Apparently FreeBSD enables some HW floating-point exceptions by default.
This can cause core dumps when Python runs. Python relies on the 754-
(and C99-) mandated default "non-stop" mode for FP exceptions. This
patch from Ben Laurie disables at least one FP exception on FreeBSD at
Python startup time.
diff --git a/Modules/python.c b/Modules/python.c
index f9262e8..2739b8b 100644
--- a/Modules/python.c
+++ b/Modules/python.c
@@ -2,8 +2,23 @@
#include "Python.h"
+#ifdef __FreeBSD__
+#include <floatingpoint.h>
+#endif
+
int
main(int argc, char **argv)
{
+ /* 754 requires that FP exceptions run in "no stop" mode by default,
+ * and until C vendors implement C99's ways to control FP exceptions,
+ * Python requires non-stop mode. Alas, some platforms enable FP
+ * exceptions by default. Here we disable them.
+ */
+#ifdef __FreeBSD__
+ fp_except_t m;
+
+ m = fpgetmask();
+ fpsetmask(m & ~FP_X_OFL);
+#endif
return Py_Main(argc, argv);
}