4 int double_format(char *buf
, char spec
, int precision
, double val
);
5 double double_signum(double val
);
6 float float_signum(float val
);
7 int double_classify(double val
);
8 int float_classify(float val
);
9 int double_compare(double a
, double b
);
10 int float_compare(float a
, float b
);