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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 | ||
20 | #include <config.h> | |
21 | #include <stdio.h> | |
22 | #include <stdint.h> | |
23 | #include <string.h> | |
24 | #include <ctype.h> | |
25 | #include <math.h> | |
26 | #include <libsigrok/libsigrok.h> | |
27 | #include "libsigrok-internal.h" | |
28 | ||
29 | /** @cond PRIVATE */ | |
30 | #define LOG_PREFIX "analog" | |
31 | /** @endcond */ | |
32 | ||
33 | /** | |
34 | * @file | |
35 | * | |
36 | * Handling and converting analog data. | |
37 | */ | |
38 | ||
39 | /** | |
40 | * @defgroup grp_analog Analog data handling | |
41 | * | |
42 | * Handling and converting analog data. | |
43 | * | |
44 | * @{ | |
45 | */ | |
46 | ||
47 | struct unit_mq_string { | |
48 | uint64_t value; | |
49 | const char *str; | |
50 | }; | |
51 | ||
52 | /* Please use the same order as in enum sr_unit (libsigrok.h). */ | |
53 | static struct unit_mq_string unit_strings[] = { | |
54 | { SR_UNIT_VOLT, "V" }, | |
55 | { SR_UNIT_AMPERE, "A" }, | |
56 | { SR_UNIT_OHM, "\xe2\x84\xa6" }, | |
57 | { SR_UNIT_FARAD, "F" }, | |
58 | { SR_UNIT_KELVIN, "K" }, | |
59 | { SR_UNIT_CELSIUS, "\xc2\xb0""C" }, | |
60 | { SR_UNIT_FAHRENHEIT, "\xc2\xb0""F" }, | |
61 | { SR_UNIT_HERTZ, "Hz" }, | |
62 | { SR_UNIT_PERCENTAGE, "%" }, | |
63 | { SR_UNIT_BOOLEAN, "" }, | |
64 | { SR_UNIT_SECOND, "s" }, | |
65 | { SR_UNIT_SIEMENS, "S" }, | |
66 | { SR_UNIT_DECIBEL_MW, "dBm" }, | |
67 | { SR_UNIT_DECIBEL_VOLT, "dBV" }, | |
68 | { SR_UNIT_UNITLESS, "" }, | |
69 | { SR_UNIT_DECIBEL_SPL, "dB" }, | |
70 | { SR_UNIT_CONCENTRATION, "ppm" }, | |
71 | { SR_UNIT_REVOLUTIONS_PER_MINUTE, "RPM" }, | |
72 | { SR_UNIT_VOLT_AMPERE, "VA" }, | |
73 | { SR_UNIT_WATT, "W" }, | |
74 | { SR_UNIT_WATT_HOUR, "Wh" }, | |
75 | { SR_UNIT_METER_SECOND, "m/s" }, | |
76 | { SR_UNIT_HECTOPASCAL, "hPa" }, | |
77 | { SR_UNIT_HUMIDITY_293K, "%rF" }, | |
78 | { SR_UNIT_DEGREE, "\xc2\xb0" }, | |
79 | { SR_UNIT_HENRY, "H" }, | |
80 | { SR_UNIT_GRAM, "g" }, | |
81 | { SR_UNIT_CARAT, "ct" }, | |
82 | { SR_UNIT_OUNCE, "oz" }, | |
83 | { SR_UNIT_TROY_OUNCE, "oz t" }, | |
84 | { SR_UNIT_POUND, "lb" }, | |
85 | { SR_UNIT_PENNYWEIGHT, "dwt" }, | |
86 | { SR_UNIT_GRAIN, "gr" }, | |
87 | { SR_UNIT_TAEL, "tael" }, | |
88 | { SR_UNIT_MOMME, "momme" }, | |
89 | { SR_UNIT_TOLA, "tola" }, | |
90 | { SR_UNIT_PIECE, "pcs" }, | |
91 | ALL_ZERO | |
92 | }; | |
93 | ||
94 | /* Please use the same order as in enum sr_mqflag (libsigrok.h). */ | |
95 | static struct unit_mq_string mq_strings[] = { | |
96 | { SR_MQFLAG_AC, " AC" }, | |
97 | { SR_MQFLAG_DC, " DC" }, | |
98 | { SR_MQFLAG_RMS, " RMS" }, | |
99 | { SR_MQFLAG_DIODE, " DIODE" }, | |
100 | { SR_MQFLAG_HOLD, " HOLD" }, | |
101 | { SR_MQFLAG_MAX, " MAX" }, | |
102 | { SR_MQFLAG_MIN, " MIN" }, | |
103 | { SR_MQFLAG_AUTORANGE, " AUTO" }, | |
104 | { SR_MQFLAG_RELATIVE, " REL" }, | |
105 | { SR_MQFLAG_SPL_FREQ_WEIGHT_A, "(A)" }, | |
