aboutsummaryrefslogtreecommitdiffstats
path: root/src/panfrost/bifrost/bi_pack.c
blob: 56181241bcf5652efe232326cb168de829832d15 (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
/*
 * Copyright (C) 2020 Collabora, Ltd.
 *
 * 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 "compiler.h"

#define RETURN_PACKED(str) { \
        uint64_t temp = 0; \
        memcpy(&temp, &str, sizeof(str)); \
        return temp; \
}

/* This file contains the final passes of the compiler. Running after
 * scheduling and RA, the IR is now finalized, so we need to emit it to actual
 * bits on the wire (as well as fixup branches) */

static uint64_t
bi_pack_header(bi_clause *clause, bi_clause *next, bool is_fragment)
{
        struct bifrost_header header = {
                .back_to_back = clause->back_to_back,
                .no_end_of_shader = (next != NULL),
                .elide_writes = is_fragment,
                .branch_cond = clause->branch_conditional,
                .datareg_writebarrier = clause->data_register_write_barrier,
                .datareg = clause->data_register,
                .scoreboard_deps = clause->dependencies,
                .scoreboard_index = clause->scoreboard_id,
                .clause_type = clause->clause_type,
                .next_clause_type = next ? next->clause_type : 0,
        };

        uint64_t u = 0;
        memcpy(&u, &header, sizeof(header));
        return u;
}

/* Represents the assignment of ports for a given bundle */

struct bi_registers {
        /* Register to assign to each port */
        unsigned port[4];

        /* Read ports can be disabled */
        bool enabled[2];

        /* Should we write FMA? what about ADD? If only a single port is
         * enabled it is in port 2, else ADD/FMA is 2/3 respectively */
        bool write_fma, write_add;

        /* Should we read with port 3? */
        bool read_port3;

        /* Packed uniform/constant */
        unsigned uniform_constant;

        /* Whether writes are actually for the last instruction */
        bool first_instruction;
};

/* Assigns a port for reading, before anything is written */

static void
bi_assign_port_read(struct bi_registers *regs, unsigned src)
{
        /* We only assign for registers */
        if (!(src & BIR_INDEX_REGISTER))
                return;

        unsigned reg = src & ~BIR_INDEX_REGISTER;

        /* Check if we already assigned the port */
        for (unsigned i = 0; i <= 1; ++i) {
                if (regs->port[i] == reg && regs->enabled[i])
                        return;
        }

        if (regs->port[3] == reg && regs->read_port3)
                return;

        /* Assign it now */

        for (unsigned i = 0; i <= 1; ++i) {
                if (!regs->enabled[i]) {
                        regs->port[i] = reg;
                        regs->enabled[i] = true;
                        return;
                }
        }

        if (!regs->read_port3) {
                regs->port[3] = reg;
                regs->read_port3 = true;
        }
}

static struct bi_registers
bi_assign_ports(bi_bundle now, bi_bundle prev)
{
        struct bi_registers regs = { 0 };

        /* We assign ports for the main register mechanism. Special ops
         * use the data registers, which has its own mechanism entirely
         * and thus gets skipped over here. */

        unsigned read_dreg = now.add &&
                bi_class_props[now.add->type] & BI_DATA_REG_SRC;

        unsigned write_dreg = prev.add &&
                bi_class_props[prev.add->type] & BI_DATA_REG_DEST;

        /* First, assign reads */

        if (now.fma)
                bi_foreach_src(now.fma, src)
                        bi_assign_port_read(&regs, now.fma->src[src]);

        if (now.add) {
                bi_foreach_src(now.add, src) {
                        if (!(src == 0 && read_dreg))
                                bi_assign_port_read(&regs, now.add->src[src]);
                }
        }

