pow.3

UNIX v6源代码 这几乎是最经典的unix版本 unix操作系统设计和莱昂氏unix源代码分析都是用的该版

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.th POW III 4/30/73
.sh NAME
pow \*- floating exponentiation
.sh SYNOPSIS
.ft B
movf	x,fr0
.br
movf	y,fr1
.br
jsr	pc,pow
.s3
.nf
double pow(x,y)
double x, y;
.fi
.s3
.ft R
.sh DESCRIPTION
.it Pow
returns
the value of
\fIx\u\s8y\s10\d\fR
(in fr0).
.it "Pow(0.0,|y)"
is 0 for any
.it y.
.it "Pow(\*-x,|y)"
returns a result only if
.it y
is an integer.
.sh "SEE ALSO"
exp (III), log (III)
.sh DIAGNOSTICS
The
carry bit is set on return in case of overflow,
.it pow(0.0,|0.0),
or
.it pow(\*-x,|y)
for non-integral
.it y.
From C there is no diagnostic.
.sh BUGS