[Operator] Add range op. (#15431)

* Add range op.
test=develop

* Add more unitests.
test=develop

* Fix API.spec
test=develop

* Fix API.spec
test=develop

* Fix API.spec
test=develop

paddle/fluid/API.spec

@@ -255,6 +255,7 @@ paddle.fluid.layers.reverse (ArgSpec(args=['x', 'axis'], varargs=None, keywords=
 paddle.fluid.layers.has_inf (ArgSpec(args=['x'], varargs=None, keywords=None, defaults=None), ('document', '8f8c0306117ea441f20dcbbdba1f0ecc'))
 paddle.fluid.layers.has_nan (ArgSpec(args=['x'], varargs=None, keywords=None, defaults=None), ('document', '2e53e83127dbfd86e7098bdfe9a549e8'))
 paddle.fluid.layers.isfinite (ArgSpec(args=['x'], varargs=None, keywords=None, defaults=None), ('document', '0a437011c3906079fd8947ed3e52d292'))
+paddle.fluid.layers.range (ArgSpec(args=['start', 'end', 'step', 'dtype'], varargs=None, keywords=None, defaults=None), ('document', '2ec937ede953ded2fdff2675883900bb'))
 paddle.fluid.layers.While.__init__ (ArgSpec(args=['self', 'cond', 'is_test', 'name'], varargs=None, keywords=None, defaults=(False, None)), ('document', '6adf97f83acf6453d4a6a4b1070f3754'))
 paddle.fluid.layers.While.block (ArgSpec(args=['self'], varargs=None, keywords=None, defaults=None), ('document', '6adf97f83acf6453d4a6a4b1070f3754'))
 paddle.fluid.layers.Switch.__init__ (ArgSpec(args=['self', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '6adf97f83acf6453d4a6a4b1070f3754'))

paddle/fluid/operators/range_op.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/fluid/operators/range_op.h"
+
+namespace paddle {
+namespace operators {
+
+class RangeOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+  void InferShape(framework::InferShapeContext *ctx) const override {
+    if (ctx->HasInput("Start")) {
+      auto s_dims = ctx->GetInputDim("Start");
+      PADDLE_ENFORCE((s_dims.size() == 1) && (s_dims[0] == 1),
+                     "The shape of Input(Start) should be [1].");
+    }
+    if (ctx->HasInput("End")) {
+      auto e_dims = ctx->GetInputDim("End");
+      PADDLE_ENFORCE((e_dims.size() == 1) && (e_dims[0] == 1),
+                     "The shape of Input(End) should be [1].");
+    }
+    if (ctx->HasInput("Step")) {
+      auto step_dims = ctx->GetInputDim("Step");
+      PADDLE_ENFORCE((step_dims.size() == 1) && (step_dims[0] == 1),
+                     "The shape of Input(Step) should be [1].");
+    }
+    ctx->SetOutputDim("Out", {-1});
+  }
+};
+
+class RangeOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  void Make() override {
+    AddInput("Start",
+             "Start of interval. The interval includes this value. It is a "
+             "tensor with shape=[1].");
+    AddInput("End",
+             "End of interval. The interval does not include this value, "
+             "except in some cases where step is not an integer and floating "
+             "point round-off affects the length of out. It is a tensor with "
+             "shape=[1].");
+    AddInput("Step", "Spacing between values. It is a tensor with shape=[1].");
+    AddOutput("Out", "A sequence of numbers.");
+    AddComment(R"DOC(
+    Return evenly spaced values within a given interval. Values are generated within the half-open interval [start, stop) (in other words, the interval including start but excluding stop). Like arange function of numpy.
+)DOC");
+  }
+};
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OP_WITHOUT_GRADIENT(range, ops::RangeOp, ops::RangeOpMaker);
+REGISTER_OP_CPU_KERNEL(range, ops::CPURangeKernel<int>,
+                       ops::CPURangeKernel<float>, ops::CPURangeKernel<double>,
+                       ops::CPURangeKernel<int64_t>);

