diff options
Diffstat (limited to 'src/H5I.c')
| -rw-r--r-- | src/H5I.c | 23 |
1 files changed, 7 insertions, 16 deletions
@@ -87,7 +87,8 @@ static herr_t H5I_init_interface(void); * Map an ID to a hash location (assumes s is a power of 2 and smaller * than the ID_MASK constant). */ -# define H5I_LOC(a,s) ((hid_t)((size_t)(a)&((s)-1))) +# define H5I_LOC(a,s) ((hid_t)((size_t)(a)&((s)-1))) +# define POWER_OF_TWO(n) ((((n) - 1) & (n)) == 0 && (n) > 1) #else /* * Map an ID to a hash location. @@ -219,6 +220,10 @@ H5I_term_interface(void) * Friday, February 19, 1999 * * Modifications: + * Bill Wendling, 2000-05-05 + * Instead of the ugly test of whether hash_size is a power of + * two, I placed it in a macro POWER_OF_TWO which uses the fact + * that a number that is a power of two has only 1 bit set. * *------------------------------------------------------------------------- */ @@ -236,21 +241,7 @@ H5I_init_group(H5I_type_t grp, size_t hash_size, uintn reserved, HGOTO_DONE(FAIL); } #ifdef HASH_SIZE_POWER_2 - /* - * If anyone knows a faster test for a power of two, please change this - * silly code -QAK - */ - if (!(hash_size == 2 || hash_size == 4 || hash_size == 8 || - hash_size == 16 || hash_size == 32 || hash_size == 64 || - hash_size == 128 || hash_size == 256 || hash_size == 512 || - hash_size == 1024 || hash_size == 2048 || hash_size == 4096 || - hash_size == 8192 || hash_size == 16374 || hash_size == 32768 || - hash_size == 65536 || hash_size == 131072 || hash_size == 262144 || - hash_size == 524288 || hash_size == 1048576 || - hash_size == 2097152 || hash_size == 4194304 || - hash_size == 8388608 || hash_size == 16777216 || - hash_size == 33554432 || hash_size == 67108864 || - hash_size == 134217728 || hash_size == 268435456)) + if (!POWER_OF_TWO(hash_size)) HGOTO_DONE(FAIL); #endif /* HASH_SIZE_POWER_2 */ |