From: "Eric S. Raymond" <esr@snark.thyrsus.com> To: kbuild-devel@lists.sourceforge.net, python-dev@python.org Subject: [kbuild-devel] CML2 compiler slowness Date: Mon, 12 Mar 2001 18:36:00 -0500 (Copied to python-dev for informational purposes.) I added some profiling apparatus to the CML2 compiler and investigated mec's reports of a twenty-second startup. I've just released the version with profiling as 0.9.3, with fixes for all known bugs. Nope, it's not the quadratic-time validation pass that's eating all the cycles. It's the expression parser I generated with John Aycock's SPARK toolkit -- that's taking up an average of 26 seconds out of an average 28-second runtime. While I was at PC9 last week somebody mumbled something about Aycock's code being cubic in time. I should have heard ominous Jaws-style theme music at that point, because that damn Earley-algorithm parser has just swum up from the deeps and bitten me on the ass. Looks like I'm going to have to hand-code an expression parser for this puppy to speed it up at all. *groan* Anybody over on the Python side know of a faster alternative LL or LR(1) parser generator or factory class? -- <a href="http://www.tuxedo.org/~esr/">Eric S. Raymond</a> It will be of little avail to the people, that the laws are made by men of their own choice, if the laws be so voluminous that they cannot be read, or so incoherent that they cannot be understood; if they be repealed or revised before they are promulgated, or undergo such incessant changes that no man, who knows what the law is to-day, can guess what it will be to-morrow. Law is defined to be a rule of action; but how can that be a rule, which is little known, and less fixed? -- James Madison, Federalist Papers 62 _______________________________________________ kbuild-devel mailing list kbuild-devel@lists.sourceforge.net http://lists.sourceforge.net/lists/listinfo/kbuild-devel