aes_neon_dec1
uint8x16_t aes_neon_dec1(const struct aesdec *, uint8x16_t, unsigned);
[0] = aes_neon_dec1(dec, b2.val[0], nrounds),
[1] = aes_neon_dec1(dec, b2.val[1], nrounds),
b = aes_neon_dec1(dec, cv, nrounds);
b = aes_neon_dec1(dec, b, nrounds);
block = aes_neon_dec1(dec, block, nrounds);