Path: nntp.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups: comp.lang.forth
Subject: Re: Parsing =?UTF-8?B?dGltZXN0YW1wcz8=?=
Date: Wed, 16 Jul 2025 16:02:41 GMT
Organization: Institut fuer Computersprachen, Technische Universitaet Wien
Lines: 24
Message-ID: <2025Jul16.180241@mips.complang.tuwien.ac.at>
References: <1f433fabcb4d053d16cbc098dedc6c370608ac01@i2pn2.org> <2025Jul11.122254@mips.complang.tuwien.ac.at> <954cf34891bed0677fd79af0b676c50613dc1443@i2pn2.org> <2025Jul13.110141@mips.complang.tuwien.ac.at> <2d6811168025a74b3ff51a78efb75947d36a0146@i2pn2.org> <2025Jul14.080413@mips.complang.tuwien.ac.at> <063d4a116fb394a776b1e9313f9903cf@www.novabbs.com> <2025Jul14.095004@mips.complang.tuwien.ac.at> <a449857495e02b4d35627f9f31d37fd8@www.novabbs.com> <2025Jul16.132504@mips.complang.tuwien.ac.at>
Injection-Date: Wed, 16 Jul 2025 18:20:08 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="585c480a77ea571ad015f54f65ea6703";
	logging-data="872988"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18+1ZUvXY33nj4Tbj1/oTd0"
Cancel-Lock: sha1:FRRi874vKG24MIFf5xNtzeGrMF0=
X-newsreader: xrn 10.11

anton@mips.complang.tuwien.ac.at (Anton Ertl) writes:
>But I decided to use a recursive approach (recursive-sum, REC) that
>uses the largest 2^k<n as the left child and the rest as the right
>child, and as base cases for the recursion use a straight-line
>balanced-tree evaluation for 2^k with k<=7 (and combine these for n
>that are not 2^k).  For systems with tiny FP stacks, I added the
>option to save intermediate results on a software stack in the
>recursive word.  Concerning the straight-line code, it turned out that
>the highest k I could use on sf64 and vfx64 is 5 (corresponding to 6
>FP stack items); it's not clear to me why; on lxf I can use k=7 (and
>it uses the 387 stack, too).

Actually, after writing that, I found out the reasons for the FP stack
overflows, and in the published versions and the results I use k=7 on
all systems.  It's really easy to leave an FP stack item on the FP
stack while calling another word, and that's not so good if you do it
while calling sum128:-).

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
     New standard: https://forth-standard.org/
EuroForth 2025 CFP: http://www.euroforth.org/ef25/cfp.html