summaryrefslogtreecommitdiffstats
path: root/src/panfrost/midgard/midgard.h
blob: c022d47aabe424e5f847098574fd4ce1407d828f (plain)
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
782
783
784
785
786
787
788
789
790
791
792
793
794
795
/* Author(s):
 *   Connor Abbott
 *   Alyssa Rosenzweig
 *
 * Copyright (c) 2013 Connor Abbott (connor@abbott.cx)
 * Copyright (c) 2018 Alyssa Rosenzweig (alyssa@rosenzweig.io)
 *
 * 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 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.
 */

#ifndef __midgard_h__
#define __midgard_h__

#include <stdint.h>
#include <stdbool.h>
#include "panfrost-job.h"

#define MIDGARD_DBG_MSGS		0x0001
#define MIDGARD_DBG_SHADERS		0x0002
#define MIDGARD_DBG_SHADERDB            0x0004

extern int midgard_debug;

typedef enum {
        midgard_word_type_alu,
        midgard_word_type_load_store,
        midgard_word_type_texture,
        midgard_word_type_unknown
} midgard_word_type;

typedef enum {
        midgard_alu_vmul,
        midgard_alu_sadd,
        midgard_alu_smul,
        midgard_alu_vadd,
        midgard_alu_lut
} midgard_alu;

/*
 * ALU words
 */

typedef enum {
        midgard_alu_op_fadd       = 0x10,
        midgard_alu_op_fmul       = 0x14,

        midgard_alu_op_fmin       = 0x28,
        midgard_alu_op_fmax       = 0x2C,

        midgard_alu_op_fmov       = 0x30, /* fmov_rte */
        midgard_alu_op_fmov_rtz   = 0x31,
        midgard_alu_op_fmov_rtn   = 0x32,
        midgard_alu_op_fmov_rtp   = 0x33,
        midgard_alu_op_froundeven = 0x34,
        midgard_alu_op_ftrunc     = 0x35,
        midgard_alu_op_ffloor     = 0x36,
        midgard_alu_op_fceil      = 0x37,
        midgard_alu_op_ffma       = 0x38,
        midgard_alu_op_fdot3      = 0x3C,
        midgard_alu_op_fdot3r     = 0x3D,
        midgard_alu_op_fdot4      = 0x3E,
        midgard_alu_op_freduce    = 0x3F,

        midgard_alu_op_iadd       = 0x40,
        midgard_alu_op_ishladd    = 0x41, /* a + (b<<1) */
        midgard_alu_op_isub       = 0x46,
        midgard_alu_op_iaddsat    = 0x48,
        midgard_alu_op_uaddsat    = 0x49,
        midgard_alu_op_isubsat    = 0x4E,
        midgard_alu_op_usubsat    = 0x4F,

        midgard_alu_op_imul       = 0x58,

        midgard_alu_op_imin       = 0x60,
        midgard_alu_op_umin       = 0x61,
        midgard_alu_op_imax       = 0x62,
        midgard_alu_op_umax       = 0x63,
        midgard_alu_op_ihadd      = 0x64,
        midgard_alu_op_uhadd      = 0x65,
        midgard_alu_op_irhadd     = 0x66,
        midgard_alu_op_urhadd     = 0x67,
        midgard_alu_op_iasr       = 0x68,
        midgard_alu_op_ilsr       = 0x69,
        midgard_alu_op_ishl       = 0x6E,

        midgard_alu_op_iand       = 0x70,
        midgard_alu_op_ior        = 0x71,
        midgard_alu_op_inand      = 0x72, /* ~(a & b), for inot let a = b */
        midgard_alu_op_inor       = 0x73, /* ~(a | b) */
        midgard_alu_op_iandnot    = 0x74, /* (a & ~b), used for not/b2f */
        midgard_alu_op_iornot     = 0x75, /* (a | ~b) */
        midgard_alu_op_ixor       = 0x76,
        midgard_alu_op_inxor      = 0x77, /* ~(a & b) */
        midgard_alu_op_iclz       = 0x78, /* Number of zeroes on left */
        midgard_alu_op_ibitcount8 = 0x7A, /* Counts bits in 8-bit increments */
        midgard_alu_op_imov       = 0x7B,
        midgard_alu_op_iabsdiff   = 0x7C,
        midgard_alu_op_uabsdiff   = 0x7D,
        midgard_alu_op_ichoose    = 0x7E, /* vector, component number - dupe for shuffle() */

