Path: csiph.com!weretis.net!feeder9.news.weretis.net!news.misty.com!news.iecc.com!.POSTED.news.iecc.com!not-for-mail From: John Levine Newsgroups: alt.folklore.computers Subject: Re: compilers and architecture, Just How Bad Was The Intel IAPX432? Date: Mon, 1 Jun 2026 01:17:31 -0000 (UTC) Organization: Taughannock Networks Message-ID: <10vimjb$1k16$1@gal.iecc.com> References: <10vgmgr$1cad4$1@dont-email.me> <10vhi8j$1jmkv$1@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Date: Mon, 1 Jun 2026 01:17:31 -0000 (UTC) Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="53286"; mail-complaints-to="abuse@iecc.com" In-Reply-To: <10vgmgr$1cad4$1@dont-email.me> <10vhi8j$1jmkv$1@dont-email.me> Cleverness: some X-Newsreader: trn 4.0-test77 (Sep 1, 2010) Originator: johnl@iecc.com (John Levine) Xref: csiph.com alt.folklore.computers:234822 According to Peter Flass : >On 5/31/26 00:03, Lev wrote: >> John Levine wrote: >> >> The PL.8 retargeting result is striking - the fact that the compiler >> designed for 801's simple instructions also produced good S/360 code >> suggests the problem wasn't that CISC was bad, but that CISC >> instructions compilers couldn't easily select were dead weight. >> Nobody was emitting the fancy string instructions or decimal >> arithmetic unless they were hand-coding. >> > >This is 100% wrong. Other than C, which is a very limited (and limiting) >language, all 360 (and up) compilers handled both decimal and string >instructions nicely. COBOL, PL/I, and I suppose, RPG all used them. Even >in assembler I used them quite extensively. ... Take a look at this paper from 25 years ago, the part on page 52 about System/370. Even though the PL.8 compiler didn't use all the instructions, its code ran much faster than the regular PL/I compiler due to the better register management and using a fast subset of the instruction set. https://acg.cis.upenn.edu/milom/cis501-Fall11/papers/cocke-RISC.pdf The paper also suggests that as pipelines got longer and caches bigger, the advantage may be less. Also, compilers now all use the graph coloring register allocator that PL.8 introduced. There have certainly been places where the CISC stuff makes sense. If you were running RPG on an 8K machine, code size was really important and it wasn't hard to keep up with a card reader and a printer. -- Regards, John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies", Please consider the environment before reading this e-mail. https://jl.ly