base/math/mathP.h

Go to the documentation of this file.

/*
 * ====================================================
 * 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.
 * ====================================================
 */

/*
 * from: @(#)fdlibm.h 5.1 93/09/24
 * $Id: mathP.h,v 1.5 2008/12/10 14:41:12 ando Exp $
 */

#ifndef _MATH_PRIVATE_H_
#define _MATH_PRIVATE_H_

#include <endian.h>
#include <sys/types.h>

/* The original fdlibm code used statements like:
    n0 = ((*(int*)&one)>>29)^1;     * index of high word *
    ix0 = *(n0+(int*)&x);           * high word of x *
    ix1 = *((1-n0)+(int*)&x);       * low word of x *
   to dig two 32 bit words out of the 64 bit IEEE floating point
   value.  That is non-ANSI, and, moreover, the gcc instruction
   scheduler gets it wrong.  We instead use the following macros.
   Unlike the original code, we determine the endianness at compile
   time, not at run time; I don't see much benefit to selecting
   endianness at run time.  */

/* A union which permits us to convert between a double and two 32 bit
   ints.  */

/*
 * Math on arm is little endian except for the FP word order which is
 * big endian.
 */

#if (__BYTE_ORDER == __BIG_ENDIAN) || defined(__arm__)

typedef union 
{
  double value;
  struct 
  {
    u_int32_t msw;
    u_int32_t lsw;
  } parts;
} ieee_double_shape_type;

#endif

#if (__BYTE_ORDER == __LITTLE_ENDIAN) && !defined(__arm__)

typedef union 
{
  double value;
  struct 
  {
    u_int32_t lsw;
    u_int32_t msw;
  } parts;
} ieee_double_shape_type;

#endif

/* Get two 32 bit ints from a double.  */

#define EXTRACT_WORDS(ix0,ix1,d)                \
do {                                \
  ieee_double_shape_type ew_u;                  \
  ew_u.value = (d);                     \
  (ix0) = ew_u.parts.msw;                   \
  (ix1) = ew_u.parts.lsw;                   \
} while (0)

/* Get the more significant 32 bit int from a double.  */

#define GET_HIGH_WORD(i,d)                  \
do {                                \
  ieee_double_shape_type gh_u;                  \
  gh_u.value = (d);                     \
  (i) = gh_u.parts.msw;                     \
} while (0)

/* Get the less significant 32 bit int from a double.  */

#define GET_LOW_WORD(i,d)                   \
do {                                \
  ieee_double_shape_type gl_u;                  \
  gl_u.value = (d);                     \
  (i) = gl_u.parts.lsw;                     \
} while (0)

/* Set a double from two 32 bit ints.  */

#define INSERT_WORDS(d,ix0,ix1)                 \
do {                                \
  ieee_double_shape_type iw_u;                  \
  iw_u.parts.msw = (ix0);                   \
  iw_u.parts.lsw = (ix1);                   \
  (d) = iw_u.value;                     \
} while (0)

/* Set the more significant 32 bits of a double from an int.  */

#define SET_HIGH_WORD(d,v)                  \
do {                                \
  ieee_double_shape_type sh_u;                  \
  sh_u.value = (d);                     \
  sh_u.parts.msw = (v);                     \
  (d) = sh_u.value;                     \
} while (0)

/* Set the less significant 32 bits of a double from an int.  */

#define SET_LOW_WORD(d,v)                   \
do {                                \
  ieee_double_shape_type sl_u;                  \
  sl_u.value = (d);                     \
  sl_u.parts.lsw = (v);                     \
  (d) = sl_u.value;                     \
} while (0)

/* A union which permits us to convert between a float and a 32 bit
   int.  */

typedef union
{
  float value;
  u_int32_t word;
} ieee_float_shape_type;

/* Get a 32 bit int from a float.  */

#define GET_FLOAT_WORD(i,d)                 \
do {                                \
  ieee_float_shape_type gf_u;                   \
  gf_u.value = (d);                     \
  (i) = gf_u.word;                      \
} while (0)

