Function safe_arch::mul_u8i8_add_horizontal_saturating_m128i

#[must_use]pub fn mul_u8i8_add_horizontal_saturating_m128i(a: m128i, b: m128i) -> m128i

This is supported with target feature ssse3 only.

This is dumb and weird.

• Vertically multiplies each u8 lane from a with an i8 lane from b, producing an i16 intermediate value.
• These intermediate i16 values are horizontally added with saturation.

let a = m128i::from([
  255_u8, 255, 0, 0, 255, 255, 1, 1, 8, 9, 10, 11, 12, 13, 14, 15,
]);
let b = m128i::from([
  127_i8, 127, 0, 0, -127, -127, 1, 1, 24, 25, 26, 27, 28, 29, 30, 31,
]);
let c: [i16; 8] = mul_u8i8_add_horizontal_saturating_m128i(a, b).into();
assert_eq!(c, [i16::MAX, 0, i16::MIN, 2, 417, 557, 713, 885]);