I added the needed flag to the my local configuration just today. It's -ieee and needed to enforce IEEE conforming math operations. It's never been part of the basic toolset because usually the IEEE conformance of the CPU itself is good enough, and using this flags may incur a significant performance penalty. So I would recommend not to add it to the basic toolset.
Strictly speaking it should be there for all math relevant boost libraries which depend on IEEE conforming math, but I always thoughr that anyone using this libraries on Alpha CPUs will know about the pitfalls.
I suspect the issue is that numeric_limits<T>::has_infinity is true, so the test attempts to verify that infinities are correctly handled, but in practice infinities trap without the -ieee flag. Is there a macro that tells you when infinities are correctly handled? John.