xref: /netbsd-src/lib/libc/arch/mips/gen/modf.S (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Ralph Campbell.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <machine/machAsmDefs.h>
38
39#if defined(LIBC_SCCS) && !defined(lint)
40	ASMSTR("from: @(#)modf.s	8.1 (Berkeley) 6/4/93")
41	ASMSTR("$Id: modf.S,v 1.3 1994/12/15 17:24:50 mycroft Exp $")
42#endif /* LIBC_SCCS and not lint */
43
44/*
45 * double modf(val, iptr)
46 *	double val, *iptr;
47 * returns: xxx and n (in *iptr) where val == n.xxx
48 */
49LEAF(modf)
50	cfc1	t0, $31			# get the control register
51	cfc1	t0, $31			# get the control register
52	or	t1, t0, 0x3		# set rounding mode to round to zero
53	xor	t1, t1, 0x2		#  (i.e., 01)
54	ctc1	t1, $31
55	cvt.w.d	$f0, $f12		# convert val to integer
56	cvt.d.w	$f0, $f0		# convert back to double
57	ctc1	t0, $31			# restore old rounding mode
58	s.d	$f0, 0(a2)		# save the integer part
59	sub.d	$f0, $f12, $f0		# subtract val - integer part
60	j	ra
61END(modf)
62