spl_fixpt31_32.h

  1/* SPDX-License-Identifier: MIT */
  2
  3/* Copyright 2024 Advanced Micro Devices, Inc. */
  4
  5#ifndef __SPL_FIXED31_32_H__
  6#define __SPL_FIXED31_32_H__
  7
  8#include "spl_debug.h"
  9#include "spl_os_types.h"   // swap
 10
 11#ifndef LLONG_MAX
 12#define LLONG_MAX 9223372036854775807ll
 13#endif
 14#ifndef LLONG_MIN
 15#define LLONG_MIN (-LLONG_MAX - 1ll)
 16#endif
 17
 18#define FIXED31_32_BITS_PER_FRACTIONAL_PART 32
 19#ifndef LLONG_MIN
 20#define LLONG_MIN (1LL<<63)
 21#endif
 22#ifndef LLONG_MAX
 23#define LLONG_MAX (-1LL>>1)
 24#endif
 25
 26/*
 27 * @brief
 28 * Arithmetic operations on real numbers
 29 * represented as fixed-point numbers.
 30 * There are: 1 bit for sign,
 31 * 31 bit for integer part,
 32 * 32 bits for fractional part.
 33 *
 34 * @note
 35 * Currently, overflows and underflows are asserted;
 36 * no special result returned.
 37 */
 38
 39struct spl_fixed31_32 {
 40	long long value;
 41};
 42
 43
 44/*
 45 * @brief
 46 * Useful constants
 47 */
 48
 49static const struct spl_fixed31_32 spl_fixpt_zero = { 0 };
 50static const struct spl_fixed31_32 spl_fixpt_epsilon = { 1LL };
 51static const struct spl_fixed31_32 spl_fixpt_half = { 0x80000000LL };
 52static const struct spl_fixed31_32 spl_fixpt_one = { 0x100000000LL };
 53
 54/*
 55 * @brief
 56 * Initialization routines
 57 */
 58
 59/*
 60 * @brief
 61 * result = numerator / denominator
 62 */
 63struct spl_fixed31_32 spl_fixpt_from_fraction(long long numerator, long long denominator);
 64
 65/*
 66 * @brief
 67 * result = arg
 68 */
 69static inline struct spl_fixed31_32 spl_fixpt_from_int(int arg)
 70{
 71	struct spl_fixed31_32 res;
 72
 73	res.value = (long long) arg << FIXED31_32_BITS_PER_FRACTIONAL_PART;
 74
 75	return res;
 76}
 77
 78/*
 79 * @brief
 80 * Unary operators
 81 */
 82
 83/*
 84 * @brief
 85 * result = -arg
 86 */
 87static inline struct spl_fixed31_32 spl_fixpt_neg(struct spl_fixed31_32 arg)
 88{
 89	struct spl_fixed31_32 res;
 90
 91	res.value = -arg.value;
 92
 93	return res;
 94}
 95
 96/*
 97 * @brief
 98 * result = abs(arg) := (arg >= 0) ? arg : -arg
 99 */
100static inline struct spl_fixed31_32 spl_fixpt_abs(struct spl_fixed31_32 arg)
101{
102	if (arg.value < 0)
103		return spl_fixpt_neg(arg);
104	else
105		return arg;
106}
107
108/*
109 * @brief
110 * Binary relational operators
111 */
112
113/*
114 * @brief
115 * result = arg1 < arg2
116 */
117static inline bool spl_fixpt_lt(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
118{
119	return arg1.value < arg2.value;
120}
121
122/*
123 * @brief
124 * result = arg1 <= arg2
125 */
126static inline bool spl_fixpt_le(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
127{
128	return arg1.value <= arg2.value;
129}
130
131/*
132 * @brief
133 * result = arg1 == arg2
134 */
135static inline bool spl_fixpt_eq(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
136{
137	return arg1.value == arg2.value;
138}
139
140/*
141 * @brief
142 * result = min(arg1, arg2) := (arg1 <= arg2) ? arg1 : arg2
