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1 // SPDX-License-Identifier: Apache-2.0
2 // ----------------------------------------------------------------------------
3 // Copyright 2019-2023 Arm Limited
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
6 // use this file except in compliance with the License. You may obtain a copy
7 // of the License at:
8 //
9 //     http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
13 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
14 // License for the specific language governing permissions and limitations
15 // under the License.
16 // ----------------------------------------------------------------------------
17 
18 /**
19  * @brief 4x32-bit vectors, implemented using plain C++.
20  *
21  * This module implements 4-wide 32-bit float, int, and mask vectors. This
22  * module provides a scalar fallback for VLA code, primarily useful for
23  * debugging VLA algorithms without the complexity of handling SIMD. Only the
24  * baseline level of functionality needed to support VLA is provided.
25  *
26  * Note that the vector conditional operators implemented by this module are
27  * designed to behave like SIMD conditional operators that generate lane masks.
28  * Rather than returning 0/1 booleans like normal C++ code they will return
29  * 0/-1 to give a full lane-width bitmask.
30  *
31  * Note that the documentation for this module still talks about "vectors" to
32  * help developers think about the implied VLA behavior when writing optimized
33  * paths.
34  */
35 
36 #ifndef ASTC_VECMATHLIB_NONE_4_H_INCLUDED
37 #define ASTC_VECMATHLIB_NONE_4_H_INCLUDED
38 
39 #ifndef ASTCENC_SIMD_INLINE
40 	#error "Include astcenc_vecmathlib.h, do not include directly"
41 #endif
42 
43 #include <algorithm>
44 #include <cstdio>
45 #include <cstring>
46 #include <cfenv>
47 
48 // ============================================================================
49 // vfloat4 data type
50 // ============================================================================
51 
52 /**
53  * @brief Data type for 4-wide floats.
54  */
55 struct vfloat4
56 {
57 	/**
58 	 * @brief Construct from zero-initialized value.
59 	 */
60 	ASTCENC_SIMD_INLINE vfloat4() = default;
61 
62 	/**
63 	 * @brief Construct from 4 values loaded from an unaligned address.
64 	 *
65 	 * Consider using loada() which is better with wider VLA vectors if data is
66 	 * aligned to vector length.
67 	 */
vfloat4vfloat468 	ASTCENC_SIMD_INLINE explicit vfloat4(const float* p)
69 	{
70 		m[0] = p[0];
71 		m[1] = p[1];
72 		m[2] = p[2];
73 		m[3] = p[3];
74 	}
75 
76 	/**
77 	 * @brief Construct from 4 scalar values replicated across all lanes.
78 	 *
79 	 * Consider using zero() for constexpr zeros.
80 	 */
vfloat4vfloat481 	ASTCENC_SIMD_INLINE explicit vfloat4(float a)
82 	{
83 		m[0] = a;
84 		m[1] = a;
85 		m[2] = a;
86 		m[3] = a;
87 	}
88 
89 	/**
90 	 * @brief Construct from 4 scalar values.
91 	 *
92 	 * The value of @c a is stored to lane 0 (LSB) in the SIMD register.
93 	 */
vfloat4vfloat494 	ASTCENC_SIMD_INLINE explicit vfloat4(float a, float b, float c, float d)
95 	{
96 		m[0] = a;
97 		m[1] = b;
98 		m[2] = c;
99 		m[3] = d;
100 	}
101 
102 	/**
103 	 * @brief Get the scalar value of a single lane.
104 	 */
lanevfloat4105 	template <int l> ASTCENC_SIMD_INLINE float lane() const
106 	{
107 		return m[l];
108 	}
109 
110 	/**
111 	 * @brief Set the scalar value of a single lane.
112 	 */
set_lanevfloat4113 	template <int l> ASTCENC_SIMD_INLINE void set_lane(float a)
114 	{
115 		m[l] = a;
116 	}
117 
118 	/**
119 	 * @brief Factory that returns a vector of zeros.
120 	 */
zerovfloat4121 	static ASTCENC_SIMD_INLINE vfloat4 zero()
122 	{
123 		return vfloat4(0.0f);
124 	}
125 
126 	/**
127 	 * @brief Factory that returns a replicated scalar loaded from memory.
128 	 */
load1vfloat4129 	static ASTCENC_SIMD_INLINE vfloat4 load1(const float* p)
130 	{
131 		return vfloat4(*p);
132 	}
133 
134 	/**
135 	 * @brief Factory that returns a vector loaded from aligned memory.
136 	 */
loadavfloat4137 	static ASTCENC_SIMD_INLINE vfloat4 loada(const float* p)
138 	{
139 		return vfloat4(p);
140 	}
141 
142 	/**
143 	 * @brief Factory that returns a vector containing the lane IDs.
144 	 */
lane_idvfloat4145 	static ASTCENC_SIMD_INLINE vfloat4 lane_id()
146 	{
147 		return vfloat4(0.0f, 1.0f, 2.0f, 3.0f);
148 	}
149 
150 	/**
151 	 * @brief Return a swizzled float 2.
152 	 */
swzvfloat4153 	template <int l0, int l1> ASTCENC_SIMD_INLINE vfloat4 swz() const
154 	{
155 		return  vfloat4(lane<l0>(), lane<l1>(), 0.0f, 0.0f);
156 	}
157 
158 	/**
159 	 * @brief Return a swizzled float 3.
160 	 */
swzvfloat4161 	template <int l0, int l1, int l2> ASTCENC_SIMD_INLINE vfloat4 swz() const
162 	{
163 		return vfloat4(lane<l0>(), lane<l1>(), lane<l2>(), 0.0f);
164 	}
165 
166 	/**
167 	 * @brief Return a swizzled float 4.
