New submission from deadshort <cploo...@gmail.com>: Apple Radar ticket 9908625 has been filed. The clang 2.1 optimizer causes overflows in Object/intobject.c:int_pow() to be missed, so 2**63 turns into a negative integer. The attached test program narrows it down. llvm-gcc is fine, so this ticket is mostly an FYI.
idiotbox:Python-2.7.2 cloomis$ ./seqpoint-OK 4000000000 4000000000 a=4000000000, b=4000000000, c(a*b)=-2446744073709551616, c/b=-611686018 overflow detected: 1 to turn into: idiotbox:Python-2.7.2 cloomis$ ./seqpoint 4294967296 4200000000 a=4294967296, b=4200000000, c(a*b)=-407881430509551616, c/b=4294967296 overflow detected: 0 ---------- components: Interpreter Core files: seqpoint.c messages: 141701 nosy: deadshort priority: normal severity: normal status: open title: Apple's clang 2.1 (xcode 4.1, OSX 10.7) optimizer miscompiles intobject.c versions: Python 2.7 Added file: http://bugs.python.org/file22845/seqpoint.c _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue12701> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