        midgard_alu_op_feq        = 0x80,
        midgard_alu_op_fne        = 0x81,
        midgard_alu_op_flt        = 0x82,
        midgard_alu_op_fle        = 0x83,
        midgard_alu_op_fball_eq   = 0x88,
        midgard_alu_op_fball_neq  = 0x89,
        midgard_alu_op_fball_lt   = 0x8A, /* all(lessThan(.., ..)) */
        midgard_alu_op_fball_lte  = 0x8B, /* all(lessThanEqual(.., ..)) */

        midgard_alu_op_fbany_eq   = 0x90,
        midgard_alu_op_fbany_neq  = 0x91,
        midgard_alu_op_fbany_lt   = 0x92, /* any(lessThan(.., ..)) */
        midgard_alu_op_fbany_lte  = 0x93, /* any(lessThanEqual(.., ..)) */

        midgard_alu_op_f2i_rte    = 0x98,
        midgard_alu_op_f2i_rtz    = 0x99,
        midgard_alu_op_f2i_rtn    = 0x9A,
        midgard_alu_op_f2i_rtp    = 0x9B,
        midgard_alu_op_f2u_rte    = 0x9C,
        midgard_alu_op_f2u_rtz    = 0x9D,
        midgard_alu_op_f2u_rtn    = 0x9E,
        midgard_alu_op_f2u_rtp    = 0x9F,

        midgard_alu_op_ieq        = 0xA0,
        midgard_alu_op_ine        = 0xA1,
        midgard_alu_op_ult        = 0xA2,
        midgard_alu_op_ule        = 0xA3,
        midgard_alu_op_ilt        = 0xA4,
        midgard_alu_op_ile        = 0xA5,
        midgard_alu_op_iball_eq   = 0xA8,
        midgard_alu_op_iball_neq  = 0xA9,
        midgard_alu_op_uball_lt   = 0xAA,
        midgard_alu_op_uball_lte  = 0xAB,
        midgard_alu_op_iball_lt   = 0xAC,
        midgard_alu_op_iball_lte  = 0xAD,

        midgard_alu_op_ibany_eq   = 0xB0,
        midgard_alu_op_ibany_neq  = 0xB1,
        midgard_alu_op_ubany_lt   = 0xB2,
        midgard_alu_op_ubany_lte  = 0xB3,
        midgard_alu_op_ibany_lt   = 0xB4, /* any(lessThan(.., ..)) */
        midgard_alu_op_ibany_lte  = 0xB5, /* any(lessThanEqual(.., ..)) */
        midgard_alu_op_i2f_rte    = 0xB8,
        midgard_alu_op_i2f_rtz    = 0xB9,
        midgard_alu_op_i2f_rtn    = 0xBA,
        midgard_alu_op_i2f_rtp    = 0xBB,
        midgard_alu_op_u2f_rte    = 0xBC,
        midgard_alu_op_u2f_rtz    = 0xBD,
        midgard_alu_op_u2f_rtn    = 0xBE,
        midgard_alu_op_u2f_rtp    = 0xBF,

        midgard_alu_op_icsel_v    = 0xC0, /* condition code r31 */
        midgard_alu_op_icsel      = 0xC1, /* condition code r31.w */
        midgard_alu_op_fcsel_v    = 0xC4,
        midgard_alu_op_fcsel      = 0xC5,
        midgard_alu_op_fround     = 0xC6,

        midgard_alu_op_fatan_pt2  = 0xE8,
        midgard_alu_op_fpow_pt1   = 0xEC,
        midgard_alu_op_fpown_pt1  = 0xED,
        midgard_alu_op_fpowr_pt1  = 0xEE,

        midgard_alu_op_frcp       = 0xF0,
        midgard_alu_op_frsqrt     = 0xF2,
        midgard_alu_op_fsqrt      = 0xF3,
        midgard_alu_op_fexp2      = 0xF4,
        midgard_alu_op_flog2      = 0xF5,
        midgard_alu_op_fsin       = 0xF6,
        midgard_alu_op_fcos       = 0xF7,
        midgard_alu_op_fatan2_pt1 = 0xF9,
} midgard_alu_op;