        /* Next, assign writes */

        if (prev.fma && prev.fma->dest & BIR_INDEX_REGISTER) {
                regs.port[2] = prev.fma->dest & ~BIR_INDEX_REGISTER;
                regs.write_fma = true;
        }

        if (prev.add && prev.add->dest & BIR_INDEX_REGISTER && !write_dreg) {
                unsigned r = prev.add->dest & ~BIR_INDEX_REGISTER;

                if (regs.write_fma) {
                        /* Scheduler constraint: cannot read 3 and write 2 */
                        assert(!regs.read_port3);
                        regs.port[3] = r;
                } else {
                        regs.port[2] = r;
                }

                regs.write_add = true;
        }

        /* Finally, ensure port 1 > port 0 for the 63-x trick to function */

        if (regs.enabled[0] && regs.enabled[1] && regs.port[1] < regs.port[0]) {
                unsigned temp = regs.port[0];
                regs.port[0] = regs.port[1];
                regs.port[1] = temp;
        }

        return regs;
}

/* Determines the register control field, ignoring the first? flag */

static enum bifrost_reg_control
bi_pack_register_ctrl_lo(struct bi_registers r)
{
        if (r.write_fma) {
                if (r.write_add) {
                        assert(!r.read_port3);
                        return BIFROST_WRITE_ADD_P2_FMA_P3;
                } else {
                        if (r.read_port3)
                                return BIFROST_WRITE_FMA_P2_READ_P3;
                        else
                                return BIFROST_WRITE_FMA_P2;
                }
        } else if (r.write_add) {
                if (r.read_port3)
                        return BIFROST_WRITE_ADD_P2_READ_P3;
                else
                        return BIFROST_WRITE_ADD_P2;
        } else if (r.read_port3)
                return BIFROST_READ_P3;
        else
                return BIFROST_REG_NONE;
}

/* Ditto but account for the first? flag this time */

static enum bifrost_reg_control
bi_pack_register_ctrl(struct bi_registers r)
{
        enum bifrost_reg_control ctrl = bi_pack_register_ctrl_lo(r);

        if (r.first_instruction) {
                if (ctrl == BIFROST_REG_NONE)
                        ctrl = BIFROST_FIRST_NONE;
                else
                        ctrl |= BIFROST_FIRST_NONE;
        }

        return ctrl;
}

static uint64_t
bi_pack_registers(struct bi_registers regs)
{
        enum bifrost_reg_control ctrl = bi_pack_register_ctrl(regs);
        struct bifrost_regs s;
        uint64_t packed = 0;

        if (regs.enabled[1]) {
                /* Gotta save that bit!~ Required by the 63-x trick */
                assert(regs.port[1] > regs.port[0]);
                assert(regs.enabled[0]);

                /* Do the 63-x trick, see docs/disasm */
                if (regs.port[0] > 31) {
                        regs.port[0] = 63 - regs.port[0];
                        regs.port[1] = 63 - regs.port[1];
                }

                assert(regs.port[0] <= 31);
                assert(regs.port[1] <= 63);

                s.ctrl = ctrl;
                s.reg1 = regs.port[1];
                s.reg0 = regs.port[0];
        } else {
                /* Port 1 disabled, so set to zero and use port 1 for ctrl */
                s.reg1 = ctrl << 2;

                if (regs.enabled[0]) {
                        /* Bit 0 upper bit of port 0 */
                        s.reg1 |= (regs.port[0] >> 5);

                        /* Rest of port 0 in usual spot */
                        s.reg0 = (regs.port[0] & 0b11111);
                } else {
                        /* Bit 1 set if port 0 also disabled */
                        s.reg1 |= (1 << 1);
                }
        }

        s.reg3 = regs.port[3];
        s.reg2 = regs.port[2];
        s.uniform_const = regs.uniform_constant;

        memcpy(&packed, &s, sizeof(s));
        return packed;
}

static enum bifrost_packed_src
bi_get_src_reg_port(struct bi_registers *regs, unsigned src)
{
        unsigned reg = src & ~BIR_INDEX_REGISTER;

        if (regs->port[0] == reg && regs->enabled[0])
                return BIFROST_SRC_PORT0;
        else if (regs->port[1] == reg && regs->enabled[1])
                return BIFROST_SRC_PORT1;
        else if (regs->port[3] == reg && regs->read_port3)
                return BIFROST_SRC_PORT3;
        else
                unreachable("Tried to access register with no port");
}

static enum bifrost_packed_src
bi_get_src_const(struct bi_registers *regs, unsigned constant)
{
        if (regs->uniform_constant & (1 << 7))
                unreachable("Tried to get constant but loading uniforms");

