1 /************************************************************************** 2 * 3 * Copyright 2008 VMware, Inc. 4 * All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sub license, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice (including the 15 * next paragraph) shall be included in all copies or substantial portions 16 * of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. 21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR 22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 25 * 26 **************************************************************************/ 27 28 29 /** 30 * Math utilities and approximations for common math functions. 31 * Reduced precision is usually acceptable in shaders... 32 * 33 * "fast" is used in the names of functions which are low-precision, 34 * or at least lower-precision than the normal C lib functions. 35 */ 36 37 38 #ifndef U_MATH_H 39 #define U_MATH_H 40 41 42 #include "c99_compat.h" 43 #include <assert.h> 44 #include <float.h> 45 #include <stdarg.h> 46 #include <math.h> 47 48 #include "bitscan.h" 49 #include "u_endian.h" /* for UTIL_ARCH_BIG_ENDIAN */ 50 51 #ifdef __cplusplus 52 extern "C" { 53 #endif 54 55 56 #ifndef M_SQRT2 57 #define M_SQRT2 1.41421356237309504880 58 #endif 59 60 61 /** 62 * Initialize math module. This should be called before using any 63 * other functions in this module. 64 */ 65 extern void 66 util_init_math(void); 67 68 69 union fi { 70 float f; 71 int32_t i; 72 uint32_t ui; 73 }; 74 75 76 union di { 77 double d; 78 int64_t i; 79 uint64_t ui; 80 }; 81 82 83 /** 84 * Extract the IEEE float32 exponent. 85 */ 86 static inline signed util_get_float32_exponent(float x)87 util_get_float32_exponent(float x) 88 { 89 union fi f; 90 91 f.f = x; 92 93 return ((f.ui >> 23) & 0xff) - 127; 94 } 95 96 97 #define LOG2_TABLE_SIZE_LOG2 8 98 #define LOG2_TABLE_SCALE (1 << LOG2_TABLE_SIZE_LOG2) 99 #define LOG2_TABLE_SIZE (LOG2_TABLE_SCALE + 1) 100 extern float log2_table[LOG2_TABLE_SIZE]; 101 102 103 /** 104 * Fast approximation to log2(x). 105 */ 106 static inline float util_fast_log2(float x)107 util_fast_log2(float x) 108 { 109 union fi num; 110 float epart, mpart; 111 num.f = x; 112 epart = (float)(((num.i & 0x7f800000) >> 23) - 127); 113 /* mpart = log2_table[mantissa*LOG2_TABLE_SCALE + 0.5] */ 114 mpart = log2_table[((num.i & 0x007fffff) + (1 << (22 - LOG2_TABLE_SIZE_LOG2))) >> (23 - LOG2_TABLE_SIZE_LOG2)]; 115 return epart + mpart; 116 } 117 118 119 /** 120 * Floor(x), returned as int. 121 */ 122 static inline int util_ifloor(float f)123 util_ifloor(float f) 124 { 125 #if defined(USE_X86_ASM) && defined(__GNUC__) && defined(__i386__) 126 /* 127 * IEEE floor for computers that round to nearest or even. 128 * 'f' must be between -4194304 and 4194303. 129 * This floor operation is done by "(iround(f + .5) + iround(f - .5)) >> 1", 130 * but uses some IEEE specific tricks for better speed. 