Add frexp.c and modf.c.

This commit is contained in:
sakamoto 1998-11-26 07:50:56 +00:00
parent 74ad07cef5
commit e3a695901c
3 changed files with 178 additions and 1 deletions

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@ -1,4 +1,5 @@
# $NetBSD: Makefile.inc,v 1.2 1998/10/03 12:30:37 tsubai Exp $
# $NetBSD: Makefile.inc,v 1.3 1998/11/26 07:50:56 sakamoto Exp $
SRCS+= _setjmp.S setjmp.S sigsetjmp.S __setjmp14.S __sigsetjmp14.S
SRCS+= isinf.c isnan.c ldexp.c fabs.S flt_rounds.c infinity.c
SRCS+= frexp.c modf.c

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/* $NetBSD: frexp.c,v 1.1 1998/11/26 07:50:56 sakamoto Exp $ */
/*-
* Copyright (c) 1991 The Regents of the University of California.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "from: @(#)frexp.c 5.1 (Berkeley) 3/6/91";
#else
__RCSID("$NetBSD: frexp.c,v 1.1 1998/11/26 07:50:56 sakamoto Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <math.h>
double
frexp(value, eptr)
double value;
int *eptr;
{
union {
double v;
struct {
u_int u_sign : 1;
u_int u_exp : 11;
u_int u_mant1 : 20;
u_int u_mant2 : 32;
} s;
} u;
if (value) {
u.v = value;
*eptr = u.s.u_exp - 1022;
u.s.u_exp = 1022;
return(u.v);
} else {
*eptr = 0;
return((double)0);
}
}

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/* $NetBSD: modf.c,v 1.1 1998/11/26 07:50:56 sakamoto Exp $ */
/*
* Copyright (c) 1994, 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Chris G. Demetriou
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/types.h>
#include <machine/ieee.h>
#include <errno.h>
#include <math.h>
/*
* double modf(double val, double *iptr)
* returns: f and i such that |f| < 1.0, (f + i) = val, and
* sign(f) == sign(i) == sign(val).
*
* Beware signedness when doing subtraction, and also operand size!
*/
double
modf(val, iptr)
double val, *iptr;
{
union doub {
double v;
struct ieee_double s;
} u, v;
u_int64_t frac;
/*
* If input is Inf or NaN, return it and leave i alone.
*/
u.v = val;
if (u.s.dbl_exp == DBL_EXP_INFNAN)
return (u.v);
/*
* If input can't have a fractional part, return
* (appropriately signed) zero, and make i be the input.
*/
if ((int)u.s.dbl_exp - DBL_EXP_BIAS > DBL_FRACBITS - 1) {
*iptr = u.v;
v.v = 0.0;
v.s.dbl_sign = u.s.dbl_sign;
return (v.v);
}
/*
* If |input| < 1.0, return it, and set i to the appropriately
* signed zero.
*/
if (u.s.dbl_exp < DBL_EXP_BIAS) {
v.v = 0.0;
v.s.dbl_sign = u.s.dbl_sign;
*iptr = v.v;
return (u.v);
}
/*
* There can be a fractional part of the input.
* If you look at the math involved for a few seconds, it's
* plain to see that the integral part is the input, with the
* low (DBL_FRACBITS - (exponent - DBL_EXP_BIAS)) bits zeroed,
* the the fractional part is the part with the rest of the
* bits zeroed. Just zeroing the high bits to get the
* fractional part would yield a fraction in need of
* normalization. Therefore, we take the easy way out, and
* just use subtraction to get the fractional part.
*/
v.v = u.v;
/* Zero the low bits of the fraction, the sleazy way. */
frac = ((u_int64_t)v.s.dbl_frach << 32) + v.s.dbl_fracl;
frac >>= DBL_FRACBITS - (u.s.dbl_exp - DBL_EXP_BIAS);
frac <<= DBL_FRACBITS - (u.s.dbl_exp - DBL_EXP_BIAS);
v.s.dbl_fracl = frac & 0xffffffff;
v.s.dbl_frach = frac >> 32;
*iptr = v.v;
u.v -= v.v;
u.s.dbl_sign = v.s.dbl_sign;
return (u.v);
}