143 */
144static inline struct spl_fixed31_32 spl_fixpt_min(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
145{
146	if (arg1.value <= arg2.value)
147		return arg1;
148	else
149		return arg2;
150}
151
152/*
153 * @brief
154 * result = max(arg1, arg2) := (arg1 <= arg2) ? arg2 : arg1
155 */
156static inline struct spl_fixed31_32 spl_fixpt_max(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
157{
158	if (arg1.value <= arg2.value)
159		return arg2;
160	else
161		return arg1;
162}
163
164/*
165 * @brief
166 *          | min_value, when arg <= min_value
167 * result = | arg, when min_value < arg < max_value
168 *          | max_value, when arg >= max_value
169 */
170static inline struct spl_fixed31_32 spl_fixpt_clamp(
171	struct spl_fixed31_32 arg,
172	struct spl_fixed31_32 min_value,
173	struct spl_fixed31_32 max_value)
174{
175	if (spl_fixpt_le(arg, min_value))
176		return min_value;
177	else if (spl_fixpt_le(max_value, arg))
178		return max_value;
179	else
180		return arg;
181}
182
183/*
184 * @brief
185 * Binary shift operators
186 */
187
188/*
189 * @brief
190 * result = arg << shift
191 */
192static inline struct spl_fixed31_32 spl_fixpt_shl(struct spl_fixed31_32 arg, unsigned int shift)
193{
194	SPL_ASSERT(((arg.value >= 0) && (arg.value <= LLONG_MAX >> shift)) ||
195		((arg.value < 0) && (arg.value >= ~(LLONG_MAX >> shift))));
196
197	arg.value = arg.value << shift;
198
199	return arg;
200}
201
202/*
203 * @brief
204 * result = arg >> shift
205 */
206static inline struct spl_fixed31_32 spl_fixpt_shr(struct spl_fixed31_32 arg, unsigned int shift)
207{
208	bool negative = arg.value < 0;
209
210	if (negative)
211		arg.value = -arg.value;
212	arg.value = arg.value >> shift;
213	if (negative)
214		arg.value = -arg.value;
215	return arg;
216}
217
218/*
219 * @brief
220 * Binary additive operators
221 */
222
223/*
224 * @brief
225 * result = arg1 + arg2
226 */
227static inline struct spl_fixed31_32 spl_fixpt_add(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
228{
229	struct spl_fixed31_32 res;
230
231	SPL_ASSERT(((arg1.value >= 0) && (LLONG_MAX - arg1.value >= arg2.value)) ||
232		((arg1.value < 0) && (LLONG_MIN - arg1.value <= arg2.value)));
233
234	res.value = arg1.value + arg2.value;
235
236	return res;
237}
238
239/*
240 * @brief
241 * result = arg1 + arg2
242 */
243static inline struct spl_fixed31_32 spl_fixpt_add_int(struct spl_fixed31_32 arg1, int arg2)
244{
245	return spl_fixpt_add(arg1, spl_fixpt_from_int(arg2));
246}
247
248/*
249 * @brief
250 * result = arg1 - arg2
251 */
252static inline struct spl_fixed31_32 spl_fixpt_sub(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
253{
254	struct spl_fixed31_32 res;
255
256	SPL_ASSERT(((arg2.value >= 0) && (LLONG_MIN + arg2.value <= arg1.value)) ||
257		((arg2.value < 0) && (LLONG_MAX + arg2.value >= arg1.value)));
258
259	res.value = arg1.value - arg2.value;
260
261	return res;
262}
263
264/*
265 * @brief
266 * result = arg1 - arg2
267 */
268static inline struct spl_fixed31_32 spl_fixpt_sub_int(struct spl_fixed31_32 arg1, int arg2)
269{
270	return spl_fixpt_sub(arg1, spl_fixpt_from_int(arg2));
271}
272
273
274/*
275 * @brief
276 * Binary multiplicative operators
277 */
278
279/*
280 * @brief
281 * result = arg1 * arg2
282 */
283struct spl_fixed31_32 spl_fixpt_mul(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2);
284
285
286/*
287 * @brief
288 * result = arg1 * arg2
289 */
290static inline struct spl_fixed31_32 spl_fixpt_mul_int(struct spl_fixed31_32 arg1, int arg2)
291{
292	return spl_fixpt_mul(arg1, spl_fixpt_from_int(arg2));
293}
294
295/*
296 * @brief
297 * result = square(arg) := arg * arg
298 */
299struct spl_fixed31_32 spl_fixpt_sqr(struct spl_fixed31_32 arg);
300
301/*
302 * @brief
303 * result = arg1 / arg2
304 */
305static inline struct spl_fixed31_32 spl_fixpt_div_int(struct spl_fixed31_32 arg1, long long arg2)
306{
307	return spl_fixpt_from_fraction(arg1.value, spl_fixpt_from_int((int)arg2).value);
308}
309
310/*
311 * @brief
312 * result = arg1 / arg2
313 */
314static inline struct spl_fixed31_32 spl_fixpt_div(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
315{
316	return spl_fixpt_from_fraction(arg1.value, arg2.value);
317}
318
319/*
320 * @brief
321 * Reciprocal function
322 */
323
324/*
325 * @brief
326 * result = reciprocal(arg) := 1 / arg
327 *
328 * @note
329 * No special actions taken in case argument is zero.
330 */
331struct spl_fixed31_32 spl_fixpt_recip(struct spl_fixed31_32 arg);
332
333/*
334 * @brief
335 * Trigonometric functions
336 */
337
338/*
339 * @brief
340 * result = sinc(arg) := sin(arg) / arg
341 *
342 * @note
343 * Argument specified in radians,
344 * internally it's normalized to [-2pi...2pi] range.
345 */
346struct spl_fixed31_32 spl_fixpt_sinc(struct spl_fixed31_32 arg);
347
348/*
349 * @brief
350 * result = sin(arg)
351 *
352 * @note
353 * Argument specified in radians,
354 * internally it's normalized to [-2pi...2pi] range.
355 */
356struct spl_fixed31_32 spl_fixpt_sin(struct spl_fixed31_32 arg);
357
358/*
359 * @brief
360 * result = cos(arg)
361 *
362 * @note
363 * Argument specified in radians
364 * and should be in [-2pi...2pi] range -
365 * passing arguments outside that range
366 * will cause incorrect result!
367 */
368struct spl_fixed31_32 spl_fixpt_cos(struct spl_fixed31_32 arg);
369
370/*
371 * @brief
372 * Transcendent functions
373 */
374
375/*
376 * @brief
377 * result = exp(arg)
378 *
379 * @note
380 * Currently, function is verified for abs(arg) <= 1.
381 */
382struct spl_fixed31_32 spl_fixpt_exp(struct spl_fixed31_32 arg);
383
384/*
385 * @brief
386 * result = log(arg)
387 *
388 * @note
389 * Currently, abs(arg) should be less than 1.
390 * No normalization is done.
391 * Currently, no special actions taken
392 * in case of invalid argument(s). Take care!
393 */
394struct spl_fixed31_32 spl_fixpt_log(struct spl_fixed31_32 arg);
395
396/*
397 * @brief
398 * Power function
399 */
400
401/*
402 * @brief
403 * result = pow(arg1, arg2)
404 *
405 * @note
406 * Currently, abs(arg1) should be less than 1. Take care!
