src/mesa/main/imports.c

   1 /**
   2  * \file imports.c
   3  * Standard C library function wrappers.
   4  *
   5  * Imports are services which the device driver or window system or
   6  * operating system provides to the core renderer.  The core renderer (Mesa)
   7  * will call these functions in order to do memory allocation, simple I/O,
   8  * etc.
   9  *
  10  * Some drivers will want to override/replace this file with something
  11  * specialized, but that'll be rare.
  12  *
  13  * Eventually, I want to move roll the glheader.h file into this.
  14  *
  15  * \todo Functions still needed:
  16  * - scanf
  17  * - qsort
  18  * - rand and RAND_MAX
  19  */
  20
  21 /*
  22  * Mesa 3-D graphics library
  23  * Version:  7.1
  24  *
  25  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
  26  *
  27  * Permission is hereby granted, free of charge, to any person obtaining a
  28  * copy of this software and associated documentation files (the "Software"),
  29  * to deal in the Software without restriction, including without limitation
  30  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  31  * and/or sell copies of the Software, and to permit persons to whom the
  32  * Software is furnished to do so, subject to the following conditions:
  33  *
  34  * The above copyright notice and this permission notice shall be included
  35  * in all copies or substantial portions of the Software.
  36  *
  37  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  38  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  39  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  40  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  41  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  42  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  43  */
  44
  45
  46
  47 #include "imports.h"
  48 #include "context.h"
  49 #include "mtypes.h"
  50 #include "version.h"
  51
  52 #ifdef _GNU_SOURCE
  53 #include <locale.h>
  54 #ifdef __APPLE__
  55 #include <xlocale.h>
  56 #endif
  57 #endif
  58
  59
  60 #ifdef _WIN32
  61 #define vsnprintf _vsnprintf
  62 #elif defined(__IBMC__) || defined(__IBMCPP__)
  63 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list arg);
  64 #endif
  65
  66 /**********************************************************************/
  67 /** \name Memory */
  68 /*@{*/
  69
  70 /**
  71  * Allocate aligned memory.
  72  *
  73  * \param bytes number of bytes to allocate.
  74  * \param alignment alignment (must be greater than zero).
  75  *
  76  * Allocates extra memory to accommodate rounding up the address for
  77  * alignment and to record the real malloc address.
  78  *
  79  * \sa _mesa_align_free().
  80  */
  81 void *
  82 _mesa_align_malloc(size_t bytes, unsigned long alignment)
  83 {
  84 #if defined(HAVE_POSIX_MEMALIGN)
  85    void *mem;
  86    int err = posix_memalign(& mem, alignment, bytes);
  87    if (err)
  88       return NULL;
  89    return mem;
  90 #elif defined(_WIN32) && defined(_MSC_VER)
  91    return _aligned_malloc(bytes, alignment);
  92 #else
  93    uintptr_t ptr, buf;
  94
  95    ASSERT( alignment > 0 );
  96
  97    ptr = (uintptr_t)malloc(bytes + alignment + sizeof(void *));
  98    if (!ptr)
  99       return NULL;
 100
 101    buf = (ptr + alignment + sizeof(void *)) & ~(uintptr_t)(alignment - 1);
 102    *(uintptr_t *)(buf - sizeof(void *)) = ptr;
 103
 104 #ifdef DEBUG
 105    /* mark the non-aligned area */
 106    while ( ptr < buf - sizeof(void *) ) {
 107       *(unsigned long *)ptr = 0xcdcdcdcd;
 108       ptr += sizeof(unsigned long);
 109    }
 110 #endif
 111
 112    return (void *) buf;
 113 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 114 }
 115
 116 /**
 117  * Same as _mesa_align_malloc(), but using calloc(1, ) instead of
 118  * malloc()
 119  */
 120 void *
 121 _mesa_align_calloc(size_t bytes, unsigned long alignment)
 122 {
 123 #if defined(HAVE_POSIX_MEMALIGN)
 124    void *mem;
 125
 126    mem = _mesa_align_malloc(bytes, alignment);
 127    if (mem != NULL) {
 128       (void) memset(mem, 0, bytes);
 129    }
 130
 131    return mem;
 132 #elif defined(_WIN32) && defined(_MSC_VER)
 133    void *mem;
 134
 135    mem = _aligned_malloc(bytes, alignment);
 136    if (mem != NULL) {
 137       (void) memset(mem, 0, bytes);
 138    }
 139
 140    return mem;
 141 #else
 142    uintptr_t ptr, buf;
 143
 144    ASSERT( alignment > 0 );
 145
 146    ptr = (uintptr_t)calloc(1, bytes + alignment + sizeof(void *));
 147    if (!ptr)
 148       return NULL;
 149
 150    buf = (ptr + alignment + sizeof(void *)) & ~(uintptr_t)(alignment - 1);
 151    *(uintptr_t *)(buf - sizeof(void *)) = ptr;
 152
 153 #ifdef DEBUG
 154    /* mark the non-aligned area */
 155    while ( ptr < buf - sizeof(void *) ) {
 156       *(unsigned long *)ptr = 0xcdcdcdcd;
 157       ptr += sizeof(unsigned long);
 158    }
 159 #endif
 160
 161    return (void *)buf;
 162 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 163 }
 164
 165 /**
 166  * Free memory which was allocated with either _mesa_align_malloc()
 167  * or _mesa_align_calloc().
