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fb019a0e BV |
1 | /* |
2 | * This file is part of the libsigrok project. | |
3 | * | |
4 | * Copyright (C) 2014 Bert Vermeulen <bert@biot.com> | |
5 | * | |
6 | * This program is free software: you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation, either version 3 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
6ec6c43b | 20 | #include <config.h> |
c2a25ebb BV |
21 | #include <stdio.h> |
22 | #include <stdint.h> | |
fb019a0e | 23 | #include <string.h> |
c2a25ebb | 24 | #include <ctype.h> |
c1aae900 | 25 | #include <libsigrok/libsigrok.h> |
fb019a0e BV |
26 | #include "libsigrok-internal.h" |
27 | ||
e00b3f58 | 28 | /** @cond PRIVATE */ |
fb019a0e | 29 | #define LOG_PREFIX "analog" |
e00b3f58 UH |
30 | /** @endcond */ |
31 | ||
32 | /** | |
33 | * @file | |
34 | * | |
35 | * Handling and converting analog data. | |
36 | */ | |
37 | ||
38 | /** | |
39 | * @defgroup grp_analog Analog data handling | |
40 | * | |
41 | * Handling and converting analog data. | |
42 | * | |
43 | * @{ | |
44 | */ | |
fb019a0e | 45 | |
a5892391 BV |
46 | struct unit_mq_string { |
47 | uint64_t value; | |
2c240774 | 48 | const char *str; |
a5892391 BV |
49 | }; |
50 | ||
ca7dbb56 | 51 | /* Please use the same order as in enum sr_unit (libsigrok.h). */ |
a5892391 BV |
52 | static struct unit_mq_string unit_strings[] = { |
53 | { SR_UNIT_VOLT, "V" }, | |
54 | { SR_UNIT_AMPERE, "A" }, | |
55 | { SR_UNIT_OHM, "\xe2\x84\xa6" }, | |
56 | { SR_UNIT_FARAD, "F" }, | |
a5892391 BV |
57 | { SR_UNIT_KELVIN, "K" }, |
58 | { SR_UNIT_CELSIUS, "\xc2\xb0""C" }, | |
59 | { SR_UNIT_FAHRENHEIT, "\xc2\xb0""F" }, | |
60 | { SR_UNIT_HERTZ, "Hz" }, | |
61 | { SR_UNIT_PERCENTAGE, "%" }, | |
f7bcc686 | 62 | { SR_UNIT_BOOLEAN, "" }, |
a5892391 BV |
63 | { SR_UNIT_SECOND, "s" }, |
64 | { SR_UNIT_SIEMENS, "S" }, | |
65 | { SR_UNIT_DECIBEL_MW, "dBu" }, | |
66 | { SR_UNIT_DECIBEL_VOLT, "dBv" }, | |
f7bcc686 | 67 | { SR_UNIT_UNITLESS, "" }, |
a5892391 BV |
68 | { SR_UNIT_DECIBEL_SPL, "dB" }, |
69 | { SR_UNIT_CONCENTRATION, "ppm" }, | |
70 | { SR_UNIT_REVOLUTIONS_PER_MINUTE, "RPM" }, | |
71 | { SR_UNIT_VOLT_AMPERE, "VA" }, | |
72 | { SR_UNIT_WATT, "W" }, | |
73 | { SR_UNIT_WATT_HOUR, "Wh" }, | |
74 | { SR_UNIT_METER_SECOND, "m/s" }, | |
75 | { SR_UNIT_HECTOPASCAL, "hPa" }, | |
76 | { SR_UNIT_HUMIDITY_293K, "%rF" }, | |
77 | { SR_UNIT_DEGREE, "\xc2\xb0" }, | |
f7bcc686 UH |
78 | { SR_UNIT_HENRY, "H" }, |
79 | { SR_UNIT_GRAM, "g" }, | |
80 | { SR_UNIT_CARAT, "ct" }, | |
81 | { SR_UNIT_OUNCE, "oz" }, | |
82 | { SR_UNIT_TROY_OUNCE, "oz t" }, | |
83 | { SR_UNIT_POUND, "lb" }, | |
84 | { SR_UNIT_PENNYWEIGHT, "dwt" }, | |
85 | { SR_UNIT_GRAIN, "gr" }, | |
86 | { SR_UNIT_TAEL, "tael" }, | |
87 | { SR_UNIT_MOMME, "momme" }, | |
88 | { SR_UNIT_TOLA, "tola" }, | |
89 | { SR_UNIT_PIECE, "pcs" }, | |
a5892391 BV |
90 | ALL_ZERO |
91 | }; | |
92 | ||
ca7dbb56 | 93 | /* Please use the same order as in enum sr_mqflag (libsigrok.h). */ |
a5892391 | 94 | static struct unit_mq_string mq_strings[] = { |
a5892391 BV |
95 | { SR_MQFLAG_AC, " AC" }, |
96 | { SR_MQFLAG_DC, " DC" }, | |
97 | { SR_MQFLAG_RMS, " RMS" }, | |
98 | { SR_MQFLAG_DIODE, " DIODE" }, | |
