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Okay, that certainly suggests a plan of action. > Conclusions: > > 1. The biggest help would be to use gawk's regexp.c instead of the system > regexp calls, at least for this particular regexec call. Regular > expression testing is complicated, so one would have to do many more > tests for a variety of arguments (and a variety of platforms) before > being certain about it. Okay. If you submit patches to make Guile use GAWK's regexp.c, I will apply them. I think it's dumb for Guile to be in the regexp business, but every other interpreted I know of has their own, probably for reasons similar to the ones you've uncovered here. You need to change the regexp sources to be namespace-clean; that is, all externally visible symbols, either in the library or the header files, must begin with scm_ or SCM_. This is give us some hope of not squashing the user's variables. > 2. Overhead in the regexp_exec call is significant, but not > substantial. Two things could be done to reduce it. The easiest > would be to malloc the space needed for matching in the rgx > structure. Then the calls to scm_must_malloc & scm_must_free could be > skipped. The other would be to skip the call to SCM_COERCE_SUBSTR, if > that's possible. I'm not so interested in this change, but if you want to implement something that does this, and supports all the public operations in regex.scm, I'll apply it. > 3. Even with these changes, deleting startup time, and commenting > everything out of scm_regexp_exec, gawk is still fundamentally faster > gawk runtime is .8 seconds vs 3.19 seconds for guile - 4x slower! > Guile's also slower than STk & scm, even though it's descended from > scm. In particular, scm manages to run the trivial function loop > about 2x faster than guile - startup time. Has the interpreter been > changed so much that it's substantially slower now? Another > possibility is that guile's sucking in so much stuff initially that > the gc scans of memory are killing us, but I don't see an easy way to > check this. There have been substantial speedups in SCM recently, although I don't know whether those made it into your RPM. Chris Hanson (one of the RnRS authors, and one of the MIT Scheme guys) has volunteered to write a bytecode compiler/interpreter for Guile, as well as a front end for the debugger. That should improve performance some, and give us low-overhead debugging as well. This should also reduce the GC overhead, by placing most variable bindings on a stack, rather than in the heap. > A general testing issue - Doing benchmarking is a pain because of the > need to include (debug-disable 'debug) at the top of files means I > need different files for other scheme implementations. How about also > -nodebug & -debug command line args & make the (configurable) default > -nodebug? If you put a file init.scm somewhere in your GUILE_LOAD_PATH, then that should be loaded whenever Guile starts up. You can put the (debug-disable 'debug) there.