patch 8.0.0190: finding duplicate tags uses a slow linear search commit https://github.com/vim/vim/commit/810f9c361c83afb36b9f1cdadca2b93f1201d039 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Jan 15 16:52:51 2017 +0100 patch 8.0.0190: finding duplicate tags uses a slow linear search Problem: Detecting duplicate tags uses a slow linear search. Solution: Use a much faster hash table solution. (James McCoy, closes https://github.com/vim/vim/issues/1046) But don't add hi_keylen, it makes hash tables 50% bigger.

"Test for benchmarking the RE engine

so small.vim
if !has("reltime") | finish | endif
func! Measure(file, pattern, arg)
	for re in range(3)
	    let sstart=reltime()
	    let cmd=printf("../vim -u NONE -N --cmd ':set re=%d'".
		\ " -c 'call search(\"%s\", \"\", \"\", 10000)' -c ':q!' %s", re, escape(a:pattern, '\\'), empty(a:arg) ? '' : a:arg)
	    call system(cmd. ' '. a:file)
	    $put =printf('file: %s, re: %d, time: %s', a:file, re, reltimestr(reltime(sstart)))
	endfor
endfunc