src/panfrost/bifrost/bi_pack.c

   1 /*
   2  * Copyright (C) 2020 Collabora, Ltd.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 #include "compiler.h"
  25
  26 #define RETURN_PACKED(str) { \
  27         uint64_t temp = 0; \
  28         memcpy(&temp, &str, sizeof(str)); \
  29         return temp; \
  30 }
  31
  32 /* This file contains the final passes of the compiler. Running after
  33  * scheduling and RA, the IR is now finalized, so we need to emit it to actual
  34  * bits on the wire (as well as fixup branches) */
  35
  36 static uint64_t
  37 bi_pack_header(bi_clause *clause, bi_clause *next, bool is_fragment)
  38 {
  39         struct bifrost_header header = {
  40                 .back_to_back = clause->back_to_back,
  41                 .no_end_of_shader = (next != NULL),
  42                 .elide_writes = is_fragment,
  43                 .branch_cond = clause->branch_conditional,
  44                 .datareg_writebarrier = clause->data_register_write_barrier,
  45                 .datareg = clause->data_register,
  46                 .scoreboard_deps = clause->dependencies,
  47                 .scoreboard_index = clause->scoreboard_id,
  48                 .clause_type = clause->clause_type,
  49                 .next_clause_type = next ? next->clause_type : 0,
  50         };
  51
  52         uint64_t u = 0;
  53         memcpy(&u, &header, sizeof(header));
  54         return u;
  55 }
  56
  57 /* Represents the assignment of ports for a given bundle */
  58
  59 struct bi_registers {
  60         /* Register to assign to each port */
  61         unsigned port[4];
  62
  63         /* Read ports can be disabled */
  64         bool enabled[2];
  65
  66         /* Should we write FMA? what about ADD? If only a single port is
  67          * enabled it is in port 2, else ADD/FMA is 2/3 respectively */
  68         bool write_fma, write_add;
  69
  70         /* Should we read with port 3? */
  71         bool read_port3;
  72
  73         /* Packed uniform/constant */
  74         uint8_t uniform_constant;
  75
  76         /* Whether writes are actually for the last instruction */
  77         bool first_instruction;
  78 };
  79
  80 /* The uniform/constant slot allows loading a contiguous 64-bit immediate or
  81  * pushed uniform per bundle. Figure out which one we need in the bundle (the
  82  * scheduler needs to ensure we only have one type per bundle), validate
  83  * everything, and rewrite away the register/uniform indices to use 3-bit
  84  * sources directly. */
  85
  86 static unsigned
  87 bi_lookup_constant(bi_clause *clause, uint64_t cons)
  88 {
  89         for (unsigned i = 0; i < clause->constant_count; ++i) {
  90                 /* Only check top 60-bits since that's what's actually embedded
  91                  * in the clause, the bottom 4-bits are bundle-inline */
  92
  93                 if ((cons >> 4) == (clause->constants[i] >> 4))
  94                         return i;
  95         }
  96
  97         unreachable("Invalid constant accessed");
  98 }
  99
 100 static unsigned
 101 bi_constant_field(unsigned idx)
 102 {
 103         assert(idx <= 5);
 104
 105         const unsigned values[] = {
 106                 4, 5, 6, 7, 2, 3
 107         };
 108
 109         return values[idx] << 4;
 110 }
 111
 112 static bool
 113 bi_assign_uniform_constant_single(
 114                 struct bi_registers *regs,
 115                 bi_clause *clause,
 116                 bi_instruction *ins, bool assigned, bool fast_zero)
 117 {
 118         if (!ins)
 119                 return assigned;
 120
 121         bi_foreach_src(ins, s) {
 122                 if (ins->src[s] & BIR_INDEX_CONSTANT) {
 123                         /* TODO: lo/hi matching? */
 124                         uint64_t cons = ins->constant.u64;
 125                         unsigned idx = bi_lookup_constant(clause, cons);
 126                         unsigned f = bi_constant_field(idx) | (cons & 0xF);
 127
 128                         if (assigned && regs->uniform_constant != f)
 129                                 unreachable("Mismatched uniform/const field: imm");
 130
 131                         regs->uniform_constant = f;
