man3/remquo.3

   1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
   3 .\"     <mtk.manpages@gmail.com>
   4 .\"
   5 .\" SPDX-License-Identifier: GPL-1.0-or-later
   6 .\"
   7 .\" based on glibc infopages
   8 .\" polished, aeb
   9 .\"
  10 .TH REMQUO 3 2021-03-22 "GNU" "Linux Programmer's Manual"
  11 .SH NAME
  12 remquo, remquof, remquol \- remainder and part of quotient
  13 .SH LIBRARY
  14 Math library
  15 .RI ( libm ", " \-lm )
  16 .SH SYNOPSIS
  17 .nf
  18 .B #include <math.h>
  19 .PP
  20 .BI "double remquo(double " x ", double " y ", int *" quo );
  21 .BI "float remquof(float " x ", float " y ", int *" quo );
  22 .BI "long double remquol(long double " x ", long double " y ", int *" quo );
  23 .fi
  24 .PP
  25 .RS -4
  26 Feature Test Macro Requirements for glibc (see
  27 .BR feature_test_macros (7)):
  28 .RE
  29 .PP
  30 .BR remquo (),
  31 .BR remquof (),
  32 .BR remquol ():
  33 .nf
  34     _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
  35 .fi
  36 .SH DESCRIPTION
  37 These functions compute the remainder and part of the quotient
  38 upon division of
  39 .I x
  40 by
  41 .IR y .
  42 A few bits of the quotient are stored via the
  43 .I quo
  44 pointer.
  45 The remainder is returned as the function result.
  46 .PP
  47 The value of the remainder is the same as that computed by the
  48 .BR remainder (3)
  49 function.
  50 .PP
  51 The value stored via the
  52 .I quo
  53 pointer has the sign of
  54 .I x\~/\~y
  55 and agrees with the quotient in at least the low order 3 bits.
  56 .PP
  57 For example, \fIremquo(29.0,\ 3.0)\fP returns \-1.0 and might store 2.
  58 Note that the actual quotient might not fit in an integer.
  59 .\" A possible application of this function might be the computation
  60 .\" of sin(x). Compute remquo(x, pi/2, &quo) or so.
  61 .\"
  62 .\" glibc, UnixWare: return 3 bits
  63 .\" MacOS 10: return 7 bits
  64 .SH RETURN VALUE
  65 On success, these functions return the same value as
  66 the analogous functions described in
  67 .BR remainder (3).
  68 .PP
  69 If
  70 .I x
  71 or
  72 .I y
  73 is a NaN, a NaN is returned.
  74 .PP
  75 If
  76 .I x
  77 is an infinity,
  78 and
  79 .I y
  80 is not a NaN,
  81 a domain error occurs, and
  82 a NaN is returned.
  83 .PP
  84 If
  85 .I y
  86 is zero,
  87 and
  88 .I x
  89 is not a NaN,
  90 a domain error occurs, and
  91 a NaN is returned.
  92 .SH ERRORS
  93 See
  94 .BR math_error (7)
  95 for information on how to determine whether an error has occurred
  96 when calling these functions.
  97 .PP
  98 The following errors can occur:
  99 .TP
 100 Domain error: \fIx\fP is an infinity or \fIy\fP is 0, \
 101 and the other argument is not a NaN
 102 .\" .I errno
 103 .\" is set to
 104 .\" .BR EDOM .
 105 An invalid floating-point exception
 106 .RB ( FE_INVALID )
 107 is raised.
 108 .PP
 109 These functions do not set
 110 .IR errno .
 111 .\" FIXME . Is it intentional that these functions do not set errno?
 112 .\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6802
 113 .SH VERSIONS
 114 These functions first appeared in glibc in version 2.1.
 115 .SH ATTRIBUTES
 116 For an explanation of the terms used in this section, see
 117 .BR attributes (7).
 118 .ad l
 119 .nh
 120 .TS
 121 allbox;
 122 lbx lb lb
 123 l l l.
 124 Interface       Attribute       Value
 125 T{
 126 .BR remquo (),
 127 .BR remquof (),
 128 .BR remquol ()
 129 T}      Thread safety   MT-Safe
 130 .TE
 131 .hy
 132 .ad
 133 .sp 1
 134 .SH CONFORMING TO
 135 C99, POSIX.1-2001, POSIX.1-2008.
 136 .SH SEE ALSO
 137 .BR fmod (3),
 138 .BR logb (3),
 139 .BR remainder (3)