106 | { SR_MQFLAG_SPL_FREQ_WEIGHT_C, "(C)" }, | |
107 | { SR_MQFLAG_SPL_FREQ_WEIGHT_Z, "(Z)" }, | |
108 | { SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT, "(SPL)" }, | |
109 | { SR_MQFLAG_SPL_TIME_WEIGHT_S, " S" }, | |
110 | { SR_MQFLAG_SPL_TIME_WEIGHT_F, " F" }, | |
111 | { SR_MQFLAG_SPL_LAT, " LAT" }, | |
112 | /* Not a standard function for SLMs, so this is a made-up notation. */ | |
113 | { SR_MQFLAG_SPL_PCT_OVER_ALARM, "%oA" }, | |
114 | { SR_MQFLAG_DURATION, " DURATION" }, | |
115 | { SR_MQFLAG_AVG, " AVG" }, | |
116 | { SR_MQFLAG_REFERENCE, " REF" }, | |
117 | { SR_MQFLAG_UNSTABLE, " UNSTABLE" }, | |
118 | { SR_MQFLAG_FOUR_WIRE, " 4-WIRE" }, | |
119 | ALL_ZERO | |
120 | }; | |
121 | ||
122 | /** @private */ | |
123 | SR_PRIV int sr_analog_init(struct sr_datafeed_analog *analog, | |
124 | struct sr_analog_encoding *encoding, | |
125 | struct sr_analog_meaning *meaning, | |
126 | struct sr_analog_spec *spec, | |
127 | int digits) | |
128 | { | |
129 | memset(analog, 0, sizeof(*analog)); | |
130 | memset(encoding, 0, sizeof(*encoding)); | |
131 | memset(meaning, 0, sizeof(*meaning)); | |
132 | memset(spec, 0, sizeof(*spec)); | |
133 | ||
134 | analog->encoding = encoding; | |
135 | analog->meaning = meaning; | |
136 | analog->spec = spec; | |
137 | ||
138 | encoding->unitsize = sizeof(float); | |
139 | encoding->is_float = TRUE; | |
140 | #ifdef WORDS_BIGENDIAN | |
141 | encoding->is_bigendian = TRUE; | |
142 | #else | |
143 | encoding->is_bigendian = FALSE; | |
144 | #endif | |
145 | encoding->digits = digits; | |
146 | encoding->is_digits_decimal = TRUE; | |
147 | encoding->scale.p = 1; | |
148 | encoding->scale.q = 1; | |
149 | encoding->offset.p = 0; | |
150 | encoding->offset.q = 1; | |
151 | ||
152 | spec->spec_digits = digits; | |
153 | ||
154 | return SR_OK; | |
155 | } | |
156 | ||
157 | /** | |
158 | * Convert an analog datafeed payload to an array of floats. | |
159 | * | |
160 | * Sufficient memory for outbuf must have been pre-allocated by the caller, | |
161 | * who is also responsible for freeing it when no longer needed. | |
162 | * | |
163 | * @param[in] analog The analog payload to convert. Must not be NULL. | |
164 | * analog->data, analog->meaning, and analog->encoding | |
165 | * must not be NULL. | |
166 | * @param[out] outbuf Memory where to store the result. Must not be NULL. | |
167 | * | |
168 | * @retval SR_OK Success. | |
169 | * @retval SR_ERR Unsupported encoding. | |
170 | * @retval SR_ERR_ARG Invalid argument. | |
171 | * | |
172 | * @since 0.4.0 | |
173 | */ | |
174 | SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog, | |
175 | float *outbuf) | |
176 | { | |
177 | float offset; | |
178 | unsigned int b, i, count; | |
179 | gboolean bigendian; | |
180 | ||
181 | if (!analog || !(analog->data) || !(analog->meaning) | |
182 | || !(analog->encoding) || !outbuf) | |
183 | return SR_ERR_ARG; | |
184 | ||
185 | count = analog->num_samples * g_slist_length(analog->meaning->channels); | |
