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63716ab2 | 1 | /* Helper macros for functions returning a narrower type. |
2b778ceb | 2 | Copyright (C) 2018-2021 Free Software Foundation, Inc. |
63716ab2 JM |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
63716ab2 JM |
18 | |
19 | #ifndef _MATH_NARROW_H | |
20 | #define _MATH_NARROW_H 1 | |
21 | ||
22 | #include <bits/floatn.h> | |
23 | #include <bits/long-double.h> | |
24 | #include <errno.h> | |
25 | #include <fenv.h> | |
26 | #include <ieee754.h> | |
b4d5b8b0 | 27 | #include <math-barriers.h> |
63716ab2 | 28 | #include <math_private.h> |
70e2ba33 | 29 | #include <fenv_private.h> |
63716ab2 JM |
30 | |
31 | /* Carry out a computation using round-to-odd. The computation is | |
32 | EXPR; the union type in which to store the result is UNION and the | |
33 | subfield of the "ieee" field of that union with the low part of the | |
34 | mantissa is MANTISSA; SUFFIX is the suffix for the libc_fe* macros | |
35 | to ensure that the correct rounding mode is used, for platforms | |
36 | with multiple rounding modes where those macros set only the | |
37 | relevant mode. This macro does not work correctly if the sign of | |
38 | an exact zero result depends on the rounding mode, so that case | |
39 | must be checked for separately. */ | |
40 | #define ROUND_TO_ODD(EXPR, UNION, SUFFIX, MANTISSA) \ | |
41 | ({ \ | |
42 | fenv_t env; \ | |
43 | UNION u; \ | |
44 | \ | |
45 | libc_feholdexcept_setround ## SUFFIX (&env, FE_TOWARDZERO); \ | |
46 | u.d = (EXPR); \ | |
47 | math_force_eval (u.d); \ | |
48 | u.ieee.MANTISSA \ | |
49 | |= libc_feupdateenv_test ## SUFFIX (&env, FE_INEXACT) != 0; \ | |
50 | \ | |
51 | u.d; \ | |
52 | }) | |
53 | ||
d8742dd8 JM |
54 | /* Check for error conditions from a narrowing add function returning |
55 | RET with arguments X and Y and set errno as needed. Overflow and | |
56 | underflow can occur for finite arguments and a domain error for | |
57 | infinite ones. */ | |
58 | #define CHECK_NARROW_ADD(RET, X, Y) \ | |
59 | do \ | |
60 | { \ | |
61 | if (!isfinite (RET)) \ | |
62 | { \ | |
63 | if (isnan (RET)) \ | |
64 | { \ | |
65 | if (!isnan (X) && !isnan (Y)) \ | |
66 | __set_errno (EDOM); \ | |
67 | } \ | |
68 | else if (isfinite (X) && isfinite (Y)) \ | |
69 | __set_errno (ERANGE); \ | |
70 | } \ | |
71 | else if ((RET) == 0 && (X) != -(Y)) \ | |
72 | __set_errno (ERANGE); \ | |
73 | } \ | |
74 | while (0) | |
75 | ||
76 | /* Implement narrowing add using round-to-odd. The arguments are X | |
77 | and Y, the return type is TYPE and UNION, MANTISSA and SUFFIX are | |
78 | as for ROUND_TO_ODD. */ | |
79 | #define NARROW_ADD_ROUND_TO_ODD(X, Y, TYPE, UNION, SUFFIX, MANTISSA) \ | |
80 | do \ | |
81 | { \ | |
82 | TYPE ret; \ | |
83 | \ | |
84 | /* Ensure a zero result is computed in the original rounding \ | |
85 | mode. */ \ | |
86 | if ((X) == -(Y)) \ | |
87 | ret = (TYPE) ((X) + (Y)); \ | |
88 | else \ | |
89 | ret = (TYPE) ROUND_TO_ODD (math_opt_barrier (X) + (Y), \ | |
90 | UNION, SUFFIX, MANTISSA); \ | |
91 | \ | |
92 | CHECK_NARROW_ADD (ret, (X), (Y)); \ | |
93 | return ret; \ | |
94 | } \ | |
95 | while (0) | |
96 | ||
97 | /* Implement a narrowing add function that is not actually narrowing | |
98 | or where no attempt is made to be correctly rounding (the latter | |