99 | { SR_MQFLAG_HOLD, " HOLD" }, | |
100 | { SR_MQFLAG_MAX, " MAX" }, | |
101 | { SR_MQFLAG_MIN, " MIN" }, | |
102 | { SR_MQFLAG_AUTORANGE, " AUTO" }, | |
103 | { SR_MQFLAG_RELATIVE, " REL" }, | |
f7bcc686 UH |
104 | { SR_MQFLAG_SPL_FREQ_WEIGHT_A, "(A)" }, |
105 | { SR_MQFLAG_SPL_FREQ_WEIGHT_C, "(C)" }, | |
106 | { SR_MQFLAG_SPL_FREQ_WEIGHT_Z, "(Z)" }, | |
107 | { SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT, "(SPL)" }, | |
108 | { SR_MQFLAG_SPL_TIME_WEIGHT_S, " S" }, | |
109 | { SR_MQFLAG_SPL_TIME_WEIGHT_F, " F" }, | |
110 | { SR_MQFLAG_SPL_LAT, " LAT" }, | |
111 | /* Not a standard function for SLMs, so this is a made-up notation. */ | |
112 | { SR_MQFLAG_SPL_PCT_OVER_ALARM, "%oA" }, | |
113 | { SR_MQFLAG_DURATION, " DURATION" }, | |
a5892391 BV |
114 | { SR_MQFLAG_AVG, " AVG" }, |
115 | { SR_MQFLAG_REFERENCE, " REF" }, | |
f7bcc686 | 116 | { SR_MQFLAG_UNSTABLE, " UNSTABLE" }, |
6d5cd3bd | 117 | { SR_MQFLAG_FOUR_WIRE, " 4-WIRE" }, |
a5892391 BV |
118 | ALL_ZERO |
119 | }; | |
120 | ||
edb691fc | 121 | SR_PRIV int sr_analog_init(struct sr_datafeed_analog *analog, |
41caa319 AJ |
122 | struct sr_analog_encoding *encoding, |
123 | struct sr_analog_meaning *meaning, | |
124 | struct sr_analog_spec *spec, | |
125 | int digits) | |
126 | { | |
127 | memset(analog, 0, sizeof(*analog)); | |
128 | memset(encoding, 0, sizeof(*encoding)); | |
129 | memset(meaning, 0, sizeof(*meaning)); | |
130 | memset(spec, 0, sizeof(*spec)); | |
131 | ||
132 | analog->encoding = encoding; | |
133 | analog->meaning = meaning; | |
134 | analog->spec = spec; | |
135 | ||
136 | encoding->unitsize = sizeof(float); | |
137 | encoding->is_float = TRUE; | |
138 | #ifdef WORDS_BIGENDIAN | |
139 | encoding->is_bigendian = TRUE; | |
140 | #else | |
141 | encoding->is_bigendian = FALSE; | |
142 | #endif | |
143 | encoding->digits = digits; | |
144 | encoding->is_digits_decimal = TRUE; | |
145 | encoding->scale.p = 1; | |
146 | encoding->scale.q = 1; | |
147 | encoding->offset.p = 0; | |
148 | encoding->offset.q = 1; | |
149 | ||
150 | spec->spec_digits = digits; | |
151 | ||
152 | return SR_OK; | |
153 | } | |
154 | ||
22fb1bff UH |
155 | /** |
156 | * Convert an analog datafeed payload to an array of floats. | |
157 | * | |
158 | * @param[in] analog The analog payload to convert. Must not be NULL. | |
159 | * analog->data, analog->meaning, and analog->encoding | |
160 | * must not be NULL. | |
161 | * @param[out] outbuf Memory where to store the result. Must not be NULL. | |
162 | * | |
163 | * Sufficient memory for outbuf must have been pre-allocated by the caller, | |
164 | * who is also responsible for freeing it when no longer needed. | |
165 | * | |
166 | * @retval SR_OK Success. | |
167 | * @retval SR_ERR Unsupported encoding. | |
168 | * @retval SR_ERR_ARG Invalid argument. | |
169 | * | |
170 | * @since 0.4.0 | |
171 | */ | |
edb691fc | 172 | SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog, |
4b4fdeea | 173 | float *outbuf) |
fb019a0e BV |
174 | { |
175 | float offset; | |
5cee3d08 | 176 | unsigned int b, i, count; |
fb019a0e | 177 | gboolean bigendian; |
5cee3d08 UH |
178 | |
179 | if (!analog || !(analog->data) || !(analog->meaning) | |