        unsigned loc = (regs->uniform_constant >> 4) & 0x7;

        if (loc != 0)
                unreachable("TODO: constants in clauses");

        unsigned lo = regs->uniform_constant & 0xF;

        if (lo == 0) {
                if (constant != 0)
                        unreachable("Tried to load !0 in 0 slot");

                return BIFROST_SRC_CONST_LO;
        } else {
                unreachable("Special slot is not a fixed immediate");
        }
}

static enum bifrost_packed_src
bi_get_src(bi_instruction *ins, struct bi_registers *regs, unsigned s, bool is_fma)
{
        unsigned src = ins->src[s];

        if (src & BIR_INDEX_REGISTER)
                return bi_get_src_reg_port(regs, src);
        else if (src & BIR_INDEX_ZERO && is_fma)
                return BIFROST_SRC_STAGE;
        else if (src & BIR_INDEX_ZERO)
                return bi_get_src_const(regs, 0);
        else if (src & BIR_INDEX_PASS)
                return src & ~BIR_INDEX_PASS;
        else if (src & BIR_INDEX_CONSTANT)
                return bi_get_src_const(regs, 0); /*TODO ins->constant.u64 */
        else
                unreachable("Unknown src");
}

static unsigned
bi_pack_fma_fma(bi_instruction *ins, struct bi_registers *regs)
{
        /* (-a)(-b) = ab, so we only need one negate bit */
        bool negate_mul = ins->src_neg[0] ^ ins->src_neg[1];

        struct bifrost_fma_fma pack = {
                .src0 = bi_get_src(ins, regs, 0, true),
                .src1 = bi_get_src(ins, regs, 1, true),
                .src2 = bi_get_src(ins, regs, 2, true),
                .src0_abs = ins->src_abs[0],
                .src1_abs = ins->src_abs[1],
                .src2_abs = ins->src_abs[2],
                .src0_neg = negate_mul,
                .src2_neg = ins->src_neg[2],
                .op = BIFROST_FMA_OP_FMA
        };

        RETURN_PACKED(pack);
}

static unsigned
bi_pack_fma_add(bi_instruction *ins, struct bi_registers *regs)
{
        /* TODO: fadd16 packing is a bit different */
        assert(ins->dest_type == nir_type_float32);

        struct bifrost_fma_add pack = {
                .src0 = bi_get_src(ins, regs, 0, true),
                .src1 = bi_get_src(ins, regs, 1, true),
                .src0_abs = ins->src_abs[0],
                .src1_abs = ins->src_abs[1],
                .src0_neg = ins->src_neg[0],
                .src1_neg = ins->src_neg[1],
                .unk = 0x0,
                .outmod = ins->outmod,
                .roundmode = ins->roundmode,
                .op = BIFROST_FMA_OP_FADD32
        };

        RETURN_PACKED(pack);
}

static unsigned
bi_pack_fma_1src(bi_instruction *ins, struct bi_registers *regs, unsigned op)
{
        struct bifrost_fma_inst pack = {
                .src0 = bi_get_src(ins, regs, 0, true),
                .op = op
        };

        RETURN_PACKED(pack);
}

static unsigned
bi_pack_fma(bi_clause *clause, bi_bundle bundle, struct bi_registers *regs)
{
        if (!bundle.fma)
                return BIFROST_FMA_NOP;

        switch (bundle.fma->type) {
        case BI_ADD:
                return bi_pack_fma_add(bundle.fma, regs);
        case BI_CMP:
        case BI_BITWISE:
        case BI_CONVERT:
        case BI_CSEL:
		return BIFROST_FMA_NOP;
        case BI_FMA:
                return bi_pack_fma_fma(bundle.fma, regs);
        case BI_FREXP:
        case BI_ISUB:
        case BI_MINMAX:
                return BIFROST_FMA_NOP;
        case BI_MOV:
                return bi_pack_fma_1src(bundle.fma, regs, BIFROST_FMA_OP_MOV);
        case BI_FMOV:
        case BI_SHIFT:
        case BI_SWIZZLE:
        case BI_ROUND:
		return BIFROST_FMA_NOP;
        default:
                unreachable("Cannot encode class as FMA");
        }
}

