#ifndef _MATH_H
#define _MATH_H

#include <bits/inline-definition.h>

// this is a posix extension
#define M_E             2.7182818284590452354
#define M_LOG2E         1.4426950408889634074
#define M_LOG10E        0.43429448190325182765
#define M_LN2           0.69314718055994530942
#define M_LN10          2.30258509299404568402
#define M_PI            3.14159265358979323846
#define M_PI_2          1.57079632679489661923
#define M_PI_4          0.78539816339744830962
#define M_1_PI          0.31830988618379067154
#define M_2_PI          0.63661977236758134308
#define M_2_SQRTPI      1.12837916709551257390
#define M_SQRT2         1.41421356237309504880
#define M_SQRT1_2       0.70710678118654752440
#define M_PIl           3.141592653589793238462643383279502884L

// The following two definitions are from musl.
#define FP_ILOGBNAN (-1 - (int)(((unsigned)-1) >> 1))
#define FP_ILOGB0 FP_ILOGBNAN

#ifdef __cplusplus
extern "C" {
#endif

typedef double double_t;
typedef float float_t;

#define HUGE_VAL (__builtin_huge_val())
#define HUGE_VALF (__builtin_huge_valf())
#define HUGE_VALL (__builtin_huge_vall())
#define INFINITY (__builtin_inff())
#define NAN (__builtin_nanf(""))

// [C11/7.12.1 Treatment of error conditions]

#define MATH_ERRNO 1
#define MATH_ERREXCEPT 2
#define math_errhandling 3

// [C11/7.12.3 Classification macros]

// NOTE: fpclassify always returns exactly one of those constants
// However making them bitwise disjoint simplifies isfinite() etc.
#define FP_INFINITE 1
#define FP_NAN 2
#define FP_NORMAL 4
#define FP_SUBNORMAL 8
#define FP_ZERO 16

#ifndef __MLIBC_ABI_ONLY

int __fpclassify(double x);
int __fpclassifyf(float x);
int __fpclassifyl(long double x);

#define fpclassify(x) \
	(sizeof(x) == sizeof(double) ? __fpclassify(x) : \
	(sizeof(x) == sizeof(float) ? __fpclassifyf(x) : \
	(sizeof(x) == sizeof(long double) ? __fpclassifyl(x) : \
	0)))

#define isfinite(x) (fpclassify(x) & (FP_NORMAL | FP_SUBNORMAL | FP_ZERO))
#define isnan(x) (fpclassify(x) == FP_NAN)
#define isinf(x) (fpclassify(x) == FP_INFINITE)
#define isnormal(x) (fpclassify(x) == FP_NORMAL)

// FIXME: this is gcc specific
#define signbit(x) (__builtin_signbit(x))

// [C11/7.12.14 Comparison macros]
#define isunordered(x,y) (isnan((x)) ? ((void)(y),1) : isnan((y)))

__MLIBC_INLINE_DEFINITION int __mlibc_isless(double_t x, double_t y) { return !isunordered(x, y) && x < y; }
__MLIBC_INLINE_DEFINITION int __mlibc_islessf(float_t x, float_t y) { return !isunordered(x, y) && x < y; }
__MLIBC_INLINE_DEFINITION int __mlibc_islessl(long double x, long double y) { return !isunordered(x, y) && x < y; }
__MLIBC_INLINE_DEFINITION int __mlibc_islessequal(double_t x, double_t y) { return !isunordered(x, y) && x <= y; }
__MLIBC_INLINE_DEFINITION int __mlibc_islessequalf(float_t x, float_t y) { return !isunordered(x, y) && x <= y; }
__MLIBC_INLINE_DEFINITION int __mlibc_islessequall(long double x, long double y) { return !isunordered(x, y) && x <= y; }
__MLIBC_INLINE_DEFINITION int __mlibc_islessgreater(double_t x, double_t y) { return !isunordered(x, y) && x != y; }
__MLIBC_INLINE_DEFINITION int __mlibc_islessgreaterf(float_t x, float_t y) { return !isunordered(x, y) && x != y; }
__MLIBC_INLINE_DEFINITION int __mlibc_islessgreaterl(long double x, long double y) { return !isunordered(x, y) && x != y; }
__MLIBC_INLINE_DEFINITION int __mlibc_isgreater(double_t x, double_t y) { return !isunordered(x, y) && x > y; }
__MLIBC_INLINE_DEFINITION int __mlibc_isgreaterf(float_t x, float_t y) { return !isunordered(x, y) && x > y; }
__MLIBC_INLINE_DEFINITION int __mlibc_isgreaterl(long double x, long double y) { return !isunordered(x, y) && x > y; }
__MLIBC_INLINE_DEFINITION int __mlibc_isgreaterequal(double_t x, double_t y) { return !isunordered(x, y) && x >= y; }
__MLIBC_INLINE_DEFINITION int __mlibc_isgreaterequalf(float_t x, float_t y) { return !isunordered(x, y) && x >= y; }
__MLIBC_INLINE_DEFINITION int __mlibc_isgreaterequall(long double x, long double y) { return !isunordered(x, y) && x >= y; }

