Subject: Re: Floating Point speed in Common Lisp
From: Erik Naggum <>
Date: 1998/03/13
Newsgroups: comp.lang.lisp
Message-ID: <>

* Christopher J. Vogt
| I forget if it was Steele or Gabriel who observed that one of the things
| that makes programming in common lisp uniquely different from other
| languages, is that to get good performance, you have to be intimately
| familiar with your implementation.  This sort of issue doesn't exist in
| C, for example.  One implementation of C is generally as fast (within a
| factor of 2) as another.  However, CL implementations can vary quite a
| bit, in different areas.  One might have (relatively) good FP performance
| but horrible Bignum performance etc.

  I beg to differ.  C systems (compilers, libraries, etc) generally differ
  by just as large factors as Common Lisp, often more, when non-trivial
  functions are used, and they tend to be for non-trivial programs, and
  optimizing C is generally very hard beyond the simple cases.

  I'm not saying that CL is doing a better job than C in the general case,
  but I'm getting somewhat peeved with the repetitive claims that C is so
  fast.  it isn't.  it never was.  it's just that the language is fairly
  transparent down to the machine level so when you change something in the
  C code, you can predict the effect on the compiled machine code.  that
  doesn't make it _fast_, it only ingratiates the control-freak aspect of
  most programmers.

  God grant me serenity to accept the code I cannot change,
  courage to change the code I can, and wisdom to know the difference.