[CUDA] Backward convolution (#2431)

mlx/backend/cuda/sort.cu

@@ -13,7 +13,6 @@
 #include <cub/device/device_segmented_sort.cuh>
 
 #include <cassert>
-#include <numeric>
 
 namespace mlx::core {
 
@@ -27,29 +26,6 @@ struct ModOp {
   }
 };
 
-// We can not use any op in eval, make an utility.
-array swapaxes_in_eval(const array& in, int axis1, int axis2) {
-  std::vector<int> axes(in.ndim());
-  std::iota(axes.begin(), axes.end(), 0);
-  std::swap(axes[axis1], axes[axis2]);
-  // TODO: Share the code with Transpose::eval.
-  Shape shape(axes.size());
-  Strides strides(in.ndim());
-  for (size_t ax = 0; ax < axes.size(); ++ax) {
-    shape[ax] = in.shape()[axes[ax]];
-    strides[ax] = in.strides()[axes[ax]];
-  }
-  auto flags = in.flags();
-  if (flags.contiguous) {
-    auto [_, row_contiguous, col_contiguous] = check_contiguity(shape, strides);
-    flags.row_contiguous = row_contiguous;
-    flags.col_contiguous = col_contiguous;
-  }
-  array out(shape, in.dtype(), nullptr, {});
-  out.copy_shared_buffer(in, strides, flags, in.data_size());
-  return out;
-}
-
 struct OffsetTransform {
   int nsort;