1/*-
2 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
3 * Copyright (c) 2015-2016 Ruslan Bukin <br@bsdpad.com>
4 * All rights reserved.
5 *
6 * Portions of this software were developed by SRI International and the
7 * University of Cambridge Computer Laboratory under DARPA/AFRL contract
8 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
9 *
10 * Portions of this software were developed by the University of Cambridge
11 * Computer Laboratory as part of the CTSRD Project, with support from the
12 * UK Higher Education Innovation Fund (HEIF).
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 *    notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *    notice, this list of conditions and the following disclaimer in the
21 *    documentation and/or other materials provided with the distribution.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * $FreeBSD$
36 */
37
38#ifndef	_FENV_H_
39#define	_FENV_H_
40
41#include <sys/_types.h>
42
43#ifndef	__fenv_static
44#define	__fenv_static	static
45#endif
46
47typedef	__uint64_t	fenv_t;
48typedef	__uint64_t	fexcept_t;
49
50/* Exception flags */
51#define	FE_INVALID	0x0010
52#define	FE_DIVBYZERO	0x0008
53#define	FE_OVERFLOW	0x0004
54#define	FE_UNDERFLOW	0x0002
55#define	FE_INEXACT	0x0001
56#define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
57			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
58
59/*
60 * RISC-V Rounding modes
61 */
62#define	_ROUND_SHIFT	5
63#define	FE_TONEAREST	(0x00 << _ROUND_SHIFT)
64#define	FE_TOWARDZERO	(0x01 << _ROUND_SHIFT)
65#define	FE_DOWNWARD	(0x02 << _ROUND_SHIFT)
66#define	FE_UPWARD	(0x03 << _ROUND_SHIFT)
67#define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
68			 FE_UPWARD | FE_TOWARDZERO)
69
70__BEGIN_DECLS
71
72/* Default floating-point environment */
73extern const fenv_t	__fe_dfl_env;
74#define	FE_DFL_ENV	(&__fe_dfl_env)
75
76#if !defined(__riscv_float_abi_soft) && !defined(__riscv_float_abi_double)
77#if defined(__riscv_float_abi_single)
78#error single precision floating point ABI not supported
79#else
80#error compiler did not set soft/hard float macros
81#endif
82#endif
83
84#ifndef __riscv_float_abi_soft
85#define	__rfs(__fcsr)	__asm __volatile("csrr %0, fcsr" : "=r" (__fcsr))
86#define	__wfs(__fcsr)	__asm __volatile("csrw fcsr, %0" :: "r" (__fcsr))
87#endif
88
89#ifdef __riscv_float_abi_soft
90int feclearexcept(int __excepts);
91int fegetexceptflag(fexcept_t *__flagp, int __excepts);
92int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
93int feraiseexcept(int __excepts);
94int fetestexcept(int __excepts);
95int fegetround(void);
96int fesetround(int __round);
97int fegetenv(fenv_t *__envp);
98int feholdexcept(fenv_t *__envp);
99int fesetenv(const fenv_t *__envp);
100int feupdateenv(const fenv_t *__envp);
101#else
102__fenv_static inline int
103feclearexcept(int __excepts)
104{
105
106	__asm __volatile("csrc fflags, %0" :: "r"(__excepts));
107
108	return (0);
109}
110
111__fenv_static inline int
112fegetexceptflag(fexcept_t *__flagp, int __excepts)
113{
114	fexcept_t __fcsr;
115
116	__rfs(__fcsr);
117	*__flagp = __fcsr & __excepts;
118
119	return (0);
120}
121
122__fenv_static inline int
123fesetexceptflag(const fexcept_t *__flagp, int __excepts)
124{
125	fexcept_t __fcsr;
126
127	__fcsr = *__flagp;
128	__asm __volatile("csrc fflags, %0" :: "r"(__excepts));
129	__asm __volatile("csrs fflags, %0" :: "r"(__fcsr & __excepts));
130
131	return (0);
132}
133
134__fenv_static inline int
135feraiseexcept(int __excepts)
136{
137
138	__asm __volatile("csrs fflags, %0" :: "r"(__excepts));
139
140	return (0);
141}
142
143__fenv_static inline int
144fetestexcept(int __excepts)
145{
146	fexcept_t __fcsr;
147
148	__rfs(__fcsr);
149
150	return (__fcsr & __excepts);
151}
152
153__fenv_static inline int
154fegetround(void)
155{
156	fexcept_t __fcsr;
157
158	__rfs(__fcsr);
159
160	return (__fcsr & _ROUND_MASK);
161}
162
163__fenv_static inline int
164fesetround(int __round)
165{
166	fexcept_t __fcsr;
167
168	if (__round & ~_ROUND_MASK)
169		return (-1);
170
171	__rfs(__fcsr);
172	__fcsr &= ~_ROUND_MASK;
173	__fcsr |= __round;
174	__wfs(__fcsr);
175
176	return (0);
177}
178
179__fenv_static inline int
180fegetenv(fenv_t *__envp)
181{
182
183	__rfs(*__envp);
184
185	return (0);
186}
187
188__fenv_static inline int
189feholdexcept(fenv_t *__envp)
190{
191
192	/* No exception traps. */
193
194	return (-1);
195}
196
197__fenv_static inline int
198fesetenv(const fenv_t *__envp)
199{
200
201	__wfs(*__envp);
202
203	return (0);
204}
205
206__fenv_static inline int
207feupdateenv(const fenv_t *__envp)
208{
209	fexcept_t __fcsr;
210
211	__rfs(__fcsr);
212	__wfs(*__envp);
213	feraiseexcept(__fcsr & FE_ALL_EXCEPT);
214
215	return (0);
216}
217#endif /* !__riscv_float_abi_soft */
218
219#if __BSD_VISIBLE
220
221/* We currently provide no external definitions of the functions below. */
222
223#ifdef __riscv_float_abi_soft
224int feenableexcept(int __mask);
225int fedisableexcept(int __mask);
226int fegetexcept(void);
227#else
228static inline int
229feenableexcept(int __mask)
230{
231
232	/* No exception traps. */
233
234	return (-1);
235}
236
237static inline int
238fedisableexcept(int __mask)
239{
240
241	/* No exception traps. */
242
243	return (0);
244}
245
246static inline int
247fegetexcept(void)
248{
249
250	/* No exception traps. */
251
252	return (0);
253}
254#endif /* !__riscv_float_abi_soft */
255
256#endif /* __BSD_VISIBLE */
257
258__END_DECLS
259
260#endif	/* !_FENV_H_ */
261