def permute_bwd

bendtorch@1.3.0.0 · tensor.bend:512

import Base

512# the gradient of permute: dy put back where each number came from
513def permute_bwd(+s: List<&2, Nat>, +p: List<&2, Nat>, dy: Tensor<permuted(s, p)>) -> TP<permuted(s, p), s>:
514  match dy:
515    case Tensor{d}:
516      tp_of(permuted(s, p), s, place_l(numel(s), 0, perm_map(s, p), Array.get(F32, d, 0), new(numel(s))))