From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: *** X-Spam-Status: No, score=3.8 required=5.0 tests=BAYES_00,INVALID_MSGID, RATWARE_MS_HASH,RATWARE_OUTLOOK_NONAME autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 109fba,baaf5f793d03d420 X-Google-Attributes: gid109fba,public X-Google-Thread: fc89c,97188312486d4578 X-Google-Attributes: gidfc89c,public X-Google-Thread: 1014db,6154de2e240de72a X-Google-Attributes: gid1014db,public X-Google-Thread: 103376,97188312486d4578 X-Google-Attributes: gid103376,public From: "Tim Behrendsen" Subject: Re: What's the best language to start with? [was: Re: Should I learn C or Pascal?] Date: 1996/09/06 Message-ID: <01bb9ba4$365fa400$32ee6fcf@timhome2>#1/1 X-Deja-AN: 178808647 references: <01bb8df1$2e19d420$87ee6fce@timpent.airshields.com><4vcac4$gm6@zeus.orl.mmc.com> <01bb8f19$9a89d820$32ee6fce@timhome2><841797763snz@genesis.demon.co.uk> content-type: text/plain; charset=ISO-8859-1 organization: A-SIS mime-version: 1.0 newsgroups: comp.lang.c,comp.lang.c++,comp.unix.programmer,comp.lang.ada Date: 1996-09-06T00:00:00+00:00 List-Id: Robert I. Eachus wrote in article ... > In article mdw@excessus.demon.co.uk (Mark Wooding) writes: > > > The One True View is that sequence of instructions; all else is an > > illusion. Maybe it's a helpful illusion, but illusion it is > > nonetheless. > > Sorry, this is completely false. On most modern processors which > typically have multiple independent pipelines, your One True View is > at best a helpful illusion. Go get a SPARC, PA-RISC, or PowerPC > reference manual and read it. (You have to sign a non-disclosure > agreement to get the same level of detail about a Pentium.) In all > cases, the illusion that there is such a thing as a processor state is > only true in some cases of traps or signals--and even then it is not > all that well defined. Assembler on a Z80 chip might correspond to > some One True View, but for all modern chips architecture manuals > sections on assembly should only be read by compiler vendors. (And > they need to read it VERY carefully, but that is a different > discussion.) The point is not that there's a single thread of execution, but that there *is* a thread of execution. His point (and mine) is that algorithms require instruction execution over time. The number of simultaneous instructions is irrelevent, and so-called "non-procedural" languages are only non-procedural in the sense that the programmer does not specify the procedure -- the compiler does. -- Tim Behrendsen (tim@a-sis.com)