glib/gtypes.h

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  20  * file for a list of people on the GLib Team.  See the ChangeLog
  21  * files for a list of changes.  These files are distributed with
  22  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  23  */
  24
  25 #ifndef __G_TYPES_H__
  26 #define __G_TYPES_H__
  27
  28 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  29 #error "Only <glib.h> can be included directly."
  30 #endif
  31
  32 #include <glibconfig.h>
  33 #include <glib/gmacros.h>
  34 #include <glib/gversionmacros.h>
  35 #include <time.h>
  36
  37 G_BEGIN_DECLS
  38
  39 /* Provide type definitions for commonly used types.
  40  *  These are useful because a "gint8" can be adjusted
  41  *  to be 1 byte (8 bits) on all platforms. Similarly and
  42  *  more importantly, "gint32" can be adjusted to be
  43  *  4 bytes (32 bits) on all platforms.
  44  */
  45
  46 typedef char   gchar;
  47 typedef short  gshort;
  48 typedef long   glong;
  49 typedef int    gint;
  50 typedef gint   gboolean;
  51
  52 typedef unsigned char   guchar;
  53 typedef unsigned short  gushort;
  54 typedef unsigned long   gulong;
  55 typedef unsigned int    guint;
  56
  57 typedef float   gfloat;
  58 typedef double  gdouble;
  59
  60 /* Define min and max constants for the fixed size numerical types */
  61 #define G_MININT8       ((gint8) -0x80)
  62 #define G_MAXINT8       ((gint8)  0x7f)
  63 #define G_MAXUINT8      ((guint8) 0xff)
  64
  65 #define G_MININT16      ((gint16) -0x8000)
  66 #define G_MAXINT16      ((gint16)  0x7fff)
  67 #define G_MAXUINT16     ((guint16) 0xffff)
  68
  69 #define G_MININT32      ((gint32) -0x80000000)
  70 #define G_MAXINT32      ((gint32)  0x7fffffff)
  71 #define G_MAXUINT32     ((guint32) 0xffffffff)
  72
  73 #define G_MININT64      ((gint64) G_GINT64_CONSTANT(-0x8000000000000000))
  74 #define G_MAXINT64      G_GINT64_CONSTANT(0x7fffffffffffffff)
  75 #define G_MAXUINT64     G_GUINT64_CONSTANT(0xffffffffffffffff)
  76
  77 typedef void* gpointer;
  78 typedef const void *gconstpointer;
  79
  80 typedef gint            (*GCompareFunc)         (gconstpointer  a,
  81                                                  gconstpointer  b);
  82 typedef gint            (*GCompareDataFunc)     (gconstpointer  a,
  83                                                  gconstpointer  b,
  84                                                  gpointer       user_data);
  85 typedef gboolean        (*GEqualFunc)           (gconstpointer  a,
  86                                                  gconstpointer  b);
  87 typedef void            (*GDestroyNotify)       (gpointer       data);
  88 typedef void            (*GFunc)                (gpointer       data,
  89                                                  gpointer       user_data);
  90 typedef guint           (*GHashFunc)            (gconstpointer  key);
  91 typedef void            (*GHFunc)               (gpointer       key,
  92                                                  gpointer       value,
  93                                                  gpointer       user_data);
  94
  95 /**
  96  * GFreeFunc:
  97  * @data: a data pointer
  98  *
  99  * Declares a type of function which takes an arbitrary
 100  * data pointer argument and has no return value. It is
 101  * not currently used in GLib or GTK+.
 102  */
 103 typedef void            (*GFreeFunc)            (gpointer       data);
 104
 105 /**
 106  * GTranslateFunc:
 107  * @str: the untranslated string
 108  * @data: user data specified when installing the function, e.g.
 109  *  in g_option_group_set_translate_func()
 110  *
 111  * The type of functions which are used to translate user-visible
 112  * strings, for <option>--help</option> output.
 113  *
 114  * Returns: a translation of the string for the current locale.
 115  *  The returned string is owned by GLib and must not be freed.