186 | ||
187 | #ifdef WORDS_BIGENDIAN | |
188 | bigendian = TRUE; | |
189 | #else | |
190 | bigendian = FALSE; | |
191 | #endif | |
192 | ||
193 | if (!analog->encoding->is_float) { | |
194 | float offset = analog->encoding->offset.p / (float)analog->encoding->offset.q; | |
195 | float scale = analog->encoding->scale.p / (float)analog->encoding->scale.q; | |
196 | gboolean is_signed = analog->encoding->is_signed; | |
197 | gboolean is_bigendian = analog->encoding->is_bigendian; | |
198 | int8_t *data8 = (int8_t *)(analog->data); | |
199 | int16_t *data16 = (int16_t *)(analog->data); | |
200 | int32_t *data32 = (int32_t *)(analog->data); | |
201 | ||
202 | switch (analog->encoding->unitsize) { | |
203 | case 1: | |
204 | if (is_signed) { | |
205 | for (unsigned int i = 0; i < count; i++) { | |
206 | outbuf[i] = scale * data8[i]; | |
207 | outbuf[i] += offset; | |
208 | } | |
209 | } else { | |
210 | for (unsigned int i = 0; i < count; i++) { | |
211 | outbuf[i] = scale * R8(data8 + i); | |
212 | outbuf[i] += offset; | |
213 | } | |
214 | } | |
215 | break; | |
216 | case 2: | |
217 | if (is_signed && is_bigendian) { | |
218 | for (unsigned int i = 0; i < count; i++) { | |
219 | outbuf[i] = scale * RB16S(&data16[i]); | |
220 | outbuf[i] += offset; | |
221 | } | |
222 | } else if (is_bigendian) { | |
223 | for (unsigned int i = 0; i < count; i++) { | |
224 | outbuf[i] = scale * RB16(&data16[i]); | |
225 | outbuf[i] += offset; | |
226 | } | |
227 | } else if (is_signed) { | |
228 | for (unsigned int i = 0; i < count; i++) { | |
229 | outbuf[i] = scale * RL16S(&data16[i]); | |
230 | outbuf[i] += offset; | |
231 | } | |
232 | } else { | |
233 | for (unsigned int i = 0; i < count; i++) { | |
234 | outbuf[i] = scale * RL16(&data16[i]); | |
235 | outbuf[i] += offset; | |
236 | } | |
237 | } | |
238 | break; | |
239 | case 4: | |
240 | if (is_signed && is_bigendian) { | |
241 | for (unsigned int i = 0; i < count; i++) { | |
242 | outbuf[i] = scale * RB32S(&data32[i]); | |
243 | outbuf[i] += offset; | |
244 | } | |
245 | } else if (is_bigendian) { | |
246 | for (unsigned int i = 0; i < count; i++) { | |
247 | outbuf[i] = scale * RB32(&data32[i]); | |
248 | outbuf[i] += offset; | |
249 | } | |
250 | } else if (is_signed) { | |
251 | for (unsigned int i = 0; i < count; i++) { | |
252 | outbuf[i] = scale * RL32S(&data32[i]); | |
253 | outbuf[i] += offset; | |
254 | } | |
255 | } else { | |
256 | for (unsigned int i = 0; i < count; i++) { | |
257 | outbuf[i] = scale * RL32(&data32[i]); | |
258 | outbuf[i] += offset; | |
259 | } | |
260 | } | |
261 | break; | |
262 | default: | |
263 | sr_err("Unsupported unit size '%d' for analog-to-float" | |
264 | " conversion.", analog->encoding->unitsize); | |
265 | return SR_ERR; | |
266 | } | |
267 | return SR_OK; | |
268 | } | |
269 | ||
270 | if (analog->encoding->unitsize == sizeof(float) | |
271 | && analog->encoding->is_bigendian == bigendian | |
