1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
|
/*
* Copyright © 2015 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
*/
#include "nir.h"
#include "nir_builder.h"
#include "c99_math.h"
/*
* Lowers some unsupported double operations, using only:
*
* - pack/unpackDouble2x32
* - conversion to/from single-precision
* - double add, mul, and fma
* - conditional select
* - 32-bit integer and floating point arithmetic
*/
/* Creates a double with the exponent bits set to a given integer value */
static nir_ssa_def *
set_exponent(nir_builder *b, nir_ssa_def *src, nir_ssa_def *exp)
{
/* Split into bits 0-31 and 32-63 */
nir_ssa_def *lo = nir_unpack_64_2x32_split_x(b, src);
nir_ssa_def *hi = nir_unpack_64_2x32_split_y(b, src);
/* The exponent is bits 52-62, or 20-30 of the high word, so set the exponent
* to 1023
*/
nir_ssa_def *new_hi = nir_bfi(b, nir_imm_int(b, 0x7ff00000), exp, hi);
/* recombine */
return nir_pack_64_2x32_split(b, lo, new_hi);
}
static nir_ssa_def *
get_exponent(nir_builder *b, nir_ssa_def *src)
{
/* get bits 32-63 */
nir_ssa_def *hi = nir_unpack_64_2x32_split_y(b, src);
/* extract bits 20-30 of the high word */
return nir_ubitfield_extract(b, hi, nir_imm_int(b, 20), nir_imm_int(b, 11));
}
/* Return infinity with the sign of the given source which is +/-0 */
static nir_ssa_def *
get_signed_inf(nir_builder *b, nir_ssa_def *zero)
{
nir_ssa_def *zero_hi = nir_unpack_64_2x32_split_y(b, zero);
/* The bit pattern for infinity is 0x7ff0000000000000, where the sign bit
* is the highest bit. Only the sign bit can be non-zero in the passed in
* source. So we essentially need to OR the infinity and the zero, except
* the low 32 bits are always 0 so we can construct the correct high 32
* bits and then pack it together with zero low 32 bits.
*/
nir_ssa_def *inf_hi = nir_ior(b, nir_imm_int(b, 0x7ff00000), zero_hi);
return nir_pack_64_2x32_split(b, nir_imm_int(b, 0), inf_hi);
}
/*
* Generates the correctly-signed infinity if the source was zero, and flushes
* the result to 0 if the source was infinity or the calculated exponent was
* too small to be representable.
*/
static nir_ssa_def *
fix_inv_result(nir_builder *b, nir_ssa_def *res, nir_ssa_def *src,
nir_ssa_def *exp)
{
/* If the exponent is too small or the original input was infinity/NaN,
* force the result to 0 (flush denorms) to avoid the work of handling
* denorms properly. Note that this doesn't preserve positive/negative
* zeros, but GLSL doesn't require it.
*/
res = nir_bcsel(b, nir_ior(b, nir_ige(b, nir_imm_int(b, 0), exp),
nir_feq(b, nir_fabs(b, src),
nir_imm_double(b, INFINITY))),
nir_imm_double(b, 0.0f), res);
/* If the original input was 0, generate the correctly-signed infinity */
res = nir_bcsel(b, nir_fne(b, src, nir_imm_double(b, 0.0f)),
res, get_signed_inf(b, src));
return res;
}
static nir_ssa_def *
lower_rcp(nir_builder *b, nir_ssa_def *src)
{
/* normalize the input to avoid range issues */
nir_ssa_def *src_norm = set_exponent(b, src, nir_imm_int(b, 1023));
/* cast to float, do an rcp, and then cast back to get an approximate
* result
*/
nir_ssa_def *ra = nir_f2f64(b, nir_frcp(b, nir_f2f32(b, src_norm)));
/* Fixup the exponent of the result - note that we check if this is too
* small below.
*/
nir_ssa_def *new_exp = nir_isub(b, get_exponent(b, ra),
nir_isub(b, get_exponent(b, src),
nir_imm_int(b, 1023)));
ra = set_exponent(b, ra, new_exp);
/* Do a few Newton-Raphson steps to improve precision.
