libm.h

/* origin: FreeBSD /usr/src/lib/msun/src/math_private.h */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#ifndef _LIBM_H
#define _LIBM_H

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <stdint.h>
#include <float.h>
#include <math.h>
#include <complex.h>
#include <endian.h>

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __LITTLE_ENDIAN
union ldshape {
	long double f;
	struct {
		uint64_t m;
		uint16_t se;
	} i;
};
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __LITTLE_ENDIAN
union ldshape {
	long double f;
	struct {
		uint64_t lo;
		uint32_t mid;
		uint16_t top;
		uint16_t se;
	} i;
	struct {
		uint64_t lo;
		uint64_t hi;
	} i2;
};
#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 && __BYTE_ORDER == __BIG_ENDIAN
union ldshape {
	long double f;
	struct {
		uint16_t se;
		uint16_t top;
		uint32_t mid;
		uint64_t lo;
	} i;
	struct {
		uint64_t hi;
		uint64_t lo;
	} i2;
};
#else
#error Unsupported long double representation
#endif

#define FORCE_EVAL(x) do {                        \
	if (sizeof(x) == sizeof(float)) {         \
		volatile float __x;               \
		__x = (x);                        \
	} else if (sizeof(x) == sizeof(double)) { \
		volatile double __x;              \
		__x = (x);                        \
	} else {                                  \
		volatile long double __x;         \
		__x = (x);                        \
	}                                         \
} while(0)

/* Get two 32 bit ints from a double.  */
#define EXTRACT_WORDS(hi,lo,d)                    \
do {                                              \
  union {double f; uint64_t i;} __u;              \
  __u.f = (d);                                    \
  (hi) = __u.i >> 32;                             \
  (lo) = (uint32_t)__u.i;                         \
} while (0)

/* Get the more significant 32 bit int from a double.  */
#define GET_HIGH_WORD(hi,d)                       \
do {                                              \
  union {double f; uint64_t i;} __u;              \
  __u.f = (d);                                    \
  (hi) = __u.i >> 32;                             \
} while (0)

/* Get the less significant 32 bit int from a double.  */
#define GET_LOW_WORD(lo,d)                        \
do {                                              \
  union {double f; uint64_t i;} __u;              \
  __u.f = (d);                                    \
  (lo) = (uint32_t)__u.i;                         \
} while (0)

/* Set a double from two 32 bit ints.  */
#define INSERT_WORDS(d,hi,lo)                     \
do {                                              \
  union {double f; uint64_t i;} __u;              \
  __u.i = ((uint64_t)(hi)<<32) | (uint32_t)(lo);  \
  (d) = __u.f;                                    \
} while (0)

/* Set the more significant 32 bits of a double from an int.  */
#define SET_HIGH_WORD(d,hi)                       \
do {                                              \
  union {double f; uint64_t i;} __u;              \
  __u.f = (d);                                    \
  __u.i &= 0xffffffff;                            \
  __u.i |= (uint64_t)(hi) << 32;                  \
  (d) = __u.f;                                    \
} while (0)

/* Set the less significant 32 bits of a double from an int.  */
#define SET_LOW_WORD(d,lo)                        \
do {                                              \
  union {double f; uint64_t i;} __u;              \
  __u.f = (d);                                    \
  __u.i &= 0xffffffff00000000ull;                 \
  __u.i |= (uint32_t)(lo);                        \
  (d) = __u.f;                                    \
} while (0)

/* Get a 32 bit int from a float.  */
#define GET_FLOAT_WORD(w,d)                       \
do {                                              \
  union {float f; uint32_t i;} __u;               \
  __u.f = (d);                                    \
  (w) = __u.i;                                    \
} while (0)

/* Set a float from a 32 bit int.  */
#define SET_FLOAT_WORD(d,w)                       \
do {                                              \
  union {float f; uint32_t i;} __u;               \
  __u.i = (w);                                    \
  (d) = __u.f;                                    \
} while (0)

#undef __CMPLX
#undef CMPLX
#undef CMPLXF
#undef CMPLXL

#define __CMPLX(x, y, t) \
	((union { _Complex t __z; t __xy[2]; }){.__xy = {(x),(y)}}.__z)

#define CMPLX(x, y) __CMPLX(x, y, double)
#define CMPLXF(x, y) __CMPLX(x, y, float)
#define CMPLXL(x, y) __CMPLX(x, y, long double)

/* fdlibm kernel functions */

int    __rem_pio2_large(double*,double*,int,int,int);

int    __rem_pio2(double,double*);
double __sin(double,double,int);
double __cos(double,double);
double __tan(double,double,int);
double __expo2(double);
double complex __ldexp_cexp(double complex,int);

int    __rem_pio2f(float,double*);
float  __sindf(double);
float  __cosdf(double);
float  __tandf(double,int);
float  __expo2f(float);
float complex __ldexp_cexpf(float complex,int);

int __rem_pio2l(long double, long double *);
long double __sinl(long double, long double, int);
long double __cosl(long double, long double);
long double __tanl(long double, long double, int);

/* polynomial evaluation */
long double __polevll(long double, const long double *, int);
long double __p1evll(long double, const long double *, int);

#endif