src/libm/math_private.h
author Sam Lantinga <slouken@libsdl.org>
Mon, 15 Sep 2008 06:33:23 +0000
changeset 2756 a98604b691c8
child 2760 02aa80d7905f
permissions -rw-r--r--
Expanded the libm support and put it into a separate directory.
     1 /*
     2  * ====================================================
     3  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
     4  *
     5  * Developed at SunPro, a Sun Microsystems, Inc. business.
     6  * Permission to use, copy, modify, and distribute this
     7  * software is freely granted, provided that this notice
     8  * is preserved.
     9  * ====================================================
    10  */
    11 
    12 /*
    13  * from: @(#)fdlibm.h 5.1 93/09/24
    14  * $Id: math_private.h,v 1.3 2004/02/09 07:10:38 andersen Exp $
    15  */
    16 
    17 #ifndef _MATH_PRIVATE_H_
    18 #define _MATH_PRIVATE_H_
    19 
    20 /*#include <endian.h>*/
    21 #include <sys/types.h>
    22 
    23 #define attribute_hidden
    24 #define libm_hidden_proto(x)
    25 #define libm_hidden_def(x)
    26 
    27 /* The original fdlibm code used statements like:
    28 	n0 = ((*(int*)&one)>>29)^1;		* index of high word *
    29 	ix0 = *(n0+(int*)&x);			* high word of x *
    30 	ix1 = *((1-n0)+(int*)&x);		* low word of x *
    31    to dig two 32 bit words out of the 64 bit IEEE floating point
    32    value.  That is non-ANSI, and, moreover, the gcc instruction
    33    scheduler gets it wrong.  We instead use the following macros.
    34    Unlike the original code, we determine the endianness at compile
    35    time, not at run time; I don't see much benefit to selecting
    36    endianness at run time.  */
    37 
    38 /* A union which permits us to convert between a double and two 32 bit
    39    ints.  */
    40 
    41 /*
    42  * Math on arm is special:
    43  * For FPA, float words are always big-endian.
    44  * For VFP, floats words follow the memory system mode.
    45  */
    46 
    47 #if (__BYTE_ORDER == __BIG_ENDIAN) || \
    48     (!defined(__VFP_FP__) && (defined(__arm__) || defined(__thumb__)))
    49 
    50 typedef union
    51 {
    52     double value;
    53     struct
    54     {
    55         u_int32_t msw;
    56         u_int32_t lsw;
    57     } parts;
    58 } ieee_double_shape_type;
    59 
    60 #else
    61 
    62 typedef union
    63 {
    64     double value;
    65     struct
    66     {
    67         u_int32_t lsw;
    68         u_int32_t msw;
    69     } parts;
    70 } ieee_double_shape_type;
    71 
    72 #endif
    73 
    74 /* Get two 32 bit ints from a double.  */
    75 
    76 #define EXTRACT_WORDS(ix0,ix1,d)				\
    77 do {								\
    78   ieee_double_shape_type ew_u;					\
    79   ew_u.value = (d);						\
    80   (ix0) = ew_u.parts.msw;					\
    81   (ix1) = ew_u.parts.lsw;					\
    82 } while (0)
    83 
    84 /* Get the more significant 32 bit int from a double.  */
    85 
    86 #define GET_HIGH_WORD(i,d)					\
    87 do {								\
    88   ieee_double_shape_type gh_u;					\
    89   gh_u.value = (d);						\
    90   (i) = gh_u.parts.msw;						\
    91 } while (0)
    92 
    93 /* Get the less significant 32 bit int from a double.  */
    94 
    95 #define GET_LOW_WORD(i,d)					\
    96 do {								\
    97   ieee_double_shape_type gl_u;					\
    98   gl_u.value = (d);						\
    99   (i) = gl_u.parts.lsw;						\
   100 } while (0)
   101 
   102 /* Set a double from two 32 bit ints.  */
   103 
   104 #define INSERT_WORDS(d,ix0,ix1)					\
   105 do {								\
   106   ieee_double_shape_type iw_u;					\
   107   iw_u.parts.msw = (ix0);					\
   108   iw_u.parts.lsw = (ix1);					\
   109   (d) = iw_u.value;						\
   110 } while (0)
   111 
   112 /* Set the more significant 32 bits of a double from an int.  */
   113 
   114 #define SET_HIGH_WORD(d,v)					\
   115 do {								\