*
* Each step doubles the precision, and we started off with around 24 bits,
* so we only need to do 2 steps to get to full precision. The step is:
*
* x_new = x * (2 - x*src)
*
* But we can re-arrange this to improve precision by using another fused
* multiply-add:
*
* x_new = x + x * (1 - x*src)
*
* See https://en.wikipedia.org/wiki/Division_algorithm for more details.
*/
ra = nir_ffma(b, ra, nir_ffma(b, ra, src, nir_imm_double(b, -1)), ra);
ra = nir_ffma(b, ra, nir_ffma(b, ra, src, nir_imm_double(b, -1)), ra);
return fix_inv_result(b, ra, src, new_exp);
}
static nir_ssa_def *
lower_sqrt_rsq(nir_builder *b, nir_ssa_def *src, bool sqrt)
{
/* We want to compute:
*
* 1/sqrt(m * 2^e)
*
* When the exponent is even, this is equivalent to:
*
* 1/sqrt(m) * 2^(-e/2)
*
* and then the exponent is odd, this is equal to:
*
* 1/sqrt(m * 2) * 2^(-(e - 1)/2)
*
* where the m * 2 is absorbed into the exponent. So we want the exponent
* inside the square root to be 1 if e is odd and 0 if e is even, and we
* want to subtract off e/2 from the final exponent, rounded to negative
* infinity. We can do the former by first computing the unbiased exponent,
* and then AND'ing it with 1 to get 0 or 1, and we can do the latter by
* shifting right by 1.
*/
nir_ssa_def *unbiased_exp = nir_isub(b, get_exponent(b, src),
nir_imm_int(b, 1023));
nir_ssa_def *even = nir_iand(b, unbiased_exp, nir_imm_int(b, 1));
nir_ssa_def *half = nir_ishr(b, unbiased_exp, nir_imm_int(b, 1));
nir_ssa_def *src_norm = set_exponent(b, src,
nir_iadd(b, nir_imm_int(b, 1023),
even));
nir_ssa_def *ra = nir_f2f64(b, nir_frsq(b, nir_f2f32(b, src_norm)));
nir_ssa_def *new_exp = nir_isub(b, get_exponent(b, ra), half);
ra = set_exponent(b, ra, new_exp);
/*
* The following implements an iterative algorithm that's very similar
* between sqrt and rsqrt. We start with an iteration of Goldschmit's
* algorithm, which looks like:
*
* a = the source
* y_0 = initial (single-precision) rsqrt estimate
*
* h_0 = .5 * y_0
* g_0 = a * y_0
* r_0 = .5 - h_0 * g_0
* g_1 = g_0 * r_0 + g_0
* h_1 = h_0 * r_0 + h_0
*
* Now g_1 ~= sqrt(a), and h_1 ~= 1/(2 * sqrt(a)). We could continue
* applying another round of Goldschmit, but since we would never refer
* back to a (the original source), we would add too much rounding error.
* So instead, we do one last round of Newton-Raphson, which has better
* rounding characteristics, to get the final rounding correct. This is
* split into two cases:
*
* 1. sqrt
*
* Normally, doing a round of Newton-Raphson for sqrt involves taking a
* reciprocal of the original estimate, which is slow since it isn't
* supported in HW. But we can take advantage of the fact that we already
* computed a good estimate of 1/(2 * g_1) by rearranging it like so:
*
* g_2 = .5 * (g_1 + a / g_1)
* = g_1 + .5 * (a / g_1 - g_1)
* = g_1 + (.5 / g_1) * (a - g_1^2)
* = g_1 + h_1 * (a - g_1^2)
*
* The second term represents the error, and by splitting it out we can get
* better precision by computing it as part of a fused multiply-add. Since
* both Newton-Raphson and Goldschmit approximately double the precision of
* the result, these two steps should be enough.