 168  * \param ptr pointer to the memory to be freed.
 169  * The actual address to free is stored in the word immediately before the
 170  * address the client sees.
 171  */
 172 void
 173 _mesa_align_free(void *ptr)
 174 {
 175 #if defined(HAVE_POSIX_MEMALIGN)
 176    free(ptr);
 177 #elif defined(_WIN32) && defined(_MSC_VER)
 178    _aligned_free(ptr);
 179 #else
 180    void **cubbyHole = (void **) ((char *) ptr - sizeof(void *));
 181    void *realAddr = *cubbyHole;
 182    free(realAddr);
 183 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 184 }
 185
 186 /**
 187  * Reallocate memory, with alignment.
 188  */
 189 void *
 190 _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
 191                     unsigned long alignment)
 192 {
 193 #if defined(_WIN32) && defined(_MSC_VER)
 194    (void) oldSize;
 195    return _aligned_realloc(oldBuffer, newSize, alignment);
 196 #else
 197    const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
 198    void *newBuf = _mesa_align_malloc(newSize, alignment);
 199    if (newBuf && oldBuffer && copySize > 0) {
 200       memcpy(newBuf, oldBuffer, copySize);
 201    }
 202    if (oldBuffer)
 203       _mesa_align_free(oldBuffer);
 204    return newBuf;
 205 #endif
 206 }
 207
 208
 209
 210 /** Reallocate memory */
 211 void *
 212 _mesa_realloc(void *oldBuffer, size_t oldSize, size_t newSize)
 213 {
 214    const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
 215    void *newBuffer = malloc(newSize);
 216    if (newBuffer && oldBuffer && copySize > 0)
 217       memcpy(newBuffer, oldBuffer, copySize);
 218    free(oldBuffer);
 219    return newBuffer;
 220 }
 221
 222 /*@}*/
 223
 224
 225 /**********************************************************************/
 226 /** \name Math */
 227 /*@{*/
 228
 229
 230 #ifndef __GNUC__
 231 /**
 232  * Find the first bit set in a word.
 233  */
 234 int
 235 ffs(int i)
 236 {
 237    register int bit = 0;
 238    if (i != 0) {
 239       if ((i & 0xffff) == 0) {
 240          bit += 16;
 241          i >>= 16;
 242       }
 243       if ((i & 0xff) == 0) {
 244          bit += 8;
 245          i >>= 8;
 246       }
 247       if ((i & 0xf) == 0) {
 248          bit += 4;
 249          i >>= 4;
 250       }
 251       while ((i & 1) == 0) {
 252          bit++;
 253          i >>= 1;
 254       }
 255       bit++;
 256    }
 257    return bit;
 258 }
 259
 260
 261 /**
 262  * Find position of first bit set in given value.
 263  * XXX Warning: this function can only be used on 64-bit systems!
 264  * \return  position of least-significant bit set, starting at 1, return zero
 265  *          if no bits set.
 266  */
 267 int
 268 ffsll(long long int val)
 269 {
 270    int bit;
 271
 272    assert(sizeof(val) == 8);
 273
 274    bit = ffs((int) val);
 275    if (bit != 0)
 276       return bit;
 277
 278    bit = ffs((int) (val >> 32));
 279    if (bit != 0)
 280       return 32 + bit;
 281
 282    return 0;
 283 }
 284 #endif /* __GNUC__ */
 285
 286
 287 #if !defined(__GNUC__) ||\
 288    ((__GNUC__ * 100 + __GNUC_MINOR__) < 304) /* Not gcc 3.4 or later */
 289 /**
 290  * Return number of bits set in given GLuint.
 291  */
 292 unsigned int
 293 _mesa_bitcount(unsigned int n)
 294 {
 295    unsigned int bits;
 296    for (bits = 0; n > 0; n = n >> 1) {
 297       bits += (n & 1);
 298    }
 299    return bits;
 300 }
 301
 302 /**
 303  * Return number of bits set in given 64-bit uint.