static unsigned
bi_pack_add_ld_vary(bi_clause *clause, bi_instruction *ins, struct bi_registers *regs)
{
        unsigned size = nir_alu_type_get_type_size(ins->dest_type);
        assert(size == 32 || size == 16);

        unsigned op = (size == 32) ?
                BIFROST_ADD_OP_LD_VAR_32 :
                BIFROST_ADD_OP_LD_VAR_16;

        unsigned cmask = bi_from_bytemask(ins->writemask, size / 8);
        unsigned channels = util_bitcount(cmask);
        assert(cmask == ((1 << channels) - 1));

        unsigned packed_addr = 0;

        if (ins->src[0] & BIR_INDEX_CONSTANT) {
                /* Direct uses address field directly */
                packed_addr = ins->src[0] & ~BIR_INDEX_CONSTANT;
                assert(packed_addr < 0b1000);
        } else {
                /* Indirect gets an extra source */
                packed_addr = bi_get_src(ins, regs, 0, false) | 0b11000;
        }

        /* The destination is thrown in the data register */
        assert(ins->dest & BIR_INDEX_REGISTER);
        clause->data_register = ins->dest & ~BIR_INDEX_REGISTER;

        assert(channels >= 1 && channels <= 4);

        struct bifrost_ld_var pack = {
                .src0 = bi_get_src(ins, regs, 1, false),
                .addr = packed_addr,
                .channels = MALI_POSITIVE(channels),
                .interp_mode = ins->load_vary.interp_mode,
                .reuse = ins->load_vary.reuse,
                .flat = ins->load_vary.flat,
                .op = op
        };

        RETURN_PACKED(pack);
}

static unsigned
bi_pack_add_atest(bi_clause *clause, bi_instruction *ins, struct bi_registers *regs)
{
        /* TODO: fp16 */
        assert(ins->src_types[1] == nir_type_float32);

        struct bifrost_add_atest pack = {
                .src0 = bi_get_src(ins, regs, 0, false),
                .src1 = bi_get_src(ins, regs, 1, false),
                .component = 1, /* Set for fp32 */
                .op = BIFROST_ADD_OP_ATEST,
        };

        /* Despite *also* writing with the usual mechanism... quirky and
         * perhaps unnecessary, but let's match the blob */
        clause->data_register = ins->dest & ~BIR_INDEX_REGISTER;

        RETURN_PACKED(pack);
}

static unsigned
bi_pack_add_blend(bi_instruction *ins, struct bi_registers *regs)
{
        struct bifrost_add_inst pack = {
                .src0 = bi_get_src(ins, regs, 0, false),
                .op = BIFROST_ADD_OP_BLEND
        };

        /* TODO: Pack location in uniform_const */
        assert(ins->blend_location == 0);

        RETURN_PACKED(pack);
}

static unsigned
bi_pack_add(bi_clause *clause, bi_bundle bundle, struct bi_registers *regs)
{
        if (!bundle.add)
                return BIFROST_ADD_NOP;

        switch (bundle.add->type) {
        case BI_ADD:
                return BIFROST_ADD_NOP;
        case BI_ATEST:
                return bi_pack_add_atest(clause, bundle.add, regs);
        case BI_BRANCH:
        case BI_CMP:
                return BIFROST_ADD_NOP;
        case BI_BLEND:
                return bi_pack_add_blend(bundle.add, regs);
        case BI_BITWISE:
        case BI_CONVERT:
        case BI_DISCARD:
        case BI_FREXP:
        case BI_ISUB:
        case BI_LOAD:
        case BI_LOAD_UNIFORM:
        case BI_LOAD_ATTR:
                return BIFROST_ADD_NOP;
        case BI_LOAD_VAR:
                return bi_pack_add_ld_vary(clause, bundle.add, regs);
        case BI_LOAD_VAR_ADDRESS:
        case BI_MINMAX:
        case BI_MOV:
        case BI_FMOV:
        case BI_SHIFT:
        case BI_STORE:
        case BI_STORE_VAR:
        case BI_SPECIAL:
        case BI_SWIZZLE:
        case BI_TEX:
        case BI_ROUND:
                return BIFROST_ADD_NOP;
        default:
                unreachable("Cannot encode class as ADD");
        }
}

