struct Scalar {
  size: vec4<u32>,
  data: array<f32>,
}

struct MatrixBatch {
  size: vec4<u32>,
  data: array<f32>,
}

@group(0) @binding(0)
var<storage, read> ds: Scalar;
@group(0) @binding(1)
var<storage, read> wa: MatrixBatch;
@group(0) @binding(2)
var<storage, read> v: MatrixBatch;
@group(0) @binding(3)
var<storage, read> otdldo: MatrixBatch;
@group(0) @binding(4)
var<storage, read_write> dlds: MatrixBatch;

@compute @workgroup_size(1)
fn main(@builtin(global_invocation_id) global_id: vec3<u32>) {
  dlds.size = wa.size;

  var s = 0f;
  var li = (global_id.z * v.size.y + global_id.x) * v.size.x;
  var ri = global_id.z * otdldo.size.x * otdldo.size.y + global_id.y;

  for (var i = 0u; i < v.size.x; i++) {
    var cs = 0f;
    var lj = global_id.z * wa.size.y * wa.size.x + global_id.y * wa.size.x;
    var mj = global_id.z * v.size.x * v.size.y + i;
    for (var j = 0u; j < wa.size.x; j++) {
      cs += wa.data[lj] * v.data[mj];
      lj++;
      mj += v.size.x;
    }

    s += (v.data[li] - cs) * otdldo.data[ri];

    li++;
    ri += otdldo.size.x;
  }

  let resi = (global_id.z * dlds.size.y + global_id.y) * dlds.size.x + global_id.x;
  dlds.data[resi] = ds.data[0] * wa.data[resi] * s;
}