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 .\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
   6 .\" Distributed under GPL
   7 .\" %%%LICENSE_END
   8 .\"
   9 .\" based on glibc infopages
  10 .\" polished, aeb
  11 .\"
  12 .TH REMQUO 3 2015-04-19 "GNU" "Linux Programmer's Manual"
  13 .SH NAME
  14 remquo, remquof, remquol \- remainder and part of quotient
  15 .SH SYNOPSIS
  16 .nf
  17 .B #include <math.h>
  18 .sp
  19 .BI "double remquo(double " x ", double " y ", int *" quo );
  20 .br
  21 .BI "float remquof(float " x ", float " y ", int *" quo );
  22 .br
  23 .BI "long double remquol(long double " x ", long double " y ", int *" quo );
  24 .fi
  25 .sp
  26 Link with \fI\-lm\fP.
  27 .sp
  28 .in -4n
  29 Feature Test Macro Requirements for glibc (see
  30 .BR feature_test_macros (7)):
  31 .in
  32 .sp
  33 .ad l
  34 .BR remquo (),
  35 .BR remquof (),
  36 .BR remquol ():
  37 .RS 4
  38 _ISOC99_SOURCE || _POSIX_C_SOURCE\ >=\ 200112L
  39 .br
  40 or
  41 .I cc\ -std=c99
  42 .RE
  43 .ad
  44 .SH DESCRIPTION
  45 These functions compute the remainder and part of the quotient
  46 upon division of
  47 .I x
  48 by
  49 .IR y .
  50 A few bits of the quotient are stored via the
  51 .I quo
  52 pointer.
  53 The remainder is returned as the function result.
  54
  55 The value of the remainder is the same as that computed by the
  56 .BR remainder (3)
  57 function.
  58
  59 The value stored via the
  60 .I quo
  61 pointer has the sign of
  62 .IR "x\ /\ y"
  63 and agrees with the quotient in at least the low order 3 bits.
  64
  65 For example, \fIremquo(29.0,\ 3.0)\fP returns \-1.0 and might store 2.
  66 Note that the actual quotient might not fit in an integer.
  67 .\" A possible application of this function might be the computation
  68 .\" of sin(x). Compute remquo(x, pi/2, &quo) or so.
  69 .\"
  70 .\" glibc, UnixWare: return 3 bits
  71 .\" MacOS 10: return 7 bits
  72 .SH RETURN VALUE
  73 On success, these functions return the same value as
  74 the analogous functions described in
  75 .BR remainder (3).
  76
  77 If
  78 .I x
  79 or
  80 .I y
  81 is a NaN, a NaN is returned.
  82
  83 If
  84 .I x
  85 is an infinity,
  86 and
  87 .I y
  88 is not a NaN,
  89 a domain error occurs, and
  90 a NaN is returned.
  91
  92 If
  93 .I y
  94 is zero,
  95 and
  96 .I x
  97 is not a NaN,
  98 a domain error occurs, and
  99 a NaN is returned.
 100 .SH ERRORS
 101 See
 102 .BR math_error (7)
 103 for information on how to determine whether an error has occurred
 104 when calling these functions.
 105 .PP
 106 The following errors can occur:
 107 .TP
 108 Domain error: \fIx\fP is an infinity or \fIy\fP is 0, \
 109 and the other argument is not a NaN
 110 .\" .I errno
 111 .\" is set to
 112 .\" .BR EDOM .
 113 An invalid floating-point exception
 114 .RB ( FE_INVALID )
 115 is raised.
 116 .PP
 117 These functions do not set
 118 .IR errno .
 119 .\" FIXME . Is it intentional that these functions do not set errno?
 120 .\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6802
 121 .SH VERSIONS
 122 These functions first appeared in glibc in version 2.1.
 123 .SH ATTRIBUTES
 124 For an explanation of the terms used in this section, see
 125 .BR attributes (7).
 126 .TS
 127 allbox;
 128 lbw30 lb lb
 129 l l l.
 130 Interface       Attribute       Value
 131 T{
 132 .BR remquo (),
 133 .BR remquof (),
 134 .BR remquol ()
 135 T}      Thread safety   MT-Safe
 136 .TE
 137 .SH CONFORMING TO
 138 C99, POSIX.1-2001, POSIX.1-2008.
 139 .SH SEE ALSO
 140 .BR fmod (3),
 141 .BR logb (3),
 142 .BR remainder (3)