paddle/fluid/operators/range_op.cu

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/range_op.h"
+#include "paddle/fluid/platform/cuda_primitives.h"
+
+namespace paddle {
+namespace operators {
+
+#define CUDA_1D_KERNEL_LOOP(i, n)                              \
+  for (int i = blockIdx.x * blockDim.x + threadIdx.x; i < (n); \
+       i += blockDim.x * gridDim.x)
+
+template <typename T>
+__global__ void RangeKernel(T start, T step, int64_t size, T* out) {
+  CUDA_1D_KERNEL_LOOP(index, size) { out[index] = start + step * index; }
+}
+
+template <typename T>
+class CUDARangeKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& context) const override {
+    auto* start_t = context.Input<framework::Tensor>("Start");
+    auto* end_t = context.Input<framework::Tensor>("End");
+    auto* step_t = context.Input<framework::Tensor>("Step");
+    auto* out = context.Output<framework::Tensor>("Out");
+
+    framework::Tensor n;
+    framework::TensorCopy(*start_t, platform::CPUPlace(), &n);
+    T start = n.data<T>()[0];
+    framework::TensorCopy(*end_t, platform::CPUPlace(), &n);
+    T end = n.data<T>()[0];
+    framework::TensorCopy(*step_t, platform::CPUPlace(), &n);
+    T step = n.data<T>()[0];
+
+    int64_t size = 0;
+    GetSize(start, end, step, &size);
+    out->Resize(framework::make_ddim({size}));
+    T* out_data = out->mutable_data<T>(context.GetPlace());
+
+    auto stream = context.cuda_device_context().stream();
+    int block = 512;
+    int grid = (size + block - 1) / block;
+    RangeKernel<T><<<grid, block, 0, stream>>>(start, step, size, out_data);
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OP_CUDA_KERNEL(range, ops::CUDARangeKernel<int>,
+                        ops::CUDARangeKernel<int64_t>,
+                        ops::CUDARangeKernel<float>,
+                        ops::CUDARangeKernel<double>);

paddle/fluid/operators/range_op.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#pragma once
+#include <functional>
+#include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/math/math_function.h"
+
+namespace paddle {
+namespace operators {
+
+template <typename T>
+void GetSize(T start, T end, T step, int64_t* size) {
+  PADDLE_ENFORCE(!std::equal_to<T>()(step, 0),
+                 "The step of range op should not be 0.");
+  PADDLE_ENFORCE(((start < end) && (step > 0)) || ((start > end) && (step < 0)),
+                 "The step should be greater than 0 while start < end. And the "
+                 "step should be less than 0 while start > end.");
+  *size = std::is_integral<T>::value
+              ? ((std::abs(end - start) + std::abs(step) - 1) / std::abs(step))
+              : std::ceil(std::abs((end - start) / step));
+}
+
+template <typename T>
+class CPURangeKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& context) const override {
+    T start = context.Input<framework::Tensor>("Start")->data<T>()[0];
+    T end = context.Input<framework::Tensor>("End")->data<T>()[0];
+    T step = context.Input<framework::Tensor>("Step")->data<T>()[0];
+    auto* out = context.Output<framework::Tensor>("Out");
+    int64_t size = 0;
+    GetSize(start, end, step, &size);
+    out->Resize(framework::make_ddim({size}));
+    T* out_data = out->mutable_data<T>(context.GetPlace());
+    T value = start;
+    for (int64_t i = 0; i < size; ++i) {
+      out_data[i] = value;
+      value += step;
+    }
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle

python/paddle/fluid/layers/tensor.py

@@ -25,10 +25,26 @@ from .layer_function_generator import templatedoc
 import numpy
 
 __all__ = [
-    'create_tensor', 'create_parameter', 'create_global_var', 'cast',
-    'tensor_array_to_tensor', 'concat', 'sums', 'assign',
-    'fill_constant_batch_size_like', 'fill_constant', 'argmin', 'argmax',
-    'argsort', 'ones', 'zeros', 'reverse', 'has_inf', 'has_nan', 'isfinite'
+    'create_tensor',
+    'create_parameter',
+    'create_global_var',
+    'cast',
+    'tensor_array_to_tensor',
+    'concat',
+    'sums',
+    'assign',
+    'fill_constant_batch_size_like',
+    'fill_constant',
+    'argmin',
+    'argmax',
+    'argsort',
+    'ones',
+    'zeros',
+    'reverse',
+    'has_inf',
+    'has_nan',
+    'isfinite',
+    'range',
 ]
 
