I'm not 100% sure what you mean by this, but it denotes some kind of bulk operation, right? I'm not too sure that that would be very useful, given that i don't only need to transfer the data, but also need to check whether the input data is different than the already existing data.

I assume that you are doing some kind of billboarding for the backdrops of your scenes. And you are attempting to optimise that by onlu updating the cells or slices if they have changed. But, often as not with these things, is frequently quicker to avoid the conditionals and simple update everything. When the screen is redrawn, because the player moved or rotated his viewpoint, everything needs to be scaled/slewed and redrawn anyway.

So, if you could do @{ $tiles[z][y] } = @tile_data[ $y*16 .. ($y+1) * 16 - 1 ];-- that is, assign a complete X-slice in one go--then you've both avoided 16*2 index calculations, but also 16 condition tests.

If you could arrange for the input data to be pre-formatted as a 2d array, then you can also avoid the slice operation and just assign pointers to arrays of 16 values, with a significant further saving.

I appreciate it might require a re-think on some of your logic to make use of this, and that may be further than you wish to go, but it can be effective.

It's similar to some descriptions of the Fischer-Yates shuffle, that test each pairing and avoid the swap if the values are the same. In most cases, it is cheaper to go ahead and swap them unconditionally, than to test the condition for every pairing.