> So your analysis appears to be correct. Even more interesting is > that if I build python 2.4.3 with Apple's gcc from Xcode 2.3, the > correct results are obtained without the need to resort to the > -fwrapv flag. So either we have a regression in gcc trunk or > Apple has a patch in their branch which was never moved over > that resolves this issue. The only difference I can see between > the builds with gcc trunk and Apple's gcc is that I have to > remove the -Wno-long-double -no-cpp-precomp flags the build > with gcc trunk (because they don't exist).
Yes Apple's 4.0 is just 4.0.2 plus some patches. VRP which is what is usually exposes signed overflow as being undefined bugs was added 4.1. This is most likely not a bug in GCC if -fwarpv fixes the problem. -- Pinski
