do_mathemu
int do_mathemu(struct pt_regs *regs);
ret = do_mathemu(regs);
int do_mathemu(struct pt_regs *regs, struct task_struct *fpt);
int do_mathemu(struct pt_regs *regs, struct fpustate *f, bool illegal_insn_trap);
ret = do_mathemu(regs, fpt);
ret = do_mathemu(regs, f, false);
if (do_mathemu(regs, f, true))