Comment by camel-cdr

I'm not aware of any GPU that implements this.

Even the interleaved execution introduced in Volta still can only execute one type of instruction at a time [1]. This feature wasn't meant to accelerate code, but to allow more composable programming models [2].

Going of the diagram, it looks equivilant to rapidly switching between predicates, not executing two different operations at once.

    if (theradIdx.x < 4) {
        A;
        B;
    } else {
        X;
        Y;
    }
    Z;

The diagram shows how this executes in the following order:

Volta:

    ->|   ->X   ->Y   ->Z|->
    ->|->A   ->B   ->Z   |->

pre Volta:

    ->|      ->X->Y|->Z
    ->|->A->B      |->Z

The SIMD equivilant of pre Volta is:

    vslt mask, vid, 4
    vopA ..., mask
    vopB ..., mask
    vopX ..., ~mask
    vopY ..., ~mask
    vopZ ...

The Volta model is:

    vslt mask, vid, 4
    vopA ..., mask
    vopX ..., ~mask
    vopB ..., mask
    vopY ..., ~mask
    vopZ ...

[1] https://chipsandcheese.com/i/138977322/shader-execution-reor...

[2] https://stackoverflow.com/questions/70987051/independent-thr...