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  *
  24  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
  25  *
  26  * Permission is hereby granted, free of charge, to any person obtaining a
  27  * copy of this software and associated documentation files (the "Software"),
  28  * to deal in the Software without restriction, including without limitation
  29  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  30  * and/or sell copies of the Software, and to permit persons to whom the
  31  * Software is furnished to do so, subject to the following conditions:
  32  *
  33  * The above copyright notice and this permission notice shall be included
  34  * in all copies or substantial portions of the Software.
  35  *
  36  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  37  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  38  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  39  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  40  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  41  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  42  * 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  * Note that it is legal to pass NULL pointer to this function and will be
 172  * handled accordingly.
 173  */
 174 void
 175 _mesa_align_free(void *ptr)
 176 {
 177 #if defined(HAVE_POSIX_MEMALIGN)
 178    free(ptr);
 179 #elif defined(_WIN32) && defined(_MSC_VER)
 180    _aligned_free(ptr);
 181 #else
 182    if (ptr) {
 183       void **cubbyHole = (void **) ((char *) ptr - sizeof(void *));
 184       void *realAddr = *cubbyHole;
 185       free(realAddr);
 186    }
 187 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 188 }
 189
 190 /**
 191  * Reallocate memory, with alignment.
 192  */
 193 void *
 194 _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
 195                     unsigned long alignment)
 196 {
 197 #if defined(_WIN32) && defined(_MSC_VER)
 198    (void) oldSize;
 199    return _aligned_realloc(oldBuffer, newSize, alignment);
 200 #else
 201    const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
 202    void *newBuf = _mesa_align_malloc(newSize, alignment);
 203    if (newBuf && oldBuffer && copySize > 0) {
 204       memcpy(newBuf, oldBuffer, copySize);
 205    }
 206
 207    _mesa_align_free(oldBuffer);
 208    return newBuf;
 209 #endif
 210 }
 211
 212
 213
 214 /** Reallocate memory */
 215 void *
 216 _mesa_realloc(void *oldBuffer, size_t oldSize, size_t newSize)
 217 {
 218    const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
 219    void *newBuffer = malloc(newSize);
 220    if (newBuffer && oldBuffer && copySize > 0)
 221       memcpy(newBuffer, oldBuffer, copySize);
 222    free(oldBuffer);
 223    return newBuffer;
 224 }
 225
 226 /*@}*/
 227
 228
 229 /**********************************************************************/
 230 /** \name Math */
 231 /*@{*/
 232
 233
 234 #ifndef __GNUC__
 235 /**
 236  * Find the first bit set in a word.
 237  */
 238 int
 239 ffs(int i)
 240 {
 241    register int bit = 0;
 242    if (i != 0) {
 243       if ((i & 0xffff) == 0) {
 244          bit += 16;
 245          i >>= 16;
 246       }
 247       if ((i & 0xff) == 0) {
 248          bit += 8;
 249          i >>= 8;
 250       }
 251       if ((i & 0xf) == 0) {
 252          bit += 4;
 253          i >>= 4;
 254       }
 255       while ((i & 1) == 0) {
 256          bit++;
 257          i >>= 1;
 258       }
 259       bit++;
 260    }
 261    return bit;
 262 }
 263
 264
 265 /**
 266  * Find position of first bit set in given value.
 267  * XXX Warning: this function can only be used on 64-bit systems!
 268  * \return  position of least-significant bit set, starting at 1, return zero
 269  *          if no bits set.
 270  */
 271 int
 272 ffsll(long long int val)
 273 {
 274    int bit;
 275
 276    assert(sizeof(val) == 8);
 277
 278    bit = ffs((int) val);
 279    if (bit != 0)
 280       return bit;
 281
 282    bit = ffs((int) (val >> 32));
 283    if (bit != 0)
 284       return 32 + bit;
 285
 286    return 0;
 287 }
 288 #endif /* __GNUC__ */
 289
 290
 291 #if !defined(__GNUC__) ||\
 292    ((__GNUC__ * 100 + __GNUC_MINOR__) < 304) /* Not gcc 3.4 or later */
 293 /**
 294  * Return number of bits set in given GLuint.
 295  */
 296 unsigned int
 297 _mesa_bitcount(unsigned int n)
 298 {
 299    unsigned int bits;
 300    for (bits = 0; n > 0; n = n >> 1) {
 301       bits += (n & 1);
 302    }
 303    return bits;
 304 }
 305
 306 /**
 307  * Return number of bits set in given 64-bit uint.
 308  */
 309 unsigned int
 310 _mesa_bitcount_64(uint64_t n)
 311 {
 312    unsigned int bits;
 313    for (bits = 0; n > 0; n = n >> 1) {
 314       bits += (n & 1);
 315    }
 316    return bits;
 317 }
 318 #endif
 319
 320
 321 /* Using C99 rounding functions for roundToEven() implementation is
 322  * difficult, because round(), rint, and nearbyint() are affected by
 323  * fesetenv(), which the application may have done for its own
 324  * purposes.  Mesa's IROUND macro is close to what we want, but it
 325  * rounds away from 0 on n + 0.5.
