SIMD: more generic shuffle function

[CakeByTheOcean]

I think the SIMD shuffle fucntion is not real shuffle for int32_t case the left and right part would be shuffled separately.

I want a real shuffle function as following:

Assumed we got __m256i and we want to shuffle 8 int32_t.

  __m256i to_shuffle = {17, 18, 20, 21, 25, 26, 29, 31};

const int imm8 = 0b10101100;

__m256i shuffled _mm256_shuffle(to_shuffle, imm8);

I hope the shuffled = {17, 20, 25, 26, -, -, -, -}, where the - represents the not relevant value. So I hope the int at the position with set bit with 1 would be placed in shuffled. (In our case: 17, 20, 25, 26 are sitting at the possition with set bit 1 in imm8).

Is such function offered by the Intel？ How could such fucntion be implemented efficiently?