1 /* Private floating point rounding and exceptions handling. C-SKY version.
2 Copyright (C) 2018-2025 Free Software Foundation, Inc.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library. If not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #ifndef CSKY_FENV_PRIVATE_H
19 #define CSKY_FENV_PRIVATE_H 1
20
21 #include <fenv.h>
22 #include <fpu_control.h>
23 #include "fenv_libc.h"
24
25 static __always_inline void
libc_feholdexcept_vfp(fenv_t * envp)26 libc_feholdexcept_vfp (fenv_t *envp)
27 {
28 fpu_control_t fpsr, fpcr;
29
30 _FPU_GETCW (fpcr);
31 envp->__fpcr = fpcr;
32
33 _FPU_GETFPSR (fpsr);
34 envp->__fpsr = fpsr;
35
36 /* Now set all exceptions to non-stop. */
37 fpcr &= ~FE_ALL_EXCEPT;
38
39 /* And clear all exception flags. */
40 fpsr &= ~(FE_ALL_EXCEPT << CAUSE_SHIFT);
41
42 _FPU_SETFPSR (fpsr);
43
44 _FPU_SETCW (fpcr);
45 }
46
47 static __always_inline void
libc_fesetround_vfp(int round)48 libc_fesetround_vfp (int round)
49 {
50 fpu_control_t fpcr;
51
52 _FPU_GETCW (fpcr);
53
54 /* Set new rounding mode if different. */
55 if (unlikely ((fpcr & FE_DOWNWARD) != round))
56 _FPU_SETCW ((fpcr & ~FE_DOWNWARD) | round);
57 }
58
59 static __always_inline void
libc_feholdexcept_setround_vfp(fenv_t * envp,int round)60 libc_feholdexcept_setround_vfp (fenv_t *envp, int round)
61 {
62 fpu_control_t fpsr, fpcr;
63
64 _FPU_GETCW (fpcr);
65 envp->__fpcr = fpcr;
66
67 _FPU_GETFPSR (fpsr);
68 envp->__fpsr = fpsr;
69
70 /* Clear exception flags, set all exceptions to non-stop,
71 and set new rounding mode. */
72 fpsr &= ~(FE_ALL_EXCEPT << CAUSE_SHIFT);
73 _FPU_SETFPSR (fpsr);
74
75 fpcr &= ~(FE_ALL_EXCEPT | FE_DOWNWARD);
76 _FPU_SETCW (fpcr | round);
77 }
78
79 static __always_inline void
libc_feholdsetround_vfp(fenv_t * envp,int round)80 libc_feholdsetround_vfp (fenv_t *envp, int round)
81 {
82 fpu_control_t fpcr;
83
84 _FPU_GETCW (fpcr);
85 envp->__fpcr = fpcr;
86
87 /* Set new rounding mode if different. */
88 if (unlikely ((fpcr & FE_DOWNWARD) != round))
89 _FPU_SETCW ((fpcr & ~FE_DOWNWARD) | round);
90 }
91
92 static __always_inline void
libc_feresetround_vfp(fenv_t * envp)93 libc_feresetround_vfp (fenv_t *envp)
94 {
95 fpu_control_t fpcr, round;
96
97 _FPU_GETCW (fpcr);
98
99 /* Check whether rounding modes are different. */
100 round = (envp->__fpcr ^ fpcr) & FE_DOWNWARD;
101
102 /* Restore the rounding mode if it was changed. */
103 if (unlikely (round != 0))
104 _FPU_SETCW (fpcr ^ round);
105 }
106
107 static __always_inline int
libc_fetestexcept_vfp(int ex)108 libc_fetestexcept_vfp (int ex)
109 {
110 fpu_control_t fpsr;
111
112 _FPU_GETFPSR (fpsr);
113 fpsr = fpsr >> CAUSE_SHIFT;
114 return fpsr & ex & FE_ALL_EXCEPT;
115 }
116
117 static __always_inline void
libc_fesetenv_vfp(const fenv_t * envp)118 libc_fesetenv_vfp (const fenv_t *envp)
119 {
120 fpu_control_t fpcr, fpsr, new_fpcr, new_fpsr;
121
122 _FPU_GETCW (fpcr);
123 _FPU_GETFPSR (fpsr);
124
125 new_fpcr = envp->__fpcr;
126 new_fpsr = envp->__fpsr;
127
128 if (unlikely (fpsr ^ new_fpsr) != 0)
129 _FPU_SETFPSR (new_fpsr);
130
131 if (unlikely (fpcr ^ new_fpcr) != 0)
132 _FPU_SETCW (new_fpcr);
133 }
134
135 static __always_inline int
libc_feupdateenv_test_vfp(const fenv_t * envp,int ex)136 libc_feupdateenv_test_vfp (const fenv_t *envp, int ex)
137 {
138 fpu_control_t fpcr, fpsr, new_fpcr, new_fpsr, excepts;
139
140 _FPU_GETCW (fpcr);
141 _FPU_GETFPSR (fpsr);
142
143 /* Merge current exception flags with the saved fenv. */
144 excepts = (fpsr >> CAUSE_SHIFT) & FE_ALL_EXCEPT;
145 new_fpcr = envp->__fpcr;
146 new_fpsr = envp->__fpsr | (excepts << CAUSE_SHIFT);
147
148 /* Write FCR and FESR if different. */
149 if (unlikely (fpsr ^ new_fpsr) != 0)
150 _FPU_SETFPSR (new_fpsr);
151
152 if (unlikely (fpcr ^ new_fpcr) != 0)
153 _FPU_SETCW (new_fpcr);
154
155 /* Raise the exceptions if enabled in the new FP state. */
156 if (unlikely (excepts & new_fpcr))
157 feraiseexcept (excepts);
158
159 return excepts & ex;
160 }
161
