xref: /aosp_15_r20/external/tensorflow/tensorflow/lite/delegates/gpu/gl/float16_conversions.cc (revision b6fb3261f9314811a0f4371741dbb8839866f948)
1 /* Copyright 2019 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 #include "tensorflow/lite/delegates/gpu/gl/float16_conversions.h"
17 
18 #include <cstdint>
19 #include <variant>
20 #include <vector>
21 
22 #include "fp16.h"  // from @FP16
23 #include "absl/types/variant.h"
24 #include "tensorflow/lite/delegates/gpu/common/data_type.h"
25 #include "tensorflow/lite/delegates/gpu/common/tensor.h"
26 
27 namespace tflite {
28 namespace gpu {
29 namespace gl {
30 namespace {
31 
32 // Performs in-place conversion of float32 into float16
ToFloat16(std::vector<uint8_t> * values)33 bool ToFloat16(std::vector<uint8_t>* values) {
34   if (values->size() % sizeof(float) != 0) {
35     return false;
36   }
37 
38   uint16_t* store_f16 = reinterpret_cast<uint16_t*>(values->data());
39   const float* load_f32 = reinterpret_cast<const float*>(values->data());
40   const float* end_load_f32 =
41       reinterpret_cast<const float*>(values->data() + values->size());
42 
43   while (load_f32 != end_load_f32) {
44     *store_f16++ = fp16_ieee_from_fp32_value(*load_f32++);
45   }
46 
47   values->resize(values->size() / 2);
48   return true;
49 }
50 
51 struct ConverterToFloat16 {
operator ()tflite::gpu::gl::__anon916b008b0111::ConverterToFloat1652   bool operator()(ObjectData& data) const {  // NOLINT
53     return ToFloat16(&data);
54   }
55 
operator ()tflite::gpu::gl::__anon916b008b0111::ConverterToFloat1656   bool operator()(ObjectRef& buffer) const {  // NOLINT
57     return true;
58   }
59 };
60 
61 }  // namespace
62 
MaybeConvertToFloat16(Object * object)63 bool MaybeConvertToFloat16(Object* object) {
64   if (object->data_type == DataType::FLOAT32 &&
65       std::visit(ConverterToFloat16(), object->object)) {
66     object->data_type = DataType::FLOAT16;
67     return true;
68   }
69   return false;
70 }
71 
72 }  // namespace gl
73 }  // namespace gpu
74 }  // namespace tflite
75