[Mesa-dev] [PATCH V2 1/3] util: move rand_xorshift128plus() to utils

[Timothy Arceri]

V2: pass the seed to rand_xorshift128plus() so that we can isolate
    its uses.
---
 src/gallium/drivers/radeon/r600_test_dma.c | 24 +++++-----------------
 src/util/Makefile.sources                  |  2 ++
 src/util/rand_xor.c                        | 20 ++++++++++++++++++
 src/util/rand_xor.h                        | 33 ++++++++++++++++++++++++++++++
 4 files changed, 60 insertions(+), 19 deletions(-)
 create mode 100644 src/util/rand_xor.c
 create mode 100644 src/util/rand_xor.h

diff --git a/src/gallium/drivers/radeon/r600_test_dma.c b/src/gallium/drivers/radeon/r600_test_dma.c
index f7e9eb5..8b4149a 100644
--- a/src/gallium/drivers/radeon/r600_test_dma.c
+++ b/src/gallium/drivers/radeon/r600_test_dma.c
@@ -19,40 +19,24 @@
  * 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.
  *
  */
 
 /* This file implements randomized SDMA texture blit tests. */
 
 #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. */
 
 struct cpu_texture {
 	uint8_t *ptr;
 	uint64_t size;
 	uint64_t layer_stride;
 	unsigned stride;
 };
@@ -84,22 +68,24 @@ static void set_random_pixels(struct pipe_context *ctx,
 		for (y = 0; y < tex->height0; y++) {
 			uint64_t *ptr = (uint64_t*)
 				(map + t->layer_stride*z + t->stride*y);
 			uint64_t *ptr_cpu = (uint64_t*)
 				(cpu->ptr + cpu->layer_stride*z + cpu->stride*y);
 			unsigned size = cpu->stride / RAND_NUM_SIZE;
 
 			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);
+			}
 		}
 	}
 
 	pipe_transfer_unmap(ctx, t);
 }
 
 static bool compare_textures(struct pipe_context *ctx,
 			     struct pipe_resource *tex,
 			     struct cpu_texture *cpu, int bpp)
 {
diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
index e6c1c76..411c1d7 100644
--- a/src/util/Makefile.sources
+++ b/src/util/Makefile.sources
@@ -18,20 +18,22 @@ MESA_UTIL_FILES :=	\
 	hash_table.c	\
 	hash_table.h \
 	list.h \
 	macros.h \
 	mesa-sha1.c \
 	mesa-sha1.h \
 	sha1/sha1.c \
 	sha1/sha1.h \
 	ralloc.c \
 	ralloc.h \
+	rand_xor.c \
+	rand_xor.h \
 	register_allocate.c \
 	register_allocate.h \
 	rgtc.c \
 	rgtc.h \
 	rounding.h \
 	set.c \
 	set.h \
 	simple_list.h \
 	slab.c \
 	slab.h \
diff --git a/src/util/rand_xor.c b/src/util/rand_xor.c
new file mode 100644
index 0000000..07b4c22
--- /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 0000000..d5144e9
--- /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 */
-- 
2.9.3