| /* Copyright 2015 The TensorFlow 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. |
| ==============================================================================*/ |
| |
| #ifndef TENSORFLOW_CORE_FRAMEWORK_BFLOAT16_H_ |
| #define TENSORFLOW_CORE_FRAMEWORK_BFLOAT16_H_ |
| |
| #include "tensorflow/core/framework/numeric_types.h" |
| #include "tensorflow/core/platform/byte_order.h" |
| #include "tensorflow/core/platform/types.h" |
| |
| // Compact 16-bit encoding of floating point numbers. This representation uses |
| // 1 bit for the sign, 8 bits for the exponent and 7 bits for the mantissa. It |
| // is assumed that floats are in IEEE 754 format so the representation is just |
| // bits 16-31 of a single precision float. |
| // |
| // NOTE: The IEEE floating point standard defines a float16 format that |
| // is different than this format (it has fewer bits of exponent and more |
| // bits of mantissa). We don't use that format here because conversion |
| // to/from 32-bit floats is more complex for that format, and the |
| // conversion for this format is very simple. |
| // |
| // Because of the existing IEEE float16 type, we do not name our representation |
| // "float16" but just use "uint16". |
| // |
| // <-----our 16bits float-------> |
| // s e e e e e e e e f f f f f f f f f f f f f f f f f f f f f f f |
| // <------------------------------float--------------------------> |
| // 3 3 2 2 1 1 0 |
| // 1 0 3 2 5 4 0 |
| // |
| // |
| // This type only supports conversion back and forth with float. |
| // |
| // This file must be compilable by nvcc. |
| // |
| // The type is defined in framework/numeric_types.h. |
| |
| namespace tensorflow { |
| |
| // Conversion routines between an array of float and bfloat16 of |
| // "size". |
| void FloatToBFloat16(const float* src, bfloat16* dst, int64 size); |
| void BFloat16ToFloat(const bfloat16* src, float* dst, int64 size); |
| |
| } // namespace tensorflow |
| |
| #endif // TENSORFLOW_CORE_FRAMEWORK_BFLOAT16_H_ |