168 	 */
swzvfloat4169 	template <int l0, int l1, int l2, int l3> ASTCENC_SIMD_INLINE vfloat4 swz() const
170 	{
171 		return vfloat4(lane<l0>(), lane<l1>(), lane<l2>(), lane<l3>());
172 	}
173 
174 	/**
175 	 * @brief The vector ...
176 	 */
177 	float m[4];
178 };
179 
180 // ============================================================================
181 // vint4 data type
182 // ============================================================================
183 
184 /**
185  * @brief Data type for 4-wide ints.
186  */
187 struct vint4
188 {
189 	/**
190 	 * @brief Construct from zero-initialized value.
191 	 */
192 	ASTCENC_SIMD_INLINE vint4() = default;
193 
194 	/**
195 	 * @brief Construct from 4 values loaded from an unaligned address.
196 	 *
197 	 * Consider using vint4::loada() which is better with wider VLA vectors
198 	 * if data is aligned.
199 	 */
vint4vint4200 	ASTCENC_SIMD_INLINE explicit vint4(const int* p)
201 	{
202 		m[0] = p[0];
203 		m[1] = p[1];
204 		m[2] = p[2];
205 		m[3] = p[3];
206 	}
207 
208 	/**
209 	 * @brief Construct from 4 uint8_t loaded from an unaligned address.
210 	 */
vint4vint4211 	ASTCENC_SIMD_INLINE explicit vint4(const uint8_t *p)
212 	{
213 		m[0] = p[0];
214 		m[1] = p[1];
215 		m[2] = p[2];
216 		m[3] = p[3];
217 	}
218 
219 	/**
220 	 * @brief Construct from 4 scalar values.
221 	 *
222 	 * The value of @c a is stored to lane 0 (LSB) in the SIMD register.
223 	 */
vint4vint4224 	ASTCENC_SIMD_INLINE explicit vint4(int a, int b, int c, int d)
225 	{
226 		m[0] = a;
227 		m[1] = b;
228 		m[2] = c;
229 		m[3] = d;
230 	}
231 
232 
233 	/**
234 	 * @brief Construct from 4 scalar values replicated across all lanes.
235 	 *
236 	 * Consider using vint4::zero() for constexpr zeros.
237 	 */
vint4vint4238 	ASTCENC_SIMD_INLINE explicit vint4(int a)
239 	{
240 		m[0] = a;
241 		m[1] = a;
242 		m[2] = a;
243 		m[3] = a;
244 	}
245 
246 	/**
247 	 * @brief Get the scalar value of a single lane.
248 	 */
lanevint4249 	template <int l> ASTCENC_SIMD_INLINE int lane() const
250 	{
251 		return m[l];
252 	}
253 
254 	/**
255 	 * @brief Set the scalar value of a single lane.
256 	 */
set_lanevint4257 	template <int l> ASTCENC_SIMD_INLINE void set_lane(int a)
258 	{
259 		m[l] = a;
260 	}
261 
262 	/**
263 	 * @brief Factory that returns a vector of zeros.
264 	 */
zerovint4265 	static ASTCENC_SIMD_INLINE vint4 zero()
266 	{
267 		return vint4(0);
268 	}
269 
270 	/**
271 	 * @brief Factory that returns a replicated scalar loaded from memory.
272 	 */
load1vint4273 	static ASTCENC_SIMD_INLINE vint4 load1(const int* p)
274 	{
275 		return vint4(*p);
276 	}
277 
278 	/**
279 	 * @brief Factory that returns a vector loaded from unaligned memory.
280 	 */
loadvint4281 	static ASTCENC_SIMD_INLINE vint4 load(const uint8_t* p)
282 	{
283 		vint4 data;
284 		std::memcpy(&data.m, p, 4 * sizeof(int));
285 		return data;
286 	}
287 
288 	/**
289 	 * @brief Factory that returns a vector loaded from 16B aligned memory.
290 	 */
loadavint4291 	static ASTCENC_SIMD_INLINE vint4 loada(const int* p)
292 	{
293 		return vint4(p);
294 	}
295 
296 	/**
297 	 * @brief Factory that returns a vector containing the lane IDs.
298 	 */
lane_idvint4299 	static ASTCENC_SIMD_INLINE vint4 lane_id()
300 	{
301 		return vint4(0, 1, 2, 3);
302 	}
303 
304 	/**
305 	 * @brief The vector ...
306 	 */
307 	int m[4];
308 };
309 
310 // ============================================================================
311 // vmask4 data type
312 // ============================================================================
313 
314 /**
315  * @brief Data type for 4-wide control plane masks.
316  */
317 struct vmask4
318 {
319 	/**
320 	 * @brief Construct from an existing mask value.
321 	 */
vmask4vmask4322 	ASTCENC_SIMD_INLINE explicit vmask4(int* p)
323 	{
324 		m[0] = p[0];
325 		m[1] = p[1];
326 		m[2] = p[2];
327 		m[3] = p[3];
328 	}
329 
330 	/**
331 	 * @brief Construct from 1 scalar value.
332 	 */
vmask4vmask4333 	ASTCENC_SIMD_INLINE explicit vmask4(bool a)
334 	{
335 		m[0] = a == false ? 0 : -1;
336 		m[1] = a == false ? 0 : -1;
337 		m[2] = a == false ? 0 : -1;
338 		m[3] = a == false ? 0 : -1;
339 	}
340 
341 	/**
342 	 * @brief Construct from 4 scalar values.
343 	 *
344 	 * The value of @c a is stored to lane 0 (LSB) in the SIMD register.
345 	 */
vmask4vmask4346 	ASTCENC_SIMD_INLINE explicit vmask4(bool a, bool b, bool c, bool d)
347 	{
348 		m[0] = a == false ? 0 : -1;
349 		m[1] = b == false ? 0 : -1;
350 		m[2] = c == false ? 0 : -1;
351 		m[3] = d == false ? 0 : -1;
352 	}
353 
354 	/**
355 	 * @brief Get the scalar value of a single lane.