 304  */
 305 unsigned int
 306 _mesa_bitcount_64(uint64_t n)
 307 {
 308    unsigned int bits;
 309    for (bits = 0; n > 0; n = n >> 1) {
 310       bits += (n & 1);
 311    }
 312    return bits;
 313 }
 314 #endif
 315
 316
 317 /* Using C99 rounding functions for roundToEven() implementation is
 318  * difficult, because round(), rint, and nearbyint() are affected by
 319  * fesetenv(), which the application may have done for its own
 320  * purposes.  Mesa's IROUND macro is close to what we want, but it
 321  * rounds away from 0 on n + 0.5.
 322  */
 323 int
 324 _mesa_round_to_even(float val)
 325 {
 326    int rounded = IROUND(val);
 327
 328    if (val - floor(val) == 0.5) {
 329       if (rounded % 2 != 0)
 330          rounded += val > 0 ? -1 : 1;
 331    }
 332
 333    return rounded;
 334 }
 335
 336
 337 /**
 338  * Convert a 4-byte float to a 2-byte half float.
 339  * Based on code from:
 340  * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html
 341  */
 342 GLhalfARB
 343 _mesa_float_to_half(float val)
 344 {
 345    const fi_type fi = {val};
 346    const int flt_m = fi.i & 0x7fffff;
 347    const int flt_e = (fi.i >> 23) & 0xff;
 348    const int flt_s = (fi.i >> 31) & 0x1;
 349    int s, e, m = 0;
 350    GLhalfARB result;
 351
 352    /* sign bit */
 353    s = flt_s;
 354
 355    /* handle special cases */
 356    if ((flt_e == 0) && (flt_m == 0)) {
 357       /* zero */
 358       /* m = 0; - already set */
 359       e = 0;
 360    }
 361    else if ((flt_e == 0) && (flt_m != 0)) {
 362       /* denorm -- denorm float maps to 0 half */
 363       /* m = 0; - already set */
 364       e = 0;
 365    }
 366    else if ((flt_e == 0xff) && (flt_m == 0)) {
 367       /* infinity */
 368       /* m = 0; - already set */
 369       e = 31;
 370    }
 371    else if ((flt_e == 0xff) && (flt_m != 0)) {
 372       /* NaN */
 373       m = 1;
 374       e = 31;
 375    }
 376    else {
 377       /* regular number */
 378       const int new_exp = flt_e - 127;
 379       if (new_exp < -24) {
 380          /* this maps to 0 */
 381          /* m = 0; - already set */
 382          e = 0;
 383       }
 384       else if (new_exp < -14) {
 385          /* this maps to a denorm */
 386          unsigned int exp_val = (unsigned int) (-14 - new_exp); /* 2^-exp_val*/
 387          e = 0;
 388          switch (exp_val) {
 389             case 0:
 390                _mesa_warning(NULL,
 391                    "float_to_half: logical error in denorm creation!\n");
 392                /* m = 0; - already set */
 393                break;
 394             case 1: m = 512 + (flt_m >> 14); break;
 395             case 2: m = 256 + (flt_m >> 15); break;
 396             case 3: m = 128 + (flt_m >> 16); break;
 397             case 4: m = 64 + (flt_m >> 17); break;
 398             case 5: m = 32 + (flt_m >> 18); break;
 399             case 6: m = 16 + (flt_m >> 19); break;
 400             case 7: m = 8 + (flt_m >> 20); break;
 401             case 8: m = 4 + (flt_m >> 21); break;
 402             case 9: m = 2 + (flt_m >> 22); break;
 403             case 10: m = 1; break;
 404          }
 405       }
 406       else if (new_exp > 15) {
 407          /* map this value to infinity */
 408          /* m = 0; - already set */
 409          e = 31;
 410       }
 411       else {
 412          /* regular */
 413          e = new_exp + 15;
 414          m = flt_m >> 13;
 415       }
 416    }
 417
 418    result = (s << 15) | (e << 10) | m;
 419    return result;
 420 }
 421
 422
 423 /**
 424  * Convert a 2-byte half float to a 4-byte float.
