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 "version.h"
  50
  51 #ifdef _GNU_SOURCE
  52 #include <locale.h>
  53 #ifdef __APPLE__
  54 #include <xlocale.h>
  55 #endif
  56 #endif
  57
  58
  59 #define MAXSTRING 4000  /* for vsnprintf() */
  60
  61 #ifdef WIN32
  62 #define vsnprintf _vsnprintf
  63 #elif defined(__IBMC__) || defined(__IBMCPP__) || ( defined(__VMS) && __CRTL_VER < 70312000 )
  64 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list arg);
  65 #ifdef __VMS
  66 #include "vsnprintf.c"
  67 #endif
  68 #endif
  69
  70 /**********************************************************************/
  71 /** \name Memory */
  72 /*@{*/
  73
  74 /** Wrapper around malloc() */
  75 void *
  76 _mesa_malloc(size_t bytes)
  77 {
  78    return malloc(bytes);
  79 }
  80
  81 /** Wrapper around calloc() */
  82 void *
  83 _mesa_calloc(size_t bytes)
  84 {
  85    return calloc(1, bytes);
  86 }
  87
  88 /** Wrapper around free() */
  89 void
  90 _mesa_free(void *ptr)
  91 {
  92    free(ptr);
  93 }
  94
  95 /**
  96  * Allocate aligned memory.
  97  *
  98  * \param bytes number of bytes to allocate.
  99  * \param alignment alignment (must be greater than zero).
 100  *
 101  * Allocates extra memory to accommodate rounding up the address for
 102  * alignment and to record the real malloc address.
 103  *
 104  * \sa _mesa_align_free().
 105  */
 106 void *
 107 _mesa_align_malloc(size_t bytes, unsigned long alignment)
 108 {
 109 #if defined(HAVE_POSIX_MEMALIGN)
 110    void *mem;
 111    int err = posix_memalign(& mem, alignment, bytes);
 112    (void) err;
 113    return mem;
 114 #elif defined(_WIN32) && defined(_MSC_VER)
 115    return _aligned_malloc(bytes, alignment);
 116 #else
 117    uintptr_t ptr, buf;
 118
 119    ASSERT( alignment > 0 );
 120
 121    ptr = (uintptr_t) _mesa_malloc(bytes + alignment + sizeof(void *));
 122    if (!ptr)
 123       return NULL;
 124
 125    buf = (ptr + alignment + sizeof(void *)) & ~(uintptr_t)(alignment - 1);
 126    *(uintptr_t *)(buf - sizeof(void *)) = ptr;
 127
 128 #ifdef DEBUG
 129    /* mark the non-aligned area */
 130    while ( ptr < buf - sizeof(void *) ) {
 131       *(unsigned long *)ptr = 0xcdcdcdcd;
 132       ptr += sizeof(unsigned long);
 133    }
 134 #endif
 135
 136    return (void *) buf;
 137 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 138 }
 139
 140 /**
 141  * Same as _mesa_align_malloc(), but using _mesa_calloc() instead of
 142  * _mesa_malloc()
 143  */
 144 void *
 145 _mesa_align_calloc(size_t bytes, unsigned long alignment)
 146 {
 147 #if defined(HAVE_POSIX_MEMALIGN)
 148    void *mem;
 149
 150    mem = _mesa_align_malloc(bytes, alignment);
 151    if (mem != NULL) {
 152       (void) memset(mem, 0, bytes);
 153    }
 154
 155    return mem;
 156 #elif defined(_WIN32) && defined(_MSC_VER)
 157    void *mem;
 158
 159    mem = _aligned_malloc(bytes, alignment);
 160    if (mem != NULL) {
 161       (void) memset(mem, 0, bytes);
 162    }
 163
 164    return mem;
 165 #else
 166    uintptr_t ptr, buf;
 167
 168    ASSERT( alignment > 0 );
 169
 170    ptr = (uintptr_t) _mesa_calloc(bytes + alignment + sizeof(void *));
 171    if (!ptr)
 172       return NULL;
 173
 174    buf = (ptr + alignment + sizeof(void *)) & ~(uintptr_t)(alignment - 1);
 175    *(uintptr_t *)(buf - sizeof(void *)) = ptr;
 176
 177 #ifdef DEBUG
 178    /* mark the non-aligned area */
 179    while ( ptr < buf - sizeof(void *) ) {
 180       *(unsigned long *)ptr = 0xcdcdcdcd;
 181       ptr += sizeof(unsigned long);
 182    }
 183 #endif
 184
 185    return (void *)buf;
 186 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 187 }
 188
 189 /**
 190  * Free memory which was allocated with either _mesa_align_malloc()
 191  * or _mesa_align_calloc().
 192  * \param ptr pointer to the memory to be freed.