 326  */
 327 int
 328 _mesa_round_to_even(float val)
 329 {
 330    int rounded = IROUND(val);
 331
 332    if (val - floor(val) == 0.5) {
 333       if (rounded % 2 != 0)
 334          rounded += val > 0 ? -1 : 1;
 335    }
 336
 337    return rounded;
 338 }
 339
 340
 341 /**
 342  * Convert a 4-byte float to a 2-byte half float.
 343  *
 344  * Not all float32 values can be represented exactly as a float16 value. We
 345  * round such intermediate float32 values to the nearest float16. When the
 346  * float32 lies exactly between to float16 values, we round to the one with
 347  * an even mantissa.
 348  *
 349  * This rounding behavior has several benefits:
 350  *   - It has no sign bias.
 351  *
 352  *   - It reproduces the behavior of real hardware: opcode F32TO16 in Intel's
 353  *     GPU ISA.
 354  *
 355  *   - By reproducing the behavior of the GPU (at least on Intel hardware),
 356  *     compile-time evaluation of constant packHalf2x16 GLSL expressions will
 357  *     result in the same value as if the expression were executed on the GPU.
 358  */
 359 GLhalfARB
 360 _mesa_float_to_half(float val)
 361 {
 362    const fi_type fi = {val};
 363    const int flt_m = fi.i & 0x7fffff;
 364    const int flt_e = (fi.i >> 23) & 0xff;
 365    const int flt_s = (fi.i >> 31) & 0x1;
 366    int s, e, m = 0;
 367    GLhalfARB result;
 368
 369    /* sign bit */
 370    s = flt_s;
 371
 372    /* handle special cases */
 373    if ((flt_e == 0) && (flt_m == 0)) {
 374       /* zero */
 375       /* m = 0; - already set */
 376       e = 0;
 377    }
 378    else if ((flt_e == 0) && (flt_m != 0)) {
 379       /* denorm -- denorm float maps to 0 half */
 380       /* m = 0; - already set */
 381       e = 0;
 382    }
 383    else if ((flt_e == 0xff) && (flt_m == 0)) {
 384       /* infinity */
 385       /* m = 0; - already set */
 386       e = 31;
 387    }
 388    else if ((flt_e == 0xff) && (flt_m != 0)) {
 389       /* NaN */
 390       m = 1;
 391       e = 31;
 392    }
 393    else {
 394       /* regular number */
 395       const int new_exp = flt_e - 127;
 396       if (new_exp < -14) {
 397          /* The float32 lies in the range (0.0, min_normal16) and is rounded
 398           * to a nearby float16 value. The result will be either zero, subnormal,
 399           * or normal.
 400           */
 401          e = 0;
 402          m = _mesa_round_to_even((1 << 24) * fabsf(fi.f));
 403       }
 404       else if (new_exp > 15) {
 405          /* map this value to infinity */
 406          /* m = 0; - already set */
 407          e = 31;
 408       }
 409       else {
 410          /* The float32 lies in the range
 411           *   [min_normal16, max_normal16 + max_step16)
 412           * and is rounded to a nearby float16 value. The result will be
 413           * either normal or infinite.
 414           */
 415          e = new_exp + 15;
 416          m = _mesa_round_to_even(flt_m / (float) (1 << 13));
 417       }
 418    }
 419
 420    assert(0 <= m && m <= 1024);
 421    if (m == 1024) {
 422       /* The float32 was rounded upwards into the range of the next exponent,
 423        * so bump the exponent. This correctly handles the case where f32
 424        * should be rounded up to float16 infinity.
 425        */
 426       ++e;
 427       m = 0;
 428    }
 429
 430    result = (s << 15) | (e << 10) | m;
 431    return result;
 432 }
 433
 434
 435 /**
 436  * Convert a 2-byte half float to a 4-byte float.
