1REMQUO(3P) POSIX Programmer's Manual REMQUO(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 remquo, remquof, remquol — remainder functions
13
15 #include <math.h>
16 double remquo(double x, double y, int *quo);
18 float remquof(float x, float y, int *quo);
19 long double remquol(long double x, long double y, int *quo);
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22 The functionality described on this reference page is aligned with the
23 ISO C standard. Any conflict between the requirements described here
24 and the ISO C standard is unintentional. This volume of POSIX.1‐2017
25 defers to the ISO C standard.
26 The remquo(), remquof(), and remquol() functions shall compute the same
28 remainder as the remainder(), remainderf(), and remainderl() functions,
29 respectively. In the object pointed to by quo, they store a value whose
30 sign is the sign of x/y and whose magnitude is congruent modulo 2n to
31 the magnitude of the integral quotient of x/y, where n is an implemen‐
32 tation-defined integer greater than or equal to 3. If y is zero, the
33 value stored in the object pointed to by quo is unspecified.
34 An application wishing to check for error situations should set errno
36 to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these
37 functions. On return, if errno is non-zero or fetestexcept(FE_INVALID |
38 FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has
39 occurred.
40
42 These functions shall return x REM y.
43 On systems that do not support the IEC 60559 Floating-Point option, if
45 y is zero, it is implementation-defined whether a domain error occurs
46 or zero is returned.
47 If x or y is NaN, a NaN shall be returned.
49 If x is ±Inf or y is zero and the other argument is non-NaN, a domain
51 error shall occur, and a NaN shall be returned.
52
54 These functions shall fail if:
55 Domain Error
57 The x argument is ±Inf, or the y argument is ±0 and the
58 other argument is non-NaN.
59 If the integer expression (math_errhandling & MATH_ERRNO)
61 is non-zero, then errno shall be set to [EDOM]. If the
62 integer expression (math_errhandling & MATH_ERREXCEPT) is
63 non-zero, then the invalid floating-point exception shall
64 be raised.
65 These functions may fail if:
67 Domain Error
69 The y argument is zero.
70 If the integer expression (math_errhandling & MATH_ERRNO)
72 is non-zero, then errno shall be set to [EDOM]. If the
73 integer expression (math_errhandling & MATH_ERREXCEPT) is
74 non-zero, then the invalid floating-point exception shall
75 be raised.
76 The following sections are informative.
78
80 None.
81
83 On error, the expressions (math_errhandling & MATH_ERRNO) and
84 (math_errhandling & MATH_ERREXCEPT) are independent of each other, but
85 at least one of them must be non-zero.
86
88 These functions are intended for implementing argument reductions which
89 can exploit a few low-order bits of the quotient. Note that x may be so
90 large in magnitude relative to y that an exact representation of the
91 quotient is not practical.
92
94 None.
95
97 feclearexcept(), fetestexcept(), remainder()
98 The Base Definitions volume of POSIX.1‐2017, Section 4.20, Treatment of
100 Error Conditions for Mathematical Functions, <math.h>
101
103 Portions of this text are reprinted and reproduced in electronic form
104 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
105 table Operating System Interface (POSIX), The Open Group Base Specifi‐
106 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
107 Electrical and Electronics Engineers, Inc and The Open Group. In the
108 event of any discrepancy between this version and the original IEEE and
109 The Open Group Standard, the original IEEE and The Open Group Standard
110 is the referee document. The original Standard can be obtained online
111 at http://www.opengroup.org/unix/online.html .
112 Any typographical or formatting errors that appear in this page are
114 most likely to have been introduced during the conversion of the source
115 files to man page format. To report such errors, see https://www.ker‐
116 nel.org/doc/man-pages/reporting_bugs.html .
117IEEE/The Open Group 2017 REMQUO(3P)