356 	 */
lanevmask4357 	template <int l> ASTCENC_SIMD_INLINE float lane() const
358 	{
359 		return m[l] != 0;
360 	}
361 
362 	/**
363 	 * @brief The vector ...
364 	 */
365 	int m[4];
366 };
367 
368 // ============================================================================
369 // vmask4 operators and functions
370 // ============================================================================
371 
372 /**
373  * @brief Overload: mask union (or).
374  */
375 ASTCENC_SIMD_INLINE vmask4 operator|(vmask4 a, vmask4 b)
376 {
377 	return vmask4(a.m[0] | b.m[0],
378 	              a.m[1] | b.m[1],
379 	              a.m[2] | b.m[2],
380 	              a.m[3] | b.m[3]);
381 }
382 
383 /**
384  * @brief Overload: mask intersect (and).
385  */
386 ASTCENC_SIMD_INLINE vmask4 operator&(vmask4 a, vmask4 b)
387 {
388 	return vmask4(a.m[0] & b.m[0],
389 	              a.m[1] & b.m[1],
390 	              a.m[2] & b.m[2],
391 	              a.m[3] & b.m[3]);
392 }
393 
394 /**
395  * @brief Overload: mask difference (xor).
396  */
397 ASTCENC_SIMD_INLINE vmask4 operator^(vmask4 a, vmask4 b)
398 {
399 	return vmask4(a.m[0] ^ b.m[0],
400 	              a.m[1] ^ b.m[1],
401 	              a.m[2] ^ b.m[2],
402 	              a.m[3] ^ b.m[3]);
403 }
404 
405 /**
406  * @brief Overload: mask invert (not).
407  */
408 ASTCENC_SIMD_INLINE vmask4 operator~(vmask4 a)
409 {
410 	return vmask4(~a.m[0],
411 	              ~a.m[1],
412 	              ~a.m[2],
413 	              ~a.m[3]);
414 }
415 
416 /**
417  * @brief Return a 1-bit mask code indicating mask status.
418  *
419  * bit0 = lane 0
420  */
mask(vmask4 a)421 ASTCENC_SIMD_INLINE unsigned int mask(vmask4 a)
422 {
423 	return ((a.m[0] >> 31) & 0x1) |
424 	       ((a.m[1] >> 30) & 0x2) |
425 	       ((a.m[2] >> 29) & 0x4) |
426 	       ((a.m[3] >> 28) & 0x8);
427 }
428 
429 // ============================================================================
430 // vint4 operators and functions
431 // ============================================================================
432 
433 /**
434  * @brief Overload: vector by vector addition.
435  */
436 ASTCENC_SIMD_INLINE vint4 operator+(vint4 a, vint4 b)
437 {
438 	return vint4(a.m[0] + b.m[0],
439 	             a.m[1] + b.m[1],
440 	             a.m[2] + b.m[2],
441 	             a.m[3] + b.m[3]);
442 }
443 
444 /**
445  * @brief Overload: vector by vector subtraction.
446  */
447 ASTCENC_SIMD_INLINE vint4 operator-(vint4 a, vint4 b)
448 {
449 	return vint4(a.m[0] - b.m[0],
450 	             a.m[1] - b.m[1],
451 	             a.m[2] - b.m[2],
452 	             a.m[3] - b.m[3]);
453 }
454 
455 /**
456  * @brief Overload: vector by vector multiplication.
457  */
458 ASTCENC_SIMD_INLINE vint4 operator*(vint4 a, vint4 b)
459 {
460 	return vint4(a.m[0] * b.m[0],
461 	             a.m[1] * b.m[1],
462 	             a.m[2] * b.m[2],
463 	             a.m[3] * b.m[3]);
464 }
465 
466 /**
467  * @brief Overload: vector bit invert.
468  */
469 ASTCENC_SIMD_INLINE vint4 operator~(vint4 a)
470 {
471 	return vint4(~a.m[0],
472 	             ~a.m[1],
473 	             ~a.m[2],
474 	             ~a.m[3]);
475 }
476 
477 /**
478  * @brief Overload: vector by vector bitwise or.
479  */
480 ASTCENC_SIMD_INLINE vint4 operator|(vint4 a, vint4 b)
481 {
482 	return vint4(a.m[0] | b.m[0],
483 	             a.m[1] | b.m[1],
484 	             a.m[2] | b.m[2],
485 	             a.m[3] | b.m[3]);
486 }
487 
488 /**
489  * @brief Overload: vector by vector bitwise and.
490  */
491 ASTCENC_SIMD_INLINE vint4 operator&(vint4 a, vint4 b)
492 {
493 	return vint4(a.m[0] & b.m[0],
494 	             a.m[1] & b.m[1],
495 	             a.m[2] & b.m[2],
496 	             a.m[3] & b.m[3]);
497 }
498 
499 /**
500  * @brief Overload: vector by vector bitwise xor.
501  */
502 ASTCENC_SIMD_INLINE vint4 operator^(vint4 a, vint4 b)
503 {
504 	return vint4(a.m[0] ^ b.m[0],
505 	             a.m[1] ^ b.m[1],
506 	             a.m[2] ^ b.m[2],
507 	             a.m[3] ^ b.m[3]);
508 }
509 
510 /**
511  * @brief Overload: vector by vector equality.
512  */
513 ASTCENC_SIMD_INLINE vmask4 operator==(vint4 a, vint4 b)
514 {
515 	return vmask4(a.m[0] == b.m[0],
516 	              a.m[1] == b.m[1],
517 	              a.m[2] == b.m[2],
518 	              a.m[3] == b.m[3]);
519 }
520 
521 /**
522  * @brief Overload: vector by vector inequality.