180 | || !(analog->encoding) || !outbuf) | |
181 | return SR_ERR_ARG; | |
182 | ||
183 | count = analog->num_samples * g_slist_length(analog->meaning->channels); | |
fb019a0e BV |
184 | |
185 | #ifdef WORDS_BIGENDIAN | |
186 | bigendian = TRUE; | |
187 | #else | |
188 | bigendian = FALSE; | |
189 | #endif | |
190 | if (!analog->encoding->is_float) { | |
4d376e08 SB |
191 | float offset = analog->encoding->offset.p / (float)analog->encoding->offset.q; |
192 | float scale = analog->encoding->scale.p / (float)analog->encoding->scale.q; | |
193 | gboolean is_signed = analog->encoding->is_signed; | |
194 | gboolean is_bigendian = analog->encoding->is_bigendian; | |
195 | int8_t *data8 = (int8_t *)(analog->data); | |
196 | int16_t *data16 = (int16_t *)(analog->data); | |
197 | int32_t *data32 = (int32_t *)(analog->data); | |
198 | ||
199 | switch (analog->encoding->unitsize) { | |
200 | case 1: | |
201 | if (is_signed) { | |
202 | for (unsigned int i = 0; i < count; i++) { | |
203 | outbuf[i] = scale * data8[i]; | |
204 | outbuf[i] += offset; | |
205 | } | |
206 | } else { | |
207 | for (unsigned int i = 0; i < count; i++) { | |
208 | outbuf[i] = scale * R8(data8 + i); | |
209 | outbuf[i] += offset; | |
210 | } | |
211 | } | |
212 | break; | |
213 | case 2: | |
214 | if (is_signed && is_bigendian) { | |
215 | for (unsigned int i = 0; i < count; i++) { | |
216 | outbuf[i] = scale * RB16S(&data16[i]); | |
217 | outbuf[i] += offset; | |
218 | } | |
219 | } else if (is_bigendian) { | |
220 | for (unsigned int i = 0; i < count; i++) { | |
221 | outbuf[i] = scale * RB16(&data16[i]); | |
222 | outbuf[i] += offset; | |
223 | } | |
224 | } else if (is_signed) { | |
225 | for (unsigned int i = 0; i < count; i++) { | |
226 | outbuf[i] = scale * RL16S(&data16[i]); | |
227 | outbuf[i] += offset; | |
228 | } | |
229 | } else { | |
230 | for (unsigned int i = 0; i < count; i++) { | |
231 | outbuf[i] = scale * RL16(&data16[i]); | |
232 | outbuf[i] += offset; | |
233 | } | |
234 | } | |
235 | break; | |
236 | case 4: | |
237 | if (is_signed && is_bigendian) { | |
238 | for (unsigned int i = 0; i < count; i++) { | |
239 | outbuf[i] = scale * RB32S(&data32[i]); | |
240 | outbuf[i] += offset; | |
241 | } | |
242 | } else if (is_bigendian) { | |
243 | for (unsigned int i = 0; i < count; i++) { | |
244 | outbuf[i] = scale * RB32(&data32[i]); | |
245 | outbuf[i] += offset; | |
246 | } | |
247 | } else if (is_signed) { | |
248 | for (unsigned int i = 0; i < count; i++) { | |
249 | outbuf[i] = scale * RL32S(&data32[i]); | |
250 | outbuf[i] += offset; | |
251 | } | |
252 | } else { | |
253 | for (unsigned int i = 0; i < count; i++) { | |
254 | outbuf[i] = scale * RL32(&data32[i]); | |
255 | outbuf[i] += offset; | |
256 | } | |
257 | } | |
258 | break; | |
259 | default: | |
260 | sr_err("Unsupported unit size '%d' for analog-to-float conversion.", | |
261 | analog->encoding->unitsize); | |
262 | return SR_ERR; | |
263 | } | |
264 | return SR_OK; | |
fb019a0e BV |
265 | } |
266 | ||
267 | if (analog->encoding->unitsize == sizeof(float) | |
268 | && analog->encoding->is_bigendian == bigendian | |
b07a1b04 ML |
269 | && analog->encoding->scale.p == 1 |