 116  */
 117 typedef const gchar *   (*GTranslateFunc)       (const gchar   *str,
 118                                                  gpointer       data);
 119
 120
 121 /* Define some mathematical constants that aren't available
 122  * symbolically in some strict ISO C implementations.
 123  *
 124  * Note that the large number of digits used in these definitions
 125  * doesn't imply that GLib or current computers in general would be
 126  * able to handle floating point numbers with an accuracy like this.
 127  * It's mostly an exercise in futility and future proofing. For
 128  * extended precision floating point support, look somewhere else
 129  * than GLib.
 130  */
 131 #define G_E     2.7182818284590452353602874713526624977572470937000
 132 #define G_LN2   0.69314718055994530941723212145817656807550013436026
 133 #define G_LN10  2.3025850929940456840179914546843642076011014886288
 134 #define G_PI    3.1415926535897932384626433832795028841971693993751
 135 #define G_PI_2  1.5707963267948966192313216916397514420985846996876
 136 #define G_PI_4  0.78539816339744830961566084581987572104929234984378
 137 #define G_SQRT2 1.4142135623730950488016887242096980785696718753769
 138
 139 /* Portable endian checks and conversions
 140  *
 141  * glibconfig.h defines G_BYTE_ORDER which expands to one of
 142  * the below macros.
 143  */
 144 #define G_LITTLE_ENDIAN 1234
 145 #define G_BIG_ENDIAN    4321
 146 #define G_PDP_ENDIAN    3412            /* unused, need specific PDP check */
 147
 148
 149 /* Basic bit swapping functions
 150  */
 151 #define GUINT16_SWAP_LE_BE_CONSTANT(val)        ((guint16) ( \
 152     (guint16) ((guint16) (val) >> 8) |  \
 153     (guint16) ((guint16) (val) << 8)))
 154
 155 #define GUINT32_SWAP_LE_BE_CONSTANT(val)        ((guint32) ( \
 156     (((guint32) (val) & (guint32) 0x000000ffU) << 24) | \
 157     (((guint32) (val) & (guint32) 0x0000ff00U) <<  8) | \
 158     (((guint32) (val) & (guint32) 0x00ff0000U) >>  8) | \
 159     (((guint32) (val) & (guint32) 0xff000000U) >> 24)))
 160
 161 #define GUINT64_SWAP_LE_BE_CONSTANT(val)        ((guint64) ( \
 162       (((guint64) (val) &                                               \
 163         (guint64) G_GINT64_CONSTANT (0x00000000000000ffU)) << 56) |     \
 164       (((guint64) (val) &                                               \
 165         (guint64) G_GINT64_CONSTANT (0x000000000000ff00U)) << 40) |     \
 166       (((guint64) (val) &                                               \
 167         (guint64) G_GINT64_CONSTANT (0x0000000000ff0000U)) << 24) |     \
 168       (((guint64) (val) &                                               \
 169         (guint64) G_GINT64_CONSTANT (0x00000000ff000000U)) <<  8) |     \
 170       (((guint64) (val) &                                               \
 171         (guint64) G_GINT64_CONSTANT (0x000000ff00000000U)) >>  8) |     \
 172       (((guint64) (val) &                                               \
 173         (guint64) G_GINT64_CONSTANT (0x0000ff0000000000U)) >> 24) |     \
 174       (((guint64) (val) &                                               \
 175         (guint64) G_GINT64_CONSTANT (0x00ff000000000000U)) >> 40) |     \
 176       (((guint64) (val) &                                               \
 177         (guint64) G_GINT64_CONSTANT (0xff00000000000000U)) >> 56)))
 178
 179 /* Arch specific stuff for speed
 180  */