typedef enum {
        midgard_outmod_none = 0,
        midgard_outmod_pos  = 1,
        /* 0x2 unknown */
        midgard_outmod_sat  = 3
} midgard_outmod_float;

typedef enum {
        midgard_outmod_int_saturate = 0,
        midgard_outmod_uint_saturate = 1,
        midgard_outmod_int_wrap = 2,
        midgard_outmod_int_high = 3, /* Overflowed portion */
} midgard_outmod_int;

typedef enum {
        midgard_reg_mode_8 = 0,
        midgard_reg_mode_16 = 1,
        midgard_reg_mode_32 = 2,
        midgard_reg_mode_64 = 3
} midgard_reg_mode;

typedef enum {
        midgard_dest_override_lower = 0,
        midgard_dest_override_upper = 1,
        midgard_dest_override_none = 2
} midgard_dest_override;

typedef enum {
        midgard_int_sign_extend = 0,
        midgard_int_zero_extend = 1,
        midgard_int_normal = 2,
        midgard_int_shift = 3
} midgard_int_mod;

#define MIDGARD_FLOAT_MOD_ABS (1 << 0)
#define MIDGARD_FLOAT_MOD_NEG (1 << 1)

typedef struct
__attribute__((__packed__))
{
        /* Either midgard_int_mod or from midgard_float_mod_*, depending on the
         * type of op */
        unsigned mod : 2;

        /* replicate lower half if dest = half, or low/high half selection if
         * dest = full
         */
        bool rep_low     : 1;
        bool rep_high    : 1; /* unused if dest = full */
        bool half        : 1; /* only matters if dest = full */
        unsigned swizzle : 8;
}
midgard_vector_alu_src;

typedef struct
__attribute__((__packed__))
{
        midgard_alu_op op               :  8;
        midgard_reg_mode reg_mode   :  2;
        unsigned src1 : 13;
        unsigned src2 : 13;
        midgard_dest_override dest_override : 2;
        unsigned outmod               : 2;
        unsigned mask                           : 8;
}
midgard_vector_alu;

typedef struct
__attribute__((__packed__))
{
        bool abs           : 1;
        bool negate        : 1;
        bool full          : 1; /* 0 = half, 1 = full */
        unsigned component : 3;
}
midgard_scalar_alu_src;

typedef struct
__attribute__((__packed__))
{
        midgard_alu_op op         :  8;
        unsigned src1             :  6;
        unsigned src2             : 11;
        unsigned unknown          :  1;
        unsigned outmod :  2;
        bool output_full          :  1;
        unsigned output_component :  3;
}
midgard_scalar_alu;

typedef struct
__attribute__((__packed__))
{
        unsigned src1_reg : 5;
        unsigned src2_reg : 5;
        unsigned out_reg  : 5;
        bool src2_imm     : 1;
}
midgard_reg_info;

/* In addition to conditional branches and jumps (unconditional branches),
 * Midgard implements a bit of fixed function functionality used in fragment
 * shaders via specially crafted branches. These have special branch opcodes,
 * which perform a fixed-function operation and/or use the results of a
 * fixed-function operation as the branch condition.  */

typedef enum {
        /* Regular branches */
        midgard_jmp_writeout_op_branch_uncond = 1,
        midgard_jmp_writeout_op_branch_cond = 2,

        /* In a fragment shader, execute a discard_if instruction, with the
         * corresponding condition code. Terminates the shader, so generally
         * set the branch target to out of the shader */
        midgard_jmp_writeout_op_discard = 4,

        /* Branch if the tilebuffer is not yet ready. At the beginning of a
         * fragment shader that reads from the tile buffer, for instance via
         * ARM_shader_framebuffer_fetch or EXT_pixel_local_storage, this branch
         * operation should be used as a loop. An instruction like
         * "br.tilebuffer.always -1" does the trick, corresponding to
         * "while(!is_tilebuffer_ready) */
        midgard_jmp_writeout_op_tilebuffer_pending = 6,

