Macro safe_arch::combined_byte_shr_imm_m128i

macro_rules! combined_byte_shr_imm_m128i {
    ($a:expr, $b:expr, $imm:expr) => { ... };
}

Counts $a as the high bytes and $b as the low bytes then performs a byte shift to the right by the immediate value.

Remember that this is all little-endian data.

let a =
  m128i::from([0_i8, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]);
let b = m128i::from([
  16_i8, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
]);
// `a` bytes come in to the high indexes because these are LE bytes.
let c: [i8; 16] = combined_byte_shr_imm_m128i!(a, b, 3).into();
assert_eq!(
  c,
  [19_i8, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 0, 1, 2]
);
// If you feed the same register to both sides it becomes a rotate
let c: [i8; 16] = combined_byte_shr_imm_m128i!(a, a, 3).into();
assert_eq!(c, [3_i8, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2,]);