523  */
524 ASTCENC_SIMD_INLINE vmask4 operator!=(vint4 a, vint4 b)
525 {
526 	return vmask4(a.m[0] != b.m[0],
527 	              a.m[1] != b.m[1],
528 	              a.m[2] != b.m[2],
529 	              a.m[3] != b.m[3]);
530 }
531 
532 /**
533  * @brief Overload: vector by vector less than.
534  */
535 ASTCENC_SIMD_INLINE vmask4 operator<(vint4 a, vint4 b)
536 {
537 	return vmask4(a.m[0] < b.m[0],
538 	              a.m[1] < b.m[1],
539 	              a.m[2] < b.m[2],
540 	              a.m[3] < b.m[3]);
541 }
542 
543 /**
544  * @brief Overload: vector by vector greater than.
545  */
546 ASTCENC_SIMD_INLINE vmask4 operator>(vint4 a, vint4 b)
547 {
548 	return vmask4(a.m[0] > b.m[0],
549 	              a.m[1] > b.m[1],
550 	              a.m[2] > b.m[2],
551 	              a.m[3] > b.m[3]);
552 }
553 
554 /**
555  * @brief Logical shift left.
556  */
lsl(vint4 a)557 template <int s> ASTCENC_SIMD_INLINE vint4 lsl(vint4 a)
558 {
559 	return vint4(a.m[0] << s,
560 	             a.m[1] << s,
561 	             a.m[2] << s,
562 	             a.m[3] << s);
563 }
564 
565 /**
566  * @brief Logical shift right.
567  */
lsr(vint4 a)568 template <int s> ASTCENC_SIMD_INLINE vint4 lsr(vint4 a)
569 {
570 	unsigned int as0 = static_cast<unsigned int>(a.m[0]) >> s;
571 	unsigned int as1 = static_cast<unsigned int>(a.m[1]) >> s;
572 	unsigned int as2 = static_cast<unsigned int>(a.m[2]) >> s;
573 	unsigned int as3 = static_cast<unsigned int>(a.m[3]) >> s;
574 
575 	return vint4(static_cast<int>(as0),
576 	             static_cast<int>(as1),
577 	             static_cast<int>(as2),
578 	             static_cast<int>(as3));
579 }
580 
581 /**
582  * @brief Arithmetic shift right.
583  */
asr(vint4 a)584 template <int s> ASTCENC_SIMD_INLINE vint4 asr(vint4 a)
585 {
586 	return vint4(a.m[0] >> s,
587 	             a.m[1] >> s,
588 	             a.m[2] >> s,
589 	             a.m[3] >> s);
590 }
591 
592 /**
593  * @brief Return the min vector of two vectors.
594  */
min(vint4 a,vint4 b)595 ASTCENC_SIMD_INLINE vint4 min(vint4 a, vint4 b)
596 {
597 	return vint4(a.m[0] < b.m[0] ? a.m[0] : b.m[0],
598 	             a.m[1] < b.m[1] ? a.m[1] : b.m[1],
599 	             a.m[2] < b.m[2] ? a.m[2] : b.m[2],
600 	             a.m[3] < b.m[3] ? a.m[3] : b.m[3]);
601 }
602 
603 /**
604  * @brief Return the min vector of two vectors.
605  */
max(vint4 a,vint4 b)606 ASTCENC_SIMD_INLINE vint4 max(vint4 a, vint4 b)
607 {
608 	return vint4(a.m[0] > b.m[0] ? a.m[0] : b.m[0],
609 	             a.m[1] > b.m[1] ? a.m[1] : b.m[1],
610 	             a.m[2] > b.m[2] ? a.m[2] : b.m[2],
611 	             a.m[3] > b.m[3] ? a.m[3] : b.m[3]);
612 }
613 
614 /**
615  * @brief Return the horizontal minimum of a single vector.
616  */
hmin(vint4 a)617 ASTCENC_SIMD_INLINE vint4 hmin(vint4 a)
618 {
619 	int b = std::min(a.m[0], a.m[1]);
620 	int c = std::min(a.m[2], a.m[3]);
621 	return vint4(std::min(b, c));
622 }
623 
624 /**
625  * @brief Return the horizontal maximum of a single vector.
626  */
hmax(vint4 a)627 ASTCENC_SIMD_INLINE vint4 hmax(vint4 a)
628 {
629 	int b = std::max(a.m[0], a.m[1]);
630 	int c = std::max(a.m[2], a.m[3]);
631 	return vint4(std::max(b, c));
632 }
633 
634 /**
635  * @brief Return the horizontal sum of vector lanes as a scalar.
636  */
hadd_s(vint4 a)637 ASTCENC_SIMD_INLINE int hadd_s(vint4 a)
638 {
639 	return a.m[0] + a.m[1] + a.m[2] + a.m[3];
640 }
641 
642 /**
643  * @brief Store a vector to an aligned memory address.
644  */
storea(vint4 a,int * p)645 ASTCENC_SIMD_INLINE void storea(vint4 a, int* p)
646 {
647 	p[0] = a.m[0];
648 	p[1] = a.m[1];
649 	p[2] = a.m[2];
650 	p[3] = a.m[3];
651 }
652 
653 /**
654  * @brief Store a vector to an unaligned memory address.
655  */
store(vint4 a,int * p)656 ASTCENC_SIMD_INLINE void store(vint4 a, int* p)
657 {
658 	p[0] = a.m[0];
659 	p[1] = a.m[1];
660 	p[2] = a.m[2];
661 	p[3] = a.m[3];
662 }
663 
664 /**
665  * @brief Store a vector to an unaligned memory address.
666  */
store(vint4 a,uint8_t * p)667 ASTCENC_SIMD_INLINE void store(vint4 a, uint8_t* p)
668 {
669 	std::memcpy(p, a.m, sizeof(int) * 4);
670 }
671 
672 /**
673  * @brief Store lowest N (vector width) bytes into an unaligned address.