 
@@ -764,3 +780,50 @@ def isfinite(x):
     out = helper.create_variable_for_type_inference(dtype=x.dtype)
     helper.append_op(type="isfinite", inputs={"X": x}, outputs={"Out": out})
     return out
+
+
+def range(start, end, step, dtype):
+    """
+    Return evenly spaced values within a given interval.
+
+    Values are generated within the half-open interval [start, stop) (in other words,
+    the interval including start but excluding stop).
+
+    args:
+        start(int|float|Variable): Start of interval. The interval includes this value.
+        end(int|float|Variable): End of interval. The interval does not include this
+                                 value, except in some cases where step is not an integer
+                                 and floating point round-off affects the length of out. 
+        step(int|float|Variable): Spacing between values. For any output out, this is the
+                                  distance between two adjacent values, out[i+1] - out[i].
+                                  The default step size is 1.
+        dtype(string): 'float32'|'int32'|..., the data type of the output tensor.
+
+    returns:
+        Evenly spaced values within a given interval.
+
+    examples:
+
+        .. code-block:: python
+
+             data = fluid.layers.range(0, 10, 2, 'int32')
+
+    """
+    helper = LayerHelper("range", **locals())
+
+    if not isinstance(start, Variable):
+        start = fill_constant([1], dtype, start)
+    if not isinstance(end, Variable):
+        end = fill_constant([1], dtype, end)
+    if not isinstance(step, Variable):
+        step = fill_constant([1], dtype, step)
+
+    out = helper.create_variable_for_type_inference(dtype=start.dtype)
+
+    helper.append_op(
+        type='range',
+        inputs={'Start': start,
+                'End': end,
+                'Step': step},
+        outputs={'Out': [out]})
+    return out

python/paddle/fluid/tests/unittests/test_layers.py

@@ -1240,6 +1240,14 @@ class TestBook(unittest.TestCase):
 
         print(str(program))
 
+    def test_range(self):
+        program = Program()
+        with program_guard(program):
+            layers.range(0, 10, 2, 'int32')
+            layers.range(0.1, 10.0, 0.2, 'float32')
+
+        print(str(program))
+
     def test_spectral_norm(self):
         program = Program()
         with program_guard(program):

python/paddle/fluid/tests/unittests/test_range.py

+#   Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import print_function
+
+import unittest
+import numpy as np
+from op_test import OpTest
+
+
+class TestRangeOp(OpTest):
+    def setUp(self):
+        self.op_type = "range"
+        self.init_config()
+        self.inputs = {
+            'Start': np.array([self.case[0]]).astype(self.dtype),
+            'End': np.array([self.case[1]]).astype(self.dtype),
+            'Step': np.array([self.case[2]]).astype(self.dtype)
+        }
+
+        self.outputs = {
+            'Out': np.arange(self.case[0], self.case[1],
+                             self.case[2]).astype(self.dtype)
+        }
+
+    def init_config(self):
+        self.dtype = np.float32
+        self.case = (0, 1, 0.2)
+
+    def test_check_output(self):
+        self.check_output()
+
+
+class TestFloatRangeOpCase0(TestRangeOp):
+    def init_config(self):
+        self.dtype = np.float32
+        self.case = (0, 5, 1)
+
+
+class TestInt32RangeOpCase0(TestRangeOp):
+    def init_config(self):
+        self.dtype = np.int32
+        self.case = (0, 5, 2)
+
+
+class TestInt32RangeOpCase1(TestRangeOp):
+    def init_config(self):
+        self.dtype = np.int32
+        self.case = (10, 1, -2)
+
+
+class TestInt32RangeOpCase2(TestRangeOp):
+    def init_config(self):
+        self.dtype = np.int32
+        self.case = (-1, -10, -2)
+
+
+if __name__ == "__main__":
+    unittest.main()