131 * Contributed by Josh Vanderhoof 132 */ 133 int ai, bi; 134 double af, bf; 135 af = (3 << 22) + 0.5 + (double)f; 136 bf = (3 << 22) + 0.5 - (double)f; 137 /* GCC generates an extra fstp/fld without this. */ 138 __asm__ ("fstps %0" : "=m" (ai) : "t" (af) : "st"); 139 __asm__ ("fstps %0" : "=m" (bi) : "t" (bf) : "st"); 140 return (ai - bi) >> 1; 141 #else 142 int ai, bi; 143 double af, bf; 144 union fi u; 145 af = (3 << 22) + 0.5 + (double) f; 146 bf = (3 << 22) + 0.5 - (double) f; 147 u.f = (float) af; ai = u.i; 148 u.f = (float) bf; bi = u.i; 149 return (ai - bi) >> 1; 150 #endif 151 } 152 153 154 /** 155 * Round float to nearest int. 156 */ 157 static inline int util_iround(float f)158 util_iround(float f) 159 { 160 #if defined(PIPE_CC_GCC) && defined(PIPE_ARCH_X86) 161 int r; 162 __asm__ ("fistpl %0" : "=m" (r) : "t" (f) : "st"); 163 return r; 164 #elif defined(PIPE_CC_MSVC) && defined(PIPE_ARCH_X86) 165 int r; 166 _asm { 167 fld f 168 fistp r 169 } 170 return r; 171 #else 172 if (f >= 0.0f) 173 return (int) (f + 0.5f); 174 else 175 return (int) (f - 0.5f); 176 #endif 177 } 178 179 180 /** 181 * Approximate floating point comparison 182 */ 183 static inline bool util_is_approx(float a,float b,float tol)184 util_is_approx(float a, float b, float tol) 185 { 186 return fabsf(b - a) <= tol; 187 } 188 189 190 /** 191 * util_is_X_inf_or_nan = test if x is NaN or +/- Inf 192 * util_is_X_nan = test if x is NaN 193 * util_X_inf_sign = return +1 for +Inf, -1 for -Inf, or 0 for not Inf 194 * 195 * NaN can be checked with x != x, however this fails with the fast math flag 196 **/ 197 198 199 /** 200 * Single-float 201 */ 202 static inline bool util_is_inf_or_nan(float x)203 util_is_inf_or_nan(float x) 204 { 205 union fi tmp; 206 tmp.f = x; 207 return (tmp.ui & 0x7f800000) == 0x7f800000; 208 } 209 210 211 static inline bool util_is_nan(float x)212 util_is_nan(float x) 213 { 214 union fi tmp; 215 tmp.f = x; 216 return (tmp.ui & 0x7fffffff) > 0x7f800000; 217 } 218 219 220 static inline int util_inf_sign(float x)221 util_inf_sign(float x) 222 { 223 union fi tmp; 224 tmp.f = x; 225 if ((tmp.ui & 0x7fffffff) != 0x7f800000) { 226 return 0; 227 } 228 229 return (x < 0) ? -1 : 1; 230 } 231 232 233 /** 234 * Double-float 235 */ 236 static inline bool util_is_double_inf_or_nan(double x)237 util_is_double_inf_or_nan(double x) 238 { 239 union di tmp; 240 tmp.d = x; 241 return (tmp.ui & 0x7ff0000000000000ULL) == 0x7ff0000000000000ULL; 242 } 243 244 245 static inline bool util_is_double_nan(double x)246 util_is_double_nan(double x) 247 { 248 union di tmp; 249 tmp.d = x; 250 return (tmp.ui & 0x7fffffffffffffffULL) > 0x7ff0000000000000ULL; 251 } 252 253 254 static inline int util_double_inf_sign(double x)255 util_double_inf_sign(double x) 256 { 257 union di tmp; 258 tmp.d = x; 259 if ((tmp.ui & 0x7fffffffffffffffULL) != 0x7ff0000000000000ULL) { 260 return 0; 261 } 262 263 return (x < 0) ? -1 : 1; 264 } 265 266 267 /** 268 * Half-float 269 */ 270 static inline bool util_is_half_inf_or_nan(int16_t x)271 util_is_half_inf_or_nan(int16_t x) 272 { 273 return (x & 0x7c00) == 0x7c00; 274 } 275 276 277 static inline bool util_is_half_nan(int16_t x)278 util_is_half_nan(int16_t x) 279 { 280 return (x & 0x7fff) > 0x7c00; 281 } 282 283 284 static inline int util_half_inf_sign(int16_t x)285 util_half_inf_sign(int16_t x) 286 { 287 if ((x & 0x7fff) != 0x7c00) { 288 return 0; 289 } 290 291 return (x < 0) ? -1 : 1; 292 } 293 294 295 /** 296 * Return float bits. 297 */ 298 static inline unsigned fui(float f)299 fui( float f ) 300 { 301 union fi fi; 302 fi.f = f; 303 return fi.ui; 304 } 305 306 static inline float uif(uint32_t ui)307 uif(uint32_t ui) 308 { 309 union fi fi; 310 fi.ui = ui; 311 return fi.f; 312 } 313 314 315 /** 316 * Convert uint8_t to float in [0, 1]. 