REMQUO(3P) POSIX Programmer's Manual REMQUO(3P)
**PROLOG**

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond-
ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
**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() func-
tions, 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 implemen-
tation-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 Condi-
tions 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 Technol-
ogy *--* 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 .
**IEEE**

/The Open Group 2003 REMQUO(3P)