/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004 Stefan Farfeleder.
 * All rights reserved.
 *
 * Copyright (c) 2012 Ed Schouten <ed@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _TGMATH_H_
#define _TGMATH_H_

#include <complex.h>
#include <math.h>

/*
 * This implementation of <tgmath.h> uses the two following macros,
 * which are based on the macros described in C11 proposal N1404:
 * __tg_impl_simple(x, y, z, fnl, fn, fnf, ...)
 *      Invokes fnl() if the corresponding real type of x, y or z is long
 *      double, fn() if it is double or any has an integer type, and fnf()
 *      otherwise.
 * __tg_impl_full(x, y, cfnl, cfn, cfnf, fnl, fn, fnf, ...)
 *      Invokes [c]fnl() if the corresponding real type of x or y is long
 *      double, [c]fn() if it is double or any has an integer type, and
 *      [c]fnf() otherwise.  The function with the 'c' prefix is called if
 *      any of x or y is a complex number.
 * Both macros call the chosen function with all additional arguments passed
 * to them, as given by __VA_ARGS__.
 *
 * Note that these macros cannot be implemented with C's ?: operator,
 * because the return type of the whole expression would incorrectly be long
 * double complex regardless of the argument types.
 *
 * The structure of the C11 implementation of these macros can in
 * principle be reused for non-C11 compilers, but due to an integer
 * promotion bug for complex types in GCC 4.2, simply let non-C11
 * compilers use an inefficient yet reliable version.
 */

#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \
    __has_extension(c_generic_selections)
#define __tg_generic(x, cfnl, cfn, cfnf, fnl, fn, fnf)                  \
        _Generic(x,                                                     \
                long double _Complex: cfnl,                             \
                double _Complex: cfn,                                   \
                float _Complex: cfnf,                                   \
                long double: fnl,                                       \
                default: fn,                                            \
                float: fnf                                              \
        )
#define __tg_type(x)                                                    \
        __tg_generic(x, (long double _Complex)0, (double _Complex)0,    \
            (float _Complex)0, (long double)0, (double)0, (float)0)
#define __tg_impl_simple(x, y, z, fnl, fn, fnf, ...)                    \
        __tg_generic(                                                   \
            __tg_type(x) + __tg_type(y) + __tg_type(z),                 \
            fnl, fn, fnf, fnl, fn, fnf)(__VA_ARGS__)
#define __tg_impl_full(x, y, cfnl, cfn, cfnf, fnl, fn, fnf, ...)        \
        __tg_generic(                                                   \
            __tg_type(x) + __tg_type(y),                                \
            cfnl, cfn, cfnf, fnl, fn, fnf)(__VA_ARGS__)
#elif defined(__generic)
#define __tg_generic_simple(x, fnl, fn, fnf)                            \
        __generic(x, long double _Complex, fnl,                         \
            __generic(x, double _Complex, fn,                           \
                __generic(x, float _Complex, fnf,                       \
                    __generic(x, long double, fnl,                      \
                        __generic(x, float, fnf, fn)))))
#define __tg_impl_simple(x, y, z, fnl, fn, fnf, ...)                    \
        __tg_generic_simple(x,                                          \
            __tg_generic_simple(y,                                      \
                __tg_generic_simple(z, fnl, fnl, fnl),                  \
                __tg_generic_simple(z, fnl, fnl, fnl),                  \
                __tg_generic_simple(z, fnl, fnl, fnl)),                 \
            __tg_generic_simple(y,                                      \
                __tg_generic_simple(z, fnl, fnl, fnl),                  \
                __tg_generic_simple(z, fnl, fn , fn ),                  \
                __tg_generic_simple(z, fnl, fn , fn )),                 \
            __tg_generic_simple(y,                                      \
                __tg_generic_simple(z, fnl, fnl, fnl),                  \
                __tg_generic_simple(z, fnl, fn , fn ),                  \
                __tg_generic_simple(z, fnl, fn , fnf)))(__VA_ARGS__)
#define __tg_generic_full(x, cfnl, cfn, cfnf, fnl, fn, fnf)             \
        __generic(x, long double _Complex, cfnl,                        \
            __generic(x, double _Complex, cfn,                          \
                __generic(x, float _Complex, cfnf,                      \
                    __generic(x, long double, fnl,                      \
                        __generic(x, float, fnf, fn)))))
#define __tg_impl_full(x, y, cfnl, cfn, cfnf, fnl, fn, fnf, ...)        \
        __tg_generic_full(x,                                            \
            __tg_generic_full(y, cfnl, cfnl, cfnl, cfnl, cfnl, cfnl),   \
            __tg_generic_full(y, cfnl, cfn , cfn , cfnl, cfn , cfn ),   \
            __tg_generic_full(y, cfnl, cfn , cfnf, cfnl, cfn , cfnf),   \
            __tg_generic_full(y, cfnl, cfnl, cfnl, fnl , fnl , fnl ),   \
            __tg_generic_full(y, cfnl, cfn , cfn , fnl , fn  , fn  ),   \
            __tg_generic_full(y, cfnl, cfn , cfnf, fnl , fn  , fnf ))   \
            (__VA_ARGS__)
#else
#error "<tgmath.h> not implemented for this compiler"
#endif

/* Macros to save lots of repetition below */
#define __tg_simple(x, fn)                                              \
        __tg_impl_simple(x, x, x, fn##l, fn, fn##f, x)
#define __tg_simple2(x, y, fn)                                          \
        __tg_impl_simple(x, x, y, fn##l, fn, fn##f, x, y)
#define __tg_simple3(x, y, z, fn)                                       \
        __tg_impl_simple(x, y, z, fn##l, fn, fn##f, x, y, z)
#define __tg_simplev(x, fn, ...)                                        \
        __tg_impl_simple(x, x, x, fn##l, fn, fn##f, __VA_ARGS__)
#define __tg_full(x, fn)                                                \
        __tg_impl_full(x, x, c##fn##l, c##fn, c##fn##f, fn##l, fn, fn##f, x)
#define __tg_full2(x, y, fn)                                            \
        __tg_impl_full(x, y, c##fn##l, c##fn, c##fn##f, fn##l, fn, fn##f, x, y)

/* 7.22#4 -- These macros expand to real or complex functions, depending on
 * the type of their arguments. */
#define acos(x)         __tg_full(x, acos)
#define asin(x)         __tg_full(x, asin)
#define atan(x)         __tg_full(x, atan)
#define acosh(x)        __tg_full(x, acosh)
#define asinh(x)        __tg_full(x, asinh)
#define atanh(x)        __tg_full(x, atanh)
#define cos(x)          __tg_full(x, cos)
#define sin(x)          __tg_full(x, sin)
#define tan(x)          __tg_full(x, tan)
#define cosh(x)         __tg_full(x, cosh)
#define sinh(x)         __tg_full(x, sinh)
#define tanh(x)         __tg_full(x, tanh)
#define exp(x)          __tg_full(x, exp)
#define log(x)          __tg_full(x, log)
#define pow(x, y)       __tg_full2(x, y, pow)
#define sqrt(x)         __tg_full(x, sqrt)

/* "The corresponding type-generic macro for fabs and cabs is fabs." */
#define fabs(x)         __tg_impl_full(x, x, cabsl, cabs, cabsf,        \
                            fabsl, fabs, fabsf, x)

/* 7.22#5 -- These macros are only defined for arguments with real type. */
#define atan2(x, y)     __tg_simple2(x, y, atan2)
#define cbrt(x)         __tg_simple(x, cbrt)
#define ceil(x)         __tg_simple(x, ceil)
#define copysign(x, y)  __tg_simple2(x, y, copysign)
#define erf(x)          __tg_simple(x, erf)
#define erfc(x)         __tg_simple(x, erfc)
#define exp2(x)         __tg_simple(x, exp2)
#define expm1(x)        __tg_simple(x, expm1)
#define fdim(x, y)      __tg_simple2(x, y, fdim)
#define floor(x)        __tg_simple(x, floor)
#define fma(x, y, z)    __tg_simple3(x, y, z, fma)
#define fmax(x, y)      __tg_simple2(x, y, fmax)
#define fmin(x, y)      __tg_simple2(x, y, fmin)
#define fmod(x, y)      __tg_simple2(x, y, fmod)
#define frexp(x, y)     __tg_simplev(x, frexp, x, y)
#define hypot(x, y)     __tg_simple2(x, y, hypot)
#define ilogb(x)        __tg_simple(x, ilogb)
#define ldexp(x, y)     __tg_simplev(x, ldexp, x, y)
#define lgamma(x)       __tg_simple(x, lgamma)
#define llrint(x)       __tg_simple(x, llrint)
#define llround(x)      __tg_simple(x, llround)
#define log10(x)        __tg_simple(x, log10)
#define log1p(x)        __tg_simple(x, log1p)
#define log2(x)         __tg_simple(x, log2)
#define logb(x)         __tg_simple(x, logb)
#define lrint(x)        __tg_simple(x, lrint)
#define lround(x)       __tg_simple(x, lround)
#define nearbyint(x)    __tg_simple(x, nearbyint)
#define nextafter(x, y) __tg_simple2(x, y, nextafter)
#define nexttoward(x, y) __tg_simplev(x, nexttoward, x, y)
#define remainder(x, y) __tg_simple2(x, y, remainder)
#define remquo(x, y, z) __tg_impl_simple(x, x, y, remquol, remquo,      \
                            remquof, x, y, z)
#define rint(x)         __tg_simple(x, rint)
#define round(x)        __tg_simple(x, round)
#define scalbn(x, y)    __tg_simplev(x, scalbn, x, y)
#define scalbln(x, y)   __tg_simplev(x, scalbln, x, y)
#define tgamma(x)       __tg_simple(x, tgamma)
#define trunc(x)        __tg_simple(x, trunc)

/* 7.22#6 -- These macros always expand to complex functions. */
#define carg(x)         __tg_simple(x, carg)
#define cimag(x)        __tg_simple(x, cimag)
#define conj(x)         __tg_simple(x, conj)
#define cproj(x)        __tg_simple(x, cproj)
#define creal(x)        __tg_simple(x, creal)

#endif /* !_TGMATH_H_ */