Here's a partial work-around: First, check if CPUID says there's SSE hardware support. If and only if it says "yes", then check for OS support by executing an SSE instruction. This will fix support for systems that don't have SSE support in hardware; and it also works for systems with full SSE support. It only leaves problems for systems with SSE hardware support but no OS support and a faulty GDB. That should be a relative minority.

-David Fuchs