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authorTimothy Arceri <tarceri@itsqueeze.com>2017-03-22 10:47:05 +1100
committerTimothy Arceri <tarceri@itsqueeze.com>2017-03-23 08:16:29 +1100
commit53660c23662edb829e6bfd54bcdc0df4688ec62b (patch)
tree88f3f160cc56b99c2cd5cb034fe0bb64b9a97472 /src/util
parente11049f2c367192dfb1540855f6571a5e29b77ec (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.sources2
-rw-r--r--src/util/rand_xor.c20
-rw-r--r--src/util/rand_xor.h33
3 files changed, 55 insertions, 0 deletions
diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
index d4a444aee3e..8ee45d56170 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 00000000000..07b4c22ee15
--- /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 00000000000..d5144e98230
--- /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 */