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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>
main
Jan Vesely 2014-11-30 13:04:23 -05:00
parent ccbb9aa887
commit 6ce06202dd
1 changed files with 6 additions and 6 deletions
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12
xf86drmRandom.c
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@ -98,7 +98,7 @@ typedef struct RandomState {
unsigned long q; /* m div a */ unsigned long q; /* m div a */
unsigned long r; /* m mod a */ unsigned long r; /* m mod a */
unsigned long check; unsigned long check;
long seed; unsigned long seed;
} RandomState; } RandomState;
#if RANDOM_MAIN #if RANDOM_MAIN
@ -147,13 +147,13 @@ int drmRandomDestroy(void *state)
unsigned long drmRandom(void *state) unsigned long drmRandom(void *state)
{ {
RandomState *s = (RandomState *)state; RandomState *s = (RandomState *)state;
long hi; unsigned long hi;
long lo; unsigned long lo;
hi = s->seed / s->q; hi = s->seed / s->q;
lo = s->seed % s->q; lo = s->seed % s->q;
s->seed = s->a * lo - s->r * hi; 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; return s->seed;
} }
@ -166,7 +166,7 @@ double drmRandomDouble(void *state)
} }
#if RANDOM_MAIN #if RANDOM_MAIN
static void check_period(long seed) static void check_period(unsigned long seed)
{ {
unsigned long count = 0; unsigned long count = 0;
unsigned long initial; unsigned long initial;
@ -178,7 +178,7 @@ static void check_period(long seed)
while (initial != drmRandom(state)) { while (initial != drmRandom(state)) {
if (!++count) break; 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); seed, count, count);
drmRandomDestroy(state); drmRandomDestroy(state);
} }