1 /* $OpenBSD: fenv.c,v 1.4 2022/12/27 17:10:07 jmc Exp $ */
2 /*-
3 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: head/lib/msun/aarch64/fenv.h 280857 2015-03-30 16:42:08Z emaste $
28 */
29
30 #include <fenv.h>
31 #include <machine/ieeefp.h>
32
33 #define __get_fcsr(r) asm volatile("frcsr %0" : "=r" (r))
34 #define __set_fcsr(r) asm volatile("fscsr %0" : "+r" (r))
35 #define __get_flags(r) asm volatile("frflags %0" : "=r" (r))
36 #define __set_flags(r) asm volatile("fsflags %0" : "+r" (r))
37 #define __get_frm(r) asm volatile("frrm %0" : "=r" (r))
38 #define __set_frm(r) asm volatile("fsrm %0" : "+r"(r) )
39
40 /*
41 * The following constant represents the default floating-point environment
42 * (that is, the one installed at program startup) and has type pointer to
43 * const-qualified fenv_t.
44 *
45 * It can be used as an argument to the functions within the <fenv.h> header
46 * that manage the floating-point environment, namely fesetenv() and
47 * feupdateenv().
48 */
49 fenv_t __fe_dfl_env = 0;
50
51 /*
52 * The feclearexcept() function clears the supported floating-point exceptions
53 * represented by `excepts'.
54 */
55 int
feclearexcept(int excepts)56 feclearexcept(int excepts)
57 {
58 fexcept_t r;
59
60 excepts &= FE_ALL_EXCEPT;
61 __get_flags(r);
62 r &= ~excepts;
63 __set_flags(r);
64 return (0);
65 }
66 DEF_STD(feclearexcept);
67
68 /*
69 * The fegetexceptflag() function stores an implementation-defined
70 * representation of the states of the floating-point status flags indicated by
71 * the argument excepts in the object pointed to by the argument flagp.
72 */
73 int
fegetexceptflag(fexcept_t * flagp,int excepts)74 fegetexceptflag(fexcept_t *flagp, int excepts)
75 {
76 fexcept_t r;
77
78 excepts &= FE_ALL_EXCEPT;
79 __get_flags(r);
80 *flagp = r & excepts;
81 return (0);
82 }
83
84 /*
85 * The feraiseexcept() function raises the supported floating-point exceptions
86 * represented by the argument `excepts'.
87 */
88 int
feraiseexcept(int excepts)89 feraiseexcept(int excepts)
90 {
91 fexcept_t r;
92
93 excepts &= FE_ALL_EXCEPT;
94 __get_flags(r);
95 r |= excepts;
96 __set_flags(r);
97 return (0);
98 }
99 DEF_STD(feraiseexcept);
100
101 /*
102 * This function sets the floating-point status flags indicated by the argument
103 * `excepts' to the states stored in the object pointed to by `flagp'. It does
104 * NOT raise any floating-point exceptions, but only sets the state of the flags.
105 */
106 int
fesetexceptflag(const fexcept_t * flagp,int excepts)107 fesetexceptflag(const fexcept_t *flagp, int excepts)
108 {
109 fexcept_t r;
110
111 excepts &= FE_ALL_EXCEPT;
112 __get_flags(r);
113 r &= ~excepts;
114 r |= *flagp & excepts;
115 __set_flags(r);
116 return (0);
117 }
118 DEF_STD(fesetexceptflag);
119
120 /*
121 * The fetestexcept() function determines which of a specified subset of the
122 * floating-point exception flags are currently set. The `excepts' argument
123 * specifies the floating-point status flags to be queried.
124 */
125 int
fetestexcept(int excepts)126 fetestexcept(int excepts)
127 {
128 fexcept_t r;
129
130 excepts &= FE_ALL_EXCEPT;
131 __get_flags(r);
132 return (r & excepts);
133 }
134 DEF_STD(fetestexcept);
135
136 /*
137 * The fegetround() function gets the current rounding direction.
138 */
139 int
fegetround(void)140 fegetround(void)
141 {
142 fenv_t r;
143
144 __get_frm(r);
145 return (r & _ROUND_MASK);
146 }
147 DEF_STD(fegetround);
148
149 /*
150 * The fesetround() function establishes the rounding direction represented by
151 * its argument `round'. If the argument is not equal to the value of a rounding
152 * direction macro, the rounding direction is not changed.
153 */
154 int
fesetround(int round)155 fesetround(int round)
156 {
157 fenv_t r;
158
159 if (round & ~_ROUND_MASK)
160 return (-1);
161 __set_frm(round);
162 return (0);
163 }
164 DEF_STD(fesetround);
165
166 /*
167 * The fegetenv() function attempts to store the current floating-point
168 * environment in the object pointed to by envp.
169 */
170 int
fegetenv(fenv_t * envp)171 fegetenv(fenv_t *envp)
172 {
173 fenv_t r;
174
175 __get_fcsr(r);
176 *envp = r;
177
178 return (0);
179 }
180 DEF_STD(fegetenv);
181
182 /*
183 * The feholdexcept() function saves the current floating-point environment
184 * in the object pointed to by envp, clears the floating-point status flags, and
185 * then installs a non-stop (continue on floating-point exceptions) mode, if
186 * available, for all floating-point exceptions.
187 */
188 int
feholdexcept(fenv_t * envp)189 feholdexcept(fenv_t *envp)
190 {
191 fenv_t r;
192
193 __get_fcsr(r);
194 *envp = r;
195 r &= ~FE_ALL_EXCEPT;
196 __set_fcsr(r);
197
198 return (0);
199 }
200 DEF_STD(feholdexcept);
201
202 /*
203 * The fesetenv() function attempts to establish the floating-point environment
204 * represented by the object pointed to by envp. The argument `envp' points
205 * to an object set by a call to fegetenv() or feholdexcept(), or equal a
206 * floating-point environment macro. The fesetenv() function does not raise
207 * floating-point exceptions, but only installs the state of the floating-point
208 * status flags represented through its argument.
209 */
210 int
fesetenv(const fenv_t * envp)211 fesetenv(const fenv_t *envp)
212 {
213
214 fenv_t r;
215 r = *envp;
216 __set_fcsr(r);
217 return (0);
218 }
219 DEF_STD(fesetenv);
220
221 /*
222 * The feupdateenv() function saves the currently raised floating-point
223 * exceptions in its automatic storage, installs the floating-point environment
224 * represented by the object pointed to by `envp', and then raises the saved
225 * floating-point exceptions. The argument `envp' shall point to an object set
226 * by a call to feholdexcept() or fegetenv(), or equal a floating-point
227 * environment macro.
228 */
229 int
feupdateenv(const fenv_t * envp)230 feupdateenv(const fenv_t *envp)
231 {
232 fexcept_t r;
233
234 __get_fcsr(r);
235 fesetenv(envp);
236 feraiseexcept(r & FE_ALL_EXCEPT);
237 return (0);
238 }
239 DEF_STD(feupdateenv);
240
241 /*
242 * The following functions are extensions to the standard
243 */
244 int
feenableexcept(int mask)245 feenableexcept(int mask)
246 {
247 return -1;
248 }
249
250 int
fedisableexcept(int mask)251 fedisableexcept(int mask)
252 {
253 return 0;
254 }
255
256 int
fegetexcept(void)257 fegetexcept(void)
258 {
259 return 0;
260 }
261