1 /*-
2 * Copyright (c) 2013 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by Matt Thomas of 3am Software Foundry.
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 *
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __RCSID("$NetBSD: fenv.c,v 1.9 2017/05/08 09:25:03 martin Exp $");
32
33 #include "namespace.h"
34
35 #include <sys/types.h>
36 #include <assert.h>
37 #include <fenv.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <inttypes.h>
41
42 #ifdef __SOFTFP__
43 #error This fenv implementation is only for hardfloat.
44 #endif
45
46 #ifdef __weak_alias
47 __weak_alias(feclearexcept,_feclearexcept)
48 __weak_alias(fedisableexcept,_fedisableexcept)
49 __weak_alias(feenableexcept,_feenableexcept)
50 __weak_alias(fegetenv,_fegetenv)
51 __weak_alias(fegetexcept,_fegetexcept)
52 __weak_alias(fegetexceptflag,_fegetexceptflag)
53 __weak_alias(fegetround,_fegetround)
54 __weak_alias(feholdexcept,_feholdexcept)
55 __weak_alias(feraiseexcept,_feraiseexcept)
56 __weak_alias(fesetenv,_fesetenv)
57 __weak_alias(fesetexceptflag,_fesetexceptflag)
58 __weak_alias(fesetround,_fesetround)
59 __weak_alias(fetestexcept,_fetestexcept)
60 __weak_alias(feupdateenv,_feupdateenv)
61 #endif
62
63 #include <arm/armreg.h>
64 #include <arm/vfpreg.h>
65
66 const fenv_t __fe_dfl_env = VFP_FPSCR_FZ|VFP_FPSCR_DN|VFP_FPSCR_RN;
67
68 /*
69 * The feclearexcept() function shall attempt to clear the supported
70 * floating-point exceptions represented by excepts.
71 */
72 int
feclearexcept(int excepts)73 feclearexcept(int excepts)
74 {
75 #ifndef lint
76 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0);
77 #endif
78 int tmp = armreg_fpscr_read() & ~__SHIFTIN(excepts, VFP_FPSCR_CSUM);
79 armreg_fpscr_write(tmp);
80 return 0;
81 }
82
83 /*
84 * The fegetexceptflag() function shall attempt to store an
85 * implementation-defined representation of the states of the floating-point
86 * status flags indicated by the argument excepts in the object pointed to by
87 * the argument flagp.
88 */
89 int
fegetexceptflag(fexcept_t * flagp,int excepts)90 fegetexceptflag(fexcept_t *flagp, int excepts)
91 {
92
93 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0);
94 *flagp = __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_CSUM) & excepts;
95 return 0;
96 }
97
98 /*
99 * The feraiseexcept() function shall attempt to raise the supported
100 * floating-point exceptions represented by the argument excepts. The order
101 * in which these floating-point exceptions are raised is unspecified.
102 */
103 int
feraiseexcept(int excepts)104 feraiseexcept(int excepts)
105 {
106 #ifndef lint
107 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0);
108 #endif
109 int fpscr = armreg_fpscr_read();
110 fpscr |= __SHIFTIN(excepts, VFP_FPSCR_CSUM);
111 armreg_fpscr_write(fpscr);
112 return 0;
113 }
114
115 /*
116 * The fesetexceptflag() function shall attempt to set the floating-point
117 * status flags indicated by the argument excepts to the states stored in the
118 * object pointed to by flagp. The value pointed to by flagp shall have been
119 * set by a previous call to fegetexceptflag() whose second argument
120 * represented at least those floating-point exceptions represented by the
121 * argument excepts. This function does not raise floating-point exceptions,
122 * but only sets the state of the flags.