 193  * The actual address to free is stored in the word immediately before the
 194  * address the client sees.
 195  */
 196 void
 197 _mesa_align_free(void *ptr)
 198 {
 199 #if defined(HAVE_POSIX_MEMALIGN)
 200    free(ptr);
 201 #elif defined(_WIN32) && defined(_MSC_VER)
 202    _aligned_free(ptr);
 203 #else
 204    void **cubbyHole = (void **) ((char *) ptr - sizeof(void *));
 205    void *realAddr = *cubbyHole;
 206    _mesa_free(realAddr);
 207 #endif /* defined(HAVE_POSIX_MEMALIGN) */
 208 }
 209
 210 /**
 211  * Reallocate memory, with alignment.
 212  */
 213 void *
 214 _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
 215                     unsigned long alignment)
 216 {
 217 #if defined(_WIN32) && defined(_MSC_VER)
 218    (void) oldSize;
 219    return _aligned_realloc(oldBuffer, newSize, alignment);
 220 #else
 221    const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
 222    void *newBuf = _mesa_align_malloc(newSize, alignment);
 223    if (newBuf && oldBuffer && copySize > 0) {
 224       _mesa_memcpy(newBuf, oldBuffer, copySize);
 225    }
 226    if (oldBuffer)
 227       _mesa_align_free(oldBuffer);
 228    return newBuf;
 229 #endif
 230 }
 231
 232
 233
 234 /** Reallocate memory */
 235 void *
 236 _mesa_realloc(void *oldBuffer, size_t oldSize, size_t newSize)
 237 {
 238    const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
 239    void *newBuffer = _mesa_malloc(newSize);
 240    if (newBuffer && oldBuffer && copySize > 0)
 241       _mesa_memcpy(newBuffer, oldBuffer, copySize);
 242    if (oldBuffer)
 243       _mesa_free(oldBuffer);
 244    return newBuffer;
 245 }
 246
 247 /** memcpy wrapper */
 248 void *
 249 _mesa_memcpy(void *dest, const void *src, size_t n)
 250 {
 251 #if defined(SUNOS4)
 252    return memcpy((char *) dest, (char *) src, (int) n);
 253 #else
 254    return memcpy(dest, src, n);
 255 #endif
 256 }
 257
 258 /** Wrapper around memset() */
 259 void
 260 _mesa_memset( void *dst, int val, size_t n )
 261 {
 262 #if defined(SUNOS4)
 263    memset( (char *) dst, (int) val, (int) n );
 264 #else
 265    memset(dst, val, n);
 266 #endif
 267 }
 268
 269 /**
 270  * Fill memory with a constant 16bit word.
 271  * \param dst destination pointer.
 272  * \param val value.
 273  * \param n number of words.
 274  */
 275 void
 276 _mesa_memset16( unsigned short *dst, unsigned short val, size_t n )
 277 {
 278    while (n-- > 0)
 279       *dst++ = val;
 280 }
 281
 282 /** Wrapper around either memset() or bzero() */
 283 void
 284 _mesa_bzero( void *dst, size_t n )
 285 {
 286 #if defined(__FreeBSD__)
 287    bzero( dst, n );
 288 #else
 289    memset( dst, 0, n );
 290 #endif
 291 }
 292
 293 /** Wrapper around memcmp() */
 294 int
 295 _mesa_memcmp( const void *s1, const void *s2, size_t n )
 296 {
 297 #if defined(SUNOS4)
 298    return memcmp( (char *) s1, (char *) s2, (int) n );
 299 #else
 300    return memcmp(s1, s2, n);
 301 #endif
 302 }
 303
 304 /*@}*/
 305
 306
 307 /**********************************************************************/
 308 /** \name Math */
 309 /*@{*/
 310
 311 /** Wrapper around sin() */
 312 double
 313 _mesa_sin(double a)
 314 {
 315    return sin(a);
 316 }
 317
 318 /** Single precision wrapper around sin() */
 319 float
 320 _mesa_sinf(float a)
 321 {
 322    return (float) sin((double) a);
 323 }
 324
 325 /** Wrapper around cos() */
 326 double
 327 _mesa_cos(double a)
 328 {
 329    return cos(a);
 330 }
 331
 332 /** Single precision wrapper around asin() */
 333 float
 334 _mesa_asinf(float x)
 335 {
 336    return (float) asin((double) x);
 337 }
 338
 339 /** Single precision wrapper around atan() */
 340 float
 341 _mesa_atanf(float x)
 342 {
 343    return (float) atan((double) x);
 344 }
 345
 346 /** Wrapper around sqrt() */
 347 double
 348 _mesa_sqrtd(double x)
 349 {
 350    return sqrt(x);
 351 }
 352
 353
 354 /*
 355  * A High Speed, Low Precision Square Root
 356  * by Paul Lalonde and Robert Dawson
 357  * from "Graphics Gems", Academic Press, 1990
 358  *
 359  * SPARC implementation of a fast square root by table
 360  * lookup.
