From mboxrd@z Thu Jan 1 00:00:00 1970 From: mike stump To: jsm28@cam.ac.uk, rth@redhat.com Cc: dewar@gnat.com, gcc@gcc.gnu.org Subject: Re: Loop unroll fixes Date: Tue, 18 Sep 2001 11:54:00 -0000 Message-id: <200109181852.LAA22164@kankakee.wrs.com> X-SW-Source: 2001-09/msg00722.html > Date: Tue, 18 Sep 2001 10:19:02 +0100 (BST) > From: "Joseph S. Myers" > * Where says > (of creating synthetic testcases for bugs shown up by confidential > code) "sometimes specific tests for fixed bugs are definitely cases > of closing the doors after the cows have fled", this is misleading > since such testcases may be necessary in future to debug problems > with the fix; so creating such testcases would not be as described > there "work that competes with everything else going on" but > something at which a reasonable effort *must* be made before a fix > is installed in FSF GCC. I think that all changes to gcc should come with at least one testcase that actually demonstrates why the change was a good idea. If the code merely changes performance, then the performance suite should have a testcase that shows the performance advantage. The last point we currently never do, so I can be dissuaded for now that it is unrealistic, but, I think for real bugs, it is possible to meet this requirement. The testsuite is invaluable to the quality of the compiler in so many ways. It should be a requirement, not optional. I do realize that sometimes a testcase isn't possible, but in my experience, those are rare. A good example of such, would be a testcase in the C++ framework to test throwing in/out and trough a shared library. The old-deja.exp framework doesn't have enough beef to do this. A testcase is impossible within it, without massive modifications to old-deja.exp. An non-example would be 112 thousand lines of customer proprietary code which changes any time almost anything is played with. Been there, done that, not that hard, just time consuming to trim the testcase and sanitize it. If the folks that contributed the testsuite we have felt the same way as dewar, it is clear to me that we would not have a gcc/g++ testsuite, or that it would be smaller.