Translating SSE to Neon: How to pack and then extract 32bit result

Question

I have to translate the following instructions from SSE to Neon

 uint32_t a = _mm_cvtsi128_si32(_mm_shuffle_epi8(a,SHUFFLE_MASK) );

Where:<

Answer 1

I would write it as so:

uint32_t extract (uint8x16_t x)
{
  uint8x8x2_t a = vuzp_u8 (vget_low_u8 (x), vget_high_u8 (x));
  uint8x8x2_t b = vuzp_u8 (a.val[0], a.val[1]);
  return vget_lane_u32 (vreinterpret_u32_u8 (b.val[0]), 0);
}

Which on a recent GCC version compiles to:

extract:
    vuzp.8  d0, d1
    vuzp.8  d0, d1
    vmov.32 r0, d0[0]
    bx  lr