        /* In a fragment shader, try to write out the value pushed to r0 to the
         * tilebuffer, subject to unknown state in r1.z and r1.w. If this
         * succeeds, the shader terminates. If it fails, it branches to the
         * specified branch target. Generally, this should be used in a loop to
         * itself, acting as "do { write(r0); } while(!write_successful);" */
        midgard_jmp_writeout_op_writeout = 7,
} midgard_jmp_writeout_op;

typedef enum {
        midgard_condition_write0 = 0,

        /* These condition codes denote a conditional branch on FALSE and on
         * TRUE respectively */
        midgard_condition_false = 1,
        midgard_condition_true = 2,

        /* This condition code always branches. For a pure branch, the
         * unconditional branch coding should be used instead, but for
         * fixed-function branch opcodes, this is still useful */
        midgard_condition_always = 3,
} midgard_condition;

typedef struct
__attribute__((__packed__))
{
        midgard_jmp_writeout_op op : 3; /* == branch_uncond */
        unsigned dest_tag : 4; /* tag of branch destination */
        unsigned unknown : 2;
        int offset : 7;
}
midgard_branch_uncond;

typedef struct
__attribute__((__packed__))
{
        midgard_jmp_writeout_op op : 3; /* == branch_cond */
        unsigned dest_tag : 4; /* tag of branch destination */
        int offset : 7;
        midgard_condition cond : 2;
}
midgard_branch_cond;

typedef struct
__attribute__((__packed__))
{
        midgard_jmp_writeout_op op : 3; /* == branch_cond */
        unsigned dest_tag : 4; /* tag of branch destination */
        unsigned unknown : 2;
        signed offset : 23;

        /* Extended branches permit inputting up to 4 conditions loaded into
         * r31 (two in r31.w and two in r31.x). In the most general case, we
         * specify a function f(A, B, C, D) mapping 4 1-bit conditions to a
         * single 1-bit branch criteria. Note that the domain of f has 2^(2^4)
         * elements, each mapping to 1-bit of output, so we can trivially
         * construct a Godel numbering of f as a (2^4)=16-bit integer. This
         * 16-bit integer serves as a lookup table to compute f, subject to
         * some swaps for ordering.
         *
         * Interesting, the standard 2-bit condition codes are also a LUT with
         * the same format (2^1-bit), but it's usually easier to use enums. */

        unsigned cond : 16;
}
midgard_branch_extended;

typedef struct
__attribute__((__packed__))
{
        midgard_jmp_writeout_op op : 3; /* == writeout */
        unsigned unknown : 13;
}
midgard_writeout;

/*
 * Load/store words
 */

typedef enum {
        midgard_op_ld_st_noop   = 0x03,

        /* Unpack a colour from a native format to fp16 */
        midgard_op_unpack_colour = 0x05,

        /* Packs a colour from fp16 to a native format */
        midgard_op_pack_colour   = 0x09,

        /* Unclear why this is on the L/S unit, but moves fp32 cube map
         * coordinates in r27 to its cube map texture coordinate destination
         * (e.g r29). */

        midgard_op_ld_cubemap_coords = 0x0E,

        /* Loads a global/local/group ID, depending on arguments */
        midgard_op_ld_compute_id = 0x10,

        /* The L/S unit can do perspective division a clock faster than the ALU
         * if you're lucky. Put the vec4 in r27, and call with 0x24 as the
         * unknown state; the output will be <x/w, y/w, z/w, 1>. Replace w with
         * z for the z version */
        midgard_op_ldst_perspective_division_z = 0x12,
        midgard_op_ldst_perspective_division_w = 0x13,

