add expm1_op

paddle/fluid/operators/activation_op.cc

@@ -182,6 +182,13 @@ Exp Operator. Computes exp of x element-wise with a natural number :math:`e` as
 
 )DOC";
 
+UNUSED constexpr char Expm1Doc[] = R"DOC(
+Expm1 Operator. Computes expm1 of x element-wise with a natural number :math:`e` as the base.
+
+$$out = e^x - 1$$
+
+)DOC";
+
 UNUSED constexpr char ReluDoc[] = R"DOC(
 Relu Activation Operator.
 
@@ -706,6 +713,7 @@ REGISTER_ACTIVATION_OP_MAKER(Sigmoid, SigmoidDoc);
 REGISTER_ACTIVATION_OP_MAKER(Silu, SiluDoc);
 REGISTER_ACTIVATION_OP_MAKER(LogSigmoid, LogSigmoidDoc);
 REGISTER_ACTIVATION_OP_MAKER(Exp, ExpDoc);
+REGISTER_ACTIVATION_OP_MAKER(Expm1, Expm1Doc);
 REGISTER_ACTIVATION_OP_MAKER(Relu, ReluDoc);
 REGISTER_ACTIVATION_OP_MAKER(Tanh, TanhDoc);
 REGISTER_ACTIVATION_OP_MAKER(TanhShrink, TanhShrinkDoc);
@@ -1346,6 +1354,34 @@ REGISTER_OP_CPU_KERNEL(
                               ops::ExpGradFunctor<int64_t>>);
 /* ========================================================================== */
 
+/* ==========================   expm1 register  ============================ */
+REGISTER_OPERATOR(
+    expm1, ops::ActivationOp, ops::Expm1OpMaker, ops::ActivationOpInferVarType,
+    ops::ActivationGradOpMaker<ops::Expm1GradFunctor<float>::FwdDeps(),
+                               paddle::framework::OpDesc>,
+    ops::ActivationGradOpMaker<ops::Expm1GradFunctor<float>::FwdDeps(),
+                               paddle::imperative::OpBase>,
+    std::conditional<ops::CanInplaceAct<ops::Expm1GradFunctor<float>>(),
+                     ops::ActFwdInplaceInferer, void>::type);
+REGISTER_OPERATOR(expm1_grad, ops::ActivationOpGrad,
+                  ops::ActivationGradOpInplaceInferer);
+
+REGISTER_OP_CPU_KERNEL(expm1,
+                       ops::ActivationKernel<paddle::platform::CPUDeviceContext,
+                                             ops::Expm1Functor<float>>,
+                       ops::ActivationKernel<paddle::platform::CPUDeviceContext,
+                                             ops::Expm1Functor<double>>,
+                       ops::ActivationKernel<paddle::platform::CPUDeviceContext,
+                                             ops::Expm1Functor<plat::float16>>);
+REGISTER_OP_CPU_KERNEL(
+    expm1_grad, ops::ActivationGradKernel<paddle::platform::CPUDeviceContext,
+                                          ops::Expm1GradFunctor<float>>,
+    ops::ActivationGradKernel<paddle::platform::CPUDeviceContext,
+                              ops::Expm1GradFunctor<double>>,
+    ops::ActivationGradKernel<paddle::platform::CPUDeviceContext,
+                              ops::Expm1GradFunctor<plat::float16>>);
+/* ========================================================================== */
+
 /* ==========================  Log register ==================================*/
 REGISTER_OPERATOR(
     log, ops::ActivationOp, ops::LogOpMaker, ops::ActivationOpInferVarType,

paddle/fluid/operators/activation_op.cu

@@ -564,6 +564,30 @@ struct CudaExpGradFunctor : public BaseActivationFunctor<T> {
   static constexpr ActBwdOpFwdDeps FwdDeps() { return kDepOut; }
 };
 
+template <typename T>
+struct CudaExpm1Functor : public BaseActivationFunctor<T> {
+  using MPType = typename details::MPTypeTrait<T>::Type;
+
+  // expm1(x) = expm1(x)
+  // Inputs: args[0], the input x
+  __device__ __forceinline__ T operator()(const T* args) const {
+    MPType x = static_cast<MPType>(args[0]);
+    return static_cast<T>(expm1(x));
+  }
+};
+
+template <typename T>
+struct CudaExpm1GradFunctor : public BaseActivationFunctor<T> {
+  // dx = dout * out
+  // Inputs: args[0], the input dout
+  //         args[1], the input out
+  __device__ __forceinline__ T operator()(const T* args) const {
+    return args[0] * args[1] + args[0];
+  }
+
+  static constexpr ActBwdOpFwdDeps FwdDeps() { return kDepOut; }
+};
+
 template <typename T>
 struct CudaLogFunctor : public BaseActivationFunctor<T> {
   using MPType = typename details::MPTypeTrait<T>::Type;
@@ -1582,6 +1606,24 @@ REGISTER_OP_CUDA_KERNEL(
                                   ops::CudaExpGradFunctor<plat::float16>>);
 /* ========================================================================== */
 
