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