improve the quality of output from rand_r

[musl] / src / prng / rand_r.c

diff --git a/src/prng/rand_r.c b/src/prng/rand_r.c
index ef26dbd..638614c 100644 (file)
--- a/src/prng/rand_r.c
+++ b/src/prng/rand_r.c
@@ -1,6 +1,15 @@
 #include <stdlib.h>
 
+static unsigned temper(unsigned x)
+{
+       x ^= x>>11;
+       x ^= x<<7 & 0x9D2C5680;
+       x ^= x<<15 & 0xEFC60000;
+       x ^= x>>18;
+       return x;
+}
+
 int rand_r(unsigned *seed)
 {
-       return (*seed = *seed * 1103515245 + 12345)/2;
+       return temper(*seed = *seed * 1103515245 + 12345)/2;
 }