float16.cpp

// Copyright (C) 2018-2023 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
//

#include "ngraph/type/float16.hpp"

#include <climits>
#include <random>

#include "gtest/gtest.h"
#include "ngraph/runtime/aligned_buffer.hpp"
#include "util/float_util.hpp"

using namespace std;
using namespace ngraph;

TEST(float16, conversions) {
    float16 f16;
    const char* source_string;
    std::string f16_string;

    // 1.f
    source_string = "0  01111  00 0000 0000";
    f16 = test::bits_to_float16(source_string);
    EXPECT_EQ(f16, float16(1.0));
    f16_string = test::float16_to_bits(f16);
    EXPECT_STREQ(source_string, f16_string.c_str());
    EXPECT_EQ(static_cast<float>(f16), 1.0);

    // -1.f
    source_string = "1  01111  00 0000 0000";
    f16 = test::bits_to_float16(source_string);
    EXPECT_EQ(f16, float16(-1.0));
    f16_string = test::float16_to_bits(f16);
    EXPECT_STREQ(source_string, f16_string.c_str());
    EXPECT_EQ(static_cast<float>(f16), -1.0);

    // 0.f
    source_string = "0  00000  00 0000 0000";
    f16 = test::bits_to_float16(source_string);
    EXPECT_EQ(f16, float16(0.0));
    f16_string = test::float16_to_bits(f16);
    EXPECT_STREQ(source_string, f16_string.c_str());
    EXPECT_EQ(static_cast<float>(f16), 0.0);

    // 1.5f
    source_string = "0  01111  10 0000 0000";
    f16 = test::bits_to_float16(source_string);
    EXPECT_EQ(f16, float16(1.5));
    f16_string = test::float16_to_bits(f16);
    EXPECT_STREQ(source_string, f16_string.c_str());
    EXPECT_EQ(static_cast<float>(f16), 1.5);
}

TEST(float16, assigns) {
    float16 f16;
    f16 = 2.0;
    EXPECT_EQ(f16, float16(2.0));

    std::vector<float> f32vec{1.0, 2.0, 4.0};
    std::vector<float16> f16vec;
    std::copy(f32vec.begin(), f32vec.end(), std::back_inserter(f16vec));
    for (size_t i = 0; i < f32vec.size(); ++i) {
        EXPECT_EQ(f32vec.at(i), f16vec.at(i));
    }

    float f32arr[] = {1.0, 2.0, 4.0};
    float16 f16arr[sizeof(f32arr)];
    for (size_t i = 0; i < sizeof(f32arr) / sizeof(f32arr[0]); ++i) {
        f16arr[i] = f32arr[i];
        EXPECT_EQ(f32arr[i], f16arr[i]);
    }
}

TEST(float16, values) {
    EXPECT_EQ(static_cast<float16>(test::FloatUnion(0, 112 - 8, (1 << 21) + 0).f).to_bits(),
              float16(0, 0, 2).to_bits());
    EXPECT_EQ(static_cast<float16>(test::FloatUnion(0, 112 - 8, (1 << 21) + 1).f).to_bits(),
              float16(0, 0, 3).to_bits());
    EXPECT_EQ(static_cast<float16>(1.0 / (256.0 * 65536.0)).to_bits(), float16(0, 0, 1).to_bits());
    EXPECT_EQ(static_cast<float16>(1.5 / (256.0 * 65536.0)).to_bits(), float16(0, 0, 2).to_bits());
    EXPECT_EQ(static_cast<float16>(1.25 / (256.0 * 65536.0)).to_bits(), float16(0, 0, 1).to_bits());
    EXPECT_EQ(static_cast<float16>(1.0 / (128.0 * 65536.0)).to_bits(), float16(0, 0, 2).to_bits());
    EXPECT_EQ(static_cast<float16>(1.5 / (128.0 * 65536.0)).to_bits(), float16(0, 0, 3).to_bits());
    EXPECT_EQ(static_cast<float16>(1.25 / (128.0 * 65536.0)).to_bits(), float16(0, 0, 2).to_bits());
    EXPECT_EQ(static_cast<float16>(std::numeric_limits<float>::infinity()).to_bits(), float16(0, 0x1F, 0).to_bits());
    EXPECT_EQ(static_cast<float16>(-std::numeric_limits<float>::infinity()).to_bits(), float16(1, 0x1F, 0).to_bits());
    EXPECT_TRUE(isnan(static_cast<float16>(std::numeric_limits<float>::quiet_NaN())));
    EXPECT_TRUE(isnan(static_cast<float16>(std::numeric_limits<float>::signaling_NaN())));
    EXPECT_EQ(static_cast<float16>(2.73786e-05).to_bits(), 459);
    EXPECT_EQ(static_cast<float16>(3.87722e-05).to_bits(), 650);
    EXPECT_EQ(static_cast<float16>(-0.0223043).to_bits(), 42422);
    EXPECT_EQ(static_cast<float16>(5.10779e-05).to_bits(), 857);
    EXPECT_EQ(static_cast<float16>(-5.10779e-05).to_bits(), 0x8359);
    EXPECT_EQ(static_cast<float16>(-2.553895e-05).to_bits(), 0x81ac);
    EXPECT_EQ(static_cast<float16>(-0.0001021558).to_bits(), 0x86b2);
    EXPECT_EQ(static_cast<float16>(5.960464477539063e-08).to_bits(), 0x01);
    EXPECT_EQ(static_cast<float16>(8.940696716308594e-08).to_bits(), 0x02);
    EXPECT_EQ(static_cast<float16>(65536.0).to_bits(), 0x7c00);
    EXPECT_EQ(static_cast<float16>(65519.0).to_bits(), 0x7bff);
    EXPECT_EQ(static_cast<float16>(65520.0).to_bits(), 0x7c00);
}