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  * THE AUTHORS 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  *
 340  * Not all float32 values can be represented exactly as a float16 value. We
 341  * round such intermediate float32 values to the nearest float16. When the
 342  * float32 lies exactly between to float16 values, we round to the one with
 343  * an even mantissa.
 344  *
 345  * This rounding behavior has several benefits:
 346  *   - It has no sign bias.
 347  *
 348  *   - It reproduces the behavior of real hardware: opcode F32TO16 in Intel's
 349  *     GPU ISA.
 350  *
 351  *   - By reproducing the behavior of the GPU (at least on Intel hardware),
 352  *     compile-time evaluation of constant packHalf2x16 GLSL expressions will
 353  *     result in the same value as if the expression were executed on the GPU.
 354  */
 355 GLhalfARB
 356 _mesa_float_to_half(float val)
 357 {
 358    const fi_type fi = {val};
 359    const int flt_m = fi.i & 0x7fffff;
 360    const int flt_e = (fi.i >> 23) & 0xff;
 361    const int flt_s = (fi.i >> 31) & 0x1;
 362    int s, e, m = 0;
 363    GLhalfARB result;
 364
 365    /* sign bit */
 366    s = flt_s;
 367
 368    /* handle special cases */
 369    if ((flt_e == 0) && (flt_m == 0)) {
 370       /* zero */
 371       /* m = 0; - already set */
 372       e = 0;
 373    }
 374    else if ((flt_e == 0) && (flt_m != 0)) {
 375       /* denorm -- denorm float maps to 0 half */
 376       /* m = 0; - already set */
 377       e = 0;
 378    }
 379    else if ((flt_e == 0xff) && (flt_m == 0)) {
 380       /* infinity */
 381       /* m = 0; - already set */
 382       e = 31;
 383    }
 384    else if ((flt_e == 0xff) && (flt_m != 0)) {
 385       /* NaN */
 386       m = 1;
 387       e = 31;
 388    }
 389    else {
 390       /* regular number */
 391       const int new_exp = flt_e - 127;
 392       if (new_exp < -14) {
 393          /* The float32 lies in the range (0.0, min_normal16) and is rounded
 394           * to a nearby float16 value. The result will be either zero, subnormal,
 395           * or normal.
 396           */
 397          e = 0;
 398          m = _mesa_round_to_even((1 << 24) * fabsf(fi.f));
 399       }
 400       else if (new_exp > 15) {
 401          /* map this value to infinity */
 402          /* m = 0; - already set */
 403          e = 31;
 404       }
 405       else {
 406          /* The float32 lies in the range
 407           *   [min_normal16, max_normal16 + max_step16)
 408           * and is rounded to a nearby float16 value. The result will be
 409           * either normal or infinite.
 410           */
 411          e = new_exp + 15;
 412          m = _mesa_round_to_even(flt_m / (float) (1 << 13));
 413       }
 414    }
 415
 416    assert(0 <= m && m <= 1024);
 417    if (m == 1024) {
 418       /* The float32 was rounded upwards into the range of the next exponent,
 419        * so bump the exponent. This correctly handles the case where f32
 420        * should be rounded up to float16 infinity.
 421        */
 422       ++e;
 423       m = 0;
 424    }
 425
 426    result = (s << 15) | (e << 10) | m;
 427    return result;
 428 }
 429
 430
 431 /**
 432  * Convert a 2-byte half float to a 4-byte float.
 433  * Based on code from:
 434  * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html
 435  */
 436 float
 437 _mesa_half_to_float(GLhalfARB val)
 438 {
 439    /* XXX could also use a 64K-entry lookup table */
 440    const int m = val & 0x3ff;
 441    const int e = (val >> 10) & 0x1f;
 442    const int s = (val >> 15) & 0x1;
 443    int flt_m, flt_e, flt_s;
 444    fi_type fi;
 445    float result;
 446
 447    /* sign bit */
 448    flt_s = s;
 449
 450    /* handle special cases */
 451    if ((e == 0) && (m == 0)) {
 452       /* zero */
 453       flt_m = 0;
 454       flt_e = 0;
 455    }
 456    else if ((e == 0) && (m != 0)) {
 457       /* denorm -- denorm half will fit in non-denorm single */
 458       const float half_denorm = 1.0f / 16384.0f; /* 2^-14 */
 459       float mantissa = ((float) (m)) / 1024.0f;
 460       float sign = s ? -1.0f : 1.0f;
 461       return sign * mantissa * half_denorm;
 462    }
 463    else if ((e == 31) && (m == 0)) {
 464       /* infinity */
 465       flt_e = 0xff;
 466       flt_m = 0;
 467    }
 468    else if ((e == 31) && (m != 0)) {
 469       /* NaN */
 470       flt_e = 0xff;
 471       flt_m = 1;
 472    }
 473    else {
 474       /* regular */
 475       flt_e = e + 112;
 476       flt_m = m << 13;
 477    }
 478
 479    fi.i = (flt_s << 31) | (flt_e << 23) | flt_m;
 480    result = fi.f;
 481    return result;
 482 }
 483
 484 /*@}*/
 485
 486
 487 /**********************************************************************/
 488 /** \name Sort & Search */
 489 /*@{*/
 490
 491 /**
 492  * Wrapper for bsearch().
