user_insn
return user_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx));
return user_insn(fnsave %[fx]; fwait, [fx] "=m" (*fx), "m" (*fx));
return user_insn(fxsave %[fx], [fx] "=m" (*fx), "m" (*fx));
return user_insn(fxsaveq %[fx], [fx] "=m" (*fx), "m" (*fx));
return user_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));
return user_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));