Implement fpclassify():

o Add a MD header private to libc called _fpmath.h; this header
  contains bitfield layouts of MD floating-point types.
o Add a MI header private to libc called fpmath.h; this header
  contains bitfield layouts of MI floating-point types.
o Add private libc variables to lib/libc/$arch/gen/infinity.c for
  storing NaN values.
o Add __double_t and __float_t to <machine/_types.h>, and provide
  double_t and float_t typedefs in <math.h>.
o Add some C99 manifest constants (FP_ILOGB0, FP_ILOGBNAN, HUGE_VALF,
  HUGE_VALL, INFINITY, NAN, and return values for fpclassify()) to
  <math.h> and others (FLT_EVAL_METHOD, DECIMAL_DIG) to <float.h> via
  <machine/float.h>.
o Add C99 macro fpclassify() which calls __fpclassify{d,f,l}() based
  on the size of its argument.  __fpclassifyl() is never called on
  alpha because (sizeof(long double) == sizeof(double)), which is good
  since __fpclassifyl() can't deal with such a small `long double'.

This was developed by David Schultz and myself with input from bde and
fenner.

PR:		23103
Submitted by:	David Schultz <dschultz@uclink.Berkeley.EDU>
		(significant portions)
Reviewed by:	bde, fenner (earlier versions)

3 files changed, 177 insertions, 2 deletions

diff --git a/lib/libc/gen/Makefile.inc b/lib/libc/gen/Makefile.inc
index 2953554..93be60b 100644
--- a/lib/libc/gen/Makefile.inc
+++ b/lib/libc/gen/Makefile.inc
@@ -9,7 +9,7 @@ SRCS+=  __xuname.c _pthread_stubs.c _rand48.c _spinlock_stub.c _thread_init.c \
 	clock.c closedir.c confstr.c \
 	crypt.c ctermid.c daemon.c devname.c dirname.c disklabel.c \
 	dlfcn.c dlfunc.c drand48.c erand48.c err.c errlst.c errno.c \
-	exec.c fmtcheck.c fmtmsg.c fnmatch.c fstab.c ftok.c fts.c \
+	exec.c fmtcheck.c fmtmsg.c fnmatch.c fpclassify.c fstab.c ftok.c fts.c \
 	getbootfile.c getbsize.c \
 	getcap.c getcwd.c getdomainname.c getgrent.c getgrouplist.c \
 	gethostname.c getloadavg.c getlogin.c getmntinfo.c getnetgrent.c \
@@ -40,7 +40,8 @@ MAN+=	alarm.3 arc4random.3 \
 	basename.3 check_utility_compat.3 clock.3 \
 	confstr.3 ctermid.3 daemon.3 \
 	devname.3 directory.3 dirname.3 dladdr.3 dllockinit.3 dlopen.3 \
-	err.3 exec.3 fmtcheck.3 fmtmsg.3 fnmatch.3 frexp.3 ftok.3 fts.3 \
+	err.3 exec.3 fmtcheck.3 fmtmsg.3 fnmatch.3 fpclassify.3 frexp.3 \
+	ftok.3 fts.3 \
 	getbootfile.3 getbsize.3 getcap.3 getcontext.3 getcwd.3 \
 	getdiskbyname.3 getdomainname.3 getfsent.3 \
 	getgrent.3 getgrouplist.3 gethostname.3 getloadavg.3 \
diff --git a/lib/libc/gen/fpclassify.3 b/lib/libc/gen/fpclassify.3
new file mode 100644
index 0000000..3ed831f
--- /dev/null
+++ b/lib/libc/gen/fpclassify.3
@@ -0,0 +1,81 @@
+.\" Copyright (c) 2003 Mike Barcroft <mike@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd February 8, 2003
+.Dt FPCLASSIFY 3
+.Os
+.Sh NAME
+.Nm fpclassify
+.Nd "classify a floating-point number"
+.Sh LIBRARY
+.Lb libc
+.Sh SYNOPSIS
+.In math.h
+.Ft int
+.Fn fpclassify "real-floating x"
+.Sh DESCRIPTION
+The
+.Fn fpclassify
+macro takes an argument of
+.Va x
+and returns one of the following manifest constants.
+.Bl -tag -width ".Dv FP_SUBNORMAL"
+.It Dv FP_INFINITE
+Indicates that
+.Va x
+is an infinite number.
+.It Dv FP_NAN
+Indicates that
+.Va x
+is not a number (NaN).
+.It Dv FP_NORMAL
+Indicates that
+.Va x
+is a normalized number.
+.It Dv FP_SUBNORMAL
+Indicates that
+.Va x
+is a denormalized number.
+.It Dv FP_ZERO
+Indicates that
+.Va x
+is zero (0 or -0).
+.El
+.Sh SEE ALSO
+.Xr math 3
+.Sh STANDARDS
+The
+.Fn fpclassify
+macro conforms to
+.St -isoC-99 .
+.Sh HISTORY
+The
+.Fn fpclassify
+macro was added in
+.Fx 5.1 .
+.Sh BUGS
+By default, the DEC Alpha architecture does not support IEEE rounding.
+See compiler documentation for additional details.
diff --git a/lib/libc/gen/fpclassify.c b/lib/libc/gen/fpclassify.c
new file mode 100644
index 0000000..26cb910
--- /dev/null
+++ b/lib/libc/gen/fpclassify.c
@@ -0,0 +1,93 @@
+/*-
+ * Copyright (c) 2003 Mike Barcroft <mike@FreeBSD.org>
+ * Copyright (c) 2002, 2003 David Schultz <dschultz@uclink.Berkeley.EDU>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/endian.h>
+
+#include <math.h>
+#include <stdint.h>
+
+#include "fpmath.h"
+
+int
+__fpclassifyf(float f)
+{
+	union IEEEf2bits u;
+
+	u.f = f;
+	if (u.bits.exp == 0) {
+		if (u.bits.man == 0)
+			return (FP_ZERO);
+		return (FP_SUBNORMAL);
+	}
+	if (u.bits.exp == 255) {
+		if (u.bits.man == 0)
+			return (FP_INFINITE);
+		return (FP_NAN);
+	}
+	return (FP_NORMAL);
+}
+
+int
+__fpclassifyd(double d)
+{
+	union IEEEd2bits u;
+
+	u.d = d;
+	if (u.bits.exp == 0) {
+		if ((u.bits.manl | u.bits.manh) == 0)
+			return (FP_ZERO);
+		return (FP_SUBNORMAL);
+	}
+	if (u.bits.exp == 2047) {
+		if ((u.bits.manl | u.bits.manh) == 0)
+			return (FP_INFINITE);
+		return (FP_NAN);
+	}
+	return (FP_NORMAL);
+}
+
+int
+__fpclassifyl(long double e)
+{
+	union IEEEl2bits u;
+
+	u.e = e;
+	if (u.bits.exp == 0) {
+		if ((u.bits.manl | u.bits.manh) == 0)
+			return (FP_ZERO);
+		return (FP_SUBNORMAL);
+	}
+	mask_nbit_l(u);		/* Mask normalization bit if applicable. */
+	if (u.bits.exp == 32767) {
+		if ((u.bits.manl | u.bits.manh) == 0)
+			return (FP_INFINITE);
+		return (FP_NAN);
+	}
+	return (FP_NORMAL);
+}