float16_t is a header only c++ library for half-precision floating-point format.
include the header file
#include "float16_t.hpp"
using numeric::float16_t;then compile using a C++17 compatible compiler with command line like:
clang++ -c -std=c++17 -Wall -Wextra -ferror-limit=1 -ftemplate-backtrace-limit=0 -funsafe-math-optimizations -Ofast -flto -pipe -march=native -DDEBUG -o ./obj/test_test.o tests/test.cc
if you do not want to dump binary information, you can ommit the -DDEBUG option.
Example code:
float16_t f = 1.1f;
{
std::cout << "f =" << f << std::endl;
std::cout << "float(f) =" << float(f) << std::endl;
std::cout << "f++ =" << f++ << std::endl;
std::cout << "++f =" << ++f << std::endl;
std::cout << "f-- =" << f-- << std::endl;
std::cout << "--f =" << --f << std::endl;
}
this produces
f =1.09961(0 01111 0001100110)
float(f) =1.09961
f++ =1.09961(0 01111 0001100110)
++f =3.09961(0 10000 1000110011)
f-- =3.09961(0 10000 1000110011)
--f =1.09961(0 01111 0001100110)
And
float16_t g = -1.3f;
{
std::cout << "f+g = " << f+g << std::endl;
std::cout << "f-g = " << f-g << std::endl;
std::cout << "f*g = " << f*g << std::endl;
std::cout << "f/g = " << f/g << std::endl;
}
produces
f+g = -0.200195(1 01100 1001101000)
f-g = 2.39844(0 10000 0011001100)
f*g = -1.42969(1 01111 0110111000)
f/g = -0.846191(1 01110 1011000101)
Moreover,
float16_t h = 0.27f;
{
std::cout << "numeric::sin(h) = " << numeric::sin(h) << std::endl;
std::cout << "numeric::cos(h) = " << numeric::cos(h) << std::endl;
std::cout << "numeric::sqrt(h) = " << numeric::sqrt(h) << std::endl;
std::cout << "numeric::cbrt(h) = " << numeric::cbrt(h) << std::endl;
}
produces
numeric::sin(h) = 0.266846(0 01101 0001000101)
numeric::cos(h) = 0.963867(0 01110 1110110110)
numeric::sqrt(h) = 0.519531(0 01110 0000101000)
numeric::cbrt(h) = 0.646484(0 01110 0100101100)
There are also some predefined constants:
using namespace numeric;
std::cout << "fp16_infinity:\t" << fp16_infinity << std::endl;
std::cout << "fp16_max:\t" << fp16_max << std::endl;
std::cout << "fp16_max_subnormal:\t" << fp16_max_subnormal << std::endl;
std::cout << "fp16_min:\t" << fp16_min << std::endl;
std::cout << "fp16_min_positive:\t" << fp16_min_positive << std::endl;
std::cout << "fp16_min_positive_subnormal:\t" << fp16_min_positive_subnormal << std::endl;
std::cout << "fp16_nan:\t" << fp16_nan << std::endl;
std::cout << "fp16_infinity_negative:\t" << fp16_infinity_negative << std::endl;
std::cout << "fp16_one:\t" << fp16_one << std::endl;
std::cout << "fp16_zero:\t" << fp16_zero << std::endl;
std::cout << "fp16_zero_negative:\t" << fp16_zero_negative << std::endl;
std::cout << "fp16_e:\t" << fp16_e << std::endl;
std::cout << "fp16_pi:\t" << fp16_pi << std::endl;
std::cout << "NAN:\t" << float16_t{std::numeric_limits<float>::quiet_NaN()} << std::endl;produces (debug mode):
fp16_infinity: inf[0x7c00](0 11111 0000000000)
fp16_max: 6.550400e+04[0x7bff](0 11110 1111111111)
fp16_max_subnormal: 6.097555e-05[0x3ff](0 00000 1111111111)
fp16_min: -6.550400e+04[0xfbff](1 11110 1111111111)
fp16_min_positive: 6.103516e-05[0x400](0 00001 0000000000)
fp16_min_positive_subnormal: 5.960464e-08[0x1](0 00000 0000000001)
fp16_nan: nan[0x7e00](0 11111 1000000000)
fp16_infinity_negative: -inf[0xfc00](1 11111 0000000000)
fp16_one: 1.000000e+00[0x3c00](0 01111 0000000000)
fp16_zero: 0.000000e+00[0x0](0 00000 0000000000)
fp16_zero_negative: -0.000000e+00[0x8000](1 00000 0000000000)
fp16_e: 2.718750e+00[0x4170](0 10000 0101110000)
fp16_pi: 3.140625e+00[0x4248](0 10000 1001001000)
E: 2.718750e+00[0x4170](0 10000 0101110000)
PI: 3.140625e+00[0x4248](0 10000 1001001000)
NAN: nan[0x7e00](0 11111 1000000000)
one: 1.000000e+00[0x3c00](0 01111 0000000000)
neg one: -1.000000e+00[0xbc00](1 01111 0000000000)
Also numeric::float16_t supports std::numeric_limits. For example:
using numeric::float16_t;
std::cout
<< std::numeric_limits<float16_t>::lowest() << '\t'
<< std::numeric_limits<float16_t>::min() << '\t'
<< std::numeric_limits<float16_t>::max() << '\n';produces -6.550400e+04 6.103516e-05 6.550400e+04
For more information, please check out the source file float16_t.hpp.
BSD License