Home | History | Annotate | Download | only in core 
      1 /* Copyright 2015 The TensorFlow Authors. All Rights Reserved.
      2 
      3 Licensed under the Apache License, Version 2.0 (the "License");
      4 you may not use this file except in compliance with the License.
      5 You may obtain a copy of the License at
      6 
      7     http://www.apache.org/licenses/LICENSE-2.0
      8 
      9 Unless required by applicable law or agreed to in writing, software
     10 distributed under the License is distributed on an "AS IS" BASIS,
     11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     12 See the License for the specific language governing permissions and
     13 limitations under the License.
     14 ==============================================================================*/
     15 
     16 #ifndef TENSORFLOW_LIB_CORE_RAW_CODING_H_
     17 #define TENSORFLOW_LIB_CORE_RAW_CODING_H_
     18 
     19 #include <string.h>
     20 #include "tensorflow/core/platform/cpu_info.h"
     21 #include "tensorflow/core/platform/types.h"
     22 
     23 namespace tensorflow {
     24 namespace core {
     25 
     26 // Lower-level versions of Get... that read directly from a character buffer
     27 // without any bounds checking.
     28 
     29 inline uint16 DecodeFixed16(const char* ptr) {
     30   if (port::kLittleEndian) {
     31     // Load the raw bytes
     32     uint16 result;
     33     memcpy(&result, ptr, sizeof(result));  // gcc optimizes this to a plain load
     34     return result;
     35   } else {
     36     return ((static_cast<uint16>(static_cast<unsigned char>(ptr[0]))) |
     37             (static_cast<uint16>(static_cast<unsigned char>(ptr[1])) << 8));
     38   }
     39 }
     40 
     41 inline uint32 DecodeFixed32(const char* ptr) {
     42   if (port::kLittleEndian) {
     43     // Load the raw bytes
     44     uint32 result;
     45     memcpy(&result, ptr, sizeof(result));  // gcc optimizes this to a plain load
     46     return result;
     47   } else {
     48     return ((static_cast<uint32>(static_cast<unsigned char>(ptr[0]))) |
     49             (static_cast<uint32>(static_cast<unsigned char>(ptr[1])) << 8) |
     50             (static_cast<uint32>(static_cast<unsigned char>(ptr[2])) << 16) |
     51             (static_cast<uint32>(static_cast<unsigned char>(ptr[3])) << 24));
     52   }
     53 }
     54 
     55 inline uint64 DecodeFixed64(const char* ptr) {
     56   if (port::kLittleEndian) {
     57     // Load the raw bytes
     58     uint64 result;
     59     memcpy(&result, ptr, sizeof(result));  // gcc optimizes this to a plain load
     60     return result;
     61   } else {
     62     uint64 lo = DecodeFixed32(ptr);
     63     uint64 hi = DecodeFixed32(ptr + 4);
     64     return (hi << 32) | lo;
     65   }
     66 }
     67 
     68 }  // namespace core
     69 }  // namespace tensorflow
     70 
     71 #endif  // TENSORFLOW_LIB_CORE_RAW_CODING_H_
     72