 361  * SPARC floating point format is as follows:
 362  *
 363  * BIT 31       30      23      22      0
 364  *     sign     exponent        mantissa
 365  */
 366 static short sqrttab[0x100];    /* declare table of square roots */
 367
 368 void
 369 _mesa_init_sqrt_table(void)
 370 {
 371 #if defined(USE_IEEE) && !defined(DEBUG)
 372    unsigned short i;
 373    fi_type fi;     /* to access the bits of a float in  C quickly  */
 374                    /* we use a union defined in glheader.h         */
 375
 376    for(i=0; i<= 0x7f; i++) {
 377       fi.i = 0;
 378
 379       /*
 380        * Build a float with the bit pattern i as mantissa
 381        * and an exponent of 0, stored as 127
 382        */
 383
 384       fi.i = (i << 16) | (127 << 23);
 385       fi.f = _mesa_sqrtd(fi.f);
 386
 387       /*
 388        * Take the square root then strip the first 7 bits of
 389        * the mantissa into the table
 390        */
 391
 392       sqrttab[i] = (fi.i & 0x7fffff) >> 16;
 393
 394       /*
 395        * Repeat the process, this time with an exponent of
 396        * 1, stored as 128
 397        */
 398
 399       fi.i = 0;
 400       fi.i = (i << 16) | (128 << 23);
 401       fi.f = sqrt(fi.f);
 402       sqrttab[i+0x80] = (fi.i & 0x7fffff) >> 16;
 403    }
 404 #else
 405    (void) sqrttab;  /* silence compiler warnings */
 406 #endif /*HAVE_FAST_MATH*/
 407 }
 408
 409
 410 /**
 411  * Single precision square root.
 412  */
 413 float
 414 _mesa_sqrtf( float x )
 415 {
 416 #if defined(USE_IEEE) && !defined(DEBUG)
 417    fi_type num;
 418                                 /* to access the bits of a float in C
 419                                  * we use a union from glheader.h     */
 420
 421    short e;                     /* the exponent */
 422    if (x == 0.0F) return 0.0F;  /* check for square root of 0 */
 423    num.f = x;
 424    e = (num.i >> 23) - 127;     /* get the exponent - on a SPARC the */
 425                                 /* exponent is stored with 127 added */
 426    num.i &= 0x7fffff;           /* leave only the mantissa */
 427    if (e & 0x01) num.i |= 0x800000;
 428                                 /* the exponent is odd so we have to */
 429                                 /* look it up in the second half of  */
 430                                 /* the lookup table, so we set the   */
 431                                 /* high bit                                */
 432    e >>= 1;                     /* divide the exponent by two */
 433                                 /* note that in C the shift */
 434                                 /* operators are sign preserving */
 435                                 /* for signed operands */
 436    /* Do the table lookup, based on the quaternary mantissa,
 437     * then reconstruct the result back into a float
 438     */
 439    num.i = ((sqrttab[num.i >> 16]) << 16) | ((e + 127) << 23);
 440
 441    return num.f;
 442 #else
 443    return (float) _mesa_sqrtd((double) x);
 444 #endif
 445 }
 446
 447
 448 /**
 449  inv_sqrt - A single precision 1/sqrt routine for IEEE format floats.
 450  written by Josh Vanderhoof, based on newsgroup posts by James Van Buskirk
 451  and Vesa Karvonen.
 452 */
 453 float
 454 _mesa_inv_sqrtf(float n)
 455 {
 456 #if defined(USE_IEEE) && !defined(DEBUG)
 457         float r0, x0, y0;
 458         float r1, x1, y1;
 459         float r2, x2, y2;
 460 #if 0 /* not used, see below -BP */
 461         float r3, x3, y3;
 462 #endif
 463         fi_type u;
 464         unsigned int magic;
 465
 466         /*
 467          Exponent part of the magic number -
 468
 469          We want to:
 470          1. subtract the bias from the exponent,
 471          2. negate it
 472          3. divide by two (rounding towards -inf)
 473          4. add the bias back
 474
 475          Which is the same as subtracting the exponent from 381 and dividing
 476          by 2.
 477
 478          floor(-(x - 127) / 2) + 127 = floor((381 - x) / 2)
 479         */
 480
 481         magic = 381 << 23;
 482
 483         /*
 484          Significand part of magic number -
 485
 486          With the current magic number, "(magic - u.i) >> 1" will give you:
 487
 488          for 1 <= u.f <= 2: 1.25 - u.f / 4
 489          for 2 <= u.f <= 4: 1.00 - u.f / 8
 490
 491          This isn't a bad approximation of 1/sqrt.  The maximum difference from
 492          1/sqrt will be around .06.  After three Newton-Raphson iterations, the
 493          maximum difference is less than 4.5e-8.  (Which is actually close
 494          enough to make the following bias academic...)
