IEEE Std 1003.1-2017 (Revision of IEEE Std 1003.1-2008)

Copyright © 2001-2018 IEEE and The Open Group

remquo, remquof, remquol - remainder functions

#include <math.h>

double remquo(doublex, doubley, int *quo);

float remquof(floatx, floaty, int *quo);

long double remquol(long doublex, long doubley, int *quo);

^{[CX]}The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2017 defers to the ISO C standard.The

remquo(),remquof(), andremquol() functions shall compute the same remainder as theremainder(),remainderf(), andremainderl() functions, respectively. In the object pointed to byquo, they store a value whose sign is the sign ofx/yand whose magnitude is congruent modulo 2to the magnitude of the integral quotient of^{n}x/y, wherenis an implementation-defined integer greater than or equal to 3. Ifyis zero, the value stored in the object pointed to byquois unspecified.An application wishing to check for error situations should set

errnoto zero and callfeclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, iferrnois non-zero orfetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred.

These functions shall return

xREMy.On systems that do not support the IEC 60559 Floating-Point option, if

yis zero, it is implementation-defined whether a domain error occurs or zero is returned.

^{[MX]}Ifxoryis NaN, a NaN shall be returned.If

xis ±Inf oryis zero and the other argument is non-NaN, a domain error shall occur, and a NaN shall be returned.

These functions shall fail if:

- Domain Error
^{[MX]}Thexargument is ±Inf, or theyargument is ±0 and the other argument is non-NaN.If the integer expression (

math_errhandling& MATH_ERRNO) is non-zero, thenerrnoshall be set to [EDOM]. If the integer expression (math_errhandling& MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception shall be raised.These functions may fail if:

- Domain Error
- The
yargument is zero.If the integer expression (

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

None.

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.

These functions are intended for implementing argument reductions which can exploit a few low-order bits of the quotient. Note that

xmay be so large in magnitude relative toythat an exact representation of the quotient is not practical.

None.

feclearexcept,fetestexcept,remainderXBD

Treatment of Error Conditions for Mathematical Functions,<math.h>

First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.

ISO/IEC 9899:1999 standard, Technical Corrigendum 2 #56 (SD5-XSH-ERN-83) is applied.

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0507 [320] is applied.

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