Function _mm_clflush
#[target_feature(enable = "sse2")]
pub unsafe fn _mm_clflush(p: *const u8)Invalidates and flushes the cache line that contains p from all levels of
the cache hierarchy.
Safety
Unlike the prefetch intrinsics, CLFLUSH is subject to all the permission
checking and faults associated with a byte load, so p must point to a
byte that is valid for reads.