317 */ 318 static inline float ubyte_to_float(uint8_t ub)319 ubyte_to_float(uint8_t ub) 320 { 321 return (float) ub * (1.0f / 255.0f); 322 } 323 324 325 /** 326 * Convert float in [0,1] to uint8_t in [0,255] with clamping. 327 */ 328 static inline uint8_t float_to_ubyte(float f)329 float_to_ubyte(float f) 330 { 331 /* return 0 for NaN too */ 332 if (!(f > 0.0f)) { 333 return (uint8_t) 0; 334 } 335 else if (f >= 1.0f) { 336 return (uint8_t) 255; 337 } 338 else { 339 union fi tmp; 340 tmp.f = f; 341 tmp.f = tmp.f * (255.0f/256.0f) + 32768.0f; 342 return (uint8_t) tmp.i; 343 } 344 } 345 346 /** 347 * Convert uint16_t to float in [0, 1]. 348 */ 349 static inline float ushort_to_float(uint16_t us)350 ushort_to_float(uint16_t us) 351 { 352 return (float) us * (1.0f / 65535.0f); 353 } 354 355 356 /** 357 * Convert float in [0,1] to uint16_t in [0,65535] with clamping. 358 */ 359 static inline uint16_t float_to_ushort(float f)360 float_to_ushort(float f) 361 { 362 /* return 0 for NaN too */ 363 if (!(f > 0.0f)) { 364 return (uint16_t) 0; 365 } 366 else if (f >= 1.0f) { 367 return (uint16_t) 65535; 368 } 369 else { 370 union fi tmp; 371 tmp.f = f; 372 tmp.f = tmp.f * (65535.0f/65536.0f) + 128.0f; 373 return (uint16_t) tmp.i; 374 } 375 } 376 377 static inline float byte_to_float_tex(int8_t b)378 byte_to_float_tex(int8_t b) 379 { 380 return (b == -128) ? -1.0F : b * 1.0F / 127.0F; 381 } 382 383 static inline int8_t float_to_byte_tex(float f)384 float_to_byte_tex(float f) 385 { 386 return (int8_t) (127.0F * f); 387 } 388 389 /** 390 * Calc log base 2 391 */ 392 static inline unsigned util_logbase2(unsigned n)393 util_logbase2(unsigned n) 394 { 395 #if defined(HAVE___BUILTIN_CLZ) 396 return ((sizeof(unsigned) * 8 - 1) - __builtin_clz(n | 1)); 397 #else 398 unsigned pos = 0; 399 if (n >= 1<<16) { n >>= 16; pos += 16; } 400 if (n >= 1<< 8) { n >>= 8; pos += 8; } 401 if (n >= 1<< 4) { n >>= 4; pos += 4; } 402 if (n >= 1<< 2) { n >>= 2; pos += 2; } 403 if (n >= 1<< 1) { pos += 1; } 404 return pos; 405 #endif 406 } 407 408 static inline uint64_t util_logbase2_64(uint64_t n)409 util_logbase2_64(uint64_t n) 410 { 411 #if defined(HAVE___BUILTIN_CLZLL) 412 return ((sizeof(uint64_t) * 8 - 1) - __builtin_clzll(n | 1)); 413 #else 414 uint64_t pos = 0ull; 415 if (n >= 1ull<<32) { n >>= 32; pos += 32; } 416 if (n >= 1ull<<16) { n >>= 16; pos += 16; } 417 if (n >= 1ull<< 8) { n >>= 8; pos += 8; } 418 if (n >= 1ull<< 4) { n >>= 4; pos += 4; } 419 if (n >= 1ull<< 2) { n >>= 2; pos += 2; } 420 if (n >= 1ull<< 1) { pos += 1; } 421 return pos; 422 #endif 423 } 424 425 /** 426 * Returns the ceiling of log n base 2, and 0 when n == 0. Equivalently, 427 * returns the smallest x such that n <= 2**x. 428 */ 429 static inline unsigned util_logbase2_ceil(unsigned n)430 util_logbase2_ceil(unsigned n) 431 { 432 if (n <= 1) 433 return 0; 434 435 return 1 + util_logbase2(n - 1); 436 } 437 438 static inline uint64_t util_logbase2_ceil64(uint64_t n)439 util_logbase2_ceil64(uint64_t n) 440 { 441 if (n <= 1) 442 return 0; 443 444 return 1ull + util_logbase2_64(n - 1); 445 } 446 447 /** 448 * Returns the smallest power of two >= x 449 */ 450 static inline unsigned util_next_power_of_two(unsigned x)451 util_next_power_of_two(unsigned x) 452 { 453 #if defined(HAVE___BUILTIN_CLZ) 454 if (x <= 1) 455 return 1; 456 457 return (1 << ((sizeof(unsigned) * 8) - __builtin_clz(x - 1))); 458 #else 459 unsigned val = x; 460 461 if (x <= 1) 462 return 1; 463 464 if (util_is_power_of_two_or_zero(x)) 465 return x; 466 467 val--; 468 val = (val >> 1) | val; 469 val = (val >> 2) | val; 470 val = (val >> 4) | val; 471 val = (val >> 8) | val; 472 val = (val >> 16) | val; 473 val++; 474 return val; 475 #endif 476 } 477 478 static inline uint64_t util_next_power_of_two64(uint64_t x)479 util_next_power_of_two64(uint64_t x) 480 { 481 #if defined(HAVE___BUILTIN_CLZLL) 482 if (x <= 1) 483 return 1; 484 485 return (1ull << ((sizeof(uint64_t) * 8) - __builtin_clzll(x - 1))); 486 #else 487 uint64_t val = x; 488 489 if (x <= 1) 490 return 1; 491 492 if (util_is_power_of_two_or_zero64(x)) 493 return x; 494 495 val--; 496 val = (val >> 1) | val; 497 val = (val >> 2) | val; 498 val = (val >> 4) | val; 499 val = (val >> 8) | val; 500 val = (val >> 16) | val; 501 val = (val >> 32) | val; 502 val++; 503 return val; 504 #endif 505 } 506 507 /** 508 * Reverse bits in n 509 * Algorithm taken from: 510 * http://stackoverflow.com/questions/9144800/c-reverse-bits-in-unsigned-integer 511 */ 512 static inline unsigned util_bitreverse(unsigned n)513 util_bitreverse(unsigned n) 514 { 515 n = ((n >> 1) & 0x55555555u) | ((n & 0x55555555u) << 1); 516 n = ((n >> 2) & 0x33333333u) | ((n & 0x33333333u) << 2); 517 n = ((n >> 4) & 0x0f0f0f0fu) | ((n & 0x0f0f0f0fu) << 4); 518 n = ((n >> 8) & 0x00ff00ffu) | ((n & 0x00ff00ffu) << 8); 519 n = ((n >> 16) & 0xffffu) | ((n & 0xffffu) << 16); 520 return n; 521 } 522 523 /** 524 * Convert from little endian to CPU byte order. 525 */ 526 527 #if UTIL_ARCH_BIG_ENDIAN 528 #define util_le64_to_cpu(x) util_bswap64(x) 529 #define util_le32_to_cpu(x) util_bswap32(x) 530 #define util_le16_to_cpu(x) util_bswap16(x) 531 #else 532 #define util_le64_to_cpu(x) (x) 533 #define util_le32_to_cpu(x) (x) 534 #define util_le16_to_cpu(x) (x) 535 #endif 536 537 #define util_cpu_to_le64(x) util_le64_to_cpu(x) 538 #define util_cpu_to_le32(x) util_le32_to_cpu(x) 539 #define util_cpu_to_le16(x) util_le16_to_cpu(x) 540 541 /** 542 * Reverse byte order of a 32 bit word. 543 */ 544 static inline uint32_t util_bswap32(uint32_t n)545 util_bswap32(uint32_t n) 546 { 547 #if defined(HAVE___BUILTIN_BSWAP32) 548 return __builtin_bswap32(n); 549 #else 550 return (n >> 24) | 551 ((n >> 8) & 0x0000ff00) | 552 ((n << 8) & 0x00ff0000) | 553 (n << 24); 554 #endif 555 } 556 557 /** 558 * Reverse byte order of a 64bit word. 559 */ 560 static inline uint64_t util_bswap64(uint64_t n)561 util_bswap64(uint64_t n) 562 { 563 #if defined(HAVE___BUILTIN_BSWAP64) 564 return __builtin_bswap64(n); 565 #else 566 return ((uint64_t)util_bswap32((uint32_t)n) << 32) | 567 util_bswap32((n >> 32)); 568 #endif 569 } 570 571 572 /** 573 * Reverse byte order of a 16 bit word. 574 */ 575 static inline uint16_t util_bswap16(uint16_t n)576 util_bswap16(uint16_t n) 577 { 578 return (n >> 8) | 579 (n << 8); 580 } 581 582 /** 583 * Mask and sign-extend a number 584 * 585 * The bit at position `width - 1` is replicated to all the higher bits. 586 * This makes no assumptions about the high bits of the value and will 587 * overwrite them with the sign bit. 588 */ 589 static inline int64_t util_mask_sign_extend(uint64_t val,unsigned width)590 util_mask_sign_extend(uint64_t val, unsigned width) 591 { 592 assert(width > 0 && width <= 64); 