*
* 2. rsqrt
*
* First off, note that the first round of the Goldschmit algorithm is
* really just a Newton-Raphson step in disguise:
*
* h_1 = h_0 * (.5 - h_0 * g_0) + h_0
* = h_0 * (1.5 - h_0 * g_0)
* = h_0 * (1.5 - .5 * a * y_0^2)
* = (.5 * y_0) * (1.5 - .5 * a * y_0^2)
*
* which is the standard formula multiplied by .5. Unlike in the sqrt case,
* we don't need the inverse to do a Newton-Raphson step; we just need h_1,
* so we can skip the calculation of g_1. Instead, we simply do another
* Newton-Raphson step:
*
* y_1 = 2 * h_1
* r_1 = .5 - h_1 * y_1 * a
* y_2 = y_1 * r_1 + y_1
*
* Where the difference from Goldschmit is that we calculate y_1 * a
* instead of using g_1. Doing it this way should be as fast as computing
* y_1 up front instead of h_1, and it lets us share the code for the
* initial Goldschmit step with the sqrt case.
*
* Putting it together, the computations are:
*
* h_0 = .5 * y_0
* g_0 = a * y_0
* r_0 = .5 - h_0 * g_0
* h_1 = h_0 * r_0 + h_0
* if sqrt:
* g_1 = g_0 * r_0 + g_0
* r_1 = a - g_1 * g_1
* g_2 = h_1 * r_1 + g_1
* else:
* y_1 = 2 * h_1
* r_1 = .5 - y_1 * (h_1 * a)
* y_2 = y_1 * r_1 + y_1
*
* For more on the ideas behind this, see "Software Division and Square
* Root Using Goldschmit's Algorithms" by Markstein and the Wikipedia page
* on square roots
* (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots).
*/
nir_ssa_def *one_half = nir_imm_double(b, 0.5);
nir_ssa_def *h_0 = nir_fmul(b, one_half, ra);
nir_ssa_def *g_0 = nir_fmul(b, src, ra);
nir_ssa_def *r_0 = nir_ffma(b, nir_fneg(b, h_0), g_0, one_half);
nir_ssa_def *h_1 = nir_ffma(b, h_0, r_0, h_0);
nir_ssa_def *res;
if (sqrt) {
nir_ssa_def *g_1 = nir_ffma(b, g_0, r_0, g_0);
nir_ssa_def *r_1 = nir_ffma(b, nir_fneg(b, g_1), g_1, src);
res = nir_ffma(b, h_1, r_1, g_1);
} else {
nir_ssa_def *y_1 = nir_fmul(b, nir_imm_double(b, 2.0), h_1);
nir_ssa_def *r_1 = nir_ffma(b, nir_fneg(b, y_1), nir_fmul(b, h_1, src),
one_half);
res = nir_ffma(b, y_1, r_1, y_1);
}
if (sqrt) {
/* Here, the special cases we need to handle are
* 0 -> 0 and
* +inf -> +inf
*/
res = nir_bcsel(b, nir_ior(b, nir_feq(b, src, nir_imm_double(b, 0.0)),
nir_feq(b, src, nir_imm_double(b, INFINITY))),
src, res);
} else {
res = fix_inv_result(b, res, src, new_exp);
}
return res;
}
static nir_ssa_def *
lower_trunc(nir_builder *b, nir_ssa_def *src)
{
nir_ssa_def *unbiased_exp = nir_isub(b, get_exponent(b, src),
nir_imm_int(b, 1023));
nir_ssa_def *frac_bits = nir_isub(b, nir_imm_int(b, 52), unbiased_exp);
/*
* Decide the operation to apply depending on the unbiased exponent:
*
* if (unbiased_exp < 0)
* return 0
* else if (unbiased_exp > 52)
* return src
* else
* return src & (~0 << frac_bits)
*
* Notice that the else branch is a 64-bit integer operation that we need
* to implement in terms of 32-bit integer arithmetics (at least until we
* support 64-bit integer arithmetics).
