man/man3/muldiv.html


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61

<head>
<title>muldiv(3) - Plan 9 from User Space</title>
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
</head>
<body bgcolor=#ffffff>
<table border=0 cellpadding=0 cellspacing=0 width=100%>
<tr height=10><td>
<tr><td width=20><td>
<tr><td width=20><td><b>MULDIV(3)</b><td align=right><b>MULDIV(3)</b>
<tr><td width=20><td colspan=2>
    <br>
<p><font size=+1><b>NAME     </b></font><br>

<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>

    muldiv, umuldiv &ndash; high-precision multiplication and division<br>
    
</table>
<p><font size=+1><b>SYNOPSIS     </b></font><br>

<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>

    <tt><font size=+1>#include &lt;u.h&gt;<br>
    #include &lt;libc.h&gt; 
    <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
    </font></tt>
    <tt><font size=+1>long &nbsp;&nbsp;&nbsp;muldiv(long a, long b, long c) 
    <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
    </font></tt>
    <tt><font size=+1>ulong umuldiv(ulong a, ulong b, ulong c)<br>
    </font></tt>
</table>
<p><font size=+1><b>DESCRIPTION     </b></font><br>

<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>

    <i>Muldiv</i> returns <tt><font size=+1>a*b/c</font></tt>, using a <tt><font size=+1>vlong</font></tt> to hold the intermediate result.
    <i>Umuldiv</i> is the equivalent for unsigned integers. They can be used
    to scale integer values without worry about overflowing the intermediate
    result. 
    <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
    
    On some architectures, these routines can generate a trap if the
    final result does not fit in a <tt><font size=+1>long</font></tt> or <tt><font size=+1>ulong</font></tt>; on others they will
    silently truncate.<br>
    
</table>

<td width=20>
<tr height=20><td>
</table>
<!-- TRAILER -->
<table border=0 cellpadding=0 cellspacing=0 width=100%>
<tr height=15><td width=10><td><td width=10>
<tr><td><td>
<center>
<a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a>
</center>
</table>
<!-- TRAILER -->
</body></html>