At Fri, 6 Jan 2012 13:15:54 -0800, John Clements wrote: > Welcome to DrRacket, version 5.2.0.7--2012-01-05(fd5e40f/g) [3m]. > Language: racket/load; memory limit: 256 MB. > a million in-module typed adds > cpu time: 404 real time: 425 gc time: 273 > a million untyped adds > cpu time: 372 real time: 394 gc time: 212 > a million untyped->typed adds > cpu time: 3763 real time: 3979 gc time: 2077 > > > ... so in fact, TR is about the same speed as plain-old racket in > adding these (even though the plain-old-racket call is across > modules);
Ignoring GC time, TR is faster, but these measurements are very small (and GC-dominated) so I don't know how significant they are. That, and the bulk of the work is happening in the looping code (which is the same in both cases), not in the loop body. > I conjecture that racket's optimizer is discovering the same > optimizations as TR, here. I don't see how it could. There's nothing about the `ut' module that could help Racket specialize its addition to floats. > However, making a cross-module call to a TR module is *much* slower. > Is this because this module-crossing requires a contract check? Yes. Both arguments to `float-add' need to be checked for float-ness every time the function is called. Vincent ____________________ Racket Users list: http://lists.racket-lang.org/users
