Tile size

[nivi1501]

Hi, How to estimate the tile size of an output feature map, weights, and ifmap using the mapper function? I wish to estimate the tile size generated in a single loop iteration (wrt DRAM). Suppose I get the following mapping from timeloop: { target = 0; type = "temporal"; factors = "C1 K1 R11 S1 P1 Q1"; permutation = "RCKSPQ"; }, { target = 1; type = "spatial"; factors = "C1 K16 R1 S1 P1 Q11"; permutation = "QKCRSP"; split = 1; }, { target = 1; type = "temporal"; factors = "C1 K1 R1 S11 P1 Q1"; permutation = "SCKRPQ"; }, { target = 2; type = "temporal"; factors = "C3 K6 R1 S1 P55 Q5"; permutation = "PQCKRS"; } Tile size for the output=55x5X6. I am not sure about this. Can anyone please help me out?

[angshuman-parashar]

Are you interested in the tile size at a particular memory level, or the delta size (i.e., the set-difference between tiles at time t and t+1)? If it's the former then the output mapping in timeloop-mapper.map.txt or timeloop-model.map.txt shows you that information for each storage level, e.g., lines 2, 6 and 13 in https://github.com/Accelergy-Project/timeloop-accelergy-exercises/blob/master/workspace/exercises/2020.ispass/timeloop/04-model-conv1d%2Boc-3levelspatial/ref-output/cp/timeloop-model.map.txt

[nivi1501]

Thanks for the response, how can we compute delta size?

[angshuman-parashar]

In general it may change from iteration to iteration, and may also depend on the state of ancestor loops. You can reason about it manually by computing the tensor tiles corresponding to two specific consecutive iterations of any loop, and then calculating the set-difference between them. If you haven't done so already, we strongly recommend watching and working through one of our tutorials, that will help you build a strong intuitive foundation.

[nivi1501]

Thanks a lot :)