bfloat16_test.cu

/* Copyright (c) 2021 PaddlePaddle 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. */

#include "paddle/fluid/platform/bfloat16.h"

#define GLOG_NO_ABBREVIATED_SEVERITIES  // msvc conflict logging with windows.h
#include <glog/logging.h>
#include <gtest/gtest.h>
#include <iostream>
#include "paddle/fluid/framework/lod_tensor.h"

#if defined(PADDLE_CUDA_BF16)
namespace paddle {
namespace platform {

TEST(bfloat16, convert_float32_to_bfloat16_on_gpu) {
  // Convert float32 to bfloat16
  EXPECT_EQ((bfloat16(1.0f)).x, 0x3f80);
  EXPECT_EQ((bfloat16(0.5f)).x, 0x3f00);
  EXPECT_EQ((bfloat16(0.33333f)).x, 0x3eab);
  EXPECT_EQ((bfloat16(0.0f)).x, 0x0000);
  EXPECT_EQ((bfloat16(-0.0f)).x, 0x8000);
  EXPECT_EQ((bfloat16(65536.0f)).x, 0x4780);
}

TEST(bfloat16, assignment_operator_on_gpu) {
  // Assignment operator
  bfloat16 v_assign;
  v_assign = nv_bfloat16(bfloat16(1.0f));
  EXPECT_EQ(v_assign.x, 0x3f80);
  v_assign = 0.33333;
  EXPECT_EQ(v_assign.x, 0x3eab);
}

TEST(bfloat16, convert_bfloat16_to_float32_on_gpu) {
  // Conversion operator
  EXPECT_EQ(static_cast<float>(bfloat16(0.5f)), 0.5f);
  EXPECT_NEAR(static_cast<double>(bfloat16(0.33333)), 0.33333, 0.01);
  EXPECT_EQ(static_cast<int>(bfloat16(-1)), -1);
  EXPECT_EQ(static_cast<bool>(bfloat16(true)), true);
}

TEST(bfloat16, lod_tensor_on_gpu) {
  framework::LoDTensor src_tensor;
  framework::LoDTensor gpu_tensor;
  framework::LoDTensor dst_tensor;

  bfloat16 *src_ptr = src_tensor.mutable_data<bfloat16>(
      framework::make_ddim({2, 2}), CPUPlace());

  bfloat16 arr[4] = {bfloat16(1.0f), bfloat16(0.5f), bfloat16(0.33333f),
                     bfloat16(0.0f)};
  memcpy(src_ptr, arr, 4 * sizeof(bfloat16));

  // CPU LoDTensor to GPU LoDTensor
  CUDAPlace gpu_place(0);
  CUDADeviceContext gpu_ctx(gpu_place);
  framework::TensorCopy(src_tensor, gpu_place, gpu_ctx, &gpu_tensor);

  // GPU LoDTensor to CPU LoDTensor
  framework::TensorCopy(gpu_tensor, CPUPlace(), gpu_ctx, &dst_tensor);

  // Sync before comparing LoDTensors
  gpu_ctx.Wait();
  const bfloat16 *dst_ptr = dst_tensor.data<bfloat16>();
  ASSERT_NE(src_ptr, dst_ptr);
  for (size_t i = 0; i < 4; ++i) {
    EXPECT_EQ(src_ptr[i].x, dst_ptr[i].x);
  }
}

TEST(bfloat16, isinf) {
  bfloat16 a;
  a.x = 0x7f80;
  bfloat16 b = bfloat16(INFINITY);
  bfloat16 c = static_cast<bfloat16>(INFINITY);
  EXPECT_EQ(std::isinf(a), true);
  EXPECT_EQ(std::isinf(b), true);
  EXPECT_EQ(std::isinf(c), true);
}

TEST(bfloat16, isnan) {
  bfloat16 a;
  a.x = 0x7fff;
  bfloat16 b = bfloat16(NAN);
  bfloat16 c = static_cast<bfloat16>(NAN);
  EXPECT_EQ(std::isnan(a), true);
  EXPECT_EQ(std::isnan(b), true);
  EXPECT_EQ(std::isnan(c), true);
}

TEST(bfloat16, cast) {
  bfloat16 a;
  a.x = 0x0070;
  auto b = a;
  {
    // change semantic, keep the same value
    bfloat16 c = reinterpret_cast<bfloat16 &>(reinterpret_cast<unsigned &>(b));
    EXPECT_EQ(b, c);
  }

  {
    // use uint32 low 16 bit store float16
    uint32_t c = reinterpret_cast<uint32_t &>(b);
    bfloat16 d;
    d.x = c;
    EXPECT_EQ(b, d);
  }
}

}  // namespace platform
}  // namespace paddle
#endif