61 lines
2.2 KiB
HTML
61 lines
2.2 KiB
HTML
<head>
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<title>muldiv(3) - Plan 9 from User Space</title>
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<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
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</head>
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<body bgcolor=#ffffff>
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<table border=0 cellpadding=0 cellspacing=0 width=100%>
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<tr height=10><td>
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<tr><td width=20><td>
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<tr><td width=20><td><b>MULDIV(3)</b><td align=right><b>MULDIV(3)</b>
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<tr><td width=20><td colspan=2>
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<br>
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<p><font size=+1><b>NAME </b></font><br>
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<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
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muldiv, umuldiv – high-precision multiplication and division<br>
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</table>
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<p><font size=+1><b>SYNOPSIS </b></font><br>
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<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
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<tt><font size=+1>#include <u.h><br>
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#include <libc.h>
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<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
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</font></tt>
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<tt><font size=+1>long muldiv(long a, long b, long c)
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<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
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</font></tt>
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<tt><font size=+1>ulong umuldiv(ulong a, ulong b, ulong c)<br>
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</font></tt>
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</table>
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<p><font size=+1><b>DESCRIPTION </b></font><br>
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<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
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<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.
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<i>Umuldiv</i> is the equivalent for unsigned integers. They can be used
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to scale integer values without worry about overflowing the intermediate
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result.
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<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
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On some architectures, these routines can generate a trap if the
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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
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silently truncate.<br>
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</table>
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<td width=20>
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<tr height=20><td>
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</table>
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<!-- TRAILER -->
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<table border=0 cellpadding=0 cellspacing=0 width=100%>
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<tr height=15><td width=10><td><td width=10>
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<tr><td><td>
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<center>
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<a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a>
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</center>
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</table>
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<!-- TRAILER -->
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</body></html>
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