272 | && analog->encoding->scale.p == 1 | |
273 | && analog->encoding->scale.q == 1 | |
274 | && analog->encoding->offset.p / (float)analog->encoding->offset.q == 0) { | |
275 | /* The data is already in the right format. */ | |
276 | memcpy(outbuf, analog->data, count * sizeof(float)); | |
277 | } else { | |
278 | for (i = 0; i < count; i += analog->encoding->unitsize) { | |
279 | for (b = 0; b < analog->encoding->unitsize; b++) { | |
280 | if (analog->encoding->is_bigendian == bigendian) | |
281 | ((uint8_t *)outbuf)[i + b] = | |
282 | ((uint8_t *)analog->data)[i * analog->encoding->unitsize + b]; | |
283 | else | |
284 | ((uint8_t *)outbuf)[i + (analog->encoding->unitsize - b)] = | |
285 | ((uint8_t *)analog->data)[i * analog->encoding->unitsize + b]; | |
286 | } | |
287 | if (analog->encoding->scale.p != 1 | |
288 | || analog->encoding->scale.q != 1) | |
289 | outbuf[i] = (outbuf[i] * analog->encoding->scale.p) / analog->encoding->scale.q; | |
290 | offset = ((float)analog->encoding->offset.p / (float)analog->encoding->offset.q); | |
291 | outbuf[i] += offset; | |
292 | } | |
293 | } | |
294 | ||
295 | return SR_OK; | |
296 | } | |
297 | ||
298 | /** | |
299 | * Scale a float value to the appropriate SI prefix. | |
300 | * | |
301 | * @param[in,out] value The float value to convert to appropriate SI prefix. | |
302 | * @param[in,out] digits The number of significant decimal digits in value. | |
303 | * | |
304 | * @return The SI prefix to which value was scaled, as a printable string. | |
305 | * | |
306 | * @since 0.5.0 | |
307 | */ | |
308 | SR_API const char *sr_analog_si_prefix(float *value, int *digits) | |
309 | { | |
310 | /** @cond PRIVATE */ | |
311 | #define NEG_PREFIX_COUNT 5 /* number of prefixes below unity */ | |
312 | #define POS_PREFIX_COUNT (int)(ARRAY_SIZE(prefixes) - NEG_PREFIX_COUNT - 1) | |
313 | /** @endcond */ | |
314 | static const char *prefixes[] = { "f", "p", "n", "ยต", "m", "", "k", "M", "G", "T" }; | |
315 | ||
316 | if (!value || !digits || isnan(*value)) | |
317 | return prefixes[NEG_PREFIX_COUNT]; | |
318 | ||
319 | float logval = log10f(fabsf(*value)); | |
320 | int prefix = (logval / 3) - (logval < 1); | |
321 | ||
322 | if (prefix < -NEG_PREFIX_COUNT) | |
323 | prefix = -NEG_PREFIX_COUNT; | |
324 | if (3 * prefix < -*digits) | |
325 | prefix = (-*digits + 2 * (*digits < 0)) / 3; | |
326 | if (prefix > POS_PREFIX_COUNT) | |
327 | prefix = POS_PREFIX_COUNT; | |
328 | ||
329 | *value *= powf(10, -3 * prefix); | |
330 | *digits += 3 * prefix; | |
331 | ||
332 | return prefixes[prefix + NEG_PREFIX_COUNT]; | |
333 | } | |
334 | ||
335 | /** | |
336 | * Check if a unit "accepts" an SI prefix. | |
337 | * | |
338 | * E.g. SR_UNIT_VOLT is SI prefix friendly while SR_UNIT_DECIBEL_MW or | |
339 | * SR_UNIT_PERCENTAGE are not. | |
340 | * | |
341 | * @param[in] unit The unit to check for SI prefix "friendliness". | |
342 | * | |
343 | * @return TRUE if the unit "accept" an SI prefix. | |
