On Tue Mar 01, 2005 at 23:02:59 +1100, Michael Knight wrote: >Hi all, > >I'm starting an honours year at uni this year. My supervisor and I are >thinking of doing a paper on trying to determine if memory-mapping >source files will speed up the lexical analysis phase of various >compilers (instead of whatever buffering method it currently employs). > >While we can't find any similar publications on the subject that >obviously doesn't mean no one out there has done anything on it. Has >anyone heard of any work done on this kind of thing before?
This sounds interesting but I would have thought that it was as much an operating systems thing as a languages compilers thing. One thing to watch out for is that this is likely to be OS dependant; how the IO system, buffering and paging is implemented will have a large affect on results. From the systems I've tested on (MacOSX/PPC, Linux2.6.10/ia32), mmap is a much faster than alternatives, the question is however, how much impact that would have on the speed of the lexer. I think the main thing you would need to show first is that in current lexers I/O is the dominating factor, and not say, the actual lexing of the data. I wouldn't have expected I/O costs to be dominant, but a quick use of gprof would definately show one way or the other. Cheers, Benno -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
