REMQUO(P) POSIX Programmer's Manual REMQUO(P)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 imple‐
mentation-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 implementa‐
tion-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 ALSOfeclearexcept() , 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 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 .
IEEE/The Open Group 2003 REMQUO(P)