407 */
408static inline struct spl_fixed31_32 spl_fixpt_pow(struct spl_fixed31_32 arg1, struct spl_fixed31_32 arg2)
409{
410	if (arg1.value == 0)
411		return arg2.value == 0 ? spl_fixpt_one : spl_fixpt_zero;
412
413	return spl_fixpt_exp(
414		spl_fixpt_mul(
415			spl_fixpt_log(arg1),
416			arg2));
417}
418
419/*
420 * @brief
421 * Rounding functions
422 */
423
424/*
425 * @brief
426 * result = floor(arg) := greatest integer lower than or equal to arg
427 */
428static inline int spl_fixpt_floor(struct spl_fixed31_32 arg)
429{
430	unsigned long long arg_value = arg.value > 0 ? arg.value : -arg.value;
431
432	if (arg.value >= 0)
433		return (int)(arg_value >> FIXED31_32_BITS_PER_FRACTIONAL_PART);
434	else
435		return -(int)(arg_value >> FIXED31_32_BITS_PER_FRACTIONAL_PART);
436}
437
438/*
439 * @brief
440 * result = round(arg) := integer nearest to arg
441 */
442static inline int spl_fixpt_round(struct spl_fixed31_32 arg)
443{
444	unsigned long long arg_value = arg.value > 0 ? arg.value : -arg.value;
445
446	const long long summand = spl_fixpt_half.value;
447
448	SPL_ASSERT(LLONG_MAX - (long long)arg_value >= summand);
449
450	arg_value += summand;
451
452	if (arg.value >= 0)
453		return (int)(arg_value >> FIXED31_32_BITS_PER_FRACTIONAL_PART);
454	else
455		return -(int)(arg_value >> FIXED31_32_BITS_PER_FRACTIONAL_PART);
456}
457
458/*
459 * @brief
460 * result = ceil(arg) := lowest integer greater than or equal to arg
461 */
462static inline int spl_fixpt_ceil(struct spl_fixed31_32 arg)
463{
464	unsigned long long arg_value = arg.value > 0 ? arg.value : -arg.value;
465
466	const long long summand = spl_fixpt_one.value -
467		spl_fixpt_epsilon.value;
468
469	SPL_ASSERT(LLONG_MAX - (long long)arg_value >= summand);
470
471	arg_value += summand;
472
473	if (arg.value >= 0)
474		return (int)(arg_value >> FIXED31_32_BITS_PER_FRACTIONAL_PART);
475	else
476		return -(int)(arg_value >> FIXED31_32_BITS_PER_FRACTIONAL_PART);
477}
478
479/* the following two function are used in scaler hw programming to convert fixed
480 * point value to format 2 bits from integer part and 19 bits from fractional
481 * part. The same applies for u0d19, 0 bits from integer part and 19 bits from
482 * fractional
483 */
484
485unsigned int spl_fixpt_u4d19(struct spl_fixed31_32 arg);
486
487unsigned int spl_fixpt_u3d19(struct spl_fixed31_32 arg);
488
489unsigned int spl_fixpt_u2d19(struct spl_fixed31_32 arg);
490
491unsigned int spl_fixpt_u0d19(struct spl_fixed31_32 arg);
492
493unsigned int spl_fixpt_clamp_u0d14(struct spl_fixed31_32 arg);
494
495unsigned int spl_fixpt_clamp_u0d10(struct spl_fixed31_32 arg);
496
497int spl_fixpt_s4d19(struct spl_fixed31_32 arg);
498
499static inline struct spl_fixed31_32 spl_fixpt_truncate(struct spl_fixed31_32 arg, unsigned int frac_bits)
500{
501	bool negative = arg.value < 0;
502
503	if (frac_bits >= FIXED31_32_BITS_PER_FRACTIONAL_PART) {
504		SPL_ASSERT(frac_bits == FIXED31_32_BITS_PER_FRACTIONAL_PART);
505		return arg;
506	}
507
508	if (negative)
509		arg.value = -arg.value;
510	arg.value &= (~0ULL) << (FIXED31_32_BITS_PER_FRACTIONAL_PART - frac_bits);
511	if (negative)
512		arg.value = -arg.value;
513	return arg;
514}
515
516struct spl_fixed31_32 spl_fixpt_from_ux_dy(unsigned int value, unsigned int integer_bits, unsigned int fractional_bits);
517struct spl_fixed31_32 spl_fixpt_from_int_dy(unsigned int int_value,
518		unsigned int frac_value,
519		unsigned int integer_bits,
520		unsigned int fractional_bits);
521
522#endif