674  */
store_nbytes(vint4 a,uint8_t * p)675 ASTCENC_SIMD_INLINE void store_nbytes(vint4 a, uint8_t* p)
676 {
677 	std::memcpy(p, a.m, sizeof(uint8_t) * 4);
678 }
679 
680 /**
681  * @brief Gather N (vector width) indices from the array.
682  */
gatheri(const int * base,vint4 indices)683 ASTCENC_SIMD_INLINE vint4 gatheri(const int* base, vint4 indices)
684 {
685 	return vint4(base[indices.m[0]],
686 	             base[indices.m[1]],
687 	             base[indices.m[2]],
688 	             base[indices.m[3]]);
689 }
690 
691 /**
692  * @brief Pack low 8 bits of N (vector width) lanes into bottom of vector.
693  */
pack_low_bytes(vint4 a)694 ASTCENC_SIMD_INLINE vint4 pack_low_bytes(vint4 a)
695 {
696 	int b0 = a.m[0] & 0xFF;
697 	int b1 = a.m[1] & 0xFF;
698 	int b2 = a.m[2] & 0xFF;
699 	int b3 = a.m[3] & 0xFF;
700 
701 	int b = b0 | (b1 << 8) | (b2 << 16) | (b3 << 24);
702 	return vint4(b, 0, 0, 0);
703 }
704 
705 /**
706  * @brief Return lanes from @c b if MSB of @c cond is set, else @c a.
707  */
select(vint4 a,vint4 b,vmask4 cond)708 ASTCENC_SIMD_INLINE vint4 select(vint4 a, vint4 b, vmask4 cond)
709 {
710 	return vint4((cond.m[0] & static_cast<int>(0x80000000)) ? b.m[0] : a.m[0],
711 	             (cond.m[1] & static_cast<int>(0x80000000)) ? b.m[1] : a.m[1],
712 	             (cond.m[2] & static_cast<int>(0x80000000)) ? b.m[2] : a.m[2],
713 	             (cond.m[3] & static_cast<int>(0x80000000)) ? b.m[3] : a.m[3]);
714 }
715 
716 // ============================================================================
717 // vfloat4 operators and functions
718 // ============================================================================
719 
720 /**
721  * @brief Overload: vector by vector addition.
722  */
723 ASTCENC_SIMD_INLINE vfloat4 operator+(vfloat4 a, vfloat4 b)
724 {
725 	return vfloat4(a.m[0] + b.m[0],
726 	               a.m[1] + b.m[1],
727 	               a.m[2] + b.m[2],
728 	               a.m[3] + b.m[3]);
729 }
730 
731 /**
732  * @brief Overload: vector by vector subtraction.
733  */
734 ASTCENC_SIMD_INLINE vfloat4 operator-(vfloat4 a, vfloat4 b)
735 {
736 	return vfloat4(a.m[0] - b.m[0],
737 	               a.m[1] - b.m[1],
738 	               a.m[2] - b.m[2],
739 	               a.m[3] - b.m[3]);
740 }
741 
742 /**
743  * @brief Overload: vector by vector multiplication.
744  */
745 ASTCENC_SIMD_INLINE vfloat4 operator*(vfloat4 a, vfloat4 b)
746 {
747 	return vfloat4(a.m[0] * b.m[0],
748 	               a.m[1] * b.m[1],
749 	               a.m[2] * b.m[2],
750 	               a.m[3] * b.m[3]);
751 }
752 
753 /**
754  * @brief Overload: vector by vector division.
755  */
756 ASTCENC_SIMD_INLINE vfloat4 operator/(vfloat4 a, vfloat4 b)
757 {
758 	return vfloat4(a.m[0] / b.m[0],
759 	               a.m[1] / b.m[1],
760 	               a.m[2] / b.m[2],
761 	               a.m[3] / b.m[3]);
762 }
763 
764 /**
765  * @brief Overload: vector by vector equality.
766  */
767 ASTCENC_SIMD_INLINE vmask4 operator==(vfloat4 a, vfloat4 b)
768 {
769 	return vmask4(a.m[0] == b.m[0],
770 	              a.m[1] == b.m[1],
771 	              a.m[2] == b.m[2],
772 	              a.m[3] == b.m[3]);
773 }
774 
775 /**
776  * @brief Overload: vector by vector inequality.
777  */
778 ASTCENC_SIMD_INLINE vmask4 operator!=(vfloat4 a, vfloat4 b)
779 {
780 	return vmask4(a.m[0] != b.m[0],
781 	              a.m[1] != b.m[1],
782 	              a.m[2] != b.m[2],
783 	              a.m[3] != b.m[3]);
784 }
785 
786 /**
787  * @brief Overload: vector by vector less than.
788  */
789 ASTCENC_SIMD_INLINE vmask4 operator<(vfloat4 a, vfloat4 b)
790 {
791 	return vmask4(a.m[0] < b.m[0],
792 	              a.m[1] < b.m[1],
793 	              a.m[2] < b.m[2],
794 	              a.m[3] < b.m[3]);
795 }
796 
797 /**
798  * @brief Overload: vector by vector greater than.
799  */
800 ASTCENC_SIMD_INLINE vmask4 operator>(vfloat4 a, vfloat4 b)
801 {
802 	return vmask4(a.m[0] > b.m[0],
803 	              a.m[1] > b.m[1],
804 	              a.m[2] > b.m[2],
805 	              a.m[3] > b.m[3]);
806 }
807 
808 /**
809  * @brief Overload: vector by vector less than or equal.
810  */
811 ASTCENC_SIMD_INLINE vmask4 operator<=(vfloat4 a, vfloat4 b)
812 {
813 	return vmask4(a.m[0] <= b.m[0],
814 	              a.m[1] <= b.m[1],
815 	              a.m[2] <= b.m[2],
816 	              a.m[3] <= b.m[3]);
817 }
818 
819 /**
820  * @brief Overload: vector by vector greater than or equal.
