Path: csiph.com!eternal-september.org!feeder.eternal-september.org!nntp.eternal-september.org!.POSTED!not-for-mail From: Tim Rentsch Newsgroups: comp.arch Subject: Re: endian history Date: Thu, 01 Oct 2026 09:15:29 -0700 Organization: A noiseless patient Spider Lines: 18 Message-ID: <864if5pfby.fsf@linuxsc.com> References: <10uks4f$1dqo$1@gal.iecc.com> <118dl5f$37cfv$1@dont-email.me> <118e8kg$3f05h$1@dont-email.me> <868q4zuhz4.fsf@linuxsc.com> <118jitv$1cm6b$1@dont-email.me> <86ik42tcf4.fsf@linuxsc.com> <118uf6m$12tta$1@dont-email.me> <86ld8srnq9.fsf@linuxsc.com> <1790188863-5857@newsgrouper.org> <86cxu3sp11.fsf@linuxsc.com> <1790269240-5857@newsgrouper.org> <119hf66$3nmbu$1@dont-email.me> <86ld8hplkd.fsf@linuxsc.com> <2026Oct1.172040@mips.complang.tuwien.ac.at> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Date: Thu, 01 Oct 2026 16:15:30 +0000 (UTC) Injection-Info: dont-email.me; logging-data="1421800"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+mnuvH3qjxP4DhRRoLd1Kqn8iI+9gxraU="; posting-host="18a74afe15b7c222d977d31c18068e17" User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.4 (gnu/linux) Cancel-Lock: sha1:jGWcOveYEcph5+cOI1YT/1ukND8= sha1:j1qiFaajaP8Y1DmkoDvuw6aool8= sha256:Sbf2BqYvmaeHDwSZLKi8dfo8Vf4C7dgjiPzsdznoJvY= sha1:m3hbsqBBFGZBKAhnUjcQC4EuIjY= sha256:yR2ofveioDK/wy3iyTGArOFFaWntc4f3NjXA8Qg05JQ= Xref: csiph.com comp.arch:118356 anton@mips.complang.tuwien.ac.at (Anton Ertl) writes: > Tim Rentsch writes: > >>> With wrapping signed arithmetic, all of the semantics of unsigned >>> arithmetic is the same, except for right shift and division >>> operations. >> >> Also left shift > > No. The funny thing is that AMD64 has both SHL and SAL mnemonics, but > they encode the same opcodes. E.g.: > > D3 /4 SAL r/m32, CL > D3 /4 SHL r/m32, CL That may be true for AMD64. It is not true for other two's complement architectures.