Added implementation of bitcast op.

libnd4j/include/ops/declarable/generic/datatypes/bitcast.cpp

@@ -0,0 +1,97 @@
+/*******************************************************************************
+ * Copyright (c) 2015-2018 Skymind, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+//
+// @author George A. Shulinok <sgazeos@gmail.com>
+//
+
+#include <op_boilerplate.h>
+#if NOT_EXCLUDED(OP_bitcast)
+
+#include <array/DataTypeUtils.h>
+#include <ops/declarable/CustomOperations.h>
+
+namespace nd4j {
+    namespace ops {
+        CUSTOM_OP_IMPL(bitcast, 1, 1, false, 0, 1) {
+            auto input = INPUT_VARIABLE(0);
+            auto output = OUTPUT_VARIABLE(0);
+
+            if(input->isEmpty()){
+                REQUIRE_TRUE(output->isEmpty(), 0, "BITCAST: If input is empty, output array must also be empty.");
+                return Status::OK();
+            }
+
+//            if (!block.isInplace())
+//                output->assign(input);
+            input->syncToHost();
+            output->syncToHost();
+            memcpy(output->buffer(), input->buffer(), input->lengthOf() * input->sizeOfT());
+            output->syncToDevice();
+            output->tickWriteDevice();
+            //STORE_RESULT(output);
+            return Status::OK();
+        }
+        DECLARE_SYN(BitCast, bitcast);
+
+        DECLARE_SHAPE_FN(bitcast) {
+            auto inShape = inputShape->at(0);
+            auto inputRank = shape::rank(inShape);
+            auto it = INT_ARG(0);
+            DataType newType = DataTypeUtils::fromInt(it);
+            DataType oldType = ArrayOptions::dataType(inShape);
+            // correct output shape to conform with output data type
+            auto inputSize = DataTypeUtils::sizeOf(oldType);
+            auto outputSize = DataTypeUtils::sizeOf(newType);
+
+            if (shape::length(inShape) == 0)
+                return SHAPELIST(ConstantShapeHelper::getInstance()->createShapeInfo(ShapeDescriptor(inShape, newType)));
+
+            if (inputSize == outputSize) {
+                // only type should be changed
+                return SHAPELIST(ConstantShapeHelper::getInstance()->createShapeInfo(ShapeDescriptor(inShape, newType)));
+            }
+            else if (inputSize > outputSize) {
+                // range of output increased by 1 with inputSize / outputSize as last dimension
+                std::vector<Nd4jLong> shapeOf(inputRank + 1);
+                int i;
+                for (i = 0; i < inputRank; ++i) {
+                    shapeOf[i] = inShape[i + 1];
+                }
+                shapeOf[i] = inputSize / outputSize;
+                auto outputShape = ConstantShapeHelper::getInstance()->createShapeInfo(newType, shape::order(inShape), shapeOf);
+                return SHAPELIST(outputShape);
+            }
+            REQUIRE_TRUE(shape::sizeAt(inShape, -1) == outputSize / inputSize, 0, "BITCAST: %ull > %ull. So last dimension should be %ull, but %i given.", inputSize, outputSize, outputSize / inputSize, shape::sizeAt(inShape, -1));
+            std::vector<Nd4jLong> shapeOf(inputRank - 1);
+
+            for (auto i = 0; i < shapeOf.size(); ++i) {
+                shapeOf[i] = inShape[i + 1];
+            }
+
+            auto outputShape = ConstantShapeHelper::getInstance()->createShapeInfo(newType, shape::order(inShape), shapeOf);
+            return SHAPELIST(outputShape);
+        }
+
+        DECLARE_TYPES(bitcast) {
+            getOpDescriptor()
+                    ->setAllowedInputTypes(nd4j::DataType::ANY)
+                    ->setAllowedOutputTypes(nd4j::DataType::ANY);
+        }
+    }
+}
+
+#endif