 495
 496          To get a better approximation you can add a bias to the magic
 497          number.  For example, if you subtract 1/2 of the maximum difference in
 498          the first approximation (.03), you will get the following function:
 499
 500          for 1 <= u.f <= 2:    1.22 - u.f / 4
 501          for 2 <= u.f <= 3.76: 0.97 - u.f / 8
 502          for 3.76 <= u.f <= 4: 0.72 - u.f / 16
 503          (The 3.76 to 4 range is where the result is < .5.)
 504
 505          This is the closest possible initial approximation, but with a maximum
 506          error of 8e-11 after three NR iterations, it is still not perfect.  If
 507          you subtract 0.0332281 instead of .03, the maximum error will be
 508          2.5e-11 after three NR iterations, which should be about as close as
 509          is possible.
 510
 511          for 1 <= u.f <= 2:    1.2167719 - u.f / 4
 512          for 2 <= u.f <= 3.73: 0.9667719 - u.f / 8
 513          for 3.73 <= u.f <= 4: 0.7167719 - u.f / 16
 514
 515         */
 516
 517         magic -= (int)(0.0332281 * (1 << 25));
 518
 519         u.f = n;
 520         u.i = (magic - u.i) >> 1;
 521
 522         /*
 523          Instead of Newton-Raphson, we use Goldschmidt's algorithm, which
 524          allows more parallelism.  From what I understand, the parallelism
 525          comes at the cost of less precision, because it lets error
 526          accumulate across iterations.
 527         */
 528         x0 = 1.0f;
 529         y0 = 0.5f * n;
 530         r0 = u.f;
 531
 532         x1 = x0 * r0;
 533         y1 = y0 * r0 * r0;
 534         r1 = 1.5f - y1;
 535
 536         x2 = x1 * r1;
 537         y2 = y1 * r1 * r1;
 538         r2 = 1.5f - y2;
 539
 540 #if 1
 541         return x2 * r2;  /* we can stop here, and be conformant -BP */
 542 #else
 543         x3 = x2 * r2;
 544         y3 = y2 * r2 * r2;
 545         r3 = 1.5f - y3;
 546
 547         return x3 * r3;
 548 #endif
 549 #else
 550         return (float) (1.0 / sqrt(n));
 551 #endif
 552 }
 553
 554
 555 /** Wrapper around pow() */
 556 double
 557 _mesa_pow(double x, double y)
 558 {
 559    return pow(x, y);
 560 }
 561
 562
 563 /**
 564  * Find the first bit set in a word.
 565  */
 566 int
 567 _mesa_ffs(int32_t i)
 568 {
 569 #if (defined(_WIN32) ) || defined(__IBMC__) || defined(__IBMCPP__)
 570    register int bit = 0;
 571    if (i != 0) {
 572       if ((i & 0xffff) == 0) {
 573          bit += 16;
 574          i >>= 16;
 575       }
 576       if ((i & 0xff) == 0) {
 577          bit += 8;
 578          i >>= 8;
 579       }
 580       if ((i & 0xf) == 0) {
 581          bit += 4;
 582          i >>= 4;
 583       }
 584       while ((i & 1) == 0) {
 585          bit++;
 586          i >>= 1;
 587       }
 588       bit++;
 589    }
 590    return bit;
 591 #else
 592    return ffs(i);
 593 #endif
 594 }
 595
 596
 597 /**
 598  * Find position of first bit set in given value.
 599  * XXX Warning: this function can only be used on 64-bit systems!
 600  * \return  position of least-significant bit set, starting at 1, return zero
 601  *          if no bits set.
 602  */
 603 int
 604 _mesa_ffsll(int64_t val)
 605 {
 606 #ifdef ffsll
 607    return ffsll(val);
 608 #else
 609    int bit;
 610
 611    assert(sizeof(val) == 8);
 612
 613    bit = _mesa_ffs((int32_t)val);
 614    if (bit != 0)
 615       return bit;
 616
 617    bit = _mesa_ffs((int32_t)(val >> 32));
 618    if (bit != 0)
 619       return 32 + bit;
 620
 621    return 0;
 622 #endif
 623 }
 624
 625
 626 /**
 627  * Return number of bits set in given GLuint.
 628  */
 629 unsigned int
 630 _mesa_bitcount(unsigned int n)
 631 {
 632 #if defined(__GNUC__)
 633    return __builtin_popcount(n);
 634 #else
 635    unsigned int bits;
 636    for (bits = 0; n > 0; n = n >> 1) {
 637       bits += (n & 1);
 638    }
 639    return bits;
 640 #endif
 641 }
 642
 643
 644 /**
 645  * Convert a 4-byte float to a 2-byte half float.