593 unsigned shift = 64 - width; 594 return (int64_t)(val << shift) >> shift; 595 } 596 597 /** 598 * Sign-extend a number 599 * 600 * The bit at position `width - 1` is replicated to all the higher bits. 601 * This assumes and asserts that the value fits into `width` bits. 602 */ 603 static inline int64_t util_sign_extend(uint64_t val,unsigned width)604 util_sign_extend(uint64_t val, unsigned width) 605 { 606 assert(width == 64 || val < (UINT64_C(1) << width)); 607 return util_mask_sign_extend(val, width); 608 } 609 610 static inline void* util_memcpy_cpu_to_le32(void * restrict dest,const void * restrict src,size_t n)611 util_memcpy_cpu_to_le32(void * restrict dest, const void * restrict src, size_t n) 612 { 613 #if UTIL_ARCH_BIG_ENDIAN 614 size_t i, e; 615 assert(n % 4 == 0); 616 617 for (i = 0, e = n / 4; i < e; i++) { 618 uint32_t * restrict d = (uint32_t* restrict)dest; 619 const uint32_t * restrict s = (const uint32_t* restrict)src; 620 d[i] = util_bswap32(s[i]); 621 } 622 return dest; 623 #else 624 return memcpy(dest, src, n); 625 #endif 626 } 627 628 /** 629 * Clamp X to [MIN, MAX]. 630 * This is a macro to allow float, int, uint, etc. types. 631 * We arbitrarily turn NaN into MIN. 632 */ 633 #define CLAMP( X, MIN, MAX ) ( (X)>(MIN) ? ((X)>(MAX) ? (MAX) : (X)) : (MIN) ) 634 635 /* Syntax sugar occuring frequently in graphics code */ 636 #define SATURATE( X ) CLAMP(X, 0.0f, 1.0f) 637 638 #define MIN2( A, B ) ( (A)<(B) ? (A) : (B) ) 639 #define MAX2( A, B ) ( (A)>(B) ? (A) : (B) ) 640 641 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C)) 642 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C)) 643 644 #define MIN4( A, B, C, D ) ((A) < (B) ? MIN3(A, C, D) : MIN3(B, C, D)) 645 #define MAX4( A, B, C, D ) ((A) > (B) ? MAX3(A, C, D) : MAX3(B, C, D)) 646 647 648 /** 649 * Align a value up to an alignment value 650 * 651 * If \c value is not already aligned to the requested alignment value, it 652 * will be rounded up. 653 * 654 * \param value Value to be rounded 655 * \param alignment Alignment value to be used. This must be a power of two. 656 * 657 * \sa ROUND_DOWN_TO() 658 */ 659 660 #if defined(ALIGN) 661 #undef ALIGN 662 #endif 663 static inline uintptr_t ALIGN(uintptr_t value,int32_t alignment)664 ALIGN(uintptr_t value, int32_t alignment) 665 { 666 assert(util_is_power_of_two_nonzero(alignment)); 667 return (((value) + (alignment) - 1) & ~((alignment) - 1)); 668 } 669 670 /** 671 * Like ALIGN(), but works with a non-power-of-two alignment. 672 */ 673 static inline uintptr_t ALIGN_NPOT(uintptr_t value,int32_t alignment)674 ALIGN_NPOT(uintptr_t value, int32_t alignment) 675 { 676 assert(alignment > 0); 677 return (value + alignment - 1) / alignment * alignment; 678 } 679 680 /** 681 * Align a value down to an alignment value 682 * 683 * If \c value is not already aligned to the requested alignment value, it 684 * will be rounded down. 685 * 686 * \param value Value to be rounded 687 * \param alignment Alignment value to be used. This must be a power of two. 688 * 689 * \sa ALIGN() 690 */ 691 static inline uint64_t ROUND_DOWN_TO(uint64_t value,int32_t alignment)692 ROUND_DOWN_TO(uint64_t value, int32_t alignment) 693 { 694 assert(util_is_power_of_two_nonzero(alignment)); 695 return ((value) & ~(alignment - 1)); 696 } 697 698 /** 699 * Align a value, only works pot alignemnts. 