1/* $NetBSD: systmodes.S,v 1.4 2008/04/28 20:23:04 martin Exp $ */
2
3/* This is a derivative work. */
4
5/*-
6 * Copyright (c) 2001 The NetBSD Foundation, Inc.
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Ross Harvey.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33
34/*
35===============================================================================
36
37This GNU assembler source file is part of TestFloat, Release 2a, a package
38of programs for testing the correctness of floating-point arithmetic
39complying to the IEC/IEEE Standard for Floating-Point.
40
41Written by John R. Hauser.  More information is available through the Web
42page `http://HTTP.CS.Berkeley.EDU/~jhauser/arithmetic/TestFloat.html'.
43
44THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort
45has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
46TIMES RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO
47PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
48AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
49
50Derivative works are acceptable, even for commercial purposes, so long as
51(1) they include prominent notice that the work is derivative, and (2) they
52include prominent notice akin to these four paragraphs for those parts of
53this code that are retained.
54
55===============================================================================
56*/
57
58	.text
59
60#include <machine/asm.h>
61
62/*
63-------------------------------------------------------------------------------
64Sets the rounding precision of subsequent extended double-precision
65operations.  The `precision' argument should be one of 0, 32, 64, or 80.
66If `precision' is 32, the rounding precision is set equivalent to single
67precision; else if `precision' is 64, the rounding precision is set
68equivalent to double precision; else the rounding precision is set to full
69extended double precision.
70-------------------------------------------------------------------------------
71*/
72
73ENTRY(syst_float_set_rounding_precision)
74	movb 4(%esp),%al
75	movb $0,%ah
76	cmpb $32,%al
77	je setRoundingPrecision
78	movb $2,%ah
79	cmpb $64,%al
80	je setRoundingPrecision
81	movb $3,%ah
82	cmpb $80,%al
83	je setRoundingPrecision
84	movb $0,%ah
85setRoundingPrecision:
86	movb $0,%al
87	subl $2,%esp
88	fnstcw 0(%esp)
89	andw $64767,0(%esp)
90	orw %ax,0(%esp)
91	fldcw 0(%esp)
92	addl $2,%esp
93	ret
94
95