 646  * Based on code from:
 647  * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html
 648  */
 649 GLhalfARB
 650 _mesa_float_to_half(float val)
 651 {
 652    const fi_type fi = {val};
 653    const int flt_m = fi.i & 0x7fffff;
 654    const int flt_e = (fi.i >> 23) & 0xff;
 655    const int flt_s = (fi.i >> 31) & 0x1;
 656    int s, e, m = 0;
 657    GLhalfARB result;
 658
 659    /* sign bit */
 660    s = flt_s;
 661
 662    /* handle special cases */
 663    if ((flt_e == 0) && (flt_m == 0)) {
 664       /* zero */
 665       /* m = 0; - already set */
 666       e = 0;
 667    }
 668    else if ((flt_e == 0) && (flt_m != 0)) {
 669       /* denorm -- denorm float maps to 0 half */
 670       /* m = 0; - already set */
 671       e = 0;
 672    }
 673    else if ((flt_e == 0xff) && (flt_m == 0)) {
 674       /* infinity */
 675       /* m = 0; - already set */
 676       e = 31;
 677    }
 678    else if ((flt_e == 0xff) && (flt_m != 0)) {
 679       /* NaN */
 680       m = 1;
 681       e = 31;
 682    }
 683    else {
 684       /* regular number */
 685       const int new_exp = flt_e - 127;
 686       if (new_exp < -24) {
 687          /* this maps to 0 */
 688          /* m = 0; - already set */
 689          e = 0;
 690       }
 691       else if (new_exp < -14) {
 692          /* this maps to a denorm */
 693          unsigned int exp_val = (unsigned int) (-14 - new_exp); /* 2^-exp_val*/
 694          e = 0;
 695          switch (exp_val) {
 696             case 0:
 697                _mesa_warning(NULL,
 698                    "float_to_half: logical error in denorm creation!\n");
 699                /* m = 0; - already set */
 700                break;
 701             case 1: m = 512 + (flt_m >> 14); break;
 702             case 2: m = 256 + (flt_m >> 15); break;
 703             case 3: m = 128 + (flt_m >> 16); break;
 704             case 4: m = 64 + (flt_m >> 17); break;
 705             case 5: m = 32 + (flt_m >> 18); break;
 706             case 6: m = 16 + (flt_m >> 19); break;
 707             case 7: m = 8 + (flt_m >> 20); break;
 708             case 8: m = 4 + (flt_m >> 21); break;
 709             case 9: m = 2 + (flt_m >> 22); break;
 710             case 10: m = 1; break;
 711          }
 712       }
 713       else if (new_exp > 15) {
 714          /* map this value to infinity */
 715          /* m = 0; - already set */
 716          e = 31;
 717       }
 718       else {
 719          /* regular */
 720          e = new_exp + 15;
 721          m = flt_m >> 13;
 722       }
 723    }
 724
 725    result = (s << 15) | (e << 10) | m;
 726    return result;
 727 }
 728
 729
 730 /**
 731  * Convert a 2-byte half float to a 4-byte float.
 732  * Based on code from:
 733  * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html
 734  */
 735 float
 736 _mesa_half_to_float(GLhalfARB val)
 737 {
 738    /* XXX could also use a 64K-entry lookup table */
 739    const int m = val & 0x3ff;
 740    const int e = (val >> 10) & 0x1f;
 741    const int s = (val >> 15) & 0x1;
 742    int flt_m, flt_e, flt_s;
 743    fi_type fi;
 744    float result;
 745
 746    /* sign bit */
 747    flt_s = s;
 748
 749    /* handle special cases */
 750    if ((e == 0) && (m == 0)) {
 751       /* zero */
 752       flt_m = 0;
 753       flt_e = 0;
 754    }
 755    else if ((e == 0) && (m != 0)) {
 756       /* denorm -- denorm half will fit in non-denorm single */
 757       const float half_denorm = 1.0f / 16384.0f; /* 2^-14 */
 758       float mantissa = ((float) (m)) / 1024.0f;
 759       float sign = s ? -1.0f : 1.0f;
 760       return sign * mantissa * half_denorm;
 761    }
 762    else if ((e == 31) && (m == 0)) {
 763       /* infinity */
 764       flt_e = 0xff;
 765       flt_m = 0;
 766    }
 767    else if ((e == 31) && (m != 0)) {
 768       /* NaN */
 769       flt_e = 0xff;
 770       flt_m = 1;
 771    }
 772    else {
 773       /* regular */
 774       flt_e = e + 112;
 775       flt_m = m << 13;
 776    }
 777
 778    fi.i = (flt_s << 31) | (flt_e << 23) | flt_m;
 779    result = fi.f;
 780    return result;
 781 }
 782
 783 /*@}*/
 784
 785
 786 /**********************************************************************/
 787 /** \name Sort & Search */
 788 /*@{*/
 789
 790 /**
 791  * Wrapper for bsearch().
