diff options
| author | Justus Winter <4winter@informatik.uni-hamburg.de> | 2014-09-30 03:58:43 +0200 |
|---|---|---|
| committer | Justus Winter <4winter@informatik.uni-hamburg.de> | 2014-09-30 09:15:08 +0200 |
| commit | 3a0fae39873c9c7d73dc978888e45b87ad27d44e (patch) | |
| tree | 061847ec497d24b684d7c1b14aa2e823295ebaba | |
| parent | 3166fe0edd4a5cf0d690c094f2fd06647ba380e5 (diff) | |
ipc: use fast modulo operation in local hash table
* ipc/ipc_table.h: Document that table sizes must be powers of two.
* ipc/ipc_hash.c (IH_LOCAL_HASH): Use fast modulo operation.
| -rw-r--r-- | ipc/ipc_hash.c | 2 | ||||
| -rw-r--r-- | ipc/ipc_table.h | 2 |
2 files changed, 3 insertions, 1 deletions
diff --git a/ipc/ipc_hash.c b/ipc/ipc_hash.c index 8285717c..c2c6d6ef 100644 --- a/ipc/ipc_hash.c +++ b/ipc/ipc_hash.c @@ -326,7 +326,7 @@ ipc_hash_global_delete( */ #define IH_LOCAL_HASH(obj, size) \ - ((((mach_port_index_t) (vm_offset_t) (obj)) >> 6) % (size)) + ((((mach_port_index_t) (vm_offset_t) (obj)) >> 6) & (size - 1)) /* * Routine: ipc_hash_local_lookup diff --git a/ipc/ipc_table.h b/ipc/ipc_table.h index 3cc5f561..311b9a78 100644 --- a/ipc/ipc_table.h +++ b/ipc/ipc_table.h @@ -45,6 +45,8 @@ * an ipc_table_size structure. These structures must * be elements of an array, ipc_table_entries. * + * Every its_size value must must be a power of two. + * * The array must end with two elements with the same its_size value. * Except for the terminating element, the its_size values must * be strictly increasing. The largest (last) its_size value |