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=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,9adfbb907494972e X-Google-Attributes: gid103376,public X-Google-Thread: 1014db,9adfbb907494972e X-Google-Attributes: gid1014db,public From: seebs@solutions.solon.com (Peter Seebach) Subject: Re: Ada to C/C++ translator needed Date: 1996/09/30 Message-ID: <52p7hl$kq4@solutions.solon.com>#1/1 X-Deja-AN: 186287009 references: <32499FA0.4B5E@magic.fr> <01bbad6e$67743f20$32ee6fcf@timhome2> <52o1ve$gra@goanna.cs.rmit.edu.au> <01bbaee1$00ee1c20$87ee6fce@timpent.a-sis.com> organization: Usenet Fact Police (Undercover) reply-to: seebs@solon.com newsgroups: comp.lang.c,comp.lang.ada Date: 1996-09-30T00:00:00+00:00 List-Id: In article <01bbaee1$00ee1c20$87ee6fce@timpent.a-sis.com>, Tim Behrendsen wrote: >I would conclude that for that *specific* problem, the C compiler >did a bad job of optimization. As I frequently point out (and >I frequently get abuse for it), optimizers are very imperfect >beasts at best. ... Right, so we *know* for sure that there exists at least one case in which C may be less efficient than Ada. This proves, absolutely, that the general statement "C is more efficient than Ada" is not true. >Do you doubt that if we brought the writers of the Sun compiler >and had them fix their optimizer, they couldn't make it produce >*exactly* the same code as the Ada compiler (or Fortran compiler, >for that matter)? Of course they could. True. Could they beat the Ada or Fortran compiler? Not as likely. Could they guarantee that, in the end, they would be able to produce better code than the Ada compiler team? No. >The real question that you refuse to come to terms with is, what >is the average case over a large set of compilers over a large set >of non-trivial programs over a large set of problem types? And >this is a very difficult question to answer. Yes. So difficult that it's essentially irrelevant. For that matter, a large set of compilers has little relevance; all I care about is the best available compilers. >Your suggestion that comparing compilers on one platform for >one program tells you something significant is laughable at >best. It does, though. It gives you a boundary. >This is not because of optimization; this is because of the >language and style in which projects are implemented. Now, >this is a significant debatable question. Comparing the output >of optimizers is completely worthless to the central question >of whether REAL WORLD projects can be implement efficiently in >a particular language or not. "can be" and "will be" are completely different questions. -s -- Peter Seebach - seebs@solon.com - Copyright 1996 - http://www.solon.com/~seebs Unix/C Wizard - send mail for help, or send money for consulting! The *other* C FAQ, the hacker FAQ, et al. See web page above. Unsolicited email (junk mail and ads) is unwelcome, and will be billed for.