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1/*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 2003 Peter Wemm.
5 * Copyright (c) 1990 Andrew Moore, Talke Studio
6 * All rights reserved.
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 * from: @(#) ieeefp.h 1.0 (Berkeley) 9/23/93
37 */
38
39#ifndef _MACHINE_IEEEFP_H_
40#define _MACHINE_IEEEFP_H_
41
42/* Deprecated historical FPU control interface */
43
44#include <x86/x86_ieeefp.h>
45
46/*
47 * IEEE floating point type, constant and function definitions.
48 * XXX: {FP,SSE}*FLD and {FP,SSE}*OFF are undocumented pollution.
49 */
50
51/*
52 * SSE mxcsr register bit-field masks.
53 */
54#define SSE_STKY_FLD 0x3f /* exception flags */
55#define SSE_DAZ_FLD 0x40 /* Denormals are zero */
56#define SSE_MSKS_FLD 0x1f80 /* exception masks field */
57#define SSE_RND_FLD 0x6000 /* rounding control */
58#define SSE_FZ_FLD 0x8000 /* flush to zero on underflow */
59
60/*
61 * SSE mxcsr register bit-field offsets (shift counts).
62 */
63#define SSE_STKY_OFF 0 /* exception flags offset */
64#define SSE_DAZ_OFF 6 /* DAZ exception mask offset */
65#define SSE_MSKS_OFF 7 /* other exception masks offset */
66#define SSE_RND_OFF 13 /* rounding control offset */
67#define SSE_FZ_OFF 15 /* flush to zero offset */
68
69/*
70 * General notes about conflicting SSE vs FP status bits.
71 * This code assumes that software will not fiddle with the control
72 * bits of the SSE and x87 in such a way to get them out of sync and
73 * still expect this to work. Break this at your peril.
74 * Because I based this on the i386 port, the x87 state is used for
75 * the fpget*() functions, and is shadowed into the SSE state for
76 * the fpset*() functions. For dual source fpget*() functions, I
77 * merge the two together. I think.
78 */
79
80static __inline fp_rnd_t
81__fpgetround(void)
82{
83 unsigned short _cw;
84
85 __fnstcw(&_cw);
86 return ((fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF));
87}
88
89static __inline fp_rnd_t
90__fpsetround(fp_rnd_t _m)
91{
92 fp_rnd_t _p;
93 unsigned _mxcsr;
94 unsigned short _cw, _newcw;
95
96 __fnstcw(&_cw);
97 _p = (fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF);
98 _newcw = _cw & ~FP_RND_FLD;
99 _newcw |= (_m << FP_RND_OFF) & FP_RND_FLD;
100 __fnldcw(_cw, _newcw);
101 __stmxcsr(&_mxcsr);
102 _mxcsr &= ~SSE_RND_FLD;
103 _mxcsr |= (_m << SSE_RND_OFF) & SSE_RND_FLD;
104 __ldmxcsr(&_mxcsr);
105 return (_p);
106}
107
108/*
109 * Get or set the rounding precision for x87 arithmetic operations.
110 * There is no equivalent SSE mode or control.
111 */
112
113static __inline fp_prec_t
114__fpgetprec(void)
115{
116 unsigned short _cw;
117
118 __fnstcw(&_cw);
119 return ((fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF));
120}
121
122static __inline fp_prec_t
123__fpsetprec(fp_prec_t _m)
124{
125 fp_prec_t _p;
126 unsigned short _cw, _newcw;
127
128 __fnstcw(&_cw);
129 _p = (fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF);
130 _newcw = _cw & ~FP_PRC_FLD;
131 _newcw |= (_m << FP_PRC_OFF) & FP_PRC_FLD;
132 __fnldcw(_cw, _newcw);
133 return (_p);
134}
135
136/*
137 * Get or set the exception mask.
138 * Note that the x87 mask bits are inverted by the API -- a mask bit of 1
139 * means disable for x87 and SSE, but for fp*mask() it means enable.
140 */
141
142static __inline fp_except_t
143__fpgetmask(void)
144{
145 unsigned short _cw;
146
147 __fnstcw(&_cw);
148 return ((~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF);
149}
150
151static __inline fp_except_t
152__fpsetmask(fp_except_t _m)
153{
154 fp_except_t _p;
155 unsigned _mxcsr;
156 unsigned short _cw, _newcw;
157
158 __fnstcw(&_cw);
159 _p = (~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF;
160 _newcw = _cw & ~FP_MSKS_FLD;
161 _newcw |= (~_m << FP_MSKS_OFF) & FP_MSKS_FLD;
162 __fnldcw(_cw, _newcw);
163 __stmxcsr(&_mxcsr);
164 /* XXX should we clear non-ieee SSE_DAZ_FLD and SSE_FZ_FLD ? */
165 _mxcsr &= ~SSE_MSKS_FLD;
166 _mxcsr |= (~_m << SSE_MSKS_OFF) & SSE_MSKS_FLD;
167 __ldmxcsr(&_mxcsr);
168 return (_p);
169}
170
171static __inline fp_except_t
172__fpgetsticky(void)
173{
174 unsigned _ex, _mxcsr;
175 unsigned short _sw;
176
177 __fnstsw(&_sw);
178 _ex = (_sw & FP_STKY_FLD) >> FP_STKY_OFF;
179 __stmxcsr(&_mxcsr);
180 _ex |= (_mxcsr & SSE_STKY_FLD) >> SSE_STKY_OFF;
181 return ((fp_except_t)_ex);
182}
183
184#if !defined(__IEEEFP_NOINLINES__)
185
186#define fpgetmask() __fpgetmask()
187#define fpgetprec() __fpgetprec()
188#define fpgetround() __fpgetround()
189#define fpgetsticky() __fpgetsticky()
190#define fpsetmask(m) __fpsetmask(m)
191#define fpsetprec(m) __fpsetprec(m)
192#define fpsetround(m) __fpsetround(m)
193
194#else /* __IEEEFP_NOINLINES__ */
195
196/* Augment the userland declarations. */
197__BEGIN_DECLS
198extern fp_rnd_t fpgetround(void);
199extern fp_rnd_t fpsetround(fp_rnd_t);
200extern fp_except_t fpgetmask(void);
201extern fp_except_t fpsetmask(fp_except_t);
202extern fp_except_t fpgetsticky(void);
203extern fp_except_t fpsetsticky(fp_except_t);
204fp_prec_t fpgetprec(void);
205fp_prec_t fpsetprec(fp_prec_t);
206__END_DECLS
207
208#endif /* !__IEEEFP_NOINLINES__ */
209
210#endif /* !_MACHINE_IEEEFP_H_ */