src/fdlibm/fdlibm.h

   1
   2 /* @(#)fdlibm.h 5.1 93/09/24 */
   3 /*
   4  * ====================================================
   5  * Copyright (C) 1993, 2000 by Sun Microsystems, Inc. All rights reserved.
   6  *
   7  * Developed at SunPro, a Sun Microsystems, Inc. business.
   8  * Permission to use, copy, modify, and distribute this
   9  * software is freely granted, provided that this notice
  10  * is preserved.
  11  * ====================================================
  12  */
  13
  14 #ifndef __CLASSPATH_FDLIBM_H__
  15 #define __CLASSPATH_FDLIBM_H__
  16
  17 /* AIX needs _XOPEN_SOURCE */
  18 #ifdef _AIX
  19 #define _XOPEN_SOURCE
  20 #endif
  21
  22 #include <config.h>
  23 #include <stdlib.h>
  24
  25 /* GCJ LOCAL: Include files.  */
  26 #include "ieeefp.h"
  27
  28 #include "mprec.h"
  29
  30 /* CYGNUS LOCAL: Default to XOPEN_MODE.  */
  31 #define _XOPEN_MODE
  32
  33 #ifdef __P
  34 #undef __P
  35 #endif
  36
  37 #ifdef __STDC__
  38 #define __P(p)  p
  39 #else
  40 #define __P(p)  ()
  41 #endif
  42
  43 #ifndef HUGE
  44 #define HUGE    ((float)3.40282346638528860e+38)
  45 #endif
  46
  47 /*
  48  * set X_TLOSS = pi*2**52, which is possibly defined in <values.h>
  49  * (one may replace the following line by "#include <values.h>")
  50  */
  51
  52 #define X_TLOSS         1.41484755040568800000e+16
  53
  54 /* These typedefs are true for the targets running Java. */
  55
  56 #define _IEEE_LIBM
  57
  58 #ifdef __cplusplus
  59 extern "C" {
  60 #endif
  61
  62 /*
  63  * ANSI/POSIX
  64  */
  65 #if !defined(isnan) && !defined(HAVE_ISNAN)
  66 #define isnan(x) ((x) != (x))
  67 #endif
  68
  69 /* ieee style elementary functions */
  70 extern double __ieee754_fmod __P((double,double));
  71
  72 /*
  73  * Functions callable from C, intended to support IEEE arithmetic.
  74  */
  75 extern double copysign __P((double, double));
  76
  77 /* The original code used statements like
  78         n0 = ((*(int*)&one)>>29)^1;             * index of high word *
  79         ix0 = *(n0+(int*)&x);                   * high word of x *
  80         ix1 = *((1-n0)+(int*)&x);               * low word of x *
  81    to dig two 32 bit words out of the 64 bit IEEE floating point
  82    value.  That is non-ANSI, and, moreover, the gcc instruction
  83    scheduler gets it wrong.  We instead use the following macros.
  84    Unlike the original code, we determine the endianness at compile
  85    time, not at run time; I don't see much benefit to selecting
  86    endianness at run time.  */
  87
  88 #ifndef __IEEE_BIG_ENDIAN
  89 #ifndef __IEEE_LITTLE_ENDIAN
  90  #error Must define endianness
  91 #endif
  92 #endif
  93
  94 /* A union which permits us to convert between a double and two 32 bit
  95    ints.  */
  96
  97 #ifdef __IEEE_BIG_ENDIAN
  98
  99 typedef union
 100 {
 101   double value;
 102   struct
 103   {
 104     uint32_t msw;
 105     uint32_t lsw;
 106   } parts;
 107 } ieee_double_shape_type;
 108
 109 #endif
 110
 111 #ifdef __IEEE_LITTLE_ENDIAN
 112
 113 typedef union
 114 {
 115   double value;
 116   struct
 117   {
 118     uint32_t lsw;
 119     uint32_t msw;
 120   } parts;
 121 } ieee_double_shape_type;
 122
 123 #endif
 124
 125 /* Get two 32 bit ints from a double.  */
 126
 127 #define EXTRACT_WORDS(ix0,ix1,d)                                \
 128 do {                                                            \
 129   ieee_double_shape_type ew_u;                                  \
 130   ew_u.value = (d);                                             \
 131   (ix0) = ew_u.parts.msw;                                       \
 132   (ix1) = ew_u.parts.lsw;                                       \
 133 } while (0)
 134
 135 /* Get the more significant 32 bit int from a double.  */
 136
 137 #define GET_HIGH_WORD(i,d)                                      \
 138 do {                                                            \
 139   ieee_double_shape_type gh_u;                                  \
 140   gh_u.value = (d);                                             \
 141   (i) = gh_u.parts.msw;                                         \
 142 } while (0)
 143
 144 /* Get the less significant 32 bit int from a double.  */
 145
 146 #define GET_LOW_WORD(i,d)                                       \
 147 do {                                                            \
 148   ieee_double_shape_type gl_u;                                  \
 149   gl_u.value = (d);                                             \
 150   (i) = gl_u.parts.lsw;                                         \
 151 } while (0)
 152
 153 /* Set a double from two 32 bit ints.  */
 154
 155 #define INSERT_WORDS(d,ix0,ix1)                                 \
 156 do {                                                            \
 157   ieee_double_shape_type iw_u;                                  \
 158   iw_u.parts.msw = (ix0);                                       \
 159   iw_u.parts.lsw = (ix1);                                       \
 160   (d) = iw_u.value;                                             \
 161 } while (0)
 162
 163 /* Set the more significant 32 bits of a double from an int.  */
 164
 165 #define SET_HIGH_WORD(d,v)                                      \
 166 do {                                                            \
 167   ieee_double_shape_type sh_u;                                  \
 168   sh_u.value = (d);                                             \
 169   sh_u.parts.msw = (v);                                         \
 170   (d) = sh_u.value;                                             \
 171 } while (0)
 172
 173 /* Set the less significant 32 bits of a double from an int.  */
 174
 175 #define SET_LOW_WORD(d,v)                                       \
 176 do {                                                            \
 177   ieee_double_shape_type sl_u;                                  \
 178   sl_u.value = (d);                                             \
 179   sl_u.parts.lsw = (v);                                         \
 180   (d) = sl_u.value;                                             \
 181 } while (0)
 182
 183 /* A union which permits us to convert between a float and a 32 bit
 184    int.  */
 185
 186 typedef union
 187 {
 188   float value;
 189   uint32_t word;
 190 } ieee_float_shape_type;
 191
 192 /* Get a 32 bit int from a float.  */
 193
 194 #define GET_FLOAT_WORD(i,d)                                     \
 195 do {                                                            \
 196   ieee_float_shape_type gf_u;                                   \
 197   gf_u.value = (d);                                             \
 198   (i) = gf_u.word;                                              \
 199 } while (0)
 200
 201 /* Set a float from a 32 bit int.  */
 202
 203 #define SET_FLOAT_WORD(d,i)                                     \
 204 do {                                                            \
 205   ieee_float_shape_type sf_u;                                   \
 206   sf_u.word = (i);                                              \
 207   (d) = sf_u.value;                                             \
 208 } while (0)
 209
 210 #ifdef __cplusplus
 211 }
 212 #endif
 213
 214 #endif /* __CLASSPATH_FDLIBM_H__ */