struct bi_packed_bundle {
        uint64_t lo;
        uint64_t hi;
};

static struct bi_packed_bundle
bi_pack_bundle(bi_clause *clause, bi_bundle bundle, bi_bundle prev, bool first_bundle)
{
        struct bi_registers regs = bi_assign_ports(bundle, prev);
        regs.first_instruction = first_bundle;

        uint64_t reg = bi_pack_registers(regs);
        uint64_t fma = bi_pack_fma(clause, bundle, &regs);
        uint64_t add = bi_pack_add(clause, bundle, &regs);

        struct bi_packed_bundle packed = {
                .lo = reg | (fma << 35) | ((add & 0b111111) << 58),
                .hi = add >> 6
        };

        return packed;
}

/* Packs the next two constants as a dedicated constant quadword at the end of
 * the clause, returning the number packed. */

static unsigned
bi_pack_constants(bi_context *ctx, bi_clause *clause,
                unsigned index,
                struct util_dynarray *emission)
{
        /* After these two, are we done? Determines tag */
        bool done = clause->constant_count <= (index + 2);
        bool only = clause->constant_count <= (index + 1);

        /* TODO: Pos */
        assert(index == 0 && clause->bundle_count == 1);

        struct bifrost_fmt_constant quad = {
                .pos = 0, /* TODO */
                .tag = done ? BIFROST_FMTC_FINAL : BIFROST_FMTC_CONSTANTS,
                .imm_1 = clause->constants[index + 0] >> 4,
                .imm_2 = only ? 0 : clause->constants[index + 1] >> 4
        };

        util_dynarray_append(emission, struct bifrost_fmt_constant, quad);

        return 2;
}

static void
bi_pack_clause(bi_context *ctx, bi_clause *clause, bi_clause *next,
                struct util_dynarray *emission)
{
        struct bi_packed_bundle ins_1 = bi_pack_bundle(clause, clause->bundles[0], clause->bundles[0], true);
        assert(clause->bundle_count == 1);

        /* Used to decide if we elide writes */
        bool is_fragment = ctx->stage == MESA_SHADER_FRAGMENT;

        /* State for packing constants throughout */
        unsigned constant_index = 0;

        struct bifrost_fmt1 quad_1 = {
                .tag = clause->constant_count ? BIFROST_FMT1_CONSTANTS : BIFROST_FMT1_FINAL,
                .header = bi_pack_header(clause, next, is_fragment),
                .ins_1 = ins_1.lo,
                .ins_2 = ins_1.hi & ((1 << 11) - 1),
                .ins_0 = (ins_1.hi >> 11) & 0b111,
        };

        util_dynarray_append(emission, struct bifrost_fmt1, quad_1);

        /* Pack the remaining constants */

        while (constant_index < clause->constant_count) {
                constant_index += bi_pack_constants(ctx, clause,
                                constant_index, emission);
        }
}

static bi_clause *
bi_next_clause(bi_context *ctx, pan_block *block, bi_clause *clause)
{
        /* Try the next clause in this block */
        if (clause->link.next != &((bi_block *) block)->clauses)
                return list_first_entry(&(clause->link), bi_clause, link);

        /* Try the next block, or the one after that if it's empty, etc .*/
        pan_block *next_block = pan_next_block(block);

        bi_foreach_block_from(ctx, next_block, block) {
                bi_block *blk = (bi_block *) block;

                if (!list_is_empty(&blk->clauses))
                        return list_first_entry(&(blk->clauses), bi_clause, link);
        }

        return NULL;
}

void
bi_pack(bi_context *ctx, struct util_dynarray *emission)
{
        util_dynarray_init(emission, NULL);

        bi_foreach_block(ctx, _block) {
                bi_block *block = (bi_block *) _block;

                bi_foreach_clause_in_block(block, clause) {
                        bi_clause *next = bi_next_clause(ctx, _block, clause);
                        bi_pack_clause(ctx, clause, next, emission);
                }
        }
}