123 */
124 int
fesetexceptflag(const fexcept_t * flagp,int excepts)125 fesetexceptflag(const fexcept_t *flagp, int excepts)
126 {
127 #ifndef lint
128 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0);
129 #endif
130 int fpscr = armreg_fpscr_read();
131 fpscr &= ~__SHIFTIN(excepts, VFP_FPSCR_CSUM);
132 fpscr |= __SHIFTIN((*flagp & excepts), VFP_FPSCR_CSUM);
133 armreg_fpscr_write(fpscr);
134 return 0;
135 }
136
137 int
feenableexcept(int excepts)138 feenableexcept(int excepts)
139 {
140 #ifndef lint
141 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0);
142 #endif
143 int fpscr = armreg_fpscr_read();
144 armreg_fpscr_write(fpscr | __SHIFTIN((excepts), VFP_FPSCR_ESUM));
145 return __SHIFTOUT(fpscr, VFP_FPSCR_ESUM) & FE_ALL_EXCEPT;
146 }
147
148 int
fedisableexcept(int excepts)149 fedisableexcept(int excepts)
150 {
151 #ifndef lint
152 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0);
153 #endif
154 int fpscr = armreg_fpscr_read();
155 armreg_fpscr_write(fpscr & ~__SHIFTIN((excepts), VFP_FPSCR_ESUM));
156 return __SHIFTOUT(fpscr, VFP_FPSCR_ESUM) & FE_ALL_EXCEPT;
157 }
158
159 /*
160 * The fetestexcept() function shall determine which of a specified subset of
161 * the floating-point exception flags are currently set. The excepts argument
162 * specifies the floating-point status flags to be queried.
163 */
164 int
fetestexcept(int excepts)165 fetestexcept(int excepts)
166 {
167 _DIAGASSERT((except & ~FE_ALL_EXCEPT) == 0);
168 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_CSUM) & excepts;
169 }
170
171 int
fegetexcept(void)172 fegetexcept(void)
173 {
174 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_ESUM);
175 }
176
177 /*
178 * The fegetround() function shall get the current rounding direction.
179 */
180 int
fegetround(void)181 fegetround(void)
182 {
183 return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_RMODE);
184 }
185
186 /*
187 * The fesetround() function shall establish the rounding direction represented
188 * by its argument round. If the argument is not equal to the value of a
189 * rounding direction macro, the rounding direction is not changed.
190 */
191 int
fesetround(int round)192 fesetround(int round)
193 {
194 #ifndef lint
195 _DIAGASSERT(!(round & ~__SHIFTOUT(VFP_FPSCR_RMODE, VFP_FPSCR_RMODE)));
196 #endif
197 int fpscr = armreg_fpscr_read() & ~VFP_FPSCR_RMODE;
198 fpscr |= __SHIFTIN(round, VFP_FPSCR_RMODE);
199 armreg_fpscr_write(fpscr);
200 return 0;
201 }
202
203 /*
204 * The fegetenv() function shall attempt to store the current floating-point
205 * environment in the object pointed to by envp.
206 */
207 int
fegetenv(fenv_t * envp)208 fegetenv(fenv_t *envp)
209 {
210
211 *envp = armreg_fpscr_read();
212 return 0;
213 }
214
215 /*
216 * The feholdexcept() function shall save the current floating-point
217 * environment in the object pointed to by envp, clear the floating-point
218 * status flags, and then install a non-stop (continue on floating-point
219 * exceptions) mode, if available, for all floating-point exceptions.
220 */
221 int
feholdexcept(fenv_t * envp)222 feholdexcept(fenv_t *envp)
223 {
224
225 *envp = armreg_fpscr_read();
226 armreg_fpscr_write((*envp) & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM));
227 return 0;
228 }
229
230 /*
231 * The fesetenv() function shall attempt to establish the floating-point
232 * environment represented by the object pointed to by envp. The fesetenv()
233 * function does not raise floating-point exceptions, but only installs the
234 * state of the floating-point status flags represented through its argument.
235 */
236 int
fesetenv(const fenv_t * envp)237 fesetenv(const fenv_t *envp)
238 {
239
240 armreg_fpscr_write(*envp);
241 return 0;
242 }
243
244 /*
245 * The feupdateenv() function shall attempt to save the currently raised
246 * floating-point exceptions in its automatic storage, attempt to install the
247 * floating-point environment represented by the object pointed to by envp,
248 * and then attempt to raise the saved floating-point exceptions.
249 */
250 int
feupdateenv(const fenv_t * envp)251 feupdateenv(const fenv_t *envp)
252 {
253 #ifndef lint
254 _DIAGASSERT(envp != NULL);
255 #endif
256 int fpscr = armreg_fpscr_read();
257 fpscr &= ~(VFP_FPSCR_ESUM|VFP_FPSCR_RMODE);
258 fpscr |= *envp;
259 armreg_fpscr_write(fpscr);
260
261 /* Success */
262 return 0;
263 }
264