   116   ieee_double_shape_type sh_u;					\
   117   sh_u.value = (d);						\
   118   sh_u.parts.msw = (v);						\
   119   (d) = sh_u.value;						\
   120 } while (0)
   121 
   122 /* Set the less significant 32 bits of a double from an int.  */
   123 
   124 #define SET_LOW_WORD(d,v)					\
   125 do {								\
   126   ieee_double_shape_type sl_u;					\
   127   sl_u.value = (d);						\
   128   sl_u.parts.lsw = (v);						\
   129   (d) = sl_u.value;						\
   130 } while (0)
   131 
   132 /* A union which permits us to convert between a float and a 32 bit
   133    int.  */
   134 
   135 typedef union
   136 {
   137     float value;
   138     u_int32_t word;
   139 } ieee_float_shape_type;
   140 
   141 /* Get a 32 bit int from a float.  */
   142 
   143 #define GET_FLOAT_WORD(i,d)					\
   144 do {								\
   145   ieee_float_shape_type gf_u;					\
   146   gf_u.value = (d);						\
   147   (i) = gf_u.word;						\
   148 } while (0)
   149 
   150 /* Set a float from a 32 bit int.  */
   151 
   152 #define SET_FLOAT_WORD(d,i)					\
   153 do {								\
   154   ieee_float_shape_type sf_u;					\
   155   sf_u.word = (i);						\
   156   (d) = sf_u.value;						\
   157 } while (0)
   158 
   159 /* ieee style elementary functions */
   160 extern double
   161 __ieee754_sqrt(double)
   162     attribute_hidden;
   163      extern double __ieee754_acos(double) attribute_hidden;
   164      extern double __ieee754_acosh(double) attribute_hidden;
   165      extern double __ieee754_log(double) attribute_hidden;
   166      extern double __ieee754_atanh(double) attribute_hidden;
   167      extern double __ieee754_asin(double) attribute_hidden;
   168      extern double __ieee754_atan2(double, double) attribute_hidden;
   169      extern double __ieee754_exp(double) attribute_hidden;
   170      extern double __ieee754_cosh(double) attribute_hidden;
   171      extern double __ieee754_fmod(double, double) attribute_hidden;
   172      extern double __ieee754_pow(double, double) attribute_hidden;
   173      extern double __ieee754_lgamma_r(double, int *) attribute_hidden;
   174      extern double __ieee754_gamma_r(double, int *) attribute_hidden;
   175      extern double __ieee754_lgamma(double) attribute_hidden;
   176      extern double __ieee754_gamma(double) attribute_hidden;
   177      extern double __ieee754_log10(double) attribute_hidden;
   178      extern double __ieee754_sinh(double) attribute_hidden;
   179      extern double __ieee754_hypot(double, double) attribute_hidden;
   180      extern double __ieee754_j0(double) attribute_hidden;
   181      extern double __ieee754_j1(double) attribute_hidden;
   182      extern double __ieee754_y0(double) attribute_hidden;
   183      extern double __ieee754_y1(double) attribute_hidden;
   184      extern double __ieee754_jn(int, double) attribute_hidden;
   185      extern double __ieee754_yn(int, double) attribute_hidden;
   186      extern double __ieee754_remainder(double, double) attribute_hidden;
   187      extern int __ieee754_rem_pio2(double, double *) attribute_hidden;
   188 #if defined(_SCALB_INT)
   189      extern double __ieee754_scalb(double, int) attribute_hidden;
   190 #else
   191      extern double __ieee754_scalb(double, double) attribute_hidden;
   192 #endif
   193 
   194 /* fdlibm kernel function */
   195 #ifndef _IEEE_LIBM
   196      extern double __kernel_standard(double, double, int) attribute_hidden;
   197 #endif
   198      extern double __kernel_sin(double, double, int) attribute_hidden;
   199      extern double __kernel_cos(double, double) attribute_hidden;
   200      extern double __kernel_tan(double, double, int) attribute_hidden;
   201      extern int __kernel_rem_pio2(double *, double *, int, int, int,
   202                                   const int *) attribute_hidden;
   203 
   204 #endif /* _MATH_PRIVATE_H_ */