/* Set a float from a 32 bit int.  */

#define SET_FLOAT_WORD(d,i)                 \
do {                                \
  ieee_float_shape_type sf_u;                   \
  sf_u.word = (i);                      \
  (d) = sf_u.value;                     \
} while (0)

/* ieee style elementary functions */
extern double __ieee754_sqrt __P((double));         
extern double __ieee754_acos __P((double));         
extern double __ieee754_acosh __P((double));            
extern double __ieee754_log __P((double));          
extern double __ieee754_atanh __P((double));            
extern double __ieee754_asin __P((double));         
extern double __ieee754_atan2 __P((double,double));         
extern double __ieee754_exp __P((double));
extern double __ieee754_cosh __P((double));
extern double __ieee754_fmod __P((double,double));
extern double __ieee754_pow __P((double,double));
extern double __ieee754_lgamma_r __P((double,int *));
extern double __ieee754_gamma_r __P((double,int *));
extern double __ieee754_lgamma __P((double));
extern double __ieee754_gamma __P((double));
extern double __ieee754_log10 __P((double));
extern double __ieee754_sinh __P((double));
extern double __ieee754_hypot __P((double,double));
extern double __ieee754_j0 __P((double));
extern double __ieee754_j1 __P((double));
extern double __ieee754_y0 __P((double));
extern double __ieee754_y1 __P((double));
extern double __ieee754_jn __P((int,double));
extern double __ieee754_yn __P((int,double));
extern double __ieee754_remainder __P((double,double));
extern int    __ieee754_rem_pio2 __P((double,double*));
#if defined(_SCALB_INT)
extern double __ieee754_scalb __P((double,int));
#else
extern double __ieee754_scalb __P((double,double));
#endif

/* fdlibm kernel function */
extern double __kernel_standard __P((double,double,int));   
extern double __kernel_sin __P((double,double,int));
extern double __kernel_cos __P((double,double));
extern double __kernel_tan __P((double,double,int));
extern int    __kernel_rem_pio2 __P((double*,double*,int,int,int,const int*));


/* ieee style elementary float functions */
extern float __ieee754_sqrtf __P((float));          
extern float __ieee754_acosf __P((float));          
extern float __ieee754_acoshf __P((float));         
extern float __ieee754_logf __P((float));           
extern float __ieee754_atanhf __P((float));         
extern float __ieee754_asinf __P((float));          
extern float __ieee754_atan2f __P((float,float));           
extern float __ieee754_expf __P((float));
extern float __ieee754_coshf __P((float));
extern float __ieee754_fmodf __P((float,float));
extern float __ieee754_powf __P((float,float));
extern float __ieee754_lgammaf_r __P((float,int *));
extern float __ieee754_gammaf_r __P((float,int *));
extern float __ieee754_lgammaf __P((float));
extern float __ieee754_gammaf __P((float));
extern float __ieee754_log10f __P((float));
extern float __ieee754_sinhf __P((float));
extern float __ieee754_hypotf __P((float,float));
extern float __ieee754_j0f __P((float));
extern float __ieee754_j1f __P((float));
extern float __ieee754_y0f __P((float));
extern float __ieee754_y1f __P((float));
extern float __ieee754_jnf __P((int,float));
extern float __ieee754_ynf __P((int,float));
extern float __ieee754_remainderf __P((float,float));
extern int   __ieee754_rem_pio2f __P((float,float*));
extern float __ieee754_scalbf __P((float,float));

/* float versions of fdlibm kernel functions */
extern float __kernel_sinf __P((float,float,int));
extern float __kernel_cosf __P((float,float));
extern float __kernel_tanf __P((float,float,int));
extern int   __kernel_rem_pio2f __P((float*,float*,int,int,int,const int*));

#endif /* _MATH_PRIVATE_H_ */

---