+/* ==========================   expm1 register  ============================ */
+
+REGISTER_OP_CUDA_KERNEL(
+    expm1, ops::ActivationCudaKernel<plat::CUDADeviceContext,
+                                     ops::CudaExpm1Functor<float>>,
+    ops::ActivationCudaKernel<plat::CUDADeviceContext,
+                              ops::CudaExpm1Functor<double>>,
+    ops::ActivationCudaKernel<plat::CUDADeviceContext,
+                              ops::CudaExpm1Functor<plat::float16>>);
+REGISTER_OP_CUDA_KERNEL(
+    expm1_grad, ops::ActivationGradCudaKernel<plat::CUDADeviceContext,
+                                              ops::CudaExpm1GradFunctor<float>>,
+    ops::ActivationGradCudaKernel<plat::CUDADeviceContext,
+                                  ops::CudaExpm1GradFunctor<double>>,
+    ops::ActivationGradCudaKernel<plat::CUDADeviceContext,
+                                  ops::CudaExpm1GradFunctor<plat::float16>>);
+/* ========================================================================== */
+
 /* ==========================  Log register ==================================*/
 REGISTER_ACTIVATION_CUDA_KERNEL(log, Log, CudaLogFunctor, CudaLogGradFunctor);
 

paddle/fluid/operators/activation_op.h

@@ -341,6 +341,26 @@ struct ExpGradFunctor : public BaseActivationFunctor<T> {
   static constexpr ActBwdOpFwdDeps FwdDeps() { return kDepOut; }
 };
 
+// expm1(x) = e^x - 1
+template <typename T>
+struct Expm1Functor : public BaseActivationFunctor<T> {
+  template <typename Device, typename X, typename Out>
+  void operator()(Device d, X x, Out out) const {
+    out.device(d) = x.expm1();
+  }
+};
+
+template <typename T>
+struct Expm1GradFunctor : public BaseActivationFunctor<T> {
+  template <typename Device, typename X, typename Out, typename dOut,
+            typename dX>
+  void operator()(Device d, X x, Out out, dOut dout, dX dx) const {
+    dx.device(d) = dout * out + dout;
+  }
+
+  static constexpr ActBwdOpFwdDeps FwdDeps() { return kDepOut; }
+};
+
 // relu(x) = max(x, 0)
 template <typename T>
 struct ReluCPUFunctor : public BaseActivationFunctor<T> {

paddle/fluid/platform/eigen_ext.h

@@ -204,6 +204,12 @@ HOSTDEVICE inline paddle::platform::bfloat16 exp(
   return paddle::platform::bfloat16(::expf(static_cast<float>(a)));
 }
 
+template <>
+HOSTDEVICE inline paddle::platform::bfloat16 expm1(
+    const paddle::platform::bfloat16& a) {
+  return paddle::platform::bfloat16(::expm1f(static_cast<float>(a)));
+}
+
 template <>
 HOSTDEVICE inline paddle::platform::bfloat16 erf(
     const paddle::platform::bfloat16& a) {
@@ -555,6 +561,11 @@ HOSTDEVICE inline float16 exp(const float16& a) {
   return float16(::expf(static_cast<float>(a)));
 }
 
+template <>
+HOSTDEVICE inline float16 expm1(const float16& a) {
+  return float16(::expm1f(static_cast<float>(a)));
+}
+
 template <>
 HOSTDEVICE inline float16 erf(const float16& a) {
   return float16(::erff(static_cast<float>(a)));

python/paddle/__init__.py

@@ -155,6 +155,7 @@
 from .tensor.math import cosh  # noqa: F401
 from .tensor.math import cumsum  # noqa: F401
 from .tensor.math import exp  # noqa: F401
+from .tensor.math import expm1  # noqa: F401
 from .tensor.math import floor  # noqa: F401
 from .tensor.math import increment  # noqa: F401
 from .tensor.math import log  # noqa: F401
@@ -409,6 +410,7 @@
            'acos',
            'logical_xor',
            'exp',
+           'expm1',
            'bernoulli',
            'summary',
            'sinh',

python/paddle/fluid/layers/ops.py

@@ -37,6 +37,7 @@
 
 __unary_func__ = [
     'exp',
+    'expm1',
     'atan',
     'sqrt',
     'rsqrt',
@@ -161,6 +162,19 @@
 
 """)
 
