compute_common.hpp

#pragma once

#include "setup.hpp"
#include <limits>

namespace glm{
namespace detail
{
        template<typename genFIType, bool /*signed*/>
        struct compute_abs
        {};

        template<typename genFIType>
        struct compute_abs<genFIType, true>
        {
                GLM_FUNC_QUALIFIER GLM_CONSTEXPR static genFIType call(genFIType x)
                {
                        GLM_STATIC_ASSERT(
                                std::numeric_limits<genFIType>::is_iec559 || std::numeric_limits<genFIType>::is_signed,
                                "'abs' only accept floating-point and integer scalar or vector inputs");

                        return x >= genFIType(0) ? x : -x;
                        // TODO, perf comp with: *(((int *) &x) + 1) &= 0x7fffffff;
                }
        };

#if GLM_COMPILER & GLM_COMPILER_CUDA
        template<>
        struct compute_abs<float, true>
        {
                GLM_FUNC_QUALIFIER GLM_CONSTEXPR static float call(float x)
                {
                        return fabsf(x);
                }
        };
#endif

        template<typename genFIType>
        struct compute_abs<genFIType, false>
        {
                GLM_FUNC_QUALIFIER GLM_CONSTEXPR static genFIType call(genFIType x)
                {
                        GLM_STATIC_ASSERT(
                                (!std::numeric_limits<genFIType>::is_signed && std::numeric_limits<genFIType>::is_integer),
                                "'abs' only accept floating-point and integer scalar or vector inputs");
                        return x;
                }
        };
}//namespace detail
}//namespace glm