821  */
822 ASTCENC_SIMD_INLINE vmask4 operator>=(vfloat4 a, vfloat4 b)
823 {
824 	return vmask4(a.m[0] >= b.m[0],
825 	              a.m[1] >= b.m[1],
826 	              a.m[2] >= b.m[2],
827 	              a.m[3] >= b.m[3]);
828 }
829 
830 /**
831  * @brief Return the min vector of two vectors.
832  *
833  * If either lane value is NaN, @c b will be returned for that lane.
834  */
min(vfloat4 a,vfloat4 b)835 ASTCENC_SIMD_INLINE vfloat4 min(vfloat4 a, vfloat4 b)
836 {
837 	return vfloat4(a.m[0] < b.m[0] ? a.m[0] : b.m[0],
838 	               a.m[1] < b.m[1] ? a.m[1] : b.m[1],
839 	               a.m[2] < b.m[2] ? a.m[2] : b.m[2],
840 	               a.m[3] < b.m[3] ? a.m[3] : b.m[3]);
841 }
842 
843 /**
844  * @brief Return the max vector of two vectors.
845  *
846  * If either lane value is NaN, @c b will be returned for that lane.
847  */
max(vfloat4 a,vfloat4 b)848 ASTCENC_SIMD_INLINE vfloat4 max(vfloat4 a, vfloat4 b)
849 {
850 	return vfloat4(a.m[0] > b.m[0] ? a.m[0] : b.m[0],
851 	               a.m[1] > b.m[1] ? a.m[1] : b.m[1],
852 	               a.m[2] > b.m[2] ? a.m[2] : b.m[2],
853 	               a.m[3] > b.m[3] ? a.m[3] : b.m[3]);
854 }
855 
856 /**
857  * @brief Return the absolute value of the float vector.
858  */
abs(vfloat4 a)859 ASTCENC_SIMD_INLINE vfloat4 abs(vfloat4 a)
860 {
861 	return vfloat4(std::abs(a.m[0]),
862 	               std::abs(a.m[1]),
863 	               std::abs(a.m[2]),
864 	               std::abs(a.m[3]));
865 }
866 
867 /**
868  * @brief Return a float rounded to the nearest integer value.
869  */
round(vfloat4 a)870 ASTCENC_SIMD_INLINE vfloat4 round(vfloat4 a)
871 {
872 	assert(std::fegetround() == FE_TONEAREST);
873 	return vfloat4(std::nearbyint(a.m[0]),
874 	               std::nearbyint(a.m[1]),
875 	               std::nearbyint(a.m[2]),
876 	               std::nearbyint(a.m[3]));
877 }
878 
879 /**
880  * @brief Return the horizontal minimum of a vector.
881  */
hmin(vfloat4 a)882 ASTCENC_SIMD_INLINE vfloat4 hmin(vfloat4 a)
883 {
884 	float tmp1 = std::min(a.m[0], a.m[1]);
885 	float tmp2 = std::min(a.m[2], a.m[3]);
886 	return vfloat4(std::min(tmp1, tmp2));
887 }
888 
889 /**
890  * @brief Return the horizontal maximum of a vector.
891  */
hmax(vfloat4 a)892 ASTCENC_SIMD_INLINE vfloat4 hmax(vfloat4 a)
893 {
894 	float tmp1 = std::max(a.m[0], a.m[1]);
895 	float tmp2 = std::max(a.m[2], a.m[3]);
896 	return vfloat4(std::max(tmp1, tmp2));
897 }
898 
899 /**
900  * @brief Return the horizontal sum of a vector.
901  */
hadd_s(vfloat4 a)902 ASTCENC_SIMD_INLINE float hadd_s(vfloat4 a)
903 {
904 	// Use halving add, gives invariance with SIMD versions
905 	return (a.m[0] + a.m[2]) + (a.m[1] + a.m[3]);
906 }
907 
908 /**
909  * @brief Return the sqrt of the lanes in the vector.
910  */
sqrt(vfloat4 a)911 ASTCENC_SIMD_INLINE vfloat4 sqrt(vfloat4 a)
912 {
913 	return vfloat4(std::sqrt(a.m[0]),
914 	               std::sqrt(a.m[1]),
915 	               std::sqrt(a.m[2]),
916 	               std::sqrt(a.m[3]));
917 }
918 
919 /**
920  * @brief Return lanes from @c b if @c cond is set, else @c a.
921  */
select(vfloat4 a,vfloat4 b,vmask4 cond)922 ASTCENC_SIMD_INLINE vfloat4 select(vfloat4 a, vfloat4 b, vmask4 cond)
923 {
924 	return vfloat4((cond.m[0] & static_cast<int>(0x80000000)) ? b.m[0] : a.m[0],
925 	               (cond.m[1] & static_cast<int>(0x80000000)) ? b.m[1] : a.m[1],
926 	               (cond.m[2] & static_cast<int>(0x80000000)) ? b.m[2] : a.m[2],
927 	               (cond.m[3] & static_cast<int>(0x80000000)) ? b.m[3] : a.m[3]);
928 }
929 
930 /**
931  * @brief Return lanes from @c b if MSB of @c cond is set, else @c a.
932  */
select_msb(vfloat4 a,vfloat4 b,vmask4 cond)933 ASTCENC_SIMD_INLINE vfloat4 select_msb(vfloat4 a, vfloat4 b, vmask4 cond)
934 {
935 	return vfloat4((cond.m[0] & static_cast<int>(0x80000000)) ? b.m[0] : a.m[0],
936 	               (cond.m[1] & static_cast<int>(0x80000000)) ? b.m[1] : a.m[1],
937 	               (cond.m[2] & static_cast<int>(0x80000000)) ? b.m[2] : a.m[2],
938 	               (cond.m[3] & static_cast<int>(0x80000000)) ? b.m[3] : a.m[3]);
939 }
940 
941 /**
942  * @brief Load a vector of gathered results from an array;
943  */
gatherf(const float * base,vint4 indices)944 ASTCENC_SIMD_INLINE vfloat4 gatherf(const float* base, vint4 indices)
945 {
946 	return vfloat4(base[indices.m[0]],
947 	               base[indices.m[1]],
948 	               base[indices.m[2]],
949 	               base[indices.m[3]]);
950 }
951 
952 /**
953  * @brief Store a vector to an unaligned memory address.
