diff options
Diffstat (limited to 'elf/dl-misc.c')
-rw-r--r-- | elf/dl-misc.c | 64 |
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; +} |