99 | only applies to IBM long double). The arguments are X and Y and | |
100 | the return type is TYPE. */ | |
101 | #define NARROW_ADD_TRIVIAL(X, Y, TYPE) \ | |
102 | do \ | |
103 | { \ | |
104 | TYPE ret; \ | |
105 | \ | |
106 | ret = (TYPE) ((X) + (Y)); \ | |
107 | CHECK_NARROW_ADD (ret, (X), (Y)); \ | |
108 | return ret; \ | |
109 | } \ | |
110 | while (0) | |
111 | ||
8d3f9e85 JM |
112 | /* Check for error conditions from a narrowing subtract function |
113 | returning RET with arguments X and Y and set errno as needed. | |
114 | Overflow and underflow can occur for finite arguments and a domain | |
115 | error for infinite ones. */ | |
116 | #define CHECK_NARROW_SUB(RET, X, Y) \ | |
117 | do \ | |
118 | { \ | |
119 | if (!isfinite (RET)) \ | |
120 | { \ | |
121 | if (isnan (RET)) \ | |
122 | { \ | |
123 | if (!isnan (X) && !isnan (Y)) \ | |
124 | __set_errno (EDOM); \ | |
125 | } \ | |
126 | else if (isfinite (X) && isfinite (Y)) \ | |
127 | __set_errno (ERANGE); \ | |
128 | } \ | |
129 | else if ((RET) == 0 && (X) != (Y)) \ | |
130 | __set_errno (ERANGE); \ | |
131 | } \ | |
132 | while (0) | |
133 | ||
134 | /* Implement narrowing subtract using round-to-odd. The arguments are | |
135 | X and Y, the return type is TYPE and UNION, MANTISSA and SUFFIX are | |
136 | as for ROUND_TO_ODD. */ | |
137 | #define NARROW_SUB_ROUND_TO_ODD(X, Y, TYPE, UNION, SUFFIX, MANTISSA) \ | |
138 | do \ | |
139 | { \ | |
140 | TYPE ret; \ | |
141 | \ | |
142 | /* Ensure a zero result is computed in the original rounding \ | |
143 | mode. */ \ | |
144 | if ((X) == (Y)) \ | |
145 | ret = (TYPE) ((X) - (Y)); \ | |
146 | else \ | |
147 | ret = (TYPE) ROUND_TO_ODD (math_opt_barrier (X) - (Y), \ | |
148 | UNION, SUFFIX, MANTISSA); \ | |
149 | \ | |
150 | CHECK_NARROW_SUB (ret, (X), (Y)); \ | |
151 | return ret; \ | |
152 | } \ | |
153 | while (0) | |
154 | ||
155 | /* Implement a narrowing subtract function that is not actually | |
156 | narrowing or where no attempt is made to be correctly rounding (the | |
157 | latter only applies to IBM long double). The arguments are X and Y | |
158 | and the return type is TYPE. */ | |
159 | #define NARROW_SUB_TRIVIAL(X, Y, TYPE) \ | |
160 | do \ | |
161 | { \ | |
162 | TYPE ret; \ | |
163 | \ | |
164 | ret = (TYPE) ((X) - (Y)); \ | |
165 | CHECK_NARROW_SUB (ret, (X), (Y)); \ | |
166 | return ret; \ | |
167 | } \ | |
168 | while (0) | |
169 | ||
69a01461 JM |
170 | /* Check for error conditions from a narrowing multiply function |
171 | returning RET with arguments X and Y and set errno as needed. | |
172 | Overflow and underflow can occur for finite arguments and a domain | |
173 | error for Inf * 0. */ | |
174 | #define CHECK_NARROW_MUL(RET, X, Y) \ | |
175 | do \ | |
176 | { \ | |
177 | if (!isfinite (RET)) \ | |
178 | { \ | |
179 | if (isnan (RET)) \ | |
180 | { \ | |
181 | if (!isnan (X) && !isnan (Y)) \ | |
182 | __set_errno (EDOM); \ | |
183 | } \ | |
184 | else if (isfinite (X) && isfinite (Y)) \ | |
185 | __set_errno (ERANGE); \ | |
186 | } \ | |
187 | else if ((RET) == 0 && (X) != 0 && (Y) != 0) \ | |
188 | __set_errno (ERANGE); \ | |
189 | } \ | |
190 | while (0) | |
191 | ||
192 | /* Implement narrowing multiply using round-to-odd. The arguments are | |
