From 5739d3c743a4c76ffb15a459b2466da3ec35061e Mon Sep 17 00:00:00 2001 From: nobu Date: Wed, 21 Dec 2016 06:22:16 +0000 Subject: st.c: fix st_hash* functions [Bug #13019] Previous implementation had an issues: - macros murmur1 assumes murmur_step takes rotation value as a second argument - but murmur_step second argument is "next block" - this makes st_hash_uint and st_hash_end to not mix high bits of hash value into lower bits - this leads to pure hash behavior on doubles and mixing hashes using st_hash_uint. It didn't matter when bins amount were prime numbers, but it hurts when bins are powers of two. Mistake were created cause of attempt to co-exist Murmur1 and Murmur2 in a same code. Change it to single hash-function implementation. - block function is in a spirit of Murmur functions, but handles inter-block dependency a bit better (imho). - final block is read in bit more optimal way on CPU with unaligned word access, - final block is mixed in simple way, - finalizer is taken from MurmurHash3 (it makes most of magic :) ) (64bit finalizer is taken from http://zimbry.blogspot.ru/2011/09/better-bit-mixing-improving-on.html) Also remove ST_USE_FNV1: it lacks implementation of many functions, and looks to be abandoned Author: Sokolov Yura aka funny_falcon git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57134 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- include/ruby/st.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/ruby/st.h b/include/ruby/st.h index 41f2913b80..47e14a3e2c 100644 --- a/include/ruby/st.h +++ b/include/ruby/st.h @@ -63,6 +63,8 @@ struct st_hash_type { st_index_t (*hash)(ANYARGS /*st_data_t*/); /* st_hash_func* */ }; +#define ST_INDEX_BITS (SIZEOF_ST_INDEX_T * CHAR_BIT) + #if defined(HAVE_BUILTIN___BUILTIN_CHOOSE_EXPR) && defined(HAVE_BUILTIN___BUILTIN_TYPES_COMPATIBLE_P) # define ST_DATA_COMPATIBLE_P(type) \ __builtin_choose_expr(__builtin_types_compatible_p(type, st_data_t), 1, 0) -- cgit v1.2.3