*/
/* Compute "~0 << frac_bits" in terms of hi/lo 32-bit integer math */
nir_ssa_def *mask_lo =
nir_bcsel(b,
nir_ige(b, frac_bits, nir_imm_int(b, 32)),
nir_imm_int(b, 0),
nir_ishl(b, nir_imm_int(b, ~0), frac_bits));
nir_ssa_def *mask_hi =
nir_bcsel(b,
nir_ilt(b, frac_bits, nir_imm_int(b, 33)),
nir_imm_int(b, ~0),
nir_ishl(b,
nir_imm_int(b, ~0),
nir_isub(b, frac_bits, nir_imm_int(b, 32))));
nir_ssa_def *src_lo = nir_unpack_64_2x32_split_x(b, src);
nir_ssa_def *src_hi = nir_unpack_64_2x32_split_y(b, src);
return
nir_bcsel(b,
nir_ilt(b, unbiased_exp, nir_imm_int(b, 0)),
nir_imm_double(b, 0.0),
nir_bcsel(b, nir_ige(b, unbiased_exp, nir_imm_int(b, 53)),
src,
nir_pack_64_2x32_split(b,
nir_iand(b, mask_lo, src_lo),
nir_iand(b, mask_hi, src_hi))));
}
static nir_ssa_def *
lower_floor(nir_builder *b, nir_ssa_def *src)
{
/*
* For x >= 0, floor(x) = trunc(x)
* For x < 0,
* - if x is integer, floor(x) = x
* - otherwise, floor(x) = trunc(x) - 1
*/
nir_ssa_def *tr = nir_ftrunc(b, src);
nir_ssa_def *positive = nir_fge(b, src, nir_imm_double(b, 0.0));
return nir_bcsel(b,
nir_ior(b, positive, nir_feq(b, src, tr)),
tr,
nir_fsub(b, tr, nir_imm_double(b, 1.0)));
}
static nir_ssa_def *
lower_ceil(nir_builder *b, nir_ssa_def *src)
{
/* if x < 0, ceil(x) = trunc(x)
* else if (x - trunc(x) == 0), ceil(x) = x
* else, ceil(x) = trunc(x) + 1
*/
nir_ssa_def *tr = nir_ftrunc(b, src);
nir_ssa_def *negative = nir_flt(b, src, nir_imm_double(b, 0.0));
return nir_bcsel(b,
nir_ior(b, negative, nir_feq(b, src, tr)),
tr,
nir_fadd(b, tr, nir_imm_double(b, 1.0)));
}
static nir_ssa_def *
lower_fract(nir_builder *b, nir_ssa_def *src)
{
return nir_fsub(b, src, nir_ffloor(b, src));
}
static nir_ssa_def *
lower_round_even(nir_builder *b, nir_ssa_def *src)
{
/* If fract(src) == 0.5, then we will have to decide the rounding direction.
* We will do this by computing the mod(abs(src), 2) and testing if it
* is < 1 or not.
*
* We compute mod(abs(src), 2) as:
* abs(src) - 2.0 * floor(abs(src) / 2.0)
*/
nir_ssa_def *two = nir_imm_double(b, 2.0);
nir_ssa_def *abs_src = nir_fabs(b, src);
nir_ssa_def *mod =
nir_fsub(b,
abs_src,
nir_fmul(b,
two,
nir_ffloor(b,
nir_fmul(b,
abs_src,
nir_imm_double(b, 0.5)))));
/*
* If fract(src) != 0.5, then we round as floor(src + 0.5)
*
* If fract(src) == 0.5, then we have to check the modulo:
*
* if it is < 1 we need a trunc operation so we get:
* 0.5 -> 0, -0.5 -> -0
* 2.5 -> 2, -2.5 -> -2
*
* otherwise we need to check if src >= 0, in which case we need to round
* upwards, or not, in which case we need to round downwards so we get:
* 1.5 -> 2, -1.5 -> -2
* 3.5 -> 4, -3.5 -> -4
*/
nir_ssa_def *fract = nir_ffract(b, src);
return nir_bcsel(b,
nir_fne(b, fract, nir_imm_double(b, 0.5)),
nir_ffloor(b, nir_fadd(b, src, nir_imm_double(b, 0.5))),
nir_bcsel(b,
nir_flt(b, mod, nir_imm_double(b, 1.0)),
nir_ftrunc(b, src),
nir_bcsel(b,
nir_fge(b, src, nir_imm_double(b, 0.0)),
nir_fadd(b, src, nir_imm_double(b, 0.5)),
nir_fsub(b, src, nir_imm_double(b, 0.5)))));
}
static nir_ssa_def *
lower_mod(nir_builder *b, nir_ssa_def *src0, nir_ssa_def *src1)
{
/* mod(x,y) = x - y * floor(x/y)
*
* If the division is lowered, it could add some rounding errors that make
* floor() to return the quotient minus one when x = N * y. If this is the
* case, we return zero because mod(x, y) output value is [0, y).