 181 #if defined (__GNUC__) && (__GNUC__ >= 2) && defined (__OPTIMIZE__)
 182
 183 #  if __GNUC__ >= 4 && defined (__GNUC_MINOR__) && __GNUC_MINOR__ >= 3
 184 #    define GUINT32_SWAP_LE_BE(val) ((guint32) __builtin_bswap32 ((gint32) (val)))
 185 #    define GUINT64_SWAP_LE_BE(val) ((guint64) __builtin_bswap64 ((gint64) (val)))
 186 #  endif
 187
 188 #  if defined (__i386__)
 189 #    define GUINT16_SWAP_LE_BE_IA32(val) \
 190        (G_GNUC_EXTENSION                                        \
 191         ({ guint16 __v, __x = ((guint16) (val));                \
 192            if (__builtin_constant_p (__x))                      \
 193              __v = GUINT16_SWAP_LE_BE_CONSTANT (__x);           \
 194            else                                                 \
 195              __asm__ ("rorw $8, %w0"                            \
 196                       : "=r" (__v)                              \
 197                       : "0" (__x)                               \
 198                       : "cc");                                  \
 199             __v; }))
 200 #    if !defined (__i486__) && !defined (__i586__) \
 201         && !defined (__pentium__) && !defined (__i686__) \
 202         && !defined (__pentiumpro__) && !defined (__pentium4__)
 203 #       define GUINT32_SWAP_LE_BE_IA32(val) \
 204           (G_GNUC_EXTENSION                                     \
 205            ({ guint32 __v, __x = ((guint32) (val));             \
 206               if (__builtin_constant_p (__x))                   \
 207                 __v = GUINT32_SWAP_LE_BE_CONSTANT (__x);        \
 208               else                                              \
 209                 __asm__ ("rorw $8, %w0\n\t"                     \
 210                          "rorl $16, %0\n\t"                     \
 211                          "rorw $8, %w0"                         \
 212                          : "=r" (__v)                           \
 213                          : "0" (__x)                            \
 214                          : "cc");                               \
 215               __v; }))
 216 #    else /* 486 and higher has bswap */
 217 #       define GUINT32_SWAP_LE_BE_IA32(val) \
 218           (G_GNUC_EXTENSION                                     \
 219            ({ guint32 __v, __x = ((guint32) (val));             \
 220               if (__builtin_constant_p (__x))                   \
 221                 __v = GUINT32_SWAP_LE_BE_CONSTANT (__x);        \
 222               else                                              \
 223                 __asm__ ("bswap %0"                             \
 224                          : "=r" (__v)                           \
 225                          : "0" (__x));                          \
 226               __v; }))
 227 #    endif /* processor specific 32-bit stuff */
 228 #    define GUINT64_SWAP_LE_BE_IA32(val) \
 229        (G_GNUC_EXTENSION                                                \
 230         ({ union { guint64 __ll;                                        \
 231                    guint32 __l[2]; } __w, __r;                          \
 232            __w.__ll = ((guint64) (val));                                \
 233            if (__builtin_constant_p (__w.__ll))                         \
 234              __r.__ll = GUINT64_SWAP_LE_BE_CONSTANT (__w.__ll);         \
 235            else                                                         \
