32 lines
639 B
Plaintext
32 lines
639 B
Plaintext
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.TH MULDIV 2
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.SH NAME
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muldiv, umuldiv \- high-precision multiplication and division
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.SH SYNOPSIS
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.B #include <u.h>
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.br
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.B #include <libc.h>
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.PP
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.B
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long muldiv(long a, long b, long c)
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.PP
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.B
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ulong umuldiv(ulong a, ulong b, ulong c)
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.SH DESCRIPTION
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.I Muldiv
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returns
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.BR a*b/c ,
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using a
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.B vlong
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to hold the intermediate result.
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.I Umuldiv
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is the equivalent for unsigned integers.
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They can be used to scale integer values without worry about
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overflowing the intermediate result.
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.PP
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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
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.B long
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or
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.BR ulong ;
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on others they will silently truncate.
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