Revise SoftPlus operation reference implementation 37559 (#5938)

* change threshold to 20 instead of max limit of data type

* add invalid input type test case

* add invalid input data check

* add input type dynamic check

* add backend test case

* add more clarity on spec and align with real implementation

* Revert "[CPU] Fix for  CoreThreadingTestsWithIterations tests (#5892)"

This reverts commit 115aa143ef.

* Revert "Revert "[CPU] Fix for  CoreThreadingTestsWithIterations tests (#5892)""

This reverts commit 95afa50d94.

* Revert "change threshold to 20 instead of max limit of data type"

This reverts commit 91af825056.

* Revert "add more clarity on spec and align with real implementation"

This reverts commit a3b232a8fb.

* add visitor attribute test case

* Revert "add visitor attribute test case"

This reverts commit 610728f1ab.

* add attribute test case

* revise the attribute visitor test per parametrized visitor API PR: #6181

ngraph/core/src/op/softplus.cpp

@@ -29,6 +29,13 @@ bool op::v4::SoftPlus::visit_attributes(AttributeVisitor& visitor)
 void op::v4::SoftPlus::validate_and_infer_types()
 {
     NGRAPH_OP_SCOPE(v4_SoftPlus_validate_and_infer_types);
+    const element::Type& input_et = get_input_element_type(0);
+
+    NODE_VALIDATION_CHECK(this,
+                          input_et.is_dynamic() || input_et.is_real(),
+                          "Input element type must be float. Got: ",
+                          input_et);
+
     set_output_size(1);
     set_output_type(0, get_input_element_type(0), get_input_partial_shape(0));
 }

ngraph/test/CMakeLists.txt

@@ -287,6 +287,7 @@ set(SRC
     visitors/op/selu.cpp
     visitors/op/shuffle_channels.cpp
     visitors/op/softmax.cpp
+    visitors/op/softplus.cpp
     visitors/op/space_to_batch.cpp
     visitors/op/space_to_depth.cpp
     visitors/op/split.cpp
@@ -463,6 +464,7 @@ set(MULTI_TEST_SRC
     backend/sin.in.cpp
     backend/sinh.in.cpp
     backend/softmax.in.cpp
+    backend/softplus.in.cpp
     backend/space_to_batch.in.cpp
     backend/split.in.cpp
     backend/sqrt.in.cpp

ngraph/test/backend/softplus.in.cpp

@@ -0,0 +1,45 @@
+// Copyright (C) 2018-2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+//
+
+#include <algorithm>
+#include <cinttypes>
+#include <cmath>
+#include <cstdlib>
+#include <random>
+#include <string>
+
+// clang-format off
+#ifdef ${BACKEND_NAME}_FLOAT_TOLERANCE_BITS
+#define DEFAULT_FLOAT_TOLERANCE_BITS ${BACKEND_NAME}_FLOAT_TOLERANCE_BITS
+#endif
+
+#ifdef ${BACKEND_NAME}_DOUBLE_TOLERANCE_BITS
+#define DEFAULT_DOUBLE_TOLERANCE_BITS ${BACKEND_NAME}_DOUBLE_TOLERANCE_BITS
+#endif
+// clang-format on
+
+#include "gtest/gtest.h"
+#include "ngraph/ngraph.hpp"
+#include "util/engine/test_engines.hpp"
+#include "util/test_case.hpp"
+#include "util/test_control.hpp"
+
+using namespace std;
+using namespace ngraph;
+
+static string s_manifest = "${MANIFEST}";
+using TestEngine = test::ENGINE_CLASS_NAME(${BACKEND_NAME});
+
+NGRAPH_TEST(${BACKEND_NAME}, softplus)
+{
+    auto A = make_shared<op::Parameter>(element::f32, Shape{4});
+    auto softplus = make_shared<op::v4::SoftPlus>(A);
+    auto function = make_shared<Function>(NodeVector{softplus}, ParameterVector{A});
+
+    auto test_case = test::TestCase<TestEngine>(function);
+    test_case.add_input(vector<float>{-1.0, 0.0, 1.0, 20.0});
+    test_case.add_expected_output(
+        vector<float>{0.31326166, 0.69314718, 1.3132616, 20.0});
+    test_case.run();
+}

ngraph/test/type_prop/softplus.cpp

@@ -40,3 +40,23 @@ TEST(type_prop, softplus_partial_static_rank)
         (PartialShape{1, Dimension::dynamic(), 6})));
     ASSERT_TRUE(softplus_func->get_output_partial_shape(0).rank().is_static());
 }
+
+TEST(type_prop, softplus_invalid_element_type)
+{
+    auto data = make_shared<op::Parameter>(element::i32, Shape{2, 2});
+
+    try
+    {
+        auto softplus = make_shared<op::v4::SoftPlus>(data);
+        // Input element type is boolean
+        FAIL() << "Invalid int element type for input not detected";
+    }
+    catch (const NodeValidationFailure& error)
+    {
+        EXPECT_HAS_SUBSTRING(error.what(), "Input element type must be float");
+    }
+    catch (...)
+    {
+        FAIL() << "Numeric element type node validation check failed for unexpected reason";
+    }
+}

ngraph/test/visitors/op/softplus.cpp

@@ -0,0 +1,12 @@
+// Copyright (C) 2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+//
+
+#include "unary_ops.hpp"
+
+using Types = ::testing::Types<UnaryOperatorType<ngraph::op::v4::SoftPlus, element::f32>>;
+
+INSTANTIATE_TYPED_TEST_CASE_P(visitor_without_atrribute,
+                              UnaryOperatorVisitor,
+                              Types,
+                              UnaryOperatorTypeName);