Richard Fateman wrote:
> Time for running in Allegro CL 7.0 on a 933 MHz Pentium II.
> as given:

> ; cpu time (non-gc) 60,202 msec (00:01:00.202) user, 421 msec system
> ; cpu time (gc)     33,623 msec user, 10 msec system
> ; cpu time (total)  93,825 msec (00:01:33.825) user, 431 msec system
> ; real time  105,632 msec (00:01:45.632)
> ; space allocation:
> ;  967,240 cons cells, 3,719,472,272 other bytes, 4,472 static bytes

> But converting all "single-float"  to double-float:

> ; cpu time (non-gc) 4,446 msec user, 120 msec system
> ; cpu time (gc)     2,524 msec user, 0 msec system
> ; cpu time (total)  6,970 msec user, 120 msec system
> ; real time  7,961 msec
> ; space allocation:
> ;  418,422 cons cells, 292,782,544 other bytes, 0 static bytes
> The compiler complained about the "shadow" statement
> warning: compile-file found "SHADOW" at the top-level --  see the
>           documentation for
>           comp:*cltl1-compile-file-toplevel-compatibility-p*

> My guess is that much of the verbosity for the sbcl version could be
> struck out of the allegro cl version without any loss in speed, and that
> careful attention to other potential optimizations/ declarations could
> squeeze out better performance.

> It could be that this single/double issue relates to your AMD64 timings.
> Most of it may be converting single to double and back.