// TODO: We chould use _Generic here but that does not work in C++ code.
#define __MLIBC_CHOOSE_COMPARISON(x, y, p) ( \
	sizeof((x)+(y)) == sizeof(float) ? p##f(x, y) : \
	sizeof((x)+(y)) == sizeof(double) ? p(x, y) : \
	p##l(x, y) )

#define isless(x, y) __MLIBC_CHOOSE_COMPARISON(x, y, __mlibc_isless)
#define islessequal(x, y) __MLIBC_CHOOSE_COMPARISON(x, y, __mlibc_islessequal)
#define islessgreater(x, y) __MLIBC_CHOOSE_COMPARISON(x, y, __mlibc_islessgreater)
#define isgreater(x, y) __MLIBC_CHOOSE_COMPARISON(x, y, __mlibc_isgreater)
#define isgreaterequal(x, y) __MLIBC_CHOOSE_COMPARISON(x, y, __mlibc_isgreaterequal)

// this is a gnu extension
void sincos(double, double *, double *);
void sincosf(float, float *, float *);
void sincosl(long double, long double *, long double *);

double exp10(double);
float exp10f(float);
long double exp10l(long double);

double pow10(double);
float pow10f(float);
long double pow10l(long double);

// [C11/7.12.4 Trigonometric functions]

double acos(double x);
float acosf(float x);
long double acosl(long double x);

double asin(double x);
float asinf(float x);
long double asinl(long double x);

double atan(double x);
float atanf(float x);
long double atanl(long double x);

double atan2(double x, double y);
float atan2f(float x, float y);
long double atan2l(long double x, long double y);

double cos(double x);
float cosf(float x);
long double cosl(long double x);

double sin(double x);
float sinf(float x);
long double sinl(long double x);

double tan(double x);
float tanf(float x);
long double tanl(long double x);

// [C11/7.12.5 Hyperbolic functions]

double acosh(double x);
float acoshf(float x);
long double acoshl(long double x);

double asinh(double x);
float asinhf(float x);
long double asinhl(long double x);

double atanh(double x);
float atanhf(float x);
long double atanhl(long double x);

double cosh(double x);
float coshf(float x);
long double coshl(long double x);

double sinh(double x);
float sinhf(float x);
long double sinhl(long double x);

double tanh(double x);
float tanhf(float x);
long double tanhl(long double x);

// [C11/7.12.6 Exponential and logarithmic functions]

double exp(double x);
float expf(float x);
long double expl(long double x);

double exp2(double x);
float exp2f(float x);
long double exp2l(long double x);

double expm1(double x);
float expm1f(float x);
long double expm1l(long double x);

double frexp(double x, int *power);
float frexpf(float x, int *power);
long double frexpl(long double x, int *power);

int ilogb(double x);
int ilogbf(float x);
int ilogbl(long double x);

double ldexp(double x, int power);
float ldexpf(float x, int power);
long double ldexpl(long double x, int power);

