summaryrefslogtreecommitdiff
path: root/elf
diff options
context:
space:
mode:
Diffstat (limited to 'elf')
-rw-r--r--elf/dl-misc.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/elf/dl-misc.c b/elf/dl-misc.c
index 7c77cd040f..7d4e1a1725 100644
--- a/elf/dl-misc.c
+++ b/elf/dl-misc.c
@@ -312,3 +312,67 @@ _dl_name_match_p (const char *name, const struct link_map *map)
return 0;
}
+
+
+unsigned long int
+_dl_higher_prime_number (unsigned long int n)
+{
+ /* These are primes that are near, but slightly smaller than, a
+ power of two. */
+ static const uint32_t primes[] = {
+ UINT32_C (7),
+ UINT32_C (13),
+ UINT32_C (31),
+ UINT32_C (61),
+ UINT32_C (127),
+ UINT32_C (251),
+ UINT32_C (509),
+ UINT32_C (1021),
+ UINT32_C (2039),
+ UINT32_C (4093),
+ UINT32_C (8191),
+ UINT32_C (16381),
+ UINT32_C (32749),
+ UINT32_C (65521),
+ UINT32_C (131071),
+ UINT32_C (262139),
+ UINT32_C (524287),
+ UINT32_C (1048573),
+ UINT32_C (2097143),
+ UINT32_C (4194301),
+ UINT32_C (8388593),
+ UINT32_C (16777213),
+ UINT32_C (33554393),
+ UINT32_C (67108859),
+ UINT32_C (134217689),
+ UINT32_C (268435399),
+ UINT32_C (536870909),
+ UINT32_C (1073741789),
+ UINT32_C (2147483647),
+ /* 4294967291L */
+ UINT32_C (2147483647) + UINT32_C (2147483644)
+ };
+
+ const uint32_t *low = &primes[0];
+ const uint32_t *high = &primes[sizeof (primes) / sizeof (primes[0])];
+
+ while (low != high)
+ {
+ const uint32_t *mid = low + (high - low) / 2;
+ if (n > *mid)
+ low = mid + 1;
+ else
+ high = mid;
+ }
+
+#if 0
+ /* If we've run out of primes, abort. */
+ if (n > *low)
+ {
+ fprintf (stderr, "Cannot find prime bigger than %lu\n", n);
+ abort ();
+ }
+#endif
+
+ return *low;
+}