shithub: riscv

ref: 1d748edeaf62b2e919db1d2d5f0066dd529ea5fa
dir: /sys/man/2/muldiv/

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.TH MULDIV 2
.SH NAME
muldiv, umuldiv \- high-precision multiplication and division
.SH SYNOPSIS
.B #include <u.h>
.br
.B #include <libc.h>
.PP
.B
long muldiv(long a, long b, long c)
.PP
.B
ulong umuldiv(ulong a, ulong b, ulong c)
.SH DESCRIPTION
.I Muldiv
returns
.BR a*b/c ,
using a
.B vlong
to hold the intermediate result.
.I Umuldiv
is the equivalent for unsigned integers.
They can be used to scale integer values without worry about
overflowing the intermediate result.
.PP
On some architectures, these routines can generate a trap if the
final result does not fit in a
.B long
or
.BR ulong ;
on others they will silently truncate.