KLEE-Float
Check out https://srg.doc.ic.ac.uk/projects/klee-float/
That is an extension project to the KLEE symbolic execution engine that supports reasoning about floating-point arithmetic. For more details see:
Floating-Point Symbolic Execution: A Case Study in N-version Programming. Daniel Liew, Daniel Schemmel, Cristian Cadar, Alastair Donaldson, Rafael Zähl, Klaus Wehrle. IEEE/ACM International Conference on Automated Software Engineering (ASE 2017)