Add unique, unique_consecutive (pytorch#8258)

Co-authored-by: mrguenther <[email protected]>

experimental/torch_xla2/test/test_ops.py

@@ -97,8 +97,6 @@
     "svd_lowrank",
     "unfold_copy",
     "unfold",
-    "unique_consecutive",
-    "unique",
     "unravel_index",
     "var_mean",
     "nanmean",
@@ -109,7 +107,7 @@
 not_support_ops_list = {
   "chalf", # Skip due to jax not support complex32 with backend: https://github.com/google/jax/issues/14180
   "__rpow__",  # NOTE: cannot fix because torch test case has undefined behavior
-                 # such as 0 to negative power.
+               # such as 0 to negative power.
   "ceil", # only failed with python 3.9
   "trunc", # only failed with python 3.9
   "to_sparse", # We are not supporting sparse tensors yet.

experimental/torch_xla2/torch_xla2/ops/jaten.py

@@ -53,6 +53,9 @@
   torch.ops.aten.scatter_reduce_.two: torch.ops.aten.scatter_reduce,
 }
 
+# Note: tuple comparisons work intuitively, e.g. `_jax_version >= (0, 4, 32)`.
+_jax_version = tuple(int(v) for v in jax.version._version.split("."))
+
 
 def make_mutation(op):
   if type(mutation_ops_to_functional[op]) is tuple:
@@ -2757,6 +2760,140 @@ def _aten_unbind(a, dim=0):
   return [jax.lax.index_in_dim(a, i, dim, keepdims=False) for i in range(a.shape[dim])]
 
 
+# aten.unique_dim
+#
+# NOTE: Like the CUDA and CPU implementations, this implementation always sorts
+# the tensor regardless of the `sorted` argument passed to `torch.unique`.
+@op(torch.ops.aten.unique_dim)
+def _aten_unique_dim(input_tensor,
+                     dim,
+                     sort=True,
+                     return_inverse=False,
+                     return_counts=False):
+  result_tensor_or_tuple = jnp.unique(input_tensor,
+                                      return_index=False,
+                                      return_inverse=return_inverse,
+                                      return_counts=return_counts,
+                                      axis=dim,
+                                      equal_nan=False)
+  result_list = (
+      list(result_tensor_or_tuple) if isinstance(result_tensor_or_tuple, tuple)
+      else [result_tensor_or_tuple])
+
+  if not return_inverse:
+    result_list.insert(1, None)
+  elif _jax_version < (0, 4, 31) and dim is not None:
+    result_list[1] = result_list[1].flatten()
+
+  if not return_counts:
+    result_list.insert(2, None)
+
+  # [result, None,    None]    if return_inverse=False and return_counts=False
+  # [result, inverse, None]    if return_inverse=True  and return_counts=False
+  # [result, None,    counts]  if return_inverse=False and return_counts=True
+  # [result, inverse, counts]  if return_inverse=True  and return_counts=True
+  return result_list
+
+
+# aten._unique
+#
+# NOTE: Like the CUDA and CPU implementations, this implementation always sorts
+# the tensor regardless of the `sorted` argument passed to `torch.unique`.
+@op(torch.ops.aten._unique)
+def _aten_unique(input_tensor,
+                 sort=True,
+                 return_inverse=False):
+  result_tensor_or_tuple = jnp.unique(input_tensor,
+                                      return_index=False,
+                                      return_inverse=return_inverse,
+                                      return_counts=False,
+                                      axis=None,
+                                      equal_nan=False)
+  if return_inverse:
+    return result_tensor_or_tuple
+  else:
+    return (result_tensor_or_tuple, None)
+
+
+# aten._unique2
+#
+# NOTE: Like the CUDA and CPU implementations, this implementation always sorts
+# the tensor regardless of the `sorted` argument passed to `torch.unique`.
+@op(torch.ops.aten._unique2)
+def _aten_unique2(input_tensor,
+                  sort=True,
+                  return_inverse=False,
+                  return_counts=False):
+  return _aten_unique_dim(input_tensor=input_tensor,
+                          dim=None,
+                          sort=sort,
+                          return_inverse=return_inverse,
+                          return_counts=return_counts)
+
+
+# aten.unique_consecutive
+@op(torch.ops.aten.unique_consecutive)
+def _aten_unique_consecutive(input_tensor,
+                             return_inverse=False,
+                             return_counts=None,
+                             dim=None):
+  # Explanation of computations (shown in 1D for simplicity):
+  #
+  #   Input                                      [a b b c c c d d d d e e e e e]
+  #   Slice dropping final element (input[:-1])    [a b b c c c d d d d e e e e]
+  #   Slice dropping first element (input[1:])     [b b c c c d d d d e e e e e]
+  #   Boolean != operation on shifted slices       [1 0 1 0 0 1 0 0 0 1 0 0 0 0]
+  #   Prepend 1 to represent the first element   [1 1 0 1 0 0 1 0 0 0 1 0 0 0 0]
+  #   Filter input by the resulting bool array   [a b   c     d       e        ]
+  #   Output                                     [a b c d e]
+
+  if dim is None:
+    inverse_shape = input_tensor.shape
+    input_tensor = input_tensor.flatten()
+    ndim = 1
+    dim = 0
+  else:
+    inverse_shape = input_tensor.shape[dim]
+    ndim = input_tensor.ndim
+    if dim < 0:
+      dim += ndim
+
+  nd_slice_0 = tuple(slice(None, -1) if d == dim else slice(None)
+                     for d in range(ndim))
+  nd_slice_1 = tuple(slice(1, None) if d == dim else slice(None)
+                     for d in range(ndim))
+
+  axes_to_reduce = tuple(d for d in range(ndim) if d != dim)
+
+  does_not_equal_prior = (
+      jnp.any(input_tensor[nd_slice_0] != input_tensor[nd_slice_1],
+              axis=axes_to_reduce,
+              keepdims=False))
+
+  if input_tensor.shape[dim] != 0:
+    # Prepend `True` to represent the first element of the input.
+    does_not_equal_prior = jnp.insert(does_not_equal_prior, 0, True)
+
+  include_indices = jnp.argwhere(does_not_equal_prior)[:, 0]
+
+  output_tensor = input_tensor[
+      tuple(include_indices if d == dim else slice(None) for d in range(ndim))]
+
+  if return_inverse or return_counts:
+    counts = (jnp.append(include_indices[1:], input_tensor.shape[dim]) -
+              include_indices[:])
+
+    inverse = (
+        jnp.reshape(jnp.repeat(jnp.arange(len(counts)), counts), inverse_shape)
+        if return_inverse
+        else None
+    )
+
+    return output_tensor, inverse, counts
+
+  return output_tensor, None, None
+
+
 # NOTE: skip aten.upsample_nearest2d and aten.upsample_bilinear2d
 # despite those being core aten ops, they also have decompositions.
 # here we are using torch decompositions.