954  */
store(vfloat4 a,float * ptr)955 ASTCENC_SIMD_INLINE void store(vfloat4 a, float* ptr)
956 {
957 	ptr[0] = a.m[0];
958 	ptr[1] = a.m[1];
959 	ptr[2] = a.m[2];
960 	ptr[3] = a.m[3];
961 }
962 
963 /**
964  * @brief Store a vector to an aligned memory address.
965  */
storea(vfloat4 a,float * ptr)966 ASTCENC_SIMD_INLINE void storea(vfloat4 a, float* ptr)
967 {
968 	ptr[0] = a.m[0];
969 	ptr[1] = a.m[1];
970 	ptr[2] = a.m[2];
971 	ptr[3] = a.m[3];
972 }
973 
974 /**
975  * @brief Return a integer value for a float vector, using truncation.
976  */
float_to_int(vfloat4 a)977 ASTCENC_SIMD_INLINE vint4 float_to_int(vfloat4 a)
978 {
979 	return vint4(static_cast<int>(a.m[0]),
980 	             static_cast<int>(a.m[1]),
981 	             static_cast<int>(a.m[2]),
982 	             static_cast<int>(a.m[3]));
983 }
984 
985 /**f
986  * @brief Return a integer value for a float vector, using round-to-nearest.
987  */
float_to_int_rtn(vfloat4 a)988 ASTCENC_SIMD_INLINE vint4 float_to_int_rtn(vfloat4 a)
989 {
990 	a = a + vfloat4(0.5f);
991 	return vint4(static_cast<int>(a.m[0]),
992 	             static_cast<int>(a.m[1]),
993 	             static_cast<int>(a.m[2]),
994 	             static_cast<int>(a.m[3]));
995 }
996 
997 /**
998  * @brief Return a float value for a integer vector.
999  */
int_to_float(vint4 a)1000 ASTCENC_SIMD_INLINE vfloat4 int_to_float(vint4 a)
1001 {
1002 	return vfloat4(static_cast<float>(a.m[0]),
1003 	               static_cast<float>(a.m[1]),
1004 	               static_cast<float>(a.m[2]),
1005 	               static_cast<float>(a.m[3]));
1006 }
1007 
1008 /**
1009  * @brief Return a float16 value for a float vector, using round-to-nearest.
1010  */
float_to_float16(vfloat4 a)1011 ASTCENC_SIMD_INLINE vint4 float_to_float16(vfloat4 a)
1012 {
1013 	return vint4(
1014 		float_to_sf16(a.lane<0>()),
1015 		float_to_sf16(a.lane<1>()),
1016 		float_to_sf16(a.lane<2>()),
1017 		float_to_sf16(a.lane<3>()));
1018 }
1019 
1020 /**
1021  * @brief Return a float16 value for a float scalar, using round-to-nearest.
1022  */
float_to_float16(float a)1023 static inline uint16_t float_to_float16(float a)
1024 {
1025 	return float_to_sf16(a);
1026 }
1027 
1028 /**
1029  * @brief Return a float value for a float16 vector.
1030  */
float16_to_float(vint4 a)1031 ASTCENC_SIMD_INLINE vfloat4 float16_to_float(vint4 a)
1032 {
1033 	return vfloat4(
1034 		sf16_to_float(static_cast<uint16_t>(a.lane<0>())),
1035 		sf16_to_float(static_cast<uint16_t>(a.lane<1>())),
1036 		sf16_to_float(static_cast<uint16_t>(a.lane<2>())),
1037 		sf16_to_float(static_cast<uint16_t>(a.lane<3>())));
1038 }
1039 
1040 /**
1041  * @brief Return a float value for a float16 scalar.
1042  */
float16_to_float(uint16_t a)1043 ASTCENC_SIMD_INLINE float float16_to_float(uint16_t a)
1044 {
1045 	return sf16_to_float(a);
1046 }
1047 
1048 /**
1049  * @brief Return a float value as an integer bit pattern (i.e. no conversion).
1050  *
1051  * It is a common trick to convert floats into integer bit patterns, perform
1052  * some bit hackery based on knowledge they are IEEE 754 layout, and then
1053  * convert them back again. This is the first half of that flip.
1054  */
float_as_int(vfloat4 a)1055 ASTCENC_SIMD_INLINE vint4 float_as_int(vfloat4 a)
1056 {
1057 	vint4 r;
1058 	std::memcpy(r.m, a.m, 4 * 4);
1059 	return r;
1060 }
1061 
1062 /**
1063  * @brief Return a integer value as a float bit pattern (i.e. no conversion).
1064  *
1065  * It is a common trick to convert floats into integer bit patterns, perform
1066  * some bit hackery based on knowledge they are IEEE 754 layout, and then
1067  * convert them back again. This is the second half of that flip.
1068  */
int_as_float(vint4 a)1069 ASTCENC_SIMD_INLINE vfloat4 int_as_float(vint4 a)
1070 {
1071 	vfloat4 r;
1072 	std::memcpy(r.m, a.m, 4 * 4);
1073 	return r;
1074 }
1075 
1076 /**
1077  * @brief Prepare a vtable lookup table for use with the native SIMD size.
1078  */
vtable_prepare(vint4 t0,vint4 & t0p)1079 ASTCENC_SIMD_INLINE void vtable_prepare(vint4 t0, vint4& t0p)
1080 {
1081 	t0p = t0;
1082 }
1083 
1084 /**
1085  * @brief Prepare a vtable lookup table for use with the native SIMD size.
