diff options
| author | Timothy Arceri <tarceri@itsqueeze.com> | 2017-03-22 10:47:05 +1100 |
|---|---|---|
| committer | Timothy Arceri <tarceri@itsqueeze.com> | 2017-03-23 08:16:29 +1100 |
| commit | 53660c23662edb829e6bfd54bcdc0df4688ec62b (patch) | |
| tree | 88f3f160cc56b99c2cd5cb034fe0bb64b9a97472 /src/util | |
| parent | e11049f2c367192dfb1540855f6571a5e29b77ec (diff) | |
util: move rand_xorshift128plus() to utils
V2: pass the seed to rand_xorshift128plus() so that we can isolate
its uses.
Reviewed-by: Grazvydas Ignotas <notasas@gmail.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Diffstat (limited to 'src/util')
| -rw-r--r-- | src/util/Makefile.sources | 2 | ||||
| -rw-r--r-- | src/util/rand_xor.c | 20 | ||||
| -rw-r--r-- | src/util/rand_xor.h | 33 |
3 files changed, 55 insertions, 0 deletions
diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources index d4a444aee3..8ee45d5617 100644 --- a/src/util/Makefile.sources +++ b/src/util/Makefile.sources @@ -25,6 +25,8 @@ MESA_UTIL_FILES := \ sha1/sha1.h \ ralloc.c \ ralloc.h \ + rand_xor.c \ + rand_xor.h \ register_allocate.c \ register_allocate.h \ rgtc.c \ diff --git a/src/util/rand_xor.c b/src/util/rand_xor.c new file mode 100644 index 0000000000..07b4c22ee1 --- /dev/null +++ b/src/util/rand_xor.c @@ -0,0 +1,20 @@ +#include "rand_xor.h" + +/* Super fast random number generator. + * + * This rand_xorshift128plus function by Sebastiano Vigna belongs + * to the public domain. + */ +uint64_t +rand_xorshift128plus(uint64_t *seed) +{ + uint64_t *s = seed; + + uint64_t s1 = s[0]; + const uint64_t s0 = s[1]; + s[0] = s0; + s1 ^= s1 << 23; + s[1] = s1 ^ s0 ^ (s1 >> 18) ^ (s0 >> 5); + + return s[1] + s0; +} diff --git a/src/util/rand_xor.h b/src/util/rand_xor.h new file mode 100644 index 0000000000..d5144e9823 --- /dev/null +++ b/src/util/rand_xor.h @@ -0,0 +1,33 @@ +/* + * Copyright 2017 Timothy Arceri + * + * 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 + * THE AUTHORS OR COPYRIGHT HOLDERS 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. + * + */ + +#ifndef RAND_XOR_H +#define RAND_XOR_H + +#include <stdint.h> + +uint64_t +rand_xorshift128plus(uint64_t *seed); + +#endif /* RAND_XOR_H */ |