 437  * Based on code from:
 438  * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html
 439  */
 440 float
 441 _mesa_half_to_float(GLhalfARB val)
 442 {
 443    /* XXX could also use a 64K-entry lookup table */
 444    const int m = val & 0x3ff;
 445    const int e = (val >> 10) & 0x1f;
 446    const int s = (val >> 15) & 0x1;
 447    int flt_m, flt_e, flt_s;
 448    fi_type fi;
 449    float result;
 450
 451    /* sign bit */
 452    flt_s = s;
 453
 454    /* handle special cases */
 455    if ((e == 0) && (m == 0)) {
 456       /* zero */
 457       flt_m = 0;
 458       flt_e = 0;
 459    }
 460    else if ((e == 0) && (m != 0)) {
 461       /* denorm -- denorm half will fit in non-denorm single */
 462       const float half_denorm = 1.0f / 16384.0f; /* 2^-14 */
 463       float mantissa = ((float) (m)) / 1024.0f;
 464       float sign = s ? -1.0f : 1.0f;
 465       return sign * mantissa * half_denorm;
 466    }
 467    else if ((e == 31) && (m == 0)) {
 468       /* infinity */
 469       flt_e = 0xff;
 470       flt_m = 0;
 471    }
 472    else if ((e == 31) && (m != 0)) {
 473       /* NaN */
 474       flt_e = 0xff;
 475       flt_m = 1;
 476    }
 477    else {
 478       /* regular */
 479       flt_e = e + 112;
 480       flt_m = m << 13;
 481    }
 482
 483    fi.i = (flt_s << 31) | (flt_e << 23) | flt_m;
 484    result = fi.f;
 485    return result;
 486 }
 487
 488 /*@}*/
 489
 490
 491 /**********************************************************************/
 492 /** \name Sort & Search */
 493 /*@{*/
 494
 495 /**
 496  * Wrapper for bsearch().
 497  */
 498 void *
 499 _mesa_bsearch( const void *key, const void *base, size_t nmemb, size_t size,
 500                int (*compar)(const void *, const void *) )
 501 {
 502 #if defined(_WIN32_WCE)
 503    void *mid;
 504    int cmp;
 505    while (nmemb) {
 506       nmemb >>= 1;
 507       mid = (char *)base + nmemb * size;
 508       cmp = (*compar)(key, mid);
 509       if (cmp == 0)
 510          return mid;
 511       if (cmp > 0) {
 512          base = (char *)mid + size;
 513          --nmemb;
 514       }
 515    }
 516    return NULL;
 517 #else
 518    return bsearch(key, base, nmemb, size, compar);
 519 #endif
 520 }
 521
 522 /*@}*/
 523
 524
 525 /**********************************************************************/
 526 /** \name Environment vars */
 527 /*@{*/
 528
 529 /**
 530  * Wrapper for getenv().
 531  */
 532 char *
 533 _mesa_getenv( const char *var )
 534 {
 535 #if defined(_XBOX) || defined(_WIN32_WCE)
 536    return NULL;
 537 #else
 538    return getenv(var);
 539 #endif
 540 }
 541
 542 /*@}*/
 543
 544
 545 /**********************************************************************/
 546 /** \name String */
 547 /*@{*/
 548
 549 /**
 550  * Implemented using malloc() and strcpy.
 551  * Note that NULL is handled accordingly.
 552  */
 553 char *
 554 _mesa_strdup( const char *s )
 555 {
 556    if (s) {
 557       size_t l = strlen(s);
 558       char *s2 = malloc(l + 1);
 559       if (s2)
 560          strcpy(s2, s);
 561       return s2;
 562    }
 563    else {
 564       return NULL;
 565    }
 566 }
 567
 568 /** Wrapper around strtof() */
 569 float
 570 _mesa_strtof( const char *s, char **end )
 571 {
 572 #if defined(_GNU_SOURCE) && !defined(__CYGWIN__) && !defined(__FreeBSD__) && \
 573    !defined(ANDROID) && !defined(__HAIKU__) && !defined(__UCLIBC__) && \
 574    !defined(__NetBSD__)
 575    static locale_t loc = NULL;
 576    if (!loc) {
 577       loc = newlocale(LC_CTYPE_MASK, "C", NULL);
 578    }
 579    return strtof_l(s, end, loc);
 580 #elif defined(_ISOC99_SOURCE) || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 600)
 581    return strtof(s, end);
 582 #else
 583    return (float)strtod(s, end);
 584 #endif
 585 }
 586
 587 /** Compute simple checksum/hash for a string */
 588 unsigned int
 589 _mesa_str_checksum(const char *str)
 590 {
 591    /* This could probably be much better */
 592    unsigned int sum, i;
 593    const char *c;
 594    sum = i = 1;
 595    for (c = str; *c; c++, i++)
 596       sum += *c * (i % 100);
 597    return sum + i;
 598 }
 599
 600
 601 /*@}*/
 602
 603
 604 /** Needed due to #ifdef's, above. */
 605 int
 606 _mesa_vsnprintf(char *str, size_t size, const char *fmt, va_list args)
 607 {
 608    return vsnprintf( str, size, fmt, args);
 609 }
 610
 611 /** Wrapper around vsnprintf() */
 612 int
 613 _mesa_snprintf( char *str, size_t size, const char *fmt, ... )
 614 {
 615    int r;
 616    va_list args;
 617    va_start( args, fmt );
 618    r = vsnprintf( str, size, fmt, args );
 619    va_end( args );
 620    return r;
 621 }
 622
 623