You're right; among my many tests I think I muddled the situation with a stray CFLAGS variable in my environment. Apologies for the misinformation. The current MacPorts portfile does not add -fwrapv. Adding -fwrapv to OPT in the Makefile solves the problem. I confirmed by manually building the v2.7.2 tag with clang and -fwrapv, and the overflow behavior is correct. I've notified the MacPorts package maintainer. -Derek On Thu, Nov 3, 2011 at 11:07 AM, Stefan Krah <stefan at bytereef.org> wrote: > Derek Shockey <derek.shockey at gmail.com> wrote: >> I believe you're right. The 2.7.2 MacPorts portfile definitely passes >> the -fwrapv flag to clang, but the bad behavior still occurs with >> exponents. >> Really? Even without the fix for issue12973 the -fwrapv flag > should be sufficient, as reported in issue13061 and Issue11149. >> For clang version 3.0 (trunk 139691) on FreeBSD this is the case. >>> Stefan Krah >>> _______________________________________________ > Python-Dev mailing list > Python-Dev at python.org > http://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: http://mail.python.org/mailman/options/python-dev/derek.shockey%40gmail.com >