        /* val in r27.y, address embedded, outputs result to argument. Invert val for sub. Let val = +-1 for inc/dec. */
        midgard_op_atomic_add = 0x40,
        midgard_op_atomic_add64 = 0x41,

        midgard_op_atomic_and = 0x44,
        midgard_op_atomic_and64 = 0x45,
        midgard_op_atomic_or = 0x48,
        midgard_op_atomic_or64 = 0x49,
        midgard_op_atomic_xor = 0x4C,
        midgard_op_atomic_xor64 = 0x4D,

        midgard_op_atomic_imin = 0x50,
        midgard_op_atomic_imin64 = 0x51,
        midgard_op_atomic_umin = 0x54,
        midgard_op_atomic_umin64 = 0x55,
        midgard_op_atomic_imax = 0x58,
        midgard_op_atomic_imax64 = 0x59,
        midgard_op_atomic_umax = 0x5C,
        midgard_op_atomic_umax64 = 0x5D,

        midgard_op_atomic_xchg = 0x60,
        midgard_op_atomic_xchg64 = 0x61,

        /* Used for compute shader's __global arguments, __local variables (or
         * for register spilling) */

        midgard_op_ld_char = 0x81,
        midgard_op_ld_char2 = 0x84,
        midgard_op_ld_short = 0x85,
        midgard_op_ld_char4 = 0x88, /* short2, int, float */
        midgard_op_ld_short4 = 0x8C, /* int2, float2, long */
        midgard_op_ld_int4 = 0x90, /* float4, long2 */

        midgard_op_ld_attr_32 = 0x94,
        midgard_op_ld_attr_16 = 0x95,
        midgard_op_ld_attr_32u = 0x96,
        midgard_op_ld_attr_32i = 0x97,
        midgard_op_ld_vary_32 = 0x98,
        midgard_op_ld_vary_16 = 0x99,
        midgard_op_ld_vary_32u = 0x9A,
        midgard_op_ld_vary_32i = 0x9B,

        /* Old version of midgard_op_ld_color_buffer_u8_as_fp16, for T720 */
        midgard_op_ld_color_buffer_u8_as_fp16_old = 0x9D,

        /* The distinction between these ops is the alignment requirement /
         * accompanying shift. Thus, the offset to ld_ubo_int4 is in 16-byte
         * units and can load 128-bit. The offset to ld_ubo_short4 is in 8-byte
         * units; ld_ubo_char4 in 4-byte units. ld_ubo_char/ld_ubo_char2 are
         * purely theoretical (never seen in the wild) since int8/int16/fp16
         * UBOs don't really exist. The ops are still listed to maintain
         * symmetry with generic I/O ops. */

        midgard_op_ld_ubo_char   = 0xA0, /* theoretical */
        midgard_op_ld_ubo_char2  = 0xA4, /* theoretical */
        midgard_op_ld_ubo_char4  = 0xA8,
        midgard_op_ld_ubo_short4 = 0xAC,
        midgard_op_ld_ubo_int4   = 0xB0,

        /* New-style blending ops. Works on T760/T860 */
        midgard_op_ld_color_buffer_u8_as_fp16 = 0xB9,
        midgard_op_ld_color_buffer_32u = 0xBA,

        midgard_op_st_char = 0xC0,
        midgard_op_st_char2 = 0xC4, /* short */
        midgard_op_st_char4 = 0xC8, /* short2, int, float */
        midgard_op_st_short4 = 0xCC, /* int2, float2, long */
        midgard_op_st_int4 = 0xD0, /* float4, long2 */

        midgard_op_st_vary_32 = 0xD4,
        midgard_op_st_vary_16 = 0xD5,
        midgard_op_st_vary_32u = 0xD6,
        midgard_op_st_vary_32i = 0xD7,

        /* Value to st in r27, location r26.w as short2 */
        midgard_op_st_image_f = 0xD8,
        midgard_op_st_image_ui = 0xDA,
        midgard_op_st_image_i = 0xDB,
} midgard_load_store_op;

typedef enum {
        midgard_interp_centroid = 1,
        midgard_interp_default = 2
} midgard_interpolation;

typedef enum {
        midgard_varying_mod_none = 0,

        /* Other values unknown */

        /* Take the would-be result and divide all components by its z/w
         * (perspective division baked in with the load)  */
        midgard_varying_mod_perspective_z = 2,
        midgard_varying_mod_perspective_w = 3,
} midgard_varying_modifier;

typedef struct
__attribute__((__packed__))
{
        unsigned zero0 : 1; /* Always zero */

        midgard_varying_modifier modifier : 2;

        unsigned zero1: 1; /* Always zero */

        /* Varying qualifiers, zero if not a varying */
        unsigned flat    : 1;
        unsigned is_varying : 1; /* Always one for varying, but maybe something else? */
        midgard_interpolation interpolation : 2;

        unsigned zero2 : 2; /* Always zero */
}
midgard_varying_parameter;

