-- | Check whether a label corresponds to a C function that has
--      a prototype in a system header somehere, or is built-in
--      to the C compiler. For these labels we avoid generating our
--      own C prototypes.
isMathFun :: CLabel -> Bool
isMathFun (ForeignLabel fs _ _ _)       = fs `elementOfUniqSet` math_funs
isMathFun :: CLabel -> Bool
isMathFun (ForeignLabel fs _ _ _)       = fs `elementOfUniqSet` math_funs
isMathFun (ForeignLabel fs _ _ _)       = fs `elementOfUniqSet` math_funs