. However, 1. GCC's vector extensions are not sufficient (especially for use of AVX-512 masks) 2. I see 0.6s difference between calling `g++ -O2 -march=skylake` on an empty file vs. a file that #includes <immintrin.h>. Whereas #include <experimental/simd> takes about 2.7s.