 425  * Based on code from:
 426  * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html
 427  */
 428 float
 429 _mesa_half_to_float(GLhalfARB val)
 430 {
 431    /* XXX could also use a 64K-entry lookup table */
 432    const int m = val & 0x3ff;
 433    const int e = (val >> 10) & 0x1f;
 434    const int s = (val >> 15) & 0x1;
 435    int flt_m, flt_e, flt_s;
 436    fi_type fi;
 437    float result;
 438
 439    /* sign bit */
 440    flt_s = s;
 441
 442    /* handle special cases */
 443    if ((e == 0) && (m == 0)) {
 444       /* zero */
 445       flt_m = 0;
 446       flt_e = 0;
 447    }
 448    else if ((e == 0) && (m != 0)) {
 449       /* denorm -- denorm half will fit in non-denorm single */
 450       const float half_denorm = 1.0f / 16384.0f; /* 2^-14 */
 451       float mantissa = ((float) (m)) / 1024.0f;
 452       float sign = s ? -1.0f : 1.0f;
 453       return sign * mantissa * half_denorm;
 454    }
 455    else if ((e == 31) && (m == 0)) {
 456       /* infinity */
 457       flt_e = 0xff;
 458       flt_m = 0;
 459    }
 460    else if ((e == 31) && (m != 0)) {
 461       /* NaN */
 462       flt_e = 0xff;
 463       flt_m = 1;
 464    }
 465    else {
 466       /* regular */
 467       flt_e = e + 112;
 468       flt_m = m << 13;
 469    }
 470
 471    fi.i = (flt_s << 31) | (flt_e << 23) | flt_m;
 472    result = fi.f;
 473    return result;
 474 }
 475
 476 /*@}*/
 477
 478
 479 /**********************************************************************/
 480 /** \name Sort & Search */
 481 /*@{*/
 482
 483 /**
 484  * Wrapper for bsearch().
 485  */
 486 void *
 487 _mesa_bsearch( const void *key, const void *base, size_t nmemb, size_t size,
 488                int (*compar)(const void *, const void *) )
 489 {
 490 #if defined(_WIN32_WCE)
 491    void *mid;
 492    int cmp;
 493    while (nmemb) {
 494       nmemb >>= 1;
 495       mid = (char *)base + nmemb * size;
 496       cmp = (*compar)(key, mid);
 497       if (cmp == 0)
 498          return mid;
 499       if (cmp > 0) {
 500          base = (char *)mid + size;
 501          --nmemb;
 502       }
 503    }
 504    return NULL;
 505 #else
 506    return bsearch(key, base, nmemb, size, compar);
 507 #endif
 508 }
 509
 510 /*@}*/
 511
 512
 513 /**********************************************************************/
 514 /** \name Environment vars */
 515 /*@{*/
 516
 517 /**
 518  * Wrapper for getenv().
 519  */
 520 char *
 521 _mesa_getenv( const char *var )
 522 {
 523 #if defined(_XBOX) || defined(_WIN32_WCE)
 524    return NULL;
 525 #else
 526    return getenv(var);
 527 #endif
 528 }
 529
 530 /*@}*/
 531
 532
 533 /**********************************************************************/
 534 /** \name String */
 535 /*@{*/
 536
 537 /**
 538  * Implemented using malloc() and strcpy.
 539  * Note that NULL is handled accordingly.
 540  */
 541 char *
 542 _mesa_strdup( const char *s )
 543 {
 544    if (s) {
 545       size_t l = strlen(s);
 546       char *s2 = malloc(l + 1);
 547       if (s2)
 548          strcpy(s2, s);
 549       return s2;
 550    }
 551    else {
 552       return NULL;
 553    }
 554 }
 555
 556 /** Wrapper around strtof() */
 557 float
 558 _mesa_strtof( const char *s, char **end )
 559 {
 560 #if defined(_GNU_SOURCE) && !defined(__CYGWIN__) && !defined(__FreeBSD__) && \
 561    !defined(ANDROID) && !defined(__HAIKU__) && !defined(__UCLIBC__)
 562    static locale_t loc = NULL;
 563    if (!loc) {
 564       loc = newlocale(LC_CTYPE_MASK, "C", NULL);
 565    }
 566    return strtof_l(s, end, loc);
 567 #elif defined(_ISOC99_SOURCE) || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 600)
 568    return strtof(s, end);
 569 #else
 570    return (float)strtod(s, end);
 571 #endif
 572 }
 573
 574 /** Compute simple checksum/hash for a string */
 575 unsigned int
 576 _mesa_str_checksum(const char *str)
 577 {
 578    /* This could probably be much better */
 579    unsigned int sum, i;
 580    const char *c;
 581    sum = i = 1;
 582    for (c = str; *c; c++, i++)
 583       sum += *c * (i % 100);
 584    return sum + i;
 585 }
 586
 587
 588 /*@}*/
 589
 590
 591 /** Needed due to #ifdef's, above. */
 592 int
 593 _mesa_vsnprintf(char *str, size_t size, const char *fmt, va_list args)
 594 {
 595    return vsnprintf( str, size, fmt, args);
 596 }
 597
 598 /** Wrapper around vsnprintf() */
 599 int
 600 _mesa_snprintf( char *str, size_t size, const char *fmt, ... )
 601 {
 602    int r;
 603    va_list args;
 604    va_start( args, fmt );
 605    r = vsnprintf( str, size, fmt, args );
 606    va_end( args );
 607    return r;
 608 }
 609
 610