See also Bug 610745 - RFE: provide "like" and "unlike" operators
I've just hit this issue too, I need to test on a machine with SSE4 ... btw, reversing the bug dependency, as "contains" is a subset of what is proposed in bug #610745
Bug 854364 will introduce a "like" operator for <hostRequires/> and <distroRequires/> criteria. *** This bug has been marked as a duplicate of bug 854364 ***