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use crate::mem as basic;
use crate::RangeError;

use super::{cpuid_avx2, cpuid_sse2};

#[inline(always)]
#[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
pub fn _memcpy_impl(dst: &mut [u8], src: &[u8]) -> Result<(), RangeError> {
    // TODO: Replace with https://github.com/rust-lang/rfcs/pull/2725
    // after stabilization
    if cpuid_avx2::get() {
        unsafe { _memcpy_avx2(dst, src) }
    } else if cpuid_sse2::get() {
        unsafe { _memcpy_sse2(dst, src) }
    } else {
        _memcpy_basic(dst, src)
    }
}

fn _memcpy_basic(dst: &mut [u8], src: &[u8]) -> Result<(), RangeError> {
    basic::_memcpy_impl(dst, src)
}

#[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
#[target_feature(enable = "sse2")]
#[allow(clippy::missing_safety_doc)]
pub unsafe fn _memcpy_sse2(dst: &mut [u8], src: &[u8]) -> Result<(), RangeError> {
    basic::_memcpy_impl(dst, src)
}

#[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
#[target_feature(enable = "avx2")]
#[allow(clippy::missing_safety_doc)]
pub unsafe fn _memcpy_avx2(dst: &mut [u8], src: &[u8]) -> Result<(), RangeError> {
    basic::_memcpy_impl(dst, src)
}