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