 792  */
 793 void *
 794 _mesa_bsearch( const void *key, const void *base, size_t nmemb, size_t size,
 795                int (*compar)(const void *, const void *) )
 796 {
 797 #if defined(_WIN32_WCE)
 798    void *mid;
 799    int cmp;
 800    while (nmemb) {
 801       nmemb >>= 1;
 802       mid = (char *)base + nmemb * size;
 803       cmp = (*compar)(key, mid);
 804       if (cmp == 0)
 805          return mid;
 806       if (cmp > 0) {
 807          base = (char *)mid + size;
 808          --nmemb;
 809       }
 810    }
 811    return NULL;
 812 #else
 813    return bsearch(key, base, nmemb, size, compar);
 814 #endif
 815 }
 816
 817 /*@}*/
 818
 819
 820 /**********************************************************************/
 821 /** \name Environment vars */
 822 /*@{*/
 823
 824 /**
 825  * Wrapper for getenv().
 826  */
 827 char *
 828 _mesa_getenv( const char *var )
 829 {
 830 #if defined(_XBOX) || defined(_WIN32_WCE)
 831    return NULL;
 832 #else
 833    return getenv(var);
 834 #endif
 835 }
 836
 837 /*@}*/
 838
 839
 840 /**********************************************************************/
 841 /** \name String */
 842 /*@{*/
 843
 844 /** Wrapper around strstr() */
 845 char *
 846 _mesa_strstr( const char *haystack, const char *needle )
 847 {
 848    return strstr(haystack, needle);
 849 }
 850
 851 /** Wrapper around strncat() */
 852 char *
 853 _mesa_strncat( char *dest, const char *src, size_t n )
 854 {
 855    return strncat(dest, src, n);
 856 }
 857
 858 /** Wrapper around strcpy() */
 859 char *
 860 _mesa_strcpy( char *dest, const char *src )
 861 {
 862    return strcpy(dest, src);
 863 }
 864
 865 /** Wrapper around strncpy() */
 866 char *
 867 _mesa_strncpy( char *dest, const char *src, size_t n )
 868 {
 869    return strncpy(dest, src, n);
 870 }
 871
 872 /** Wrapper around strlen() */
 873 size_t
 874 _mesa_strlen( const char *s )
 875 {
 876    return strlen(s);
 877 }
 878
 879 /** Wrapper around strcmp() */
 880 int
 881 _mesa_strcmp( const char *s1, const char *s2 )
 882 {
 883    return strcmp(s1, s2);
 884 }
 885
 886 /** Wrapper around strncmp() */
 887 int
 888 _mesa_strncmp( const char *s1, const char *s2, size_t n )
 889 {
 890    return strncmp(s1, s2, n);
 891 }
 892
 893 /**
 894  * Implemented using _mesa_malloc() and _mesa_strcpy.
 895  * Note that NULL is handled accordingly.
 896  */
 897 char *
 898 _mesa_strdup( const char *s )
 899 {
 900    if (s) {
 901       size_t l = _mesa_strlen(s);
 902       char *s2 = (char *) _mesa_malloc(l + 1);
 903       if (s2)
 904          _mesa_strcpy(s2, s);
 905       return s2;
 906    }
 907    else {
 908       return NULL;
 909    }
 910 }
 911
 912 /** Wrapper around atoi() */
 913 int
 914 _mesa_atoi(const char *s)
 915 {
 916    return atoi(s);
 917 }
 918
 919 /** Wrapper around strtod() */
 920 double
 921 _mesa_strtod( const char *s, char **end )
 922 {
 923 #ifdef _GNU_SOURCE
 924    static locale_t loc = NULL;
 925    if (!loc) {
 926       loc = newlocale(LC_CTYPE_MASK, "C", NULL);
 927    }
 928    return strtod_l(s, end, loc);
 929 #else
 930    return strtod(s, end);
 931 #endif
 932 }
 933
 934 /** Compute simple checksum/hash for a string */
 935 unsigned int
 936 _mesa_str_checksum(const char *str)
 937 {
 938    /* This could probably be much better */
 939    unsigned int sum, i;
 940    const char *c;
 941    sum = i = 1;
 942    for (c = str; *c; c++, i++)
 943       sum += *c * (i % 100);
 944    return sum + i;
 945 }
 946
 947
 948 /*@}*/
 949
 950
 951 /**********************************************************************/
 952 /** \name I/O */
 953 /*@{*/
 954
 955 /** Wrapper around vsprintf() */
 956 int
 957 _mesa_sprintf( char *str, const char *fmt, ... )
 958 {
 959    int r;
 960    va_list args;
 961    va_start( args, fmt );
