diff options
| -rw-r--r-- | ChangeLog | 5 | ||||
| -rw-r--r-- | st.c | 25 |
2 files changed, 26 insertions, 4 deletions
@@ -1,3 +1,8 @@ +Fri Oct 3 06:06:28 2014 Eric Wong <[email protected]> + + * st.c (next_pow2): new function (from old bignum.c) + (new_size): use next_pow2 function + Fri Oct 3 05:58:58 2014 Eric Wong <[email protected]> * vm_trace.c (rb_tp_t): pack 56 => 48 bytes on 64-bit @@ -141,13 +141,30 @@ remove_safe_packed_entry(st_table *table, st_index_t i, st_data_t never) } static st_index_t +next_pow2(st_index_t x) +{ + x |= x >> 1; + x |= x >> 2; + x |= x >> 4; + x |= x >> 8; + x |= x >> 16; +#if SIZEOF_ST_INDEX_T == 8 + x |= x >> 32; +#endif + return x + 1; +} + +static st_index_t new_size(st_index_t size) { - st_index_t i; + st_index_t n; - for (i=3; i<31; i++) { - if ((st_index_t)(1<<i) > size) return 1<<i; - } + if (size && (size & ~(size - 1)) == size) /* already a power-of-two? */ + return size; + + n = next_pow2(size); + if (n > size) + return n; #ifndef NOT_RUBY rb_raise(rb_eRuntimeError, "st_table too big"); #endif |