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freebsd/lib/libc/gen/fpclassify.c
Mike Barcroft 8cf5ed5125 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)
2003-02-08 20:37:55 +00:00

94 lines
2.5 KiB
C

/*-
* 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);
}