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authorJan Vesely <jan.vesely@rutgers.edu>2014-11-30 13:04:23 -0500
committerJan Vesely <jan.vesely@rutgers.edu>2015-02-10 15:24:35 -0500
commit6ce06202ddcb979db47b67a508db96ed049f0768 (patch)
treef274cb6b0e5b95140650fdb259e3e51be7ad9a12
parentccbb9aa887f992359335ecf2d26919b04e14e63f (diff)
random: Use unsigned long for seed
v2: Remove unrelated change in main() This is more consistent with the rest, and avoids potential undefined behavior (signed overflow) ind drmRandom() Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu> Reviewed-by: Ian Romanick <idr@freedesktop.org> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
-rw-r--r--xf86drmRandom.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/xf86drmRandom.c b/xf86drmRandom.c
index ecab9e2d..94922ad7 100644
--- a/xf86drmRandom.c
+++ b/xf86drmRandom.c
@@ -98,7 +98,7 @@ typedef struct RandomState {
unsigned long q; /* m div a */
unsigned long r; /* m mod a */
unsigned long check;
- long seed;
+ unsigned long seed;
} RandomState;
#if RANDOM_MAIN
@@ -147,13 +147,13 @@ int drmRandomDestroy(void *state)
unsigned long drmRandom(void *state)
{
RandomState *s = (RandomState *)state;
- long hi;
- long lo;
+ unsigned long hi;
+ unsigned long lo;
hi = s->seed / s->q;
lo = s->seed % s->q;
s->seed = s->a * lo - s->r * hi;
- if (s->seed <= 0) s->seed += s->m;
+ if ((s->a * lo) <= (s->r * hi)) s->seed += s->m;
return s->seed;
}
@@ -166,7 +166,7 @@ double drmRandomDouble(void *state)
}
#if RANDOM_MAIN
-static void check_period(long seed)
+static void check_period(unsigned long seed)
{
unsigned long count = 0;
unsigned long initial;
@@ -178,7 +178,7 @@ static void check_period(long seed)
while (initial != drmRandom(state)) {
if (!++count) break;
}
- printf("With seed of %10ld, period = %10lu (0x%08lx)\n",
+ printf("With seed of %10lu, period = %10lu (0x%08lx)\n",
seed, count, count);
drmRandomDestroy(state);
}