On Wed, Feb 27, 2008 at 05:45:34AM -0500, Neal Becker wrote: > We are trying to track down a numerical problem with unuran that occurs on > gcc-4.3. I know that gcc now has a very extensive test suite, and bugs are > not common. I'm just wondering, are others finding similar problems with > gcc-4.3? > > We are working on preparing a bug report. The symptoms are: > 1) Problem disappears if -O0 > 2) Problem disappears if a printf is added > 3) valgrind is silent If it is on i?86, might very well be a problem caused by excess precision. Try -O2 -msse2 -mfpmath=sse to see if it helps, you likely need some volatile temporaries to ensure results are rounded down to the desired float resp. double precision (when results are kept within FP stack, they use extended precision). If not, using binary search between -O0 and -O2 objects you can easily find the problematic object and with some extra effort even the problematic function. Create a self-contained testcase from it (main calling the problematic function with some arguments that reproduce it (if needed make it __attribute__((noinline)), add stubs for functions the problematic function calls) and report. Jakub -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list