193 | X and Y, the return type is TYPE and UNION, MANTISSA and SUFFIX are | |
194 | as for ROUND_TO_ODD. */ | |
195 | #define NARROW_MUL_ROUND_TO_ODD(X, Y, TYPE, UNION, SUFFIX, MANTISSA) \ | |
196 | do \ | |
197 | { \ | |
198 | TYPE ret; \ | |
199 | \ | |
200 | ret = (TYPE) ROUND_TO_ODD (math_opt_barrier (X) * (Y), \ | |
201 | UNION, SUFFIX, MANTISSA); \ | |
202 | \ | |
203 | CHECK_NARROW_MUL (ret, (X), (Y)); \ | |
204 | return ret; \ | |
205 | } \ | |
206 | while (0) | |
207 | ||
208 | /* Implement a narrowing multiply function that is not actually | |
209 | narrowing or where no attempt is made to be correctly rounding (the | |
210 | latter only applies to IBM long double). The arguments are X and Y | |
211 | and the return type is TYPE. */ | |
212 | #define NARROW_MUL_TRIVIAL(X, Y, TYPE) \ | |
213 | do \ | |
214 | { \ | |
215 | TYPE ret; \ | |
216 | \ | |
217 | ret = (TYPE) ((X) * (Y)); \ | |
218 | CHECK_NARROW_MUL (ret, (X), (Y)); \ | |
219 | return ret; \ | |
220 | } \ | |
221 | while (0) | |
222 | ||
632a6cbe JM |
223 | /* Check for error conditions from a narrowing divide function |
224 | returning RET with arguments X and Y and set errno as needed. | |
225 | Overflow, underflow and divide-by-zero can occur for finite | |
226 | arguments and a domain error for Inf / Inf and 0 / 0. */ | |
227 | #define CHECK_NARROW_DIV(RET, X, Y) \ | |
228 | do \ | |
229 | { \ | |
230 | if (!isfinite (RET)) \ | |
231 | { \ | |
232 | if (isnan (RET)) \ | |
233 | { \ | |
234 | if (!isnan (X) && !isnan (Y)) \ | |
235 | __set_errno (EDOM); \ | |
236 | } \ | |
237 | else if (isfinite (X)) \ | |
238 | __set_errno (ERANGE); \ | |
239 | } \ | |
240 | else if ((RET) == 0 && (X) != 0 && !isinf (Y)) \ | |
241 | __set_errno (ERANGE); \ | |
242 | } \ | |
243 | while (0) | |
244 | ||
245 | /* Implement narrowing divide using round-to-odd. The arguments are | |
246 | X and Y, the return type is TYPE and UNION, MANTISSA and SUFFIX are | |
247 | as for ROUND_TO_ODD. */ | |
248 | #define NARROW_DIV_ROUND_TO_ODD(X, Y, TYPE, UNION, SUFFIX, MANTISSA) \ | |
249 | do \ | |
250 | { \ | |
251 | TYPE ret; \ | |
252 | \ | |
253 | ret = (TYPE) ROUND_TO_ODD (math_opt_barrier (X) / (Y), \ | |
254 | UNION, SUFFIX, MANTISSA); \ | |
255 | \ | |
256 | CHECK_NARROW_DIV (ret, (X), (Y)); \ | |
257 | return ret; \ | |
258 | } \ | |
259 | while (0) | |
260 | ||
261 | /* Implement a narrowing divide function that is not actually | |
262 | narrowing or where no attempt is made to be correctly rounding (the | |
263 | latter only applies to IBM long double). The arguments are X and Y | |
264 | and the return type is TYPE. */ | |
265 | #define NARROW_DIV_TRIVIAL(X, Y, TYPE) \ | |
266 | do \ | |
267 | { \ | |
268 | TYPE ret; \ | |
269 | \ | |
270 | ret = (TYPE) ((X) / (Y)); \ | |
271 | CHECK_NARROW_DIV (ret, (X), (Y)); \ | |
272 | return ret; \ | |
273 | } \ | |
274 | while (0) | |
275 | ||
63716ab2 JM |
276 | /* The following macros declare aliases for a narrowing function. The |
277 | sole argument is the base name of a family of functions, such as | |
278 | "add". If any platform changes long double format after the | |
279 | introduction of narrowing functions, in a way requiring symbol | |
280 | versioning compatibility, additional variants of these macros will | |
281 | be needed. */ | |
