1/* $OpenBSD: modf.S,v 1.5 2005/08/07 11:30:38 espie Exp $ */
2/*-
3 * Copyright (c) 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Sean Eric Fagan.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <machine/asm.h>
35
36	.text
37
38/*
39 * modf(value, iptr): return fractional part of value, and stores the
40 * integral part into iptr (a pointer to double).
41 *
42 * Written by Sean Eric Fagan (sef@kithrup.COM)
43 * Sun Mar 11 20:27:30 PST 1990
44 */
45
46/* With CHOP mode on, frndint behaves as TRUNC does.  Useful. */
47ENTRY(modf)
48	pushl	%ebp
49	movl	%esp,%ebp
50	subl	$16,%esp
51	fnstcw	-12(%ebp)
52	movw	-12(%ebp),%dx
53	orw	$3072,%dx
54	movw	%dx,-16(%ebp)
55	fldcw	-16(%ebp)
56	fldl	8(%ebp)
57	frndint
58	fstpl	-8(%ebp)
59	fldcw	-12(%ebp)
60	movl	16(%ebp),%eax
61	movl	-8(%ebp),%edx
62	movl	-4(%ebp),%ecx
63	movl	%edx,(%eax)
64	movl	%ecx,4(%eax)
65	fldl	8(%ebp)
66	fsubl	-8(%ebp)
67	jmp	L1
68L1:
69	leave
70	ret
71