Function safe_arch::pack_i16_to_u8_m128i

#[must_use]pub fn pack_i16_to_u8_m128i(a: m128i, b: m128i) -> m128i

This is supported with target feature sse2 only.

Saturating convert i16 to u8, and pack the values.

let a = m128i::from([-1_i16, 2, -3, 4, -5, 6, -7, 8]);
let b = m128i::from([9_i16, 10, 11, 12, 13, -14, 15, -16]);
let c: [u8; 16] = pack_i16_to_i8_m128i(a, b).into();
assert_eq!(
  c,
  [255_u8, 2, 253, 4, 251, 6, 249, 8, 9, 10, 11, 12, 13, 242, 15, 240]
);