 236              {                                                          \
 237                __r.__l[0] = GUINT32_SWAP_LE_BE (__w.__l[1]);            \
 238                __r.__l[1] = GUINT32_SWAP_LE_BE (__w.__l[0]);            \
 239              }                                                          \
 240            __r.__ll; }))
 241      /* Possibly just use the constant version and let gcc figure it out? */
 242 #    define GUINT16_SWAP_LE_BE(val) (GUINT16_SWAP_LE_BE_IA32 (val))
 243 #    ifndef GUINT32_SWAP_LE_BE
 244 #      define GUINT32_SWAP_LE_BE(val) (GUINT32_SWAP_LE_BE_IA32 (val))
 245 #    endif
 246 #    ifndef GUINT64_SWAP_LE_BE
 247 #      define GUINT64_SWAP_LE_BE(val) (GUINT64_SWAP_LE_BE_IA32 (val))
 248 #    endif
 249 #  elif defined (__ia64__)
 250 #    define GUINT16_SWAP_LE_BE_IA64(val) \
 251        (G_GNUC_EXTENSION                                        \
 252         ({ guint16 __v, __x = ((guint16) (val));                \
 253            if (__builtin_constant_p (__x))                      \
 254              __v = GUINT16_SWAP_LE_BE_CONSTANT (__x);           \
 255            else                                                 \
 256              __asm__ __volatile__ ("shl %0 = %1, 48 ;;"         \
 257                                    "mux1 %0 = %0, @rev ;;"      \
 258                                     : "=r" (__v)                \
 259                                     : "r" (__x));               \
 260             __v; }))
 261 #    define GUINT32_SWAP_LE_BE_IA64(val) \
 262        (G_GNUC_EXTENSION                                        \
 263          ({ guint32 __v, __x = ((guint32) (val));               \
 264             if (__builtin_constant_p (__x))                     \
 265               __v = GUINT32_SWAP_LE_BE_CONSTANT (__x);          \
 266             else                                                \
 267              __asm__ __volatile__ ("shl %0 = %1, 32 ;;"         \
 268                                    "mux1 %0 = %0, @rev ;;"      \
 269                                     : "=r" (__v)                \
 270                                     : "r" (__x));               \
 271             __v; }))
 272 #    define GUINT64_SWAP_LE_BE_IA64(val) \
 273        (G_GNUC_EXTENSION                                        \
 274         ({ guint64 __v, __x = ((guint64) (val));                \
 275            if (__builtin_constant_p (__x))                      \
 276              __v = GUINT64_SWAP_LE_BE_CONSTANT (__x);           \
 277            else                                                 \
 278              __asm__ __volatile__ ("mux1 %0 = %1, @rev ;;"      \
 279                                    : "=r" (__v)                 \
 280                                    : "r" (__x));                \
 281            __v; }))
 282 #    define GUINT16_SWAP_LE_BE(val) (GUINT16_SWAP_LE_BE_IA64 (val))
 283 #    ifndef GUINT32_SWAP_LE_BE
 284 #      define GUINT32_SWAP_LE_BE(val) (GUINT32_SWAP_LE_BE_IA64 (val))
 285 #    endif
 286 #    ifndef GUINT64_SWAP_LE_BE
 287 #      define GUINT64_SWAP_LE_BE(val) (GUINT64_SWAP_LE_BE_IA64 (val))
 288 #    endif
 289 #  elif defined (__x86_64__)
 290 #    define GUINT32_SWAP_LE_BE_X86_64(val) \
 291        (G_GNUC_EXTENSION                                        \
 292          ({ guint32 __v, __x = ((guint32) (val));               \
 293             if (__builtin_constant_p (__x))                     \