270 | && analog->encoding->scale.q == 1 | |
4b4fdeea | 271 | && analog->encoding->offset.p / (float)analog->encoding->offset.q == 0) { |
fb019a0e | 272 | /* The data is already in the right format. */ |
7d65dd3a | 273 | memcpy(outbuf, analog->data, count * sizeof(float)); |
fb019a0e | 274 | } else { |
7d65dd3a | 275 | for (i = 0; i < count; i += analog->encoding->unitsize) { |
fb019a0e BV |
276 | for (b = 0; b < analog->encoding->unitsize; b++) { |
277 | if (analog->encoding->is_bigendian == bigendian) | |
3e277549 ML |
278 | ((uint8_t *)outbuf)[i + b] = |
279 | ((uint8_t *)analog->data)[i * analog->encoding->unitsize + b]; | |
fb019a0e | 280 | else |
3e277549 ML |
281 | ((uint8_t *)outbuf)[i + (analog->encoding->unitsize - b)] = |
282 | ((uint8_t *)analog->data)[i * analog->encoding->unitsize + b]; | |
fb019a0e | 283 | } |
b07a1b04 ML |
284 | if (analog->encoding->scale.p != 1 |
285 | || analog->encoding->scale.q != 1) | |
4b4fdeea BV |
286 | outbuf[i] = (outbuf[i] * analog->encoding->scale.p) / analog->encoding->scale.q; |
287 | offset = ((float)analog->encoding->offset.p / (float)analog->encoding->offset.q); | |
288 | outbuf[i] += offset; | |
fb019a0e BV |
289 | } |
290 | } | |
291 | ||
292 | return SR_OK; | |
293 | } | |
c2a25ebb | 294 | |
22fb1bff | 295 | /** |
a5892391 BV |
296 | * Convert the unit/MQ/MQ flags in the analog struct to a string. |
297 | * | |
22fb1bff UH |
298 | * @param[in] analog Struct containing the unit, MQ and MQ flags. |
299 | * Must not be NULL. analog->meaning must not be NULL. | |
300 | * @param[out] result Pointer to store result. Must not be NULL. | |
a24da9a8 ML |
301 | * |
302 | * The string is allocated by the function and must be freed by the caller | |
303 | * after use by calling g_free(). | |
a5892391 | 304 | * |
22fb1bff UH |
305 | * @retval SR_OK Success. |
306 | * @retval SR_ERR_ARG Invalid argument. | |
a5892391 BV |
307 | * |
308 | * @since 0.4.0 | |
309 | */ | |
edb691fc | 310 | SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog, |
a24da9a8 | 311 | char **result) |
a5892391 | 312 | { |
a24da9a8 | 313 | int i; |
5cee3d08 UH |
314 | GString *buf; |
315 | ||
316 | if (!analog || !(analog->meaning) || !result) | |
317 | return SR_ERR_ARG; | |
318 | ||
319 | buf = g_string_new(NULL); | |
a5892391 | 320 | |
a5892391 BV |
321 | for (i = 0; unit_strings[i].value; i++) { |
322 | if (analog->meaning->unit == unit_strings[i].value) { | |
a24da9a8 | 323 | g_string_assign(buf, unit_strings[i].str); |
a5892391 BV |
324 | break; |
325 | } | |
326 | } | |
327 | ||
328 | /* More than one MQ flag may apply. */ | |
a24da9a8 ML |
329 | for (i = 0; mq_strings[i].value; i++) |
330 | if (analog->meaning->mqflags & mq_strings[i].value) | |
331 | g_string_append(buf, mq_strings[i].str); | |
332 | ||
333 | *result = buf->str; | |
334 | g_string_free(buf, FALSE); | |
a5892391 BV |
335 | |
336 | return SR_OK; | |
337 | } | |
338 | ||
22fb1bff | 339 | /** |
90cefe0c BV |
340 | * Set sr_rational r to the given value. |
341 | * | |
22fb1bff UH |
342 | * @param[out] r Rational number struct to set. Must not be NULL. |
343 | * @param[in] p Numerator. | |
344 | * @param[in] q Denominator. | |
345 | * | |