344 | * | |
345 | * @since 0.5.0 | |
346 | */ | |
347 | SR_API gboolean sr_analog_si_prefix_friendly(enum sr_unit unit) | |
348 | { | |
349 | static const enum sr_unit prefix_friendly_units[] = { | |
350 | SR_UNIT_VOLT, | |
351 | SR_UNIT_AMPERE, | |
352 | SR_UNIT_OHM, | |
353 | SR_UNIT_FARAD, | |
354 | SR_UNIT_KELVIN, | |
355 | SR_UNIT_HERTZ, | |
356 | SR_UNIT_SECOND, | |
357 | SR_UNIT_SIEMENS, | |
358 | SR_UNIT_VOLT_AMPERE, | |
359 | SR_UNIT_WATT, | |
360 | SR_UNIT_WATT_HOUR, | |
361 | SR_UNIT_METER_SECOND, | |
362 | SR_UNIT_HENRY, | |
363 | SR_UNIT_GRAM | |
364 | }; | |
365 | unsigned int i; | |
366 | ||
367 | for (i = 0; i < ARRAY_SIZE(prefix_friendly_units); i++) | |
368 | if (unit == prefix_friendly_units[i]) | |
369 | break; | |
370 | ||
371 | if (unit != prefix_friendly_units[i]) | |
372 | return FALSE; | |
373 | ||
374 | return TRUE; | |
375 | } | |
376 | ||
377 | /** | |
378 | * Convert the unit/MQ/MQ flags in the analog struct to a string. | |
379 | * | |
380 | * The string is allocated by the function and must be freed by the caller | |
381 | * after use by calling g_free(). | |
382 | * | |
383 | * @param[in] analog Struct containing the unit, MQ and MQ flags. | |
384 | * Must not be NULL. analog->meaning must not be NULL. | |
385 | * @param[out] result Pointer to store result. Must not be NULL. | |
386 | * | |
387 | * @retval SR_OK Success. | |
388 | * @retval SR_ERR_ARG Invalid argument. | |
389 | * | |
390 | * @since 0.4.0 | |
391 | */ | |
392 | SR_API int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog, | |
393 | char **result) | |
394 | { | |
395 | int i; | |
396 | GString *buf; | |
397 | ||
398 | if (!analog || !(analog->meaning) || !result) | |
399 | return SR_ERR_ARG; | |
400 | ||
401 | buf = g_string_new(NULL); | |
402 | ||
403 | for (i = 0; unit_strings[i].value; i++) { | |
404 | if (analog->meaning->unit == unit_strings[i].value) { | |
405 | g_string_assign(buf, unit_strings[i].str); | |
406 | break; | |
407 | } | |
408 | } | |
409 | ||
410 | /* More than one MQ flag may apply. */ | |
411 | for (i = 0; mq_strings[i].value; i++) | |
412 | if (analog->meaning->mqflags & mq_strings[i].value) | |
413 | g_string_append(buf, mq_strings[i].str); | |
414 | ||
415 | *result = buf->str; | |
416 | g_string_free(buf, FALSE); | |
417 | ||
418 | return SR_OK; | |
419 | } | |
420 | ||
421 | /** | |
422 | * Set sr_rational r to the given value. | |
423 | * | |
424 | * @param[out] r Rational number struct to set. Must not be NULL. | |
425 | * @param[in] p Numerator. | |
426 | * @param[in] q Denominator. | |
427 | * | |
428 | * @since 0.4.0 | |
429 | */ | |
430 | SR_API void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q) | |
431 | { | |
432 | if (!r) | |
433 | return; | |
434 | ||
435 | r->p = p; | |
436 | r->q = q; | |
437 | } | |
438 | ||
439 | #ifndef HAVE___INT128_T | |
440 | struct sr_int128_t { | |
441 | int64_t high; | |
442 | uint64_t low; | |
443 | }; | |
444 | ||
445 | struct sr_uint128_t { | |
