summaryrefslogtreecommitdiff
path: root/src/mesa/drivers/dri/dri_client/xf86drmRandom.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/mesa/drivers/dri/dri_client/xf86drmRandom.c')
-rw-r--r--src/mesa/drivers/dri/dri_client/xf86drmRandom.c217
1 files changed, 0 insertions, 217 deletions
diff --git a/src/mesa/drivers/dri/dri_client/xf86drmRandom.c b/src/mesa/drivers/dri/dri_client/xf86drmRandom.c
deleted file mode 100644
index cca831d751..0000000000
--- a/src/mesa/drivers/dri/dri_client/xf86drmRandom.c
+++ /dev/null
@@ -1,217 +0,0 @@
-/* xf86drmRandom.c -- "Minimal Standard" PRNG Implementation
- * Created: Mon Apr 19 08:28:13 1999 by faith@precisioninsight.com
- *
- * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
- * All Rights Reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
- * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
- * DEALINGS IN THE SOFTWARE.
- *
- * Authors: Rickard E. (Rik) Faith <faith@valinux.com>
- *
- * $XFree86: xc/programs/Xserver/hw/xfree86/os-support/linux/drm/xf86drmRandom.c,v 1.4 2000/06/17 00:03:34 martin Exp $
- *
- * DESCRIPTION
- *
- * This file contains a simple, straightforward implementation of the Park
- * & Miller "Minimal Standard" PRNG [PM88, PMS93], which is a Lehmer
- * multiplicative linear congruential generator (MLCG) with a period of
- * 2^31-1.
- *
- * This implementation is intended to provide a reliable, portable PRNG
- * that is suitable for testing a hash table implementation and for
- * implementing skip lists.
- *
- * FUTURE ENHANCEMENTS
- *
- * If initial seeds are not selected randomly, two instances of the PRNG
- * can be correlated. [Knuth81, pp. 32-33] describes a shuffling technique
- * that can eliminate this problem.
- *
- * If PRNGs are used for simulation, the period of the current
- * implementation may be too short. [LE88] discusses methods of combining
- * MLCGs to produce much longer periods, and suggests some alternative
- * values for A and M. [LE90 and Sch92] also provide information on
- * long-period PRNGs.
- *
- * REFERENCES
- *
- * [Knuth81] Donald E. Knuth. The Art of Computer Programming. Volume 2:
- * Seminumerical Algorithms. Reading, Massachusetts: Addison-Wesley, 1981.
- *
- * [LE88] Pierre L'Ecuyer. "Efficient and Portable Combined Random Number
- * Generators". CACM 31(6), June 1988, pp. 742-774.
- *
- * [LE90] Pierre L'Ecuyer. "Random Numbers for Simulation". CACM 33(10,
- * October 1990, pp. 85-97.
- *
- * [PM88] Stephen K. Park and Keith W. Miller. "Random Number Generators:
- * Good Ones are Hard to Find". CACM 31(10), October 1988, pp. 1192-1201.
- *
- * [Sch92] Bruce Schneier. "Pseudo-Ransom Sequence Generator for 32-Bit
- * CPUs". Dr. Dobb's Journal 17(2), February 1992, pp. 34, 37-38, 40.
- *
- * [PMS93] Stephen K. Park, Keith W. Miller, and Paul K. Stockmeyer. In
- * "Technical Correspondence: Remarks on Choosing and Implementing Random
- * Number Generators". CACM 36(7), July 1993, pp. 105-110.
- *
- */
-
-#define RANDOM_MAIN 0
-
-#if RANDOM_MAIN
-# include <stdio.h>
-# include <stdlib.h>
-#else
-# include "xf86drm.h"
-# ifdef XFree86LOADER
-# include "xf86.h"
-# include "xf86_ansic.h"
-# else
-# include <stdio.h>
-# include <stdlib.h>
-# endif
-#endif
-
-#define RANDOM_MAGIC 0xfeedbeef
-#define RANDOM_DEBUG 0
-
-#if RANDOM_MAIN
-#define RANDOM_ALLOC malloc
-#define RANDOM_FREE free
-#else
-#define RANDOM_ALLOC drmMalloc
-#define RANDOM_FREE drmFree
-#endif
-
-typedef struct RandomState {
- unsigned long magic;
- unsigned long a;
- unsigned long m;
- unsigned long q; /* m div a */
- unsigned long r; /* m mod a */
- unsigned long check;
- long seed;
-} RandomState;
-
-#if RANDOM_MAIN
-extern void *drmRandomCreate(unsigned long seed);
-extern int drmRandomDestroy(void *state);
-extern unsigned long drmRandom(void *state);
-extern double drmRandomDouble(void *state);
-#endif
-
-void *drmRandomCreate(unsigned long seed)
-{
- RandomState *state;
-
- state = RANDOM_ALLOC(sizeof(*state));
- if (!state) return NULL;
- state->magic = RANDOM_MAGIC;
-#if 0
- /* Park & Miller, October 1988 */
- state->a = 16807;
- state->m = 2147483647;
- state->check = 1043618065; /* After 10000 iterations */
-#else
- /* Park, Miller, and Stockmeyer, July 1993 */
- state->a = 48271;
- state->m = 2147483647;
- state->check = 399268537; /* After 10000 iterations */
-#endif
- state->q = state->m / state->a;
- state->r = state->m % state->a;
-
- state->seed = seed;
- /* Check for illegal boundary conditions,
- and choose closest legal value. */
- if (state->seed <= 0) state->seed = 1;
- if (state->seed >= state->m) state->seed = state->m - 1;
-
- return state;
-}
-
-int drmRandomDestroy(void *state)
-{
- RANDOM_FREE(state);
- return 0;
-}
-
-unsigned long drmRandom(void *state)
-{
- RandomState *s = (RandomState *)state;
- long hi;
- long lo;
-
- hi = s->seed / s->q;
- lo = s->seed % s->q;
- s->seed = s->a * lo - s->r * hi;
- if (s->seed <= 0) s->seed += s->m;
-
- return s->seed;
-}
-
-double drmRandomDouble(void *state)
-{
- RandomState *s = (RandomState *)state;
-
- return (double)drmRandom(state)/(double)s->m;
-}
-
-#if RANDOM_MAIN
-static void check_period(long seed)
-{
- unsigned long count = 0;
- unsigned long initial;
- void *state;
-
- state = drmRandomCreate(seed);
- initial = drmRandom(state);
- ++count;
- while (initial != drmRandom(state)) {
- if (!++count) break;
- }
- printf("With seed of %10ld, period = %10lu (0x%08lx)\n",
- seed, count, count);
- drmRandomDestroy(state);
-}
-
-int main(void)
-{
- RandomState *state;
- int i;
- unsigned long rand;
-
- state = drmRandomCreate(1);
- for (i = 0; i < 10000; i++) {
- rand = drmRandom(state);
- }
- printf("After 10000 iterations: %lu (%lu expected): %s\n",
- rand, state->check,
- rand - state->check ? "*INCORRECT*" : "CORRECT");
- drmRandomDestroy(state);
-
- printf("Checking periods...\n");
- check_period(1);
- check_period(2);
- check_period(31415926);
-
- return 0;
-}
-#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 18:30:55 +0000