NAME

       remquo, remquof, remquol - remainder functions

SYNOPSIS

       #include <math.h>

       double remquo(double x, double y, int *quo);
       float remquof(float x, float y, int *quo);
       long double remquol(long double x, long double y, int *quo);

DESCRIPTION

       The  remquo(),  remquof(), and remquol() functions shall compute the same remainder as the
       remainder(), remainderf(), and remainderl() functions, respectively. In the object pointed
       to  by  quo,  they  store  a  value  whose sign is the sign of x/ y and whose magnitude is
       congruent modulo 2**n to the magnitude of the integral quotient of x/ y,  where  n  is  an
       implementation-defined integer greater than or equal to 3.

       An  application  wishing  to  check for error situations should set errno to zero and call
       feclearexcept(FE_ALL_EXCEPT) before calling these functions.  On return, if errno is  non-
       zero  or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero,
       an error has occurred.

RETURN VALUE

       These functions shall return x REM y.

       If x or y is NaN, a NaN shall be returned.

       If x is ±Inf or y is zero and the other argument is non-NaN, a domain error  shall  occur,
       and either a NaN (if supported), or an implementation-defined value shall be returned.

ERRORS

       These functions shall fail if:

       Domain Error
              The x argument is ±Inf, or the y argument is ±0 and the other argument is non-NaN.

       If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be
       set to [EDOM]. If the integer expression (math_errhandling & MATH_ERREXCEPT) is  non-zero,
       then the invalid floating-point exception shall be raised.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       On  error,  the  expressions  (math_errhandling  &  MATH_ERRNO)  and  (math_errhandling  &
       MATH_ERREXCEPT) are independent of each other, but at least one of them must be non-zero.

RATIONALE

       These functions are intended for implementing argument reductions which can exploit a  few
       low-order  bits  of  the  quotient. Note that x may be so large in magnitude relative to y
       that an exact representation of the quotient is not practical.

FUTURE DIRECTIONS

       None.

SEE ALSO

       feclearexcept()  ,  fetestexcept()  ,  remainder()  ,  the  Base  Definitions  volume   of
       IEEE Std 1003.1-2001,  Section  4.18,  Treatment  of  Error  Conditions  for  Mathematical
       Functions, <math.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1,  2003  Edition,  Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard,  the  original  IEEE  and  The  Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .