Program Listing for File RangeCastImpl.hpp
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/*
* SPDX-FileCopyrightText: Copyright (c) 2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*/
#ifndef NVCV_CUDA_DETAIL_RANGE_CAST_IMPL_HPP
#define NVCV_CUDA_DETAIL_RANGE_CAST_IMPL_HPP
// Internal implementation of range cast functionality.
// Not to be used directly.
#include "MathWrappersImpl.hpp" // for RoundImpl, etc.
#include "Metaprogramming.hpp" // for TypeTraits, etc.
#include "SaturateCastImpl.hpp" // for BaseSaturateImpl, etc.
namespace nvcv::cuda::detail {
template<typename T, typename U>
inline __host__ __device__ T RangeCastImpl(U u)
{
if constexpr (std::is_floating_point_v<U> && std::is_floating_point_v<T> && sizeof(U) > sizeof(T))
{
// any-float -> any-float, big -> small
return u <= -TypeTraits<T>::max ? -TypeTraits<T>::max
: (u >= TypeTraits<T>::max ? TypeTraits<T>::max : static_cast<T>(u));
}
else if constexpr (std::is_floating_point_v<U> && std::is_integral_v<T> && std::is_signed_v<T>)
{
// any-float -> any-integral-signed
return u >= U{1} ? TypeTraits<T>::max
: (u <= U{-1} ? -TypeTraits<T>::max : RoundImpl<T, U>(TypeTraits<T>::max * u));
}
else if constexpr (std::is_integral_v<U> && std::is_signed_v<U> && std::is_floating_point_v<T>)
{
// any-integral-signed -> any-float
constexpr T invmax = T{1} / TypeTraits<U>::max;
T out = static_cast<T>(u) * invmax;
return out < T{-1} ? T{-1} : out;
}
else if constexpr (std::is_floating_point_v<U> && std::is_integral_v<T> && std::is_unsigned_v<T>)
{
// any-float -> any-integral-unsigned
return u >= U{1} ? TypeTraits<T>::max : (u <= U{0} ? T{0} : RoundImpl<T, U>(TypeTraits<T>::max * u));
}
else if constexpr (std::is_integral_v<U> && std::is_unsigned_v<U> && std::is_floating_point_v<T>)
{
// any-integral-unsigned -> any-float
constexpr T invmax = T{1} / TypeTraits<U>::max;
return static_cast<T>(u) * invmax;
}
else if constexpr (std::is_integral_v<U> && std::is_integral_v<T>)
{
// any-integral -> any-integral, range cast reduces to saturate cast
return BaseSaturateCastImpl<T, U>(u);
}
else
{
// any-float -> any-float, small -> big and equal, range cast reduces to none
return u;
}
}
} // namespace nvcv::cuda::detail
#endif // NVCV_CUDA_DETAIL_RANGE_CAST_IMPL_HPP