 294               __v = GUINT32_SWAP_LE_BE_CONSTANT (__x);          \
 295             else                                                \
 296              __asm__ ("bswapl %0"                               \
 297                       : "=r" (__v)                              \
 298                       : "0" (__x));                             \
 299             __v; }))
 300 #    define GUINT64_SWAP_LE_BE_X86_64(val) \
 301        (G_GNUC_EXTENSION                                        \
 302         ({ guint64 __v, __x = ((guint64) (val));                \
 303            if (__builtin_constant_p (__x))                      \
 304              __v = GUINT64_SWAP_LE_BE_CONSTANT (__x);           \
 305            else                                                 \
 306              __asm__ ("bswapq %0"                               \
 307                       : "=r" (__v)                              \
 308                       : "0" (__x));                             \
 309            __v; }))
 310      /* gcc seems to figure out optimal code for this on its own */
 311 #    define GUINT16_SWAP_LE_BE(val) (GUINT16_SWAP_LE_BE_CONSTANT (val))
 312 #    ifndef GUINT32_SWAP_LE_BE
 313 #      define GUINT32_SWAP_LE_BE(val) (GUINT32_SWAP_LE_BE_X86_64 (val))
 314 #    endif
 315 #    ifndef GUINT64_SWAP_LE_BE
 316 #      define GUINT64_SWAP_LE_BE(val) (GUINT64_SWAP_LE_BE_X86_64 (val))
 317 #    endif
 318 #  else /* generic gcc */
 319 #    define GUINT16_SWAP_LE_BE(val) (GUINT16_SWAP_LE_BE_CONSTANT (val))
 320 #    ifndef GUINT32_SWAP_LE_BE
 321 #      define GUINT32_SWAP_LE_BE(val) (GUINT32_SWAP_LE_BE_CONSTANT (val))
 322 #    endif
 323 #    ifndef GUINT64_SWAP_LE_BE
 324 #      define GUINT64_SWAP_LE_BE(val) (GUINT64_SWAP_LE_BE_CONSTANT (val))
 325 #    endif
 326 #  endif
 327 #else /* generic */
 328 #  define GUINT16_SWAP_LE_BE(val) (GUINT16_SWAP_LE_BE_CONSTANT (val))
 329 #  define GUINT32_SWAP_LE_BE(val) (GUINT32_SWAP_LE_BE_CONSTANT (val))
 330 #  define GUINT64_SWAP_LE_BE(val) (GUINT64_SWAP_LE_BE_CONSTANT (val))
 331 #endif /* generic */
 332
 333 #define GUINT16_SWAP_LE_PDP(val)        ((guint16) (val))
 334 #define GUINT16_SWAP_BE_PDP(val)        (GUINT16_SWAP_LE_BE (val))
 335 #define GUINT32_SWAP_LE_PDP(val)        ((guint32) ( \
 336     (((guint32) (val) & (guint32) 0x0000ffffU) << 16) | \
 337     (((guint32) (val) & (guint32) 0xffff0000U) >> 16)))
 338 #define GUINT32_SWAP_BE_PDP(val)        ((guint32) ( \
 339     (((guint32) (val) & (guint32) 0x00ff00ffU) << 8) | \
 340     (((guint32) (val) & (guint32) 0xff00ff00U) >> 8)))
 341
 342 /* The G*_TO_?E() macros are defined in glibconfig.h.
 343  * The transformation is symmetric, so the FROM just maps to the TO.
 344  */
 345 #define GINT16_FROM_LE(val)     (GINT16_TO_LE (val))
 346 #define GUINT16_FROM_LE(val)    (GUINT16_TO_LE (val))
 347 #define GINT16_FROM_BE(val)     (GINT16_TO_BE (val))
 348 #define GUINT16_FROM_BE(val)    (GUINT16_TO_BE (val))
 349 #define GINT32_FROM_LE(val)     (GINT32_TO_LE (val))
 350 #define GUINT32_FROM_LE(val)    (GUINT32_TO_LE (val))
 351 #define GINT32_FROM_BE(val)     (GINT32_TO_BE (val))
 352 #define GUINT32_FROM_BE(val)    (GUINT32_TO_BE (val))
 353
 354 #define GINT64_FROM_LE(val)     (GINT64_TO_LE (val))
 355 #define GUINT64_FROM_LE(val)    (GUINT64_TO_LE (val))
 356 #define GINT64_FROM_BE(val)     (GINT64_TO_BE (val))
 357 #define GUINT64_FROM_BE(val)    (GUINT64_TO_BE (val))