346 | * @since 0.4.0 | |
90cefe0c | 347 | */ |
53e5d3d1 | 348 | SR_API void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q) |
90cefe0c | 349 | { |
5cee3d08 UH |
350 | if (!r) |
351 | return; | |
352 | ||
90cefe0c BV |
353 | r->p = p; |
354 | r->q = q; | |
355 | } | |
356 | ||
bdba3626 SB |
357 | #ifndef HAVE___INT128_T |
358 | struct sr_int128_t { | |
359 | int64_t high; | |
360 | uint64_t low; | |
361 | }; | |
362 | ||
363 | struct sr_uint128_t { | |
364 | uint64_t high; | |
365 | uint64_t low; | |
366 | }; | |
367 | ||
368 | static void mult_int64(struct sr_int128_t *res, const int64_t a, | |
369 | const int64_t b) | |
370 | { | |
371 | uint64_t t1, t2, t3, t4; | |
372 | ||
373 | t1 = (UINT32_MAX & a) * (UINT32_MAX & b); | |
374 | t2 = (UINT32_MAX & a) * (b >> 32); | |
375 | t3 = (a >> 32) * (UINT32_MAX & b); | |
376 | t4 = (a >> 32) * (b >> 32); | |
377 | ||
378 | res->low = t1 + (t2 << 32) + (t3 << 32); | |
379 | res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3)); | |
380 | res->high >>= 32; | |
381 | res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4; | |
382 | } | |
383 | ||
384 | static void mult_uint64(struct sr_uint128_t *res, const uint64_t a, | |
385 | const uint64_t b) | |
386 | { | |
387 | uint64_t t1, t2, t3, t4; | |
388 | ||
389 | // (x1 + x2) * (y1 + y2) = x1*y1 + x1*y2 + x2*y1 + x2*y2 | |
390 | t1 = (UINT32_MAX & a) * (UINT32_MAX & b); | |
391 | t2 = (UINT32_MAX & a) * (b >> 32); | |
392 | t3 = (a >> 32) * (UINT32_MAX & b); | |
393 | t4 = (a >> 32) * (b >> 32); | |
394 | ||
395 | res->low = t1 + (t2 << 32) + (t3 << 32); | |
396 | res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3)); | |
397 | res->high >>= 32; | |
398 | res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4; | |
399 | } | |
400 | #endif | |
401 | ||
402 | /** | |
403 | * Compare two sr_rational for equality | |
404 | * | |
405 | * @param[in] a First value | |
406 | * @param[in] b Second value | |
407 | * | |
408 | * The values are compared for numerical equality, i.e. 2/10 == 1/5 | |
409 | * | |
410 | * @retval 1 if both values are equal | |
411 | * @retval 0 otherwise | |
412 | * | |
413 | * @since 0.5.0 | |
414 | */ | |
415 | SR_API int sr_rational_eq(const struct sr_rational *a, const struct sr_rational *b) | |
416 | { | |
417 | #ifdef HAVE___INT128_T | |
418 | __int128_t m1, m2; | |
419 | ||
420 | /* p1/q1 = p2/q2 <=> p1*q2 = p2*q1 */ | |
421 | m1 = ((__int128_t)(b->p)) * ((__uint128_t)a->q); | |
422 | m2 = ((__int128_t)(a->p)) * ((__uint128_t)b->q); | |
423 | ||
424 | return (m1 == m2); | |
425 | ||
426 | #else | |
427 | struct sr_int128_t m1, m2; | |
428 | ||
429 | mult_int64(&m1, a->q, b->p); | |
430 | mult_int64(&m2, a->p, b->q); | |
431 | ||
432 | return (m1.high == m2.high) && (m1.low == m2.low); | |
433 | #endif | |
434 | } | |
435 | ||
ee1b6054 SB |
436 | /** |
437 | * Multiply two sr_rational | |
438 | * | |
439 | * @param[in] a First value | |
440 | * @param[in] b Second value | |
441 | * @param[out] res Result | |
442 | * | |
443 | * The resulting nominator/denominator are reduced if the result would not fit | |
444 | * otherwise. If the resulting nominator/denominator are relatively prime, | |
