[Relay, TOPI] Add numpy style cumsum op

include/tvm/relay/attrs/transform.h

@@ -438,6 +438,16 @@ struct MatrixSetDiagAttrs : public tvm::AttrsNode<MatrixSetDiagAttrs> {
   }
 };  // struct MatrixSetDiagAttrs
 
+/*! \brief Attributes used in cumsum operator */
+struct CumsumAttrs : public tvm::AttrsNode<CumsumAttrs> {
+  Integer axis;
+  DataType dtype;
+  TVM_DECLARE_ATTRS(CumsumAttrs, "relay.attrs.CumsumAttrs") {
+    TVM_ATTR_FIELD(axis).describe("The axis to sum over").set_default(NullValue<Integer>());
+    TVM_ATTR_FIELD(dtype).describe("Output data type").set_default(NullValue<DataType>());
+  }
+};
+
 }  // namespace relay
 }  // namespace tvm
 #endif  // TVM_RELAY_ATTRS_TRANSFORM_H_

python/tvm/relay/op/_transform.py

@@ -103,7 +103,7 @@ def compute_scatter_add(attrs, inputs, output_type):
 
 _reg.register_strategy("scatter_add", strategy.scatter_add_strategy)
 
-# scatter
+# scatter_nd
 @_reg.register_compute("scatter_nd")
 def compute_scatter_nd(attrs, inputs, output_type):
     """Compute definition of scatter_nd"""
@@ -112,6 +112,16 @@ def compute_scatter_nd(attrs, inputs, output_type):
 
 _reg.register_strategy("scatter_nd", strategy.scatter_nd_strategy)
 
+# cumsum
+@_reg.register_compute("cumsum")
+def compute_cumsum(attrs, inputs, output_type):
+    """Compute definition of cumsum"""
+    return [topi.cumsum(inputs[0], attrs.axis, attrs.dtype)]
+
+
+_reg.register_strategy("cumsum", strategy.cumsum_strategy)
+_reg.register_shape_func("cumsum", False, elemwise_shape_func)
+
 #####################
 #  Shape functions  #
 #####################

python/tvm/relay/op/strategy/cuda.py

@@ -996,3 +996,15 @@ def argwhere_strategy_cuda(attrs, inputs, out_type, target):
         name="argwhere.cuda",
     )
     return strategy
+
+
+@cumsum_strategy.register(["cuda", "gpu"])
+def cumsum_strategy_cuda(attrs, inputs, out_type, target):
+    """cumsum cuda strategy"""
+    strategy = _op.OpStrategy()
+    strategy.add_implementation(
+        wrap_compute_cumsum(topi.cuda.cumsum),
+        wrap_topi_schedule(topi.cuda.schedule_scan),
+        name="cumsum.cuda",
+    )
+    return strategy

python/tvm/relay/op/strategy/generic.py

@@ -1361,3 +1361,24 @@ def threefry_split_strategy(attrs, inputs, out_type, target):
         name="threefry_split.generic",
     )
     return strategy
+
+
+def wrap_compute_cumsum(topi_compute):
+    """Wrap cumsum topi compute"""
+
+    def _compute_cumsum(attrs, inputs, _):
+        return [topi_compute(inputs[0], attrs.axis, attrs.dtype)]
+
+    return _compute_cumsum
+
+
+@override_native_generic_func("cumsum_strategy")
+def cumsum_strategy(attrs, inputs, out_type, target):
+    """cumsum generic strategy"""
+    strategy = _op.OpStrategy()
+    strategy.add_implementation(
+        wrap_compute_cumsum(topi.cumsum),
+        wrap_topi_schedule(topi.generic.schedule_extern),
+        name="cumsum.generic",
+    )
+    return strategy

python/tvm/relay/op/transform.py

@@ -1320,3 +1320,52 @@ def adv_index(inputs):
         Output tensor.
     """
     return _make.adv_index(Tuple(inputs))
+
+
+def cumsum(data, axis=None, dtype=None):
+    """Numpy style cumsum op. Return the cumulative inclusive sum of the elements along
+    a given axis.
+
+    Parameters
+    ----------
+    data : relay.Expr
+        The input data to the operator.
+
+    axis : int, optional
+        Axis along which the cumulative sum is computed. The default (None) is to compute
+        the cumsum over the flattened array.
+
+    dtype : string, optional
+        Type of the returned array and of the accumulator in which the elements are summed.
+        If dtype is not specified, it defaults to the dtype of data.
+
+    Returns
+    -------
+    result : relay.Expr
+        The result has the same size as data, and the same shape as data if axis is not None.
+        If axis is None, the result is a 1-d array.
+
+    Examples
+    --------
+    .. code-block:: python
+        a = [[1,2,3], [4,5,6]]
+
+        cumsum(a)  # if axis is not provided, cumsum is done over the flattened input.
+        -> [ 1,  3,  6, 10, 15, 21]
+
+        cumsum(a, dtype="float32")
+        -> [  1.,   3.,   6.,  10.,  15.,  21.]
+
+        cumsum(a, axis=0)  # sum over rows for each of the 3 columns
+        -> [[1, 2, 3],
+            [5, 7, 9]]
+
+        cumsum(a, axis=1)
+        -> [[ 1,  3,  6],
+            [ 4,  9, 15]]
+
+        a = [1, 0, 1, 0, 1, 1, 0]  # a is a boolean array
+        cumsum(a, dtype=int32)  # dtype should be provided to get the expected results
+        -> [1, 1, 2, 2, 3, 4, 4]
+    """
+    return _make.cumsum(data, axis, dtype)

python/tvm/topi/__init__.py

@@ -40,6 +40,7 @@
 from .scatter import *
 from .scatter_add import *
 from .argwhere import *
+from .cumsum import *
 from . import generic
 from . import nn
 from . import x86

python/tvm/topi/cuda/__init__.py

@@ -56,3 +56,4 @@
 from .correlation import *
 from .sparse import *
 from .argwhere import *
+from .scan import *

python/tvm/topi/cuda/nms.py

@@ -609,7 +609,8 @@ def _get_sorted_indices(data, data_buf, score_index, score_shape):
         tag="fetch_score",
     )
 
-    if is_thrust_available():
+    target = tvm.target.Target.current()
+    if target and target.kind.name == "cuda" and is_thrust_available():
         sort_tensor = argsort_thrust(score_tensor, axis=1, is_ascend=False, dtype="int32")
     else:
         sort_tensor = argsort(score_tensor, axis=1, is_ascend=False, dtype="int32")