Re: [Matlisp-users] m.*! not native?

[Raymond T. <to...@rt...>]

>>>>> "Jefferson" == Jefferson Provost <jp...@cs...> writes:

    Jefferson> On 2/1/02 7:28 AM, "Raymond Toy" <to...@rt...> wrote:
    Jefferson> D = 1x500 real matrix
    >> 
    >> You do realize that a*b is O(500^3), a+b is O(500^2) and c*d is also
    >> O(500^2).  So it's not surprising that a*b takes 157 times longer than
    >> a+b and 88 times longer than c*d.

    Jefferson> Yes, I realize that.  But I wasn't doing a*b, I was doing a.*b, which is
    Jefferson> O(500x500), same as a+b, and c*d.

Sorry, I missed the dot!

You are right.  A peek at the generated code on Solaris seems to show
that we are calling out to generic functions way too often and could
be vastly optimized.

I know with CMUCL, a Lisp version of m+ was almost as fast (< 5%
slower?) than Fortran, so m.* should be as fast, even in Lisp.

I'll look in to it soon.

Ray