From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.devel Subject: Re: Bignum performance (was: Shrinking the C core) Date: Fri, 11 Aug 2023 14:10:27 +0200 Message-ID: <87h6p5kcek.fsf@dataswamp.org> References: <20230809094655.793FC18A4654@snark.thyrsus.com> <87il9owg0f.fsf@yahoo.com> <83fs4rjq9j.fsf@gnu.org> <87jzu2tvfc.fsf@dataswamp.org> <87y1ih3mc1.fsf@localhost> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="35370"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: emacs-devel@gnu.org Cancel-Lock: sha1:2aRu/XVMnUr/Y6m9Jw7bjfpH3LI= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Aug 11 14:11:50 2023 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qUQze-00093y-LV for ged-emacs-devel@m.gmane-mx.org; Fri, 11 Aug 2023 14:11:50 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qUQzO-0007Bb-FI; Fri, 11 Aug 2023 08:11:34 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qUQyV-0006XM-Az for emacs-devel@gnu.org; Fri, 11 Aug 2023 08:10:39 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qUQyT-0003l6-DQ for emacs-devel@gnu.org; Fri, 11 Aug 2023 08:10:39 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1qUQyQ-0007Sd-B6 for emacs-devel@gnu.org; Fri, 11 Aug 2023 14:10:34 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: emacs-devel@gnu.org Mail-Copies-To: never Received-SPF: pass client-ip=116.202.254.214; envelope-from=ged-emacs-devel@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Fri, 11 Aug 2023 08:11:24 -0400 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:308575 Archived-At: Ihor Radchenko wrote: >> In theory Lisp can be as fast as any other language but in >> practice it is not the case with Elisp and Emacs at least. >> >> Here is a n experiment with stats how Emacs/Elisp compares >> to SBCL/CL, for this particular one it shows that Elisp, >> even natively compiled, is still +78875% slower than >> Common Lisp. >> >> ... >> (defun fib (reps num) >> (let ((z 0)) >> (dotimes (_ reps) >> (let ((p1 1) >> (p2 1)) >> (dotimes (_ (- num 2)) >> (setf z (+ p1 p2) >> p2 p1 >> p1 z)))) >> z)) >> >> (let ((beg (float-time))) >> (fib 10000 1000) >> (message "%.3f s" (- (float-time) beg)) ) > > Most of the time is spent in (1) GC; (2) Creating bigint: > > perf record emacs -Q -batch -l /tmp/fib.eln > > perf report: > > Creating bignums: > 40.95% emacs emacs [.] allocate_vectorlike > GC: > 20.21% emacs emacs [.] process_mark_stack > 3.41% emacs libgmp.so.10.5.0 [.] __gmpz_sizeinbase > GC: > 3.21% emacs emacs [.] mark_char_table > 2.82% emacs emacs [.] pdumper_marked_p_impl > 2.23% emacs libc.so.6 [.] 0x0000000000090076 > 1.78% emacs libgmp.so.10.5.0 [.] __gmpz_add > 1.71% emacs emacs [.] pdumper_set_marked_impl > 1.59% emacs emacs [.] arith_driver > 1.31% emacs libc.so.6 [.] malloc > GC: > 1.15% emacs emacs [.] sweep_vectors > 1.03% emacs libgmp.so.10.5.0 [.] __gmpn_add_n_coreisbr > 0.88% emacs libc.so.6 [.] cfree > 0.87% emacs fib.eln [.] F666962_fib_0 > 0.85% emacs emacs [.] check_number_coerce_marker > 0.80% emacs libc.so.6 [.] 0x0000000000091043 > 0.74% emacs emacs [.] allocate_pseudovector > 0.65% emacs emacs [.] Flss > 0.57% emacs libgmp.so.10.5.0 [.] __gmpz_realloc > 0.56% emacs emacs [.] make_bignum_bits > > My conclusion from this is that big number implementation is > not optimal. Mostly because it does not reuse the existing > bignum objects and always create new ones - every single > time we perform an arithmetic operation. Okay, interesting, how can you see that from the above data? So is this a problem with the compiler? Or some associated library? If so, I'll see if I can upgrade gcc to gcc 13 and see if that improves it, maybe they already fixed it ... -- underground experts united https://dataswamp.org/~incal