+add_sample_code(globals()["expm1"], r"""
+Examples:
+    .. code-block:: python
+
+        import paddle
+
+        x = paddle.to_tensor([-0.4, -0.2, 0.1, 0.3])
+        out = paddle.expm1(x)
+        print(out)
+        # [-0.32967997, -0.18126924,  0.10517092,  0.34985882]
+
+""")
+
 add_sample_code(globals()["tanh"], r"""
 Examples:
     .. code-block:: python

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

@@ -73,6 +73,70 @@ def init_kernel_type(self):
         pass
 
 
+class TestExpm1(TestActivation):
+    def setUp(self):
+        self.op_type = "expm1"
+        self.init_dtype()
+
+        np.random.seed(2049)
+        x = np.random.uniform(0.1, 1, [11, 17]).astype(self.dtype)
+        out = np.expm1(x)
+
+        self.inputs = {'X': OpTest.np_dtype_to_fluid_dtype(x)}
+        self.outputs = {'Out': out}
+
+    def test_check_grad(self):
+        self.check_grad(['X'], 'Out')
+
+
+class TestExpm1API(unittest.TestCase):
+    def init_dtype(self):
+        self.dtype = 'float64'
+        self.shape = [11, 17]
+
+    def setUp(self):
+        self.init_dtype()
+        self.x = np.random.uniform(0.1, 1, self.shape).astype(self.dtype)
+        self.out_ref = np.expm1(self.x)
+
+        self.place = [paddle.CPUPlace()]
+        if core.is_compiled_with_cuda():
+            self.place.append(paddle.CUDAPlace(0))
+
+    def test_static_api(self):
+        paddle.enable_static()
+
+        def run(place):
+            with paddle.static.program_guard(paddle.static.Program()):
+                X = paddle.fluid.data('X', self.shape, dtype=self.dtype)
+                out = paddle.expm1(X)
+                exe = paddle.static.Executor(place)
+                res = exe.run(feed={'X': self.x})
+            for r in res:
+                self.assertEqual(np.allclose(self.out_ref, r), True)
+
+        for place in self.place:
+            run(place)
+
+    def test_dygraph_api(self):
+        def run(place):
+            paddle.disable_static(place)
+            X = paddle.to_tensor(self.x)
+            out = paddle.expm1(X)
+            self.assertEqual(np.allclose(self.out_ref, out.numpy()), True)
+            paddle.enable_static()
+
+        for place in self.place:
+            run(place)
+
+    def test_errors(self):
+        paddle.enable_static()
+        with paddle.static.program_guard(paddle.static.Program()):
+            X = paddle.fluid.data('X', self.shape, dtype='int32')
+            self.assertRaises(TypeError, paddle.expm1, X)
+        # The input dtype must be float16, float32, float64.
+
+
 class TestParameter(object):
     def test_out_name(self):
         with fluid.program_guard(fluid.Program()):
@@ -2701,6 +2765,7 @@ def test_check_grad(self):
 
 
 create_test_act_fp16_class(TestActivation)
+create_test_act_fp16_class(TestExpm1)
 create_test_act_fp16_class(TestSigmoid)
 create_test_act_fp16_class(TestSilu)
 create_test_act_fp16_class(TestLogSigmoid)

python/paddle/tensor/__init__.py

@@ -103,6 +103,7 @@
 from .math import cumsum  # noqa: F401
 from .math import exp  # noqa: F401
 from .math import exp_  # noqa: F401
+from .math import expm1  # noqa: F401
 from .math import floor  # noqa: F401
 from .math import floor_  # noqa: F401
 from .math import increment  # noqa: F401

python/paddle/tensor/math.py

@@ -45,6 +45,7 @@
 from ..fluid.layers import cosh    # noqa: F401
 from ..fluid.layers import exp    # noqa: F401
 from ..fluid.layers import exp_    # noqa: F401
+from ..fluid.layers import expm1    # noqa: F401
 from ..fluid.layers import floor    # noqa: F401
 from ..fluid.layers import floor_    # noqa: F401
 from ..fluid.layers import log    # noqa: F401