1 files changed, 56 insertions, 8 deletions
diff --git a/lib/libc/gen/fpclassify.3 b/lib/libc/gen/fpclassify.3
index 3ed831fb08e40..795887da2a60e 100644
--- a/lib/libc/gen/fpclassify.3
+++ b/lib/libc/gen/fpclassify.3
@@ -24,11 +24,11 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 8, 2003
+.Dd February 12, 2003
 .Dt FPCLASSIFY 3
 .Os
 .Sh NAME
-.Nm fpclassify
+.Nm fpclassify , isfinite , isinf , isnan , isnormal
 .Nd "classify a floating-point number"
 .Sh LIBRARY
 .Lb libc
@@ -36,6 +36,14 @@
 .In math.h
 .Ft int
 .Fn fpclassify "real-floating x"
+.Ft int
+.Fn isfinite "real-floating x"
+.Ft int
+.Fn isinf "real-floating x"
+.Ft int
+.Fn isnan "real-floating x"
+.Ft int
+.Fn isnormal "real-floating x"
 .Sh DESCRIPTION
 The
 .Fn fpclassify
@@ -64,18 +72,58 @@ Indicates that
 .Va x
 is zero (0 or -0).
 .El
+.Pp
+The
+.Fn isfinite
+macro returns a non-zero value if and only if its argument has
+a finite (zero, subnormal, or normal) value.  The
+.Fn isinf ,
+.Fn isnan ,
+and
+.Fn isnormal
+macros return non-zero if and only if
+.Va x
+is an infinity, NaN,
+or a non-zero normalized number, respectively.
+.Pp
+The symbol
+.Fn isnanf
+is provided as an alias to
+.Fn isnan
+for compatibility, and its use is deprecated.
 .Sh SEE ALSO
-.Xr math 3
+.Xr isgreater 3 ,
+.Xr math 3 ,
+.Xr signbit 3
 .Sh STANDARDS
 The
-.Fn fpclassify
-macro conforms to
+.Fn fpclassify ,
+.Fn isfinite ,
+.Fn isinf ,
+.Fn isnan ,
+and
+.Fn isnormal
+macros conform to
 .St -isoC-99 .
 .Sh HISTORY
 The
-.Fn fpclassify
-macro was added in
+.Fn fpclassify ,
+.Fn isfinite ,
+.Fn isinf ,
+.Fn isnan ,
+and
+.Fn isnormal
+macros were added in
 .Fx 5.1 .
+.Bx 3
+introduced
+.Fn isinf
+and
+.Fn isnan
+functions, which accepted
+.Ft double
+arguments; these have been superseded by the macros
+described above.
 .Sh BUGS
 By default, the DEC Alpha architecture does not support IEEE rounding.
-See compiler documentation for additional details.
+See the compiler documentation for additional details.