445 | * this may not be possible. | |
446 | * | |
17d5a11c SB |
447 | * It is save to use the same variable for result and input values |
448 | * | |
ee1b6054 SB |
449 | * @retval SR_OK Success. |
450 | * @retval SR_ERR_ARG Resulting value to large | |
451 | * | |
452 | * @since 0.5.0 | |
453 | */ | |
454 | SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a, | |
455 | const struct sr_rational *b) | |
456 | { | |
457 | #ifdef HAVE___INT128_T | |
458 | __int128_t p; | |
459 | __uint128_t q; | |
460 | ||
461 | p = (__int128_t)(a->p) * (__int128_t)(b->p); | |
462 | q = (__uint128_t)(a->q) * (__uint128_t)(b->q); | |
463 | ||
464 | if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) { | |
465 | while (!((p & 1) || (q & 1))) { | |
466 | p /= 2; | |
467 | q /= 2; | |
468 | } | |
469 | } | |
470 | ||
471 | if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) { | |
472 | // TODO: determine gcd to do further reduction | |
473 | return SR_ERR_ARG; | |
474 | } | |
475 | ||
476 | res->p = (int64_t)(p); | |
477 | res->q = (uint64_t)(q); | |
478 | ||
479 | return SR_OK; | |
480 | ||
481 | #else | |
482 | struct sr_int128_t p; | |
483 | struct sr_uint128_t q; | |
484 | ||
485 | mult_int64(&p, a->p, b->p); | |
486 | mult_uint64(&q, a->q, b->q); | |
487 | ||
488 | while (!(p.low & 1) && !(q.low & 1)) { | |
489 | p.low /= 2; | |
490 | if (p.high & 1) p.low |= (1ll << 63); | |
491 | p.high >>= 1; | |
492 | q.low /= 2; | |
493 | if (q.high & 1) q.low |= (1ll << 63); | |
494 | q.high >>= 1; | |
495 | } | |
496 | ||
497 | if (q.high) | |
498 | return SR_ERR_ARG; | |
499 | if ((p.high >= 0) && (p.low > INT64_MAX)) | |
500 | return SR_ERR_ARG; | |
501 | if (p.high < -1) | |
502 | return SR_ERR_ARG; | |
503 | ||
504 | res->p = (int64_t)p.low; | |
505 | res->q = q.low; | |
506 | ||
507 | return SR_OK; | |
508 | #endif | |
509 | } | |
510 | ||
17d5a11c SB |
511 | /** |
512 | * Divide rational a by rational b | |
513 | * | |
514 | * @param[in] num numerator | |
515 | * @param[in] div divisor | |
516 | * @param[out] res Result | |
517 | * | |
518 | * The resulting nominator/denominator are reduced if the result would not fit | |
519 | * otherwise. If the resulting nominator/denominator are relatively prime, | |
520 | * this may not be possible. | |
521 | * | |
522 | * It is save to use the same variable for result and input values | |
523 | * | |
524 | * @retval SR_OK Success. | |
525 | * @retval SR_ERR_ARG Division by zero | |
526 | * @retval SR_ERR_ARG Denominator of divisor to large | |
527 | * @retval SR_ERR_ARG Resulting value to large | |
528 | * | |
529 | * @since 0.5.0 | |
530 | */ | |
531 | SR_API int sr_rational_div(struct sr_rational *res, const struct sr_rational *num, | |
532 | const struct sr_rational *div) | |
533 | { | |
534 | struct sr_rational t; | |
535 | ||
536 | if (div->q > INT64_MAX) | |
537 | return SR_ERR_ARG; | |
538 | if (div->p == 0) | |
539 | return SR_ERR_ARG; | |
540 | ||
541 | if (div->p > 0) { | |
542 | t.p = div->q; | |
543 | t.q = div->p; | |
544 | } else { | |
545 | t.p = -div->q; | |
546 | t.q = -div->p; | |
547 | } | |
548 | ||
549 | return sr_rational_mult(res, num, &t); | |
550 | } | |
551 | ||
e00b3f58 | 552 | /** @} */ |