 358
 359 #define GLONG_FROM_LE(val)      (GLONG_TO_LE (val))
 360 #define GULONG_FROM_LE(val)     (GULONG_TO_LE (val))
 361 #define GLONG_FROM_BE(val)      (GLONG_TO_BE (val))
 362 #define GULONG_FROM_BE(val)     (GULONG_TO_BE (val))
 363
 364 #define GINT_FROM_LE(val)       (GINT_TO_LE (val))
 365 #define GUINT_FROM_LE(val)      (GUINT_TO_LE (val))
 366 #define GINT_FROM_BE(val)       (GINT_TO_BE (val))
 367 #define GUINT_FROM_BE(val)      (GUINT_TO_BE (val))
 368
 369 #define GSIZE_FROM_LE(val)      (GSIZE_TO_LE (val))
 370 #define GSSIZE_FROM_LE(val)     (GSSIZE_TO_LE (val))
 371 #define GSIZE_FROM_BE(val)      (GSIZE_TO_BE (val))
 372 #define GSSIZE_FROM_BE(val)     (GSSIZE_TO_BE (val))
 373
 374 /* Portable versions of host-network order stuff
 375  */
 376 #define g_ntohl(val) (GUINT32_FROM_BE (val))
 377 #define g_ntohs(val) (GUINT16_FROM_BE (val))
 378 #define g_htonl(val) (GUINT32_TO_BE (val))
 379 #define g_htons(val) (GUINT16_TO_BE (val))
 380
 381 /* Overflow-checked unsigned integer arithmetic
 382  */
 383 #ifndef _GLIB_TEST_OVERFLOW_FALLBACK
 384 /* https://bugzilla.gnome.org/show_bug.cgi?id=769104 */
 385 #if __GNUC__ >= 5 && !defined(__INTEL_COMPILER)
 386 #define _GLIB_HAVE_BUILTIN_OVERFLOW_CHECKS
 387 #elif __has_builtin(__builtin_uadd_overflow)
 388 #define _GLIB_HAVE_BUILTIN_OVERFLOW_CHECKS
 389 #endif
 390 #endif
 391
 392 #define g_uint_checked_add(dest, a, b) \
 393     _GLIB_CHECKED_ADD_U32(dest, a, b)
 394 #define g_uint_checked_mul(dest, a, b) \
 395     _GLIB_CHECKED_MUL_U32(dest, a, b)
 396
 397 #define g_uint64_checked_add(dest, a, b) \
 398     _GLIB_CHECKED_ADD_U64(dest, a, b)
 399 #define g_uint64_checked_mul(dest, a, b) \
 400     _GLIB_CHECKED_MUL_U64(dest, a, b)
 401
 402 #if GLIB_SIZEOF_SIZE_T == 8
 403 #define g_size_checked_add(dest, a, b) \
 404     _GLIB_CHECKED_ADD_U64(dest, a, b)
 405 #define g_size_checked_mul(dest, a, b) \
 406     _GLIB_CHECKED_MUL_U64(dest, a, b)
 407 #else
 408 #define g_size_checked_add(dest, a, b) \
 409     _GLIB_CHECKED_ADD_U32(dest, a, b)
 410 #define g_size_checked_mul(dest, a, b) \
 411     _GLIB_CHECKED_MUL_U32(dest, a, b)
 412 #endif
 413
 414 /* The names of the following inlines are private.  Use the macro
 415  * definitions above.
 416  */
 417 #ifdef _GLIB_HAVE_BUILTIN_OVERFLOW_CHECKS
 418 static inline gboolean _GLIB_CHECKED_ADD_U32 (guint32 *dest, guint32 a, guint32 b) {
 419   return !__builtin_uadd_overflow(a, b, dest); }
 420 static inline gboolean _GLIB_CHECKED_MUL_U32 (guint32 *dest, guint32 a, guint32 b) {
 421   return !__builtin_umul_overflow(a, b, dest); }
 422 static inline gboolean _GLIB_CHECKED_ADD_U64 (guint64 *dest, guint64 a, guint64 b) {
 423   G_STATIC_ASSERT(sizeof (unsigned long long) == sizeof (guint64));
 424   return !__builtin_uaddll_overflow(a, b, (unsigned long long *) dest); }
 425 static inline gboolean _GLIB_CHECKED_MUL_U64 (guint64 *dest, guint64 a, guint64 b) {
 426   return !__builtin_umulll_overflow(a, b, (unsigned long long *) dest); }
 427 #else
 428 static inline gboolean _GLIB_CHECKED_ADD_U32 (guint32 *dest, guint32 a, guint32 b) {
 429   *dest = a + b; return *dest >= a; }
 430 static inline gboolean _GLIB_CHECKED_MUL_U32 (guint32 *dest, guint32 a, guint32 b) {
 431   *dest = a * b; return !a || *dest / a == b; }
 432 static inline gboolean _GLIB_CHECKED_ADD_U64 (guint64 *dest, guint64 a, guint64 b) {
 433   *dest = a + b; return *dest >= a; }