446 | uint64_t high; | |
447 | uint64_t low; | |
448 | }; | |
449 | ||
450 | static void mult_int64(struct sr_int128_t *res, const int64_t a, | |
451 | const int64_t b) | |
452 | { | |
453 | uint64_t t1, t2, t3, t4; | |
454 | ||
455 | t1 = (UINT32_MAX & a) * (UINT32_MAX & b); | |
456 | t2 = (UINT32_MAX & a) * (b >> 32); | |
457 | t3 = (a >> 32) * (UINT32_MAX & b); | |
458 | t4 = (a >> 32) * (b >> 32); | |
459 | ||
460 | res->low = t1 + (t2 << 32) + (t3 << 32); | |
461 | res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3)); | |
462 | res->high >>= 32; | |
463 | res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4; | |
464 | } | |
465 | ||
466 | static void mult_uint64(struct sr_uint128_t *res, const uint64_t a, | |
467 | const uint64_t b) | |
468 | { | |
469 | uint64_t t1, t2, t3, t4; | |
470 | ||
471 | // (x1 + x2) * (y1 + y2) = x1*y1 + x1*y2 + x2*y1 + x2*y2 | |
472 | t1 = (UINT32_MAX & a) * (UINT32_MAX & b); | |
473 | t2 = (UINT32_MAX & a) * (b >> 32); | |
474 | t3 = (a >> 32) * (UINT32_MAX & b); | |
475 | t4 = (a >> 32) * (b >> 32); | |
476 | ||
477 | res->low = t1 + (t2 << 32) + (t3 << 32); | |
478 | res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3)); | |
479 | res->high >>= 32; | |
480 | res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4; | |
481 | } | |
482 | #endif | |
483 | ||
484 | /** | |
485 | * Compare two sr_rational for equality. | |
486 | * | |
487 | * The values are compared for numerical equality, i.e. 2/10 == 1/5. | |
488 | * | |
489 | * @param[in] a First value. | |
490 | * @param[in] b Second value. | |
491 | * | |
492 | * @retval 1 if both values are equal. | |
493 | * @retval 0 Otherwise. | |
494 | * | |
495 | * @since 0.5.0 | |
496 | */ | |
497 | SR_API int sr_rational_eq(const struct sr_rational *a, const struct sr_rational *b) | |
498 | { | |
499 | #ifdef HAVE___INT128_T | |
500 | __int128_t m1, m2; | |
501 | ||
502 | /* p1/q1 = p2/q2 <=> p1*q2 = p2*q1 */ | |
503 | m1 = ((__int128_t)(b->p)) * ((__uint128_t)a->q); | |
504 | m2 = ((__int128_t)(a->p)) * ((__uint128_t)b->q); | |
505 | ||
506 | return (m1 == m2); | |
507 | ||
508 | #else | |
509 | struct sr_int128_t m1, m2; | |
510 | ||
511 | mult_int64(&m1, a->q, b->p); | |
512 | mult_int64(&m2, a->p, b->q); | |
513 | ||
514 | return (m1.high == m2.high) && (m1.low == m2.low); | |
515 | #endif | |
516 | } | |
517 | ||
518 | /** | |
519 | * Multiply two sr_rational. | |
520 | * | |
521 | * The resulting nominator/denominator are reduced if the result would not fit | |
522 | * otherwise. If the resulting nominator/denominator are relatively prime, | |
523 | * this may not be possible. | |
524 | * | |
525 | * It is safe to use the same variable for result and input values. | |
526 | * | |
527 | * @param[in] a First value. | |
528 | * @param[in] b Second value. | |
529 | * @param[out] res Result. | |
530 | * | |
531 | * @retval SR_OK Success. | |
532 | * @retval SR_ERR_ARG Resulting value too large. | |