282 | ||
283 | #define libm_alias_float_double_main(func) \ | |
284 | weak_alias (__f ## func, f ## func) \ | |
285 | weak_alias (__f ## func, f32 ## func ## f64) \ | |
286 | weak_alias (__f ## func, f32 ## func ## f32x) | |
287 | ||
288 | #ifdef NO_LONG_DOUBLE | |
289 | # define libm_alias_float_double(func) \ | |
290 | libm_alias_float_double_main (func) \ | |
291 | weak_alias (__f ## func, f ## func ## l) | |
292 | #else | |
293 | # define libm_alias_float_double(func) \ | |
294 | libm_alias_float_double_main (func) | |
295 | #endif | |
296 | ||
297 | #define libm_alias_float32x_float64_main(func) \ | |
298 | weak_alias (__f32x ## func ## f64, f32x ## func ## f64) | |
299 | ||
300 | #ifdef NO_LONG_DOUBLE | |
301 | # define libm_alias_float32x_float64(func) \ | |
302 | libm_alias_float32x_float64_main (func) \ | |
303 | weak_alias (__f32x ## func ## f64, d ## func ## l) | |
304 | #elif defined __LONG_DOUBLE_MATH_OPTIONAL | |
305 | # define libm_alias_float32x_float64(func) \ | |
306 | libm_alias_float32x_float64_main (func) \ | |
307 | weak_alias (__f32x ## func ## f64, __nldbl_d ## func ## l) | |
308 | #else | |
309 | # define libm_alias_float32x_float64(func) \ | |
310 | libm_alias_float32x_float64_main (func) | |
311 | #endif | |
312 | ||
313 | #if __HAVE_FLOAT128 && !__HAVE_DISTINCT_FLOAT128 | |
314 | # define libm_alias_float_ldouble_f128(func) \ | |
315 | weak_alias (__f ## func ## l, f32 ## func ## f128) | |
316 | # define libm_alias_double_ldouble_f128(func) \ | |
317 | weak_alias (__d ## func ## l, f32x ## func ## f128) \ | |
318 | weak_alias (__d ## func ## l, f64 ## func ## f128) | |
319 | #else | |
320 | # define libm_alias_float_ldouble_f128(func) | |
321 | # define libm_alias_double_ldouble_f128(func) | |
322 | #endif | |
323 | ||
324 | #if __HAVE_FLOAT64X_LONG_DOUBLE | |
325 | # define libm_alias_float_ldouble_f64x(func) \ | |
326 | weak_alias (__f ## func ## l, f32 ## func ## f64x) | |
327 | # define libm_alias_double_ldouble_f64x(func) \ | |
328 | weak_alias (__d ## func ## l, f32x ## func ## f64x) \ | |
329 | weak_alias (__d ## func ## l, f64 ## func ## f64x) | |
330 | #else | |
331 | # define libm_alias_float_ldouble_f64x(func) | |
332 | # define libm_alias_double_ldouble_f64x(func) | |
333 | #endif | |
334 | ||
335 | #define libm_alias_float_ldouble(func) \ | |
336 | weak_alias (__f ## func ## l, f ## func ## l) \ | |
337 | libm_alias_float_ldouble_f128 (func) \ | |
338 | libm_alias_float_ldouble_f64x (func) | |
339 | ||
340 | #define libm_alias_double_ldouble(func) \ | |
341 | weak_alias (__d ## func ## l, d ## func ## l) \ | |
342 | libm_alias_double_ldouble_f128 (func) \ | |
343 | libm_alias_double_ldouble_f64x (func) | |
344 | ||
345 | #define libm_alias_float64x_float128(func) \ | |
346 | weak_alias (__f64x ## func ## f128, f64x ## func ## f128) | |
347 | ||
348 | #define libm_alias_float32_float128_main(func) \ | |
349 | weak_alias (__f32 ## func ## f128, f32 ## func ## f128) | |
350 | ||
351 | #define libm_alias_float64_float128_main(func) \ | |
352 | weak_alias (__f64 ## func ## f128, f64 ## func ## f128) \ | |
353 | weak_alias (__f64 ## func ## f128, f32x ## func ## f128) | |
354 | ||
218dad29 | 355 | #include <math-narrow-alias-float128.h> |
63716ab2 JM |
356 | |
357 | #endif /* math-narrow.h. */ |