 434 static inline gboolean _GLIB_CHECKED_MUL_U64 (guint64 *dest, guint64 a, guint64 b) {
 435   *dest = a * b; return !a || *dest / a == b; }
 436 #endif
 437
 438 /* IEEE Standard 754 Single Precision Storage Format (gfloat):
 439  *
 440  *        31 30           23 22            0
 441  * +--------+---------------+---------------+
 442  * | s 1bit | e[30:23] 8bit | f[22:0] 23bit |
 443  * +--------+---------------+---------------+
 444  * B0------------------->B1------->B2-->B3-->
 445  *
 446  * IEEE Standard 754 Double Precision Storage Format (gdouble):
 447  *
 448  *        63 62            52 51            32   31            0
 449  * +--------+----------------+----------------+ +---------------+
 450  * | s 1bit | e[62:52] 11bit | f[51:32] 20bit | | f[31:0] 32bit |
 451  * +--------+----------------+----------------+ +---------------+
 452  * B0--------------->B1---------->B2--->B3---->  B4->B5->B6->B7->
 453  */
 454 /* subtract from biased_exponent to form base2 exponent (normal numbers) */
 455 typedef union  _GDoubleIEEE754  GDoubleIEEE754;
 456 typedef union  _GFloatIEEE754   GFloatIEEE754;
 457 #define G_IEEE754_FLOAT_BIAS    (127)
 458 #define G_IEEE754_DOUBLE_BIAS   (1023)
 459 /* multiply with base2 exponent to get base10 exponent (normal numbers) */
 460 #define G_LOG_2_BASE_10         (0.30102999566398119521)
 461 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
 462 union _GFloatIEEE754
 463 {
 464   gfloat v_float;
 465   struct {
 466     guint mantissa : 23;
 467     guint biased_exponent : 8;
 468     guint sign : 1;
 469   } mpn;
 470 };
 471 union _GDoubleIEEE754
 472 {
 473   gdouble v_double;
 474   struct {
 475     guint mantissa_low : 32;
 476     guint mantissa_high : 20;
 477     guint biased_exponent : 11;
 478     guint sign : 1;
 479   } mpn;
 480 };
 481 #elif G_BYTE_ORDER == G_BIG_ENDIAN
 482 union _GFloatIEEE754
 483 {
 484   gfloat v_float;
 485   struct {
 486     guint sign : 1;
 487     guint biased_exponent : 8;
 488     guint mantissa : 23;
 489   } mpn;
 490 };
 491 union _GDoubleIEEE754
 492 {
 493   gdouble v_double;
 494   struct {
 495     guint sign : 1;
 496     guint biased_exponent : 11;
 497     guint mantissa_high : 20;
 498     guint mantissa_low : 32;
 499   } mpn;
 500 };
 501 #else /* !G_LITTLE_ENDIAN && !G_BIG_ENDIAN */
 502 #error unknown ENDIAN type
 503 #endif /* !G_LITTLE_ENDIAN && !G_BIG_ENDIAN */
 504
 505 typedef struct _GTimeVal                GTimeVal;
 506
 507 struct _GTimeVal
 508 {
 509   glong tv_sec;
 510   glong tv_usec;
 511 };
 512
 513 G_END_DECLS
 514
 515 /* We prefix variable declarations so they can
 516  * properly get exported in Windows DLLs.
 517  */
 518 #ifndef GLIB_VAR
 519 #  ifdef G_PLATFORM_WIN32
 520 #    ifdef GLIB_STATIC_COMPILATION
 521 #      define GLIB_VAR extern
 522 #    else /* !GLIB_STATIC_COMPILATION */
 523 #      ifdef GLIB_COMPILATION
 524 #        ifdef DLL_EXPORT
 525 #          define GLIB_VAR __declspec(dllexport)
 526 #        else /* !DLL_EXPORT */
 527 #          define GLIB_VAR extern
 528 #        endif /* !DLL_EXPORT */
 529 #      else /* !GLIB_COMPILATION */
 530 #        define GLIB_VAR extern __declspec(dllimport)
 531 #      endif /* !GLIB_COMPILATION */
 532 #    endif /* !GLIB_STATIC_COMPILATION */
 533 #  else /* !G_PLATFORM_WIN32 */
 534 #    define GLIB_VAR _GLIB_EXTERN
 535 #  endif /* !G_PLATFORM_WIN32 */
 536 #endif /* GLIB_VAR */
 537
 538 #endif /* __G_TYPES_H__ */