 962    r = vsprintf( str, fmt, args );
 963    va_end( args );
 964    return r;
 965 }
 966
 967 /** Wrapper around vsnprintf() */
 968 int
 969 _mesa_snprintf( char *str, size_t size, const char *fmt, ... )
 970 {
 971    int r;
 972    va_list args;
 973    va_start( args, fmt );
 974    r = vsnprintf( str, size, fmt, args );
 975    va_end( args );
 976    return r;
 977 }
 978
 979 /** Wrapper around printf(), using vsprintf() for the formatting. */
 980 void
 981 _mesa_printf( const char *fmtString, ... )
 982 {
 983    va_list args;
 984    va_start( args, fmtString );
 985    vfprintf(stderr, fmtString, args);
 986    va_end( args );
 987 }
 988
 989 /** Wrapper around fprintf(), using vsprintf() for the formatting. */
 990 void
 991 _mesa_fprintf( FILE *f, const char *fmtString, ... )
 992 {
 993    char s[MAXSTRING];
 994    va_list args;
 995    va_start( args, fmtString );
 996    vsnprintf(s, MAXSTRING, fmtString, args);
 997    va_end( args );
 998    fprintf(f, "%s", s);
 999 }
1000
1001
1002 /** Wrapper around vsprintf() */
1003 int
1004 _mesa_vsprintf( char *str, const char *fmt, va_list args )
1005 {
1006    return vsprintf( str, fmt, args );
1007 }
1008
1009 /*@}*/
1010
1011
1012 /**********************************************************************/
1013 /** \name Diagnostics */
1014 /*@{*/
1015
1016 static void
1017 output_if_debug(const char *prefixString, const char *outputString,
1018                 GLboolean newline)
1019 {
1020    static int debug = -1;
1021
1022    /* Check the MESA_DEBUG environment variable if it hasn't
1023     * been checked yet.  We only have to check it once...
1024     */
1025    if (debug == -1) {
1026       char *env = _mesa_getenv("MESA_DEBUG");
1027
1028       /* In a debug build, we print warning messages *unless*
1029        * MESA_DEBUG is 0.  In a non-debug build, we don't
1030        * print warning messages *unless* MESA_DEBUG is
1031        * set *to any value*.
1032        */
1033 #ifdef DEBUG
1034       debug = (env != NULL && _mesa_atoi(env) == 0) ? 0 : 1;
1035 #else
1036       debug = (env != NULL) ? 1 : 0;
1037 #endif
1038    }
1039
1040    /* Now only print the string if we're required to do so. */
1041    if (debug) {
1042       fprintf(stderr, "%s: %s", prefixString, outputString);
1043       if (newline)
1044          fprintf(stderr, "\n");
1045
1046 #if defined(_WIN32) && !defined(_WIN32_WCE)
1047       /* stderr from windows applications without console is not usually
1048        * visible, so communicate with the debugger instead */
1049       {
1050          char buf[4096];
1051          _mesa_snprintf(buf, sizeof(buf), "%s: %s%s", prefixString, outputString, newline ? "\n" : "");
1052          OutputDebugStringA(buf);
1053       }
1054 #endif
1055    }
1056 }
1057
1058
1059 /**
1060  * Return string version of GL error code.
1061  */
1062 static const char *
1063 error_string( GLenum error )
1064 {
1065    switch (error) {
1066    case GL_NO_ERROR:
1067       return "GL_NO_ERROR";
1068    case GL_INVALID_VALUE:
1069       return "GL_INVALID_VALUE";
1070    case GL_INVALID_ENUM:
1071       return "GL_INVALID_ENUM";
1072    case GL_INVALID_OPERATION:
1073       return "GL_INVALID_OPERATION";
1074    case GL_STACK_OVERFLOW:
1075       return "GL_STACK_OVERFLOW";
1076    case GL_STACK_UNDERFLOW:
1077       return "GL_STACK_UNDERFLOW";
1078    case GL_OUT_OF_MEMORY:
1079       return "GL_OUT_OF_MEMORY";
1080    case GL_TABLE_TOO_LARGE:
1081       return "GL_TABLE_TOO_LARGE";
1082    case GL_INVALID_FRAMEBUFFER_OPERATION_EXT:
1083       return "GL_INVALID_FRAMEBUFFER_OPERATION";
1084    default:
1085       return "unknown";
1086    }
1087 }
1088
1089
1090 /**
1091  * When a new type of error is recorded, print a message describing
1092  * previous errors which were accumulated.
