Calling these failed to compile: `_mm256_round_pd` passed a u8 where
the intrinsic takes a u32, `_mm256_blend_pd` misspelt its parameter,
`_mm256_dp_ps` took its mask as an i8, `_mm_permute_ps/pd` used
SSE/SSE2 helpers without enabling them, and `_mm256_permute2f128_pd`
did not return its result.
bbodi
1e8419d1d4