*/
nir_ssa_def *floor = nir_ffloor(b, nir_fdiv(b, src0, src1));
nir_ssa_def *mod = nir_fsub(b, src0, nir_fmul(b, src1, floor));
return nir_bcsel(b,
nir_fne(b, mod, src1),
mod,
nir_imm_double(b, 0.0));
}
static bool
lower_doubles_instr_to_soft(nir_builder *b, nir_alu_instr *instr,
nir_lower_doubles_options options)
{
if (!(options & nir_lower_fp64_full_software))
return false;
assert(instr->dest.dest.is_ssa);
const char *name;
const struct glsl_type *return_type = glsl_uint64_t_type();
switch (instr->op) {
case nir_op_f2i64:
if (instr->src[0].src.ssa->bit_size == 64)
name = "__fp64_to_int64";
else
name = "__fp32_to_int64";
return_type = glsl_int64_t_type();
break;
case nir_op_f2u64:
if (instr->src[0].src.ssa->bit_size == 64)
name = "__fp64_to_uint64";
else
name = "__fp32_to_uint64";
break;
case nir_op_f2f64:
name = "__fp32_to_fp64";
break;
case nir_op_f2f32:
name = "__fp64_to_fp32";
return_type = glsl_float_type();
break;
case nir_op_f2i32:
name = "__fp64_to_int";
return_type = glsl_int_type();
break;
case nir_op_f2u32:
name = "__fp64_to_uint";
return_type = glsl_uint_type();
break;
case nir_op_f2b1:
case nir_op_f2b32:
name = "__fp64_to_bool";
return_type = glsl_bool_type();
break;
case nir_op_b2f64:
name = "__bool_to_fp64";
break;
case nir_op_i2f32:
if (instr->src[0].src.ssa->bit_size != 64)
return false;
name = "__int64_to_fp32";
return_type = glsl_float_type();
break;
case nir_op_u2f32:
if (instr->src[0].src.ssa->bit_size != 64)
return false;
name = "__uint64_to_fp32";
return_type = glsl_float_type();
break;
case nir_op_i2f64:
if (instr->src[0].src.ssa->bit_size == 64)
name = "__int64_to_fp64";
else
name = "__int_to_fp64";
break;
case nir_op_u2f64:
if (instr->src[0].src.ssa->bit_size == 64)
name = "__uint64_to_fp64";
else
name = "__uint_to_fp64";
break;
case nir_op_fabs:
name = "__fabs64";
break;
case nir_op_fneg:
name = "__fneg64";
break;
case nir_op_fround_even:
name = "__fround64";
break;
case nir_op_ftrunc:
name = "__ftrunc64";
break;
case nir_op_ffloor:
name = "__ffloor64";
break;
case nir_op_ffract:
name = "__ffract64";
break;
case nir_op_fsign:
name = "__fsign64";
break;
case nir_op_feq:
name = "__feq64";
return_type = glsl_bool_type();
break;
case nir_op_fne:
name = "__fne64";
return_type = glsl_bool_type();
break;
case nir_op_flt:
name = "__flt64";
return_type = glsl_bool_type();
break;
case nir_op_fge:
name = "__fge64";
return_type = glsl_bool_type();
break;
case nir_op_fmin:
name = "__fmin64";
break;
case nir_op_fmax:
name = "__fmax64";
break;
case nir_op_fadd:
name = "__fadd64";
break;
case nir_op_fmul:
name = "__fmul64";
break;
case nir_op_ffma:
name = "__ffma64";
break;
default:
return false;
}
nir_shader *shader = b->shader;
nir_function *func = NULL;
nir_foreach_function(function, shader) {
if (strcmp(function->name, name) == 0) {
func = function;
break;
}
}
if (!func) {
fprintf(stderr, "Cannot find function \"%s\"\n", name);
assert(func);
}
b->cursor = nir_before_instr(&instr->instr);
nir_call_instr *call = nir_call_instr_create(shader, func);
nir_variable *ret_tmp =
nir_local_variable_create(b->impl, return_type, "return_tmp");
nir_deref_instr *ret_deref = nir_build_deref_var(b, ret_tmp);
call->params[0] = nir_src_for_ssa(&ret_deref->dest.ssa);
for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