700 */ 701 static inline int align(int value,int alignment)702 align(int value, int alignment) 703 { 704 return (value + alignment - 1) & ~(alignment - 1); 705 } 706 707 static inline uint64_t align64(uint64_t value,unsigned alignment)708 align64(uint64_t value, unsigned alignment) 709 { 710 return (value + alignment - 1) & ~((uint64_t)alignment - 1); 711 } 712 713 /** 714 * Works like align but on npot alignments. 715 */ 716 static inline size_t util_align_npot(size_t value,size_t alignment)717 util_align_npot(size_t value, size_t alignment) 718 { 719 if (value % alignment) 720 return value + (alignment - (value % alignment)); 721 return value; 722 } 723 724 static inline unsigned u_minify(unsigned value,unsigned levels)725 u_minify(unsigned value, unsigned levels) 726 { 727 return MAX2(1, value >> levels); 728 } 729 730 #ifndef COPY_4V 731 #define COPY_4V( DST, SRC ) \ 732 do { \ 733 (DST)[0] = (SRC)[0]; \ 734 (DST)[1] = (SRC)[1]; \ 735 (DST)[2] = (SRC)[2]; \ 736 (DST)[3] = (SRC)[3]; \ 737 } while (0) 738 #endif 739 740 741 #ifndef COPY_4FV 742 #define COPY_4FV( DST, SRC ) COPY_4V(DST, SRC) 743 #endif 744 745 746 #ifndef ASSIGN_4V 747 #define ASSIGN_4V( DST, V0, V1, V2, V3 ) \ 748 do { \ 749 (DST)[0] = (V0); \ 750 (DST)[1] = (V1); \ 751 (DST)[2] = (V2); \ 752 (DST)[3] = (V3); \ 753 } while (0) 754 #endif 755 756 757 static inline uint32_t util_unsigned_fixed(float value,unsigned frac_bits)758 util_unsigned_fixed(float value, unsigned frac_bits) 759 { 760 return value < 0 ? 0 : (uint32_t)(value * (1<<frac_bits)); 761 } 762 763 static inline int32_t util_signed_fixed(float value,unsigned frac_bits)764 util_signed_fixed(float value, unsigned frac_bits) 765 { 766 return (int32_t)(value * (1<<frac_bits)); 767 } 768 769 unsigned 770 util_fpstate_get(void); 771 unsigned 772 util_fpstate_set_denorms_to_zero(unsigned current_fpstate); 773 void 774 util_fpstate_set(unsigned fpstate); 775 776 /** 777 * For indexed draw calls, return true if the vertex count to be drawn is 778 * much lower than the vertex count that has to be uploaded, meaning 779 * that the driver should flatten indices instead of trying to upload 780 * a too big range. 781 * 782 * This is used by vertex upload code in u_vbuf and glthread. 783 */ 784 static inline bool util_is_vbo_upload_ratio_too_large(unsigned draw_vertex_count,unsigned upload_vertex_count)785 util_is_vbo_upload_ratio_too_large(unsigned draw_vertex_count, 786 unsigned upload_vertex_count) 787 { 788 if (draw_vertex_count > 1024) 789 return upload_vertex_count > draw_vertex_count * 4; 790 else if (draw_vertex_count > 32) 791 return upload_vertex_count > draw_vertex_count * 8; 792 else 793 return upload_vertex_count > draw_vertex_count * 16; 794 } 795 796 bool util_invert_mat4x4(float *out, const float *m); 797 798 /* Quantize the lod bias value to reduce the number of sampler state 799 * variants in gallium because apps use it for smooth mipmap transitions, 800 * thrashing cso_cache and degrading performance. 801 * 802 * This quantization matches the AMD hw specification, so having more 803 * precision would have no effect anyway. 804 */ 805 static inline float util_quantize_lod_bias(float lod)806 util_quantize_lod_bias(float lod) 807 { 808 lod = CLAMP(lod, -16, 16); 809 return roundf(lod * 256) / 256; 810 } 811 812 #ifdef __cplusplus 813 } 814 #endif 815 816 #endif /* U_MATH_H */ 817