 132                         ins->src[s] = BIR_INDEX_PASS | BIFROST_SRC_CONST_LO;
 133                         assigned = true;
 134                 } else if (ins->src[s] & BIR_INDEX_ZERO && (ins->type == BI_LOAD_UNIFORM || ins->type == BI_LOAD_VAR)) {
 135                         /* XXX: HACK UNTIL WE HAVE HI MATCHING DUE TO OVERFLOW XXX */
 136                         ins->src[s] = BIR_INDEX_PASS | BIFROST_SRC_CONST_HI;
 137                 } else if (ins->src[s] & BIR_INDEX_ZERO && !fast_zero) {
 138                         /* FMAs have a fast zero port, ADD needs to use the
 139                          * uniform/const port's special 0 mode handled here */
 140                         unsigned f = 0;
 141
 142                         if (assigned && regs->uniform_constant != f)
 143                                 unreachable("Mismatched uniform/const field: 0");
 144
 145                         regs->uniform_constant = f;
 146                         ins->src[s] = BIR_INDEX_PASS | BIFROST_SRC_CONST_LO;
 147                         assigned = true;
 148                 } else if (s & BIR_INDEX_UNIFORM) {
 149                         unreachable("Push uniforms not implemented yet");
 150                 }
 151         }
 152
 153         return assigned;
 154 }
 155
 156 static void
 157 bi_assign_uniform_constant(
 158                 bi_clause *clause,
 159                 struct bi_registers *regs,
 160                 bi_bundle bundle)
 161 {
 162         bool assigned =
 163                 bi_assign_uniform_constant_single(regs, clause, bundle.fma, false, true);
 164
 165         bi_assign_uniform_constant_single(regs, clause, bundle.add, assigned, false);
 166 }
 167
 168 /* Assigns a port for reading, before anything is written */
 169
 170 static void
 171 bi_assign_port_read(struct bi_registers *regs, unsigned src)
 172 {
 173         /* We only assign for registers */
 174         if (!(src & BIR_INDEX_REGISTER))
 175                 return;
 176
 177         unsigned reg = src & ~BIR_INDEX_REGISTER;
 178
 179         /* Check if we already assigned the port */
 180         for (unsigned i = 0; i <= 1; ++i) {
 181                 if (regs->port[i] == reg && regs->enabled[i])
 182                         return;
 183         }
 184
 185         if (regs->port[3] == reg && regs->read_port3)
 186                 return;
 187
 188         /* Assign it now */
 189
 190         for (unsigned i = 0; i <= 1; ++i) {
 191                 if (!regs->enabled[i]) {
 192                         regs->port[i] = reg;
 193                         regs->enabled[i] = true;
 194                         return;
 195                 }
 196         }
 197
 198         if (!regs->read_port3) {
 199                 regs->port[3] = reg;
 200                 regs->read_port3 = true;
 201         }
 202 }
 203
 204 static struct bi_registers
 205 bi_assign_ports(bi_bundle now, bi_bundle prev)
 206 {
 207         struct bi_registers regs = { 0 };
 208
 209         /* We assign ports for the main register mechanism. Special ops
 210          * use the data registers, which has its own mechanism entirely
 211          * and thus gets skipped over here. */
 212
 213         unsigned read_dreg = now.add &&
 214                 bi_class_props[now.add->type] & BI_DATA_REG_SRC;
 215
 216         unsigned write_dreg = prev.add &&
 217                 bi_class_props[prev.add->type] & BI_DATA_REG_DEST;
 218
 219         /* First, assign reads */
 220
 221         if (now.fma)
 222                 bi_foreach_src(now.fma, src)
 223                         bi_assign_port_read(&regs, now.fma->src[src]);
 224
 225         if (now.add) {
 226                 bi_foreach_src(now.add, src) {
 227                         if (!(src == 0 && read_dreg))
 228                                 bi_assign_port_read(&regs, now.add->src[src]);
 229                 }
 230         }
 231
 232         /* Next, assign writes */
 233
 234         if (prev.fma && prev.fma->dest & BIR_INDEX_REGISTER) {
 235                 regs.port[2] = prev.fma->dest & ~BIR_INDEX_REGISTER;
 236                 regs.write_fma = true;
 237         }
 238