nir_src arg = nir_src_for_ssa(nir_imov_alu(b, instr->src[i], 1));
nir_src_copy(&call->params[i + 1], &arg, call);
}
nir_builder_instr_insert(b, &call->instr);
nir_ssa_def_rewrite_uses(&instr->dest.dest.ssa,
nir_src_for_ssa(nir_load_deref(b, ret_deref)));
nir_instr_remove(&instr->instr);
return true;
}
static bool
lower_doubles_instr(nir_builder *b, nir_alu_instr *instr,
nir_lower_doubles_options options)
{
assert(instr->dest.dest.is_ssa);
bool is_64 = instr->dest.dest.ssa.bit_size == 64;
unsigned num_srcs = nir_op_infos[instr->op].num_inputs;
for (unsigned i = 0; i < num_srcs; i++) {
is_64 |= (nir_src_bit_size(instr->src[i].src) == 64);
}
if (!is_64)
return false;
if (lower_doubles_instr_to_soft(b, instr, options))
return true;
switch (instr->op) {
case nir_op_frcp:
if (!(options & nir_lower_drcp))
return false;
break;
case nir_op_fsqrt:
if (!(options & nir_lower_dsqrt))
return false;
break;
case nir_op_frsq:
if (!(options & nir_lower_drsq))
return false;
break;
case nir_op_ftrunc:
if (!(options & nir_lower_dtrunc))
return false;
break;
case nir_op_ffloor:
if (!(options & nir_lower_dfloor))
return false;
break;
case nir_op_fceil:
if (!(options & nir_lower_dceil))
return false;
break;
case nir_op_ffract:
if (!(options & nir_lower_dfract))
return false;
break;
case nir_op_fround_even:
if (!(options & nir_lower_dround_even))
return false;
break;
case nir_op_fmod:
if (!(options & nir_lower_dmod))
return false;
break;
default:
return false;
}
b->cursor = nir_before_instr(&instr->instr);
nir_ssa_def *src = nir_fmov_alu(b, instr->src[0],
instr->dest.dest.ssa.num_components);
nir_ssa_def *result;
switch (instr->op) {
case nir_op_frcp:
result = lower_rcp(b, src);
break;
case nir_op_fsqrt:
result = lower_sqrt_rsq(b, src, true);
break;
case nir_op_frsq:
result = lower_sqrt_rsq(b, src, false);
break;
case nir_op_ftrunc:
result = lower_trunc(b, src);
break;
case nir_op_ffloor:
result = lower_floor(b, src);
break;
case nir_op_fceil:
result = lower_ceil(b, src);
break;
case nir_op_ffract:
result = lower_fract(b, src);
break;
case nir_op_fround_even:
result = lower_round_even(b, src);
break;
case nir_op_fmod: {
nir_ssa_def *src1 = nir_fmov_alu(b, instr->src[1],
instr->dest.dest.ssa.num_components);
result = lower_mod(b, src, src1);
}
break;
default:
unreachable("unhandled opcode");
}
nir_ssa_def_rewrite_uses(&instr->dest.dest.ssa, nir_src_for_ssa(result));
nir_instr_remove(&instr->instr);
return true;
}
static bool
nir_lower_doubles_impl(nir_function_impl *impl,
nir_lower_doubles_options options)
{
bool progress = false;
nir_builder b;
nir_builder_init(&b, impl);
nir_foreach_block(block, impl) {
nir_foreach_instr_safe(instr, block) {
if (instr->type == nir_instr_type_alu)
progress |= lower_doubles_instr(&b, nir_instr_as_alu(instr),
options);
}
}
if (progress) {
nir_metadata_preserve(impl, nir_metadata_block_index |
nir_metadata_dominance);
} else {
#ifndef NDEBUG
impl->valid_metadata &= ~nir_metadata_not_properly_reset;
#endif
}
return progress;
}
bool
nir_lower_doubles(nir_shader *shader, nir_lower_doubles_options options)
{
bool progress = false;
nir_foreach_function(function, shader) {
if (function->impl) {
progress |= nir_lower_doubles_impl(function->impl, options);
}
}
return progress;
}
|