1086  */
vtable_prepare(vint4 t0,vint4 t1,vint4 & t0p,vint4 & t1p)1087 ASTCENC_SIMD_INLINE void vtable_prepare(vint4 t0, vint4 t1, vint4& t0p, vint4& t1p)
1088 {
1089 	t0p = t0;
1090 	t1p = t1;
1091 }
1092 
1093 /**
1094  * @brief Prepare a vtable lookup table for use with the native SIMD size.
1095  */
vtable_prepare(vint4 t0,vint4 t1,vint4 t2,vint4 t3,vint4 & t0p,vint4 & t1p,vint4 & t2p,vint4 & t3p)1096 ASTCENC_SIMD_INLINE void vtable_prepare(
1097 	vint4 t0, vint4 t1, vint4 t2, vint4 t3,
1098 	vint4& t0p, vint4& t1p, vint4& t2p, vint4& t3p)
1099 {
1100 	t0p = t0;
1101 	t1p = t1;
1102 	t2p = t2;
1103 	t3p = t3;
1104 }
1105 
1106 /**
1107  * @brief Perform an 8-bit 16-entry table lookup, with 32-bit indexes.
1108  */
vtable_8bt_32bi(vint4 t0,vint4 idx)1109 ASTCENC_SIMD_INLINE vint4 vtable_8bt_32bi(vint4 t0, vint4 idx)
1110 {
1111 	uint8_t table[16];
1112 
1113 	std::memcpy(table +  0, t0.m, 4 * sizeof(int));
1114 
1115 	return vint4(table[idx.lane<0>()],
1116 	             table[idx.lane<1>()],
1117 	             table[idx.lane<2>()],
1118 	             table[idx.lane<3>()]);
1119 }
1120 
1121 
1122 /**
1123  * @brief Perform an 8-bit 32-entry table lookup, with 32-bit indexes.
1124  */
vtable_8bt_32bi(vint4 t0,vint4 t1,vint4 idx)1125 ASTCENC_SIMD_INLINE vint4 vtable_8bt_32bi(vint4 t0, vint4 t1, vint4 idx)
1126 {
1127 	uint8_t table[32];
1128 
1129 	std::memcpy(table +  0, t0.m, 4 * sizeof(int));
1130 	std::memcpy(table + 16, t1.m, 4 * sizeof(int));
1131 
1132 	return vint4(table[idx.lane<0>()],
1133 	             table[idx.lane<1>()],
1134 	             table[idx.lane<2>()],
1135 	             table[idx.lane<3>()]);
1136 }
1137 
1138 /**
1139  * @brief Perform an 8-bit 64-entry table lookup, with 32-bit indexes.
1140  */
vtable_8bt_32bi(vint4 t0,vint4 t1,vint4 t2,vint4 t3,vint4 idx)1141 ASTCENC_SIMD_INLINE vint4 vtable_8bt_32bi(vint4 t0, vint4 t1, vint4 t2, vint4 t3, vint4 idx)
1142 {
1143 	uint8_t table[64];
1144 
1145 	std::memcpy(table +  0, t0.m, 4 * sizeof(int));
1146 	std::memcpy(table + 16, t1.m, 4 * sizeof(int));
1147 	std::memcpy(table + 32, t2.m, 4 * sizeof(int));
1148 	std::memcpy(table + 48, t3.m, 4 * sizeof(int));
1149 
1150 	return vint4(table[idx.lane<0>()],
1151 	             table[idx.lane<1>()],
1152 	             table[idx.lane<2>()],
1153 	             table[idx.lane<3>()]);
1154 }
1155 
1156 /**
1157  * @brief Return a vector of interleaved RGBA data.
1158  *
1159  * Input vectors have the value stored in the bottom 8 bits of each lane,
1160  * with high  bits set to zero.
1161  *
1162  * Output vector stores a single RGBA texel packed in each lane.
1163  */
interleave_rgba8(vint4 r,vint4 g,vint4 b,vint4 a)1164 ASTCENC_SIMD_INLINE vint4 interleave_rgba8(vint4 r, vint4 g, vint4 b, vint4 a)
1165 {
1166 	return r + lsl<8>(g) + lsl<16>(b) + lsl<24>(a);
1167 }
1168 
1169 /**
1170  * @brief Store a single vector lane to an unaligned address.
1171  */
store_lane(uint8_t * base,int data)1172 ASTCENC_SIMD_INLINE void store_lane(uint8_t* base, int data)
1173 {
1174 	std::memcpy(base, &data, sizeof(int));
1175 }
1176 
1177 /**
1178  * @brief Store a vector, skipping masked lanes.
1179  *
1180  * All masked lanes must be at the end of vector, after all non-masked lanes.
1181  * Input is a byte array of at least 4 bytes per unmasked entry.
1182  */
store_lanes_masked(uint8_t * base,vint4 data,vmask4 mask)1183 ASTCENC_SIMD_INLINE void store_lanes_masked(uint8_t* base, vint4 data, vmask4 mask)
1184 {
1185 	if (mask.m[3])
1186 	{
1187 		store(data, base);
1188 	}
1189 	else if (mask.m[2])
1190 	{
1191 		store_lane(base + 0, data.lane<0>());
1192 		store_lane(base + 4, data.lane<1>());
1193 		store_lane(base + 8, data.lane<2>());
1194 	}
1195 	else if (mask.m[1])
1196 	{
1197 		store_lane(base + 0, data.lane<0>());
1198 		store_lane(base + 4, data.lane<1>());
1199 	}
1200 	else if (mask.m[0])
1201 	{
1202 		store_lane(base + 0, data.lane<0>());
1203 	}
1204 }
1205 
1206 #endif // #ifndef ASTC_VECMATHLIB_NONE_4_H_INCLUDED
1207