/* 8-bit register/etc selector for load/store ops */
typedef struct
__attribute__((__packed__))
{
        /* Indexes into the register */
        unsigned component : 2;

        /* Register select between r26/r27 */
        unsigned select : 1;

        unsigned unknown : 2;

        /* Like any good Arm instruction set, load/store arguments can be
         * implicitly left-shifted... but only the second argument. Zero for no
         * shifting, up to <<7 possible though. This is useful for indexing.
         *
         * For the first argument, it's unknown what these bits mean */
        unsigned shift : 3;
}
midgard_ldst_register_select;

typedef struct
__attribute__((__packed__))
{
        midgard_load_store_op op : 8;
        unsigned reg     : 5;
        unsigned mask    : 4;
        unsigned swizzle : 8;

        /* Load/store ops can take two additional registers as arguments, but
         * these are limited to load/store registers with only a few supported
         * mask/swizzle combinations. The tradeoff is these are much more
         * compact, requiring 8-bits each rather than 17-bits for a full
         * reg/mask/swizzle. Usually (?) encoded as
         * midgard_ldst_register_select. */
        unsigned arg_1   : 8;
        unsigned arg_2   : 8;

        unsigned varying_parameters : 10;

        unsigned address : 9;
}
midgard_load_store_word;

typedef struct
__attribute__((__packed__))
{
        unsigned type      : 4;
        unsigned next_type : 4;
        uint64_t word1     : 60;
        uint64_t word2     : 60;
}
midgard_load_store;

/* 8-bit register selector used in texture ops to select a bias/LOD/gradient
 * register, shoved into the `bias` field */

typedef struct
__attribute__((__packed__))
{
        /* 32-bit register, clear for half-register */
        unsigned full : 1;

        /* Register select between r28/r29 */
        unsigned select : 1;

        /* For a half-register, selects the upper half */
        unsigned upper : 1;

        /* Indexes into the register */
        unsigned component : 2;

        /* Padding to make this 8-bit */
        unsigned zero : 3;
}
midgard_tex_register_select;

/* Texture pipeline results are in r28-r29 */
#define REG_TEX_BASE 28

/* Texture opcodes... maybe? */
#define TEXTURE_OP_NORMAL 0x11          /* texture */
#define TEXTURE_OP_LOD 0x12             /* textureLod */
#define TEXTURE_OP_TEXEL_FETCH 0x14     /* texelFetch */

/* Implements barrier() */
#define TEXTURE_OP_BARRIER 0x0B

/* Computes horizontal and vertical derivatives respectively. Use with a float
 * sampler and a "2D" texture.  Leave texture/sampler IDs as zero; they ought
 * to be ignored. Only works for fp32 on 64-bit at a time, so derivatives of a
 * vec4 require 2 texture ops.  For some reason, the blob computes both X and Y
 * derivatives at the same time and just throws out whichever is unused; it's
 * not known if this is a quirk of the hardware or just of the blob. */

#define TEXTURE_OP_DFDX 0x0D
#define TEXTURE_OP_DFDY 0x1D

enum mali_sampler_type {
        MALI_SAMPLER_UNK        = 0x0,
        MALI_SAMPLER_FLOAT      = 0x1, /* sampler */
        MALI_SAMPLER_UNSIGNED   = 0x2, /* usampler */
        MALI_SAMPLER_SIGNED     = 0x3, /* isampler */
};

typedef struct
__attribute__((__packed__))
{
        unsigned type      : 4;
        unsigned next_type : 4;

        unsigned op  : 6;
        unsigned shadow    : 1;
        unsigned is_gather  : 1;

        /* A little obscure, but last is set for the last texture operation in
         * a shader. cont appears to just be last's opposite (?). Yeah, I know,
         * kind of funky.. BiOpen thinks it could do with memory hinting, or
         * tile locking? */

        unsigned cont  : 1;
        unsigned last  : 1;

        enum mali_texture_type format : 2;

