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- From: hrubin@pop.stat.purdue.edu (Herman Rubin)
- Newsgroups: comp.arch
- Subject: Re: CISC Microcode (was Re: RISC Mainframe)
- Message-ID: <55117@mentor.cc.purdue.edu>
- Date: 26 Jul 92 15:51:35 GMT
- References: <l6mlr0INN7tu@spim.mips.com> <54638@mentor.cc.purdue.edu> <id.YGRR.V_5@ferranti.com>
- Sender: news@mentor.cc.purdue.edu
- Organization: Purdue University Statistics Department
- Lines: 37
-
- In article <id.YGRR.V_5@ferranti.com> peter@ferranti.com (Peter da Silva) writes:
- >In article <54638@mentor.cc.purdue.edu> hrubin@pop.stat.purdue.edu (Herman Rubin) writes:
- >> > 1) The compilers can't figure out how to use them often.
-
- >> We keep hearing that compilers can do as well as humans.
-
- >They do, but not in the same way. Similarly there are optimisations compilers
- >will use that humans can't.
-
- If an optimization involves extensive calculation, a superfast sub-imbecile
- can do it better than a human.
-
- >> > or 2) Most realistic code doesn't lend itself to the mode.
-
- >> What is realistic code? I will code differently if there is hardware
- >> auto-increment for addresses.
-
- >I won't.
-
- Why not? Because this would involve using an optimization not in the
- usual set? This is the vicious cycle which has removed many useful and
- cheap instructions even from present computers.
-
- >> I expect any good programmer to do as well;
-
- >I expect any good programmer to code for the abstract machine defined for
- >the language. Remember, software longa, hardware brevis.
-
- This might be reasonable if we had a language produced by people who have
- some respect for the capabilities of humans. An analogy to the present
- programming languages would be a car-controller in which one could feed
- in a destination, but would not allow manual control.
- --
- Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399
- Phone: (317)494-6054
- hrubin@pop.stat.purdue.edu (Internet, bitnet)
- {purdue,pur-ee}!pop.stat!hrubin(UUCP)
-