1093  */
1094 static void
1095 flush_delayed_errors( GLcontext *ctx )
1096 {
1097    char s[MAXSTRING];
1098
1099    if (ctx->ErrorDebugCount) {
1100       _mesa_snprintf(s, MAXSTRING, "%d similar %s errors",
1101                      ctx->ErrorDebugCount,
1102                      error_string(ctx->ErrorValue));
1103
1104       output_if_debug("Mesa", s, GL_TRUE);
1105
1106       ctx->ErrorDebugCount = 0;
1107    }
1108 }
1109
1110
1111 /**
1112  * Report a warning (a recoverable error condition) to stderr if
1113  * either DEBUG is defined or the MESA_DEBUG env var is set.
1114  *
1115  * \param ctx GL context.
1116  * \param fmtString printf()-like format string.
1117  */
1118 void
1119 _mesa_warning( GLcontext *ctx, const char *fmtString, ... )
1120 {
1121    char str[MAXSTRING];
1122    va_list args;
1123    va_start( args, fmtString );
1124    (void) vsnprintf( str, MAXSTRING, fmtString, args );
1125    va_end( args );
1126
1127    if (ctx)
1128       flush_delayed_errors( ctx );
1129
1130    output_if_debug("Mesa warning", str, GL_TRUE);
1131 }
1132
1133
1134 /**
1135  * Report an internal implementation problem.
1136  * Prints the message to stderr via fprintf().
1137  *
1138  * \param ctx GL context.
1139  * \param fmtString problem description string.
1140  */
1141 void
1142 _mesa_problem( const GLcontext *ctx, const char *fmtString, ... )
1143 {
1144    va_list args;
1145    char str[MAXSTRING];
1146    (void) ctx;
1147
1148    va_start( args, fmtString );
1149    vsnprintf( str, MAXSTRING, fmtString, args );
1150    va_end( args );
1151
1152    fprintf(stderr, "Mesa %s implementation error: %s\n", MESA_VERSION_STRING, str);
1153    fprintf(stderr, "Please report at bugzilla.freedesktop.org\n");
1154 }
1155
1156
1157 /**
1158  * Record an OpenGL state error.  These usually occur when the user
1159  * passes invalid parameters to a GL function.
1160  *
1161  * If debugging is enabled (either at compile-time via the DEBUG macro, or
1162  * run-time via the MESA_DEBUG environment variable), report the error with
1163  * _mesa_debug().
1164  *
1165  * \param ctx the GL context.
1166  * \param error the error value.
1167  * \param fmtString printf() style format string, followed by optional args
1168  */
1169 void
1170 _mesa_error( GLcontext *ctx, GLenum error, const char *fmtString, ... )
1171 {
1172    static GLint debug = -1;
1173
1174    /* Check debug environment variable only once:
1175     */
1176    if (debug == -1) {
1177       const char *debugEnv = _mesa_getenv("MESA_DEBUG");
1178
1179 #ifdef DEBUG
1180       if (debugEnv && _mesa_strstr(debugEnv, "silent"))
1181          debug = GL_FALSE;
1182       else
1183          debug = GL_TRUE;
1184 #else
1185       if (debugEnv)
1186          debug = GL_TRUE;
1187       else
1188          debug = GL_FALSE;
1189 #endif
1190    }
1191
1192    if (debug) {
1193       if (ctx->ErrorValue == error &&
1194           ctx->ErrorDebugFmtString == fmtString) {
1195          ctx->ErrorDebugCount++;
1196       }
1197       else {
1198          char s[MAXSTRING], s2[MAXSTRING];
1199          va_list args;
1200
1201          flush_delayed_errors( ctx );
1202
1203          va_start(args, fmtString);
1204          vsnprintf(s, MAXSTRING, fmtString, args);
1205          va_end(args);
1206
1207          _mesa_snprintf(s2, MAXSTRING, "%s in %s", error_string(error), s);
1208          output_if_debug("Mesa: User error", s2, GL_TRUE);
1209
1210          ctx->ErrorDebugFmtString = fmtString;
1211          ctx->ErrorDebugCount = 0;
1212       }
1213    }
1214
1215    _mesa_record_error(ctx, error);
1216 }
1217
1218
1219 /**
1220  * Report debug information.  Print error message to stderr via fprintf().
1221  * No-op if DEBUG mode not enabled.
1222  *
1223  * \param ctx GL context.
1224  * \param fmtString printf()-style format string, followed by optional args.
1225  */
1226 void
1227 _mesa_debug( const GLcontext *ctx, const char *fmtString, ... )
1228 {
1229 #ifdef DEBUG
1230    char s[MAXSTRING];
1231    va_list args;
1232    va_start(args, fmtString);
1233    vsnprintf(s, MAXSTRING, fmtString, args);
1234    va_end(args);
1235    output_if_debug("Mesa", s, GL_FALSE);
1236 #endif /* DEBUG */
1237    (void) ctx;
1238    (void) fmtString;
1239 }
1240
1241 /*@}*/