Function core::arch::x86_64::_xsetbv

pub unsafe fn _xsetbv(a: u32, val: u64)

This is supported on (non-crate feature miri-test-libstd or test or doctest) and x86-64 and target feature xsave only.

Copies 64-bits from val to the extended control register (XCR) specified by a.

Currently only XFEATURE_ENABLED_MASK XCR is supported.

Intel’s documentation