double log(double x);
float logf(float x);
long double logl(long double x);

double log10(double x);
float log10f(float x);
long double log10l(long double x);

double log1p(double x);
float log1pf(float x);
long double log1pl(long double x);

double log2(double x);
float log2f(float x);
long double log2l(long double x);

double logb(double x);
float logbf(float x);
long double logbl(long double x);

double modf(double x, double *integral);
float modff(float x, float *integral);
long double modfl(long double x, long double *integral);

double scalbn(double x, int power);
float scalbnf(float x, int power);
long double scalbnl(long double x, int power);

double scalbln(double x, long power);
float scalblnf(float x, long power);
long double scalblnl(long double x, long power);

// [C11/7.12.7 Power and absolute-value functions]

double cbrt(double x);
float cbrtf(float x);
long double cbrtl(long double x);

double fabs(double x);
float fabsf(float x);
long double fabsl(long double x);

double hypot(double x, double y);
float hypotf(float x, float y);
long double hypotl(long double x, long double y);

double pow(double x, double y);
float powf(float x, float y);
long double powl(long double x, long double y);

double sqrt(double x);
float sqrtf(float x);
long double sqrtl(long double x);

// [C11/7.12.8 Error and gamma functions]

double erf(double x);
float erff(float x);
long double erfl(long double x);

double erfc(double x);
float erfcf(float x);
long double erfcl(long double x);

double lgamma(double x);
float lgammaf(float x);
long double lgammal(long double x);

double tgamma(double x);
float tgammaf(float x);
long double tgammal(long double x);

// [C11/7.12.9 Nearest integer functions]

double ceil(double x);
float ceilf(float x);
long double ceill(long double x);

double floor(double x);
float floorf(float x);
long double floorl(long double x);

double nearbyint(double x);
float nearbyintf(float x);
long double nearbyintl(long double x);

double rint(double x);
float rintf(float x);
long double rintl(long double x);

long lrint(double x);
long lrintf(float x);
long lrintl(long double x);

long long llrint(double x);
long long llrintf(float x);
long long llrintl(long double x);

double round(double x);
float roundf(float x);
long double roundl(long double x);

long lround(double x);
long lroundf(float x);
long lroundl(long double x);

long long llround(double x);
long long llroundf(float x);
long long llroundl(long double x);

double trunc(double x);
float truncf(float x);
long double truncl(long double x);

// [C11/7.12.10 Remainder functions]

double fmod(double x, double y);
float fmodf(float x, float y);
long double fmodl(long double x, long double y);

double remainder(double x, double y);
float remainderf(float x, float y);
long double remainderl(long double x, long double y);

double remquo(double x, double y, int *quotient);
float remquof(float x, float y, int *quotient);
long double remquol(long double x, long double y, int *quotient);

// [C11/7.12.11 Manipulation functions]

double copysign(double x, double sign);
float copysignf(float x, float sign);
long double copysignl(long double x, long double sign);

double nan(const char *tag);
float nanf(const char *tag);
long double nanl(const char *tag);

double nextafter(double x, double dir);
float nextafterf(float x, float dir);
long double nextafterl(long double x, long double dir);

double nexttoward(double x, long double dir);
float nexttowardf(float x, long double dir);
long double nexttowardl(long double x, long double dir);

// [C11/7.12.12 Maximum, minimum and positive difference functions]

double fdim(double x, double y);
float fdimf(float x, float y);
long double fdiml(long double x, long double y);

double fmax(double x, double y);
float fmaxf(float x, float y);
long double fmaxl(long double x, long double y);

double fmin(double x, double y);
float fminf(float x, float y);
long double fminl(long double x, long double y);

// [C11/7.12.13 Floating multiply-add]

double fma(double, double, double);
float fmaf(float, float, float);
long double fmal(long double, long double, long double);

extern int signgam;
#define __signgam signgam

// BSD floating-point classification functions - obsolete

int finite(double x);
int finitef(float x);

#endif /* !__MLIBC_ABI_ONLY */

#ifdef __cplusplus
}
#endif

#endif // _MATH_H