 493  */
 494 void *
 495 _mesa_bsearch( const void *key, const void *base, size_t nmemb, size_t size,
 496                int (*compar)(const void *, const void *) )
 497 {
 498 #if defined(_WIN32_WCE)
 499    void *mid;
 500    int cmp;
 501    while (nmemb) {
 502       nmemb >>= 1;
 503       mid = (char *)base + nmemb * size;
 504       cmp = (*compar)(key, mid);
 505       if (cmp == 0)
 506          return mid;
 507       if (cmp > 0) {
 508          base = (char *)mid + size;
 509          --nmemb;
 510       }
 511    }
 512    return NULL;
 513 #else
 514    return bsearch(key, base, nmemb, size, compar);
 515 #endif
 516 }
 517
 518 /*@}*/
 519
 520
 521 /**********************************************************************/
 522 /** \name Environment vars */
 523 /*@{*/
 524
 525 /**
 526  * Wrapper for getenv().
 527  */
 528 char *
 529 _mesa_getenv( const char *var )
 530 {
 531 #if defined(_XBOX) || defined(_WIN32_WCE)
 532    return NULL;
 533 #else
 534    return getenv(var);
 535 #endif
 536 }
 537
 538 /*@}*/
 539
 540
 541 /**********************************************************************/
 542 /** \name String */
 543 /*@{*/
 544
 545 /**
 546  * Implemented using malloc() and strcpy.
 547  * Note that NULL is handled accordingly.
 548  */
 549 char *
 550 _mesa_strdup( const char *s )
 551 {
 552    if (s) {
 553       size_t l = strlen(s);
 554       char *s2 = malloc(l + 1);
 555       if (s2)
 556          strcpy(s2, s);
 557       return s2;
 558    }
 559    else {
 560       return NULL;
 561    }
 562 }
 563
 564 /** Wrapper around strtof() */
 565 float
 566 _mesa_strtof( const char *s, char **end )
 567 {
 568 #if defined(_GNU_SOURCE) && !defined(__CYGWIN__) && !defined(__FreeBSD__) && \
 569    !defined(ANDROID) && !defined(__HAIKU__) && !defined(__UCLIBC__)
 570    static locale_t loc = NULL;
 571    if (!loc) {
 572       loc = newlocale(LC_CTYPE_MASK, "C", NULL);
 573    }
 574    return strtof_l(s, end, loc);
 575 #elif defined(_ISOC99_SOURCE) || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 600)
 576    return strtof(s, end);
 577 #else
 578    return (float)strtod(s, end);
 579 #endif
 580 }
 581
 582 /** Compute simple checksum/hash for a string */
 583 unsigned int
 584 _mesa_str_checksum(const char *str)
 585 {
 586    /* This could probably be much better */
 587    unsigned int sum, i;
 588    const char *c;
 589    sum = i = 1;
 590    for (c = str; *c; c++, i++)
 591       sum += *c * (i % 100);
 592    return sum + i;
 593 }
 594
 595
 596 /*@}*/
 597
 598
 599 /** Needed due to #ifdef's, above. */
 600 int
 601 _mesa_vsnprintf(char *str, size_t size, const char *fmt, va_list args)
 602 {
 603    return vsnprintf( str, size, fmt, args);
 604 }
 605
 606 /** Wrapper around vsnprintf() */
 607 int
 608 _mesa_snprintf( char *str, size_t size, const char *fmt, ... )
 609 {
 610    int r;
 611    va_list args;
 612    va_start( args, fmt );
 613    r = vsnprintf( str, size, fmt, args );
 614    va_end( args );
 615    return r;
 616 }
 617
 618