.\" <mtk.manpages@gmail.com>
.\" Distributed under GPL.
.\"
-.TH FDIM 3 2008-08-11 "" "Linux Programmer's Manual"
+.TH FDIM 3 2010-09-20 "" "Linux Programmer's Manual"
.SH NAME
fdim, fdimf, fdiml \- positive difference
.SH SYNOPSIS
.ad l
.BR fdimf (),
.BR fdiml ():
-_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE; or
+.RS 4
+_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
+_POSIX_C_SOURCE\ >=\ 200112L;
+.br
+or
.I cc\ -std=c99
-.ad b
+.RE
+.ad
.SH DESCRIPTION
These functions return the positive difference, max(\fIx\fP-\fIy\fP,0),
between their arguments.