        /* Are sampler_handle/texture_handler respectively set by registers? If
         * true, the lower 8-bits of the respective field is a register word.
         * If false, they are an immediate */

        unsigned sampler_register : 1;
        unsigned texture_register : 1;

        /* Is a register used to specify the
         * LOD/bias/offset? If set, use the `bias` field as
         * a register index. If clear, use the `bias` field
         * as an immediate. */
        unsigned lod_register : 1;

        /* Is a register used to specify an offset? If set, use the
         * offset_reg_* fields to encode this, duplicated for each of the
         * components. If clear, there is implcitly always an immediate offst
         * specificed in offset_imm_* */
        unsigned offset_register : 1;

        unsigned in_reg_full  : 1;
        unsigned in_reg_select : 1;
        unsigned in_reg_upper  : 1;
        unsigned in_reg_swizzle : 8;

        unsigned unknown8  : 2;

        unsigned out_full  : 1;

        enum mali_sampler_type sampler_type : 2;

        unsigned out_reg_select : 1;
        unsigned out_upper : 1;

        unsigned mask : 4;

        /* Intriguingly, textures can take an outmod just like textures. Int
         * outmods are not supported as far as I can tell, so this is only
         * meaningful for float samplers */
        midgard_outmod_float outmod  : 2;

        unsigned swizzle  : 8;

        /* For barriers, control barriers are implied regardless, but these
         * bits also enable memory barriers of various types. For regular
         * textures, these bits are not yet understood. */
        unsigned barrier_buffer : 1;
        unsigned barrier_shared : 1;

        unsigned unknown4  : 10;

        /* In immediate mode, each offset field is an immediate range [0, 7].
         *
         * In register mode, offset_x becomes a register full / select / upper
         * triplet followed by a vec3 swizzle is splattered across
         * offset_y/offset_z in a genuinely bizarre way.
         *
         * For texel fetches in immediate mode, the range is the full [-8, 7],
         * but for normal texturing the top bit must be zero and a register
         * used instead. It's not clear where this limitation is from.
         *
         * union {
         *      struct {
         *              signed offset_x  : 4;
         *              signed offset_y  : 4;
         *              signed offset_z  : 4;
         *      } immediate;
         *      struct {
         *              bool full        : 1;
         *              bool select      : 1;
         *              bool upper       : 1;
         *              unsigned swizzle : 8;
         *              unsigned zero    : 1;
         *      } register;
         * }
         */

        unsigned offset : 12;

        /* In immediate bias mode, for a normal texture op, this is
         * texture bias, computed as int(2^8 * frac(biasf)), with
         * bias_int = floor(bias). For a textureLod, it's that, but
         * s/bias/lod. For a texel fetch, this is the LOD as-is.
         *
         * In register mode, this is a midgard_tex_register_select
         * structure and bias_int is zero */

        unsigned bias : 8;
        signed bias_int  : 8;

        /* If sampler/texture_register is set, the bottom 8-bits are
         * midgard_tex_register_select and the top 8-bits are zero. If they are
         * clear, they are immediate texture indices */

        unsigned sampler_handle : 16;
        unsigned texture_handle : 16;
}
midgard_texture_word;

/* Technically barriers are texture instructions but it's less work to add them
 * as an explicitly zeroed special case, since most fields are forced to go to
 * zero */

typedef struct
__attribute__((__packed__))
{
        unsigned type      : 4;
        unsigned next_type : 4;

        /* op = TEXTURE_OP_BARRIER */
        unsigned op  : 6;
        unsigned zero1    : 2;

        /* Since helper invocations don't make any sense, these are forced to one */
        unsigned cont  : 1;
        unsigned last  : 1;
        unsigned zero2 : 14;

        unsigned zero3 : 24;
        unsigned buffer : 1;
        unsigned shared : 1;
        unsigned zero4 : 6;

        uint64_t zero5;
} midgard_texture_barrier_word;

typedef union midgard_constants {
        double f64[2];
        uint64_t u64[2];
        int64_t i64[2];
        float f32[4];
        uint32_t u32[4];
        int32_t i32[4];
        uint16_t f16[8];
        uint16_t u16[8];
        int16_t i16[8];
        uint8_t u8[16];
        int8_t i8[16];
}
midgard_constants;

#endif