util: move rand_xorshift128plus() to utils

V2: pass the seed to rand_xorshift128plus() so that we can isolate
    its uses.

Reviewed-by: Grazvydas Ignotas <[email protected]>
Reviewed-by: Nicolai Hähnle <[email protected]>

4 files changed, 60 insertions, 19 deletions

diff --git a/src/gallium/drivers/radeon/r600_test_dma.c b/src/gallium/drivers/radeon/r600_test_dma.c
index f7e9eb5fc38..8b4149af53c 100644
--- a/src/gallium/drivers/radeon/r600_test_dma.c
+++ b/src/gallium/drivers/radeon/r600_test_dma.c
@@ -26,26 +26,10 @@
 
 #include "r600_pipe_common.h"
 #include "util/u_surface.h"
+#include "util/rand_xor.h"
 
 static uint64_t seed_xorshift128plus[2];
 
-/* Super fast random number generator.
- *
- * This rand_xorshift128plus function by Sebastiano Vigna belongs
- * to the public domain.
- */
-static uint64_t rand_xorshift128plus(void)
-{
-	uint64_t *s = seed_xorshift128plus;
-
-	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;
-}
-
 #define RAND_NUM_SIZE 8
 
 /* The GPU blits are emulated on the CPU using these CPU textures. */
@@ -91,8 +75,10 @@ static void set_random_pixels(struct pipe_context *ctx,
 			assert(t->stride % RAND_NUM_SIZE == 0);
 			assert(cpu->stride % RAND_NUM_SIZE == 0);
 
-			for (x = 0; x < size; x++)
-				*ptr++ = *ptr_cpu++ = rand_xorshift128plus();
+			for (x = 0; x < size; x++) {
+				*ptr++ = *ptr_cpu++ =
+					rand_xorshift128plus(seed_xorshift128plus);
+			}
 		}
 	}
 
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 */