162 static __always_inline void
libc_feupdateenv_vfp(const fenv_t * envp)163 libc_feupdateenv_vfp (const fenv_t *envp)
164 {
165 libc_feupdateenv_test_vfp (envp, 0);
166 }
167
168 static __always_inline void
libc_feholdsetround_vfp_ctx(struct rm_ctx * ctx,int r)169 libc_feholdsetround_vfp_ctx (struct rm_ctx *ctx, int r)
170 {
171 fpu_control_t fpcr, fpsr, round;
172
173 _FPU_GETCW (fpcr);
174 _FPU_GETFPSR (fpsr);
175 ctx->updated_status = false;
176 ctx->env.__fpcr = fpcr;
177 ctx->env.__fpsr = fpsr;
178
179 /* Check whether rounding modes are different. */
180 round = (fpcr ^ r) & FE_DOWNWARD;
181
182 /* Set the rounding mode if changed. */
183 if (unlikely (round != 0))
184 {
185 ctx->updated_status = true;
186 _FPU_SETCW (fpcr ^ round);
187 }
188 }
189
190 static __always_inline void
libc_feresetround_vfp_ctx(struct rm_ctx * ctx)191 libc_feresetround_vfp_ctx (struct rm_ctx *ctx)
192 {
193 /* Restore the rounding mode if updated. */
194 if (unlikely (ctx->updated_status))
195 {
196 fpu_control_t fpcr;
197
198 _FPU_GETCW (fpcr);
199 fpcr = (fpcr & ~FE_DOWNWARD) | (ctx->env.__fpcr & FE_DOWNWARD);
200 _FPU_SETCW (fpcr);
201 }
202 }
203
204 static __always_inline void
libc_fesetenv_vfp_ctx(struct rm_ctx * ctx)205 libc_fesetenv_vfp_ctx (struct rm_ctx *ctx)
206 {
207 fpu_control_t fpcr, fpsr, new_fpcr, new_fpsr;
208
209 _FPU_GETCW (fpcr);
210 _FPU_GETFPSR (fpsr);
211
212 new_fpcr = ctx->env.__fpcr;
213 new_fpsr = ctx->env.__fpsr;
214
215 if (unlikely (fpsr ^ new_fpsr) != 0)
216 _FPU_SETFPSR (new_fpsr);
217
218 if (unlikely (fpcr ^ new_fpcr) != 0)
219 _FPU_SETCW (new_fpcr);
220 }
221
222 #define libc_feholdexcept libc_feholdexcept_vfp
223 #define libc_feholdexceptf libc_feholdexcept_vfp
224 #define libc_feholdexceptl libc_feholdexcept_vfp
225
226 #define libc_fesetround libc_fesetround_vfp
227 #define libc_fesetroundf libc_fesetround_vfp
228 #define libc_fesetroundl libc_fesetround_vfp
229
230 #define libc_feresetround libc_feresetround_vfp
231 #define libc_feresetroundf libc_feresetround_vfp
232 #define libc_feresetroundl libc_feresetround_vfp
233
234 #define libc_feresetround_noex libc_fesetenv_vfp
235 #define libc_feresetround_noexf libc_fesetenv_vfp
236 #define libc_feresetround_noexl libc_fesetenv_vfp
237
238 #define libc_feholdexcept_setround libc_feholdexcept_setround_vfp
239 #define libc_feholdexcept_setroundf libc_feholdexcept_setround_vfp
240 #define libc_feholdexcept_setroundl libc_feholdexcept_setround_vfp
241
242 #define libc_feholdsetround libc_feholdsetround_vfp
243 #define libc_feholdsetroundf libc_feholdsetround_vfp
244 #define libc_feholdsetroundl libc_feholdsetround_vfp
245
246 #define libc_fetestexcept libc_fetestexcept_vfp
247 #define libc_fetestexceptf libc_fetestexcept_vfp
248 #define libc_fetestexceptl libc_fetestexcept_vfp
249
250 #define libc_fesetenv libc_fesetenv_vfp
251 #define libc_fesetenvf libc_fesetenv_vfp
252 #define libc_fesetenvl libc_fesetenv_vfp
253
254 #define libc_feupdateenv libc_feupdateenv_vfp
255 #define libc_feupdateenvf libc_feupdateenv_vfp
256 #define libc_feupdateenvl libc_feupdateenv_vfp
257
258 #define libc_feupdateenv_test libc_feupdateenv_test_vfp
259 #define libc_feupdateenv_testf libc_feupdateenv_test_vfp
260 #define libc_feupdateenv_testl libc_feupdateenv_test_vfp
261
262 /* We have support for rounding mode context. */
263 #define HAVE_RM_CTX 1
264
265 #define libc_feholdsetround_ctx libc_feholdsetround_vfp_ctx
266 #define libc_feresetround_ctx libc_feresetround_vfp_ctx
267 #define libc_feresetround_noex_ctx libc_fesetenv_vfp_ctx
268
269 #define libc_feholdsetroundf_ctx libc_feholdsetround_vfp_ctx
270 #define libc_feresetroundf_ctx libc_feresetround_vfp_ctx
271 #define libc_feresetround_noexf_ctx libc_fesetenv_vfp_ctx
272
273 #define libc_feholdsetroundl_ctx libc_feholdsetround_vfp_ctx
274 #define libc_feresetroundl_ctx libc_feresetround_vfp_ctx
275 #define libc_feresetround_noexl_ctx libc_fesetenv_vfp_ctx
276
277 #endif /* CSKY_FENV_PRIVATE_H */
278