533 | * | |
534 | * @since 0.5.0 | |
535 | */ | |
536 | SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a, | |
537 | const struct sr_rational *b) | |
538 | { | |
539 | #ifdef HAVE___INT128_T | |
540 | __int128_t p; | |
541 | __uint128_t q; | |
542 | ||
543 | p = (__int128_t)(a->p) * (__int128_t)(b->p); | |
544 | q = (__uint128_t)(a->q) * (__uint128_t)(b->q); | |
545 | ||
546 | if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) { | |
547 | while (!((p & 1) || (q & 1))) { | |
548 | p /= 2; | |
549 | q /= 2; | |
550 | } | |
551 | } | |
552 | ||
553 | if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) { | |
554 | // TODO: determine gcd to do further reduction | |
555 | return SR_ERR_ARG; | |
556 | } | |
557 | ||
558 | res->p = (int64_t)(p); | |
559 | res->q = (uint64_t)(q); | |
560 | ||
561 | return SR_OK; | |
562 | ||
563 | #else | |
564 | struct sr_int128_t p; | |
565 | struct sr_uint128_t q; | |
566 | ||
567 | mult_int64(&p, a->p, b->p); | |
568 | mult_uint64(&q, a->q, b->q); | |
569 | ||
570 | while (!(p.low & 1) && !(q.low & 1)) { | |
571 | p.low /= 2; | |
572 | if (p.high & 1) | |
573 | p.low |= (1ll << 63); | |
574 | p.high >>= 1; | |
575 | q.low /= 2; | |
576 | if (q.high & 1) | |
577 | q.low |= (1ll << 63); | |
578 | q.high >>= 1; | |
579 | } | |
580 | ||
581 | if (q.high) | |
582 | return SR_ERR_ARG; | |
583 | if ((p.high >= 0) && (p.low > INT64_MAX)) | |
584 | return SR_ERR_ARG; | |
585 | if (p.high < -1) | |
586 | return SR_ERR_ARG; | |
587 | ||
588 | res->p = (int64_t)p.low; | |
589 | res->q = q.low; | |
590 | ||
591 | return SR_OK; | |
592 | #endif | |
593 | } | |
594 | ||
595 | /** | |
596 | * Divide rational a by rational b. | |
597 | * | |
598 | * The resulting nominator/denominator are reduced if the result would not fit | |
599 | * otherwise. If the resulting nominator/denominator are relatively prime, | |
600 | * this may not be possible. | |
601 | * | |
602 | * It is safe to use the same variable for result and input values. | |
603 | * | |
604 | * @param[in] num Numerator. | |
605 | * @param[in] div Divisor. | |
606 | * @param[out] res Result. | |
607 | * | |
608 | * @retval SR_OK Success. | |
609 | * @retval SR_ERR_ARG Division by zero. | |
610 | * @retval SR_ERR_ARG Denominator of divisor too large. | |
611 | * @retval SR_ERR_ARG Resulting value too large. | |
612 | * | |
613 | * @since 0.5.0 | |
614 | */ | |
615 | SR_API int sr_rational_div(struct sr_rational *res, const struct sr_rational *num, | |
616 | const struct sr_rational *div) | |
617 | { | |
618 | struct sr_rational t; | |
619 | ||
620 | if (div->q > INT64_MAX) | |
621 | return SR_ERR_ARG; | |
622 | if (div->p == 0) | |
623 | return SR_ERR_ARG; | |
624 | ||
625 | if (div->p > 0) { | |
626 | t.p = div->q; | |
627 | t.q = div->p; | |
628 | } else { | |
629 | t.p = -div->q; | |
630 | t.q = -div->p; | |
631 | } | |
632 | ||
633 | return sr_rational_mult(res, num, &t); | |
634 | } | |
635 | ||
636 | /** @} */ |