diff options
Diffstat (limited to 'st.c')
-rw-r--r-- | st.c | 24 |
1 files changed, 2 insertions, 22 deletions
@@ -1750,26 +1750,6 @@ st_numcmp(st_data_t x, st_data_t y) st_index_t st_numhash(st_data_t n) { - /* - * This hash function is lightly-tuned for Ruby. Further tuning - * should be possible. Notes: - * - * - (n >> 3) alone is great for heap objects and OK for fixnum, - * however symbols perform poorly. - * - (n >> (RUBY_SPECIAL_SHIFT+3)) was added to make symbols hash well, - * n.b.: +3 to remove ID scope, +1 worked well initially, too - * - (n << 3) was finally added to avoid losing bits for fixnums - * - avoid expensive modulo instructions, it is currently only - * shifts and bitmask operations. - * - flonum (on 64-bit) is pathologically bad, mix the actual - * float value in, but do not use the float value as-is since - * many integers get interpreted as 2.0 or -2.0 [Bug #10761] - */ -#ifdef USE_FLONUM /* RUBY */ - if (FLONUM_P(n)) { - n ^= (st_data_t)rb_float_value(n); - } -#endif - - return (st_index_t)((n>>(RUBY_SPECIAL_SHIFT+3)|(n<<3)) ^ (n>>3)); + enum {s1 = 11, s2 = 3}; + return (st_index_t)((n>>s1|(n<<s2)) ^ (n>>s2)); } |