 239         if (prev.add && prev.add->dest & BIR_INDEX_REGISTER && !write_dreg) {
 240                 unsigned r = prev.add->dest & ~BIR_INDEX_REGISTER;
 241
 242                 if (regs.write_fma) {
 243                         /* Scheduler constraint: cannot read 3 and write 2 */
 244                         assert(!regs.read_port3);
 245                         regs.port[3] = r;
 246                 } else {
 247                         regs.port[2] = r;
 248                 }
 249
 250                 regs.write_add = true;
 251         }
 252
 253         /* Finally, ensure port 1 > port 0 for the 63-x trick to function */
 254
 255         if (regs.enabled[0] && regs.enabled[1] && regs.port[1] < regs.port[0]) {
 256                 unsigned temp = regs.port[0];
 257                 regs.port[0] = regs.port[1];
 258                 regs.port[1] = temp;
 259         }
 260
 261         return regs;
 262 }
 263
 264 /* Determines the register control field, ignoring the first? flag */
 265
 266 static enum bifrost_reg_control
 267 bi_pack_register_ctrl_lo(struct bi_registers r)
 268 {
 269         if (r.write_fma) {
 270                 if (r.write_add) {
 271                         assert(!r.read_port3);
 272                         return BIFROST_WRITE_ADD_P2_FMA_P3;
 273                 } else {
 274                         if (r.read_port3)
 275                                 return BIFROST_WRITE_FMA_P2_READ_P3;
 276                         else
 277                                 return BIFROST_WRITE_FMA_P2;
 278                 }
 279         } else if (r.write_add) {
 280                 if (r.read_port3)
 281                         return BIFROST_WRITE_ADD_P2_READ_P3;
 282                 else
 283                         return BIFROST_WRITE_ADD_P2;
 284         } else if (r.read_port3)
 285                 return BIFROST_READ_P3;
 286         else
 287                 return BIFROST_REG_NONE;
 288 }
 289
 290 /* Ditto but account for the first? flag this time */
 291
 292 static enum bifrost_reg_control
 293 bi_pack_register_ctrl(struct bi_registers r)
 294 {
 295         enum bifrost_reg_control ctrl = bi_pack_register_ctrl_lo(r);
 296
 297         if (r.first_instruction) {
 298                 if (ctrl == BIFROST_REG_NONE)
 299                         ctrl = BIFROST_FIRST_NONE;
 300                 else
 301                         ctrl |= BIFROST_FIRST_NONE;
 302         }
 303
 304         return ctrl;
 305 }
 306
 307 static uint64_t
 308 bi_pack_registers(struct bi_registers regs)
 309 {
 310         enum bifrost_reg_control ctrl = bi_pack_register_ctrl(regs);
 311         struct bifrost_regs s;
 312         uint64_t packed = 0;
 313
 314         if (regs.enabled[1]) {
 315                 /* Gotta save that bit!~ Required by the 63-x trick */
 316                 assert(regs.port[1] > regs.port[0]);
 317                 assert(regs.enabled[0]);
 318
 319                 /* Do the 63-x trick, see docs/disasm */
 320                 if (regs.port[0] > 31) {
 321                         regs.port[0] = 63 - regs.port[0];
 322                         regs.port[1] = 63 - regs.port[1];
 323                 }
 324
 325                 assert(regs.port[0] <= 31);
 326                 assert(regs.port[1] <= 63);
 327
 328                 s.ctrl = ctrl;
 329                 s.reg1 = regs.port[1];
 330                 s.reg0 = regs.port[0];
 331         } else {
 332                 /* Port 1 disabled, so set to zero and use port 1 for ctrl */
 333                 s.reg1 = ctrl << 2;
 334
 335                 if (regs.enabled[0]) {
 336                         /* Bit 0 upper bit of port 0 */
 337                         s.reg1 |= (regs.port[0] >> 5);
 338
 339                         /* Rest of port 0 in usual spot */
 340                         s.reg0 = (regs.port[0] & 0b11111);
 341                 } else {
 342                         /* Bit 1 set if port 0 also disabled */
 343                         s.reg1 |= (1 << 1);
 344                 }
 345         }
 346
 347         s.reg3 = regs.port[3];
 348         s.reg2 = regs.port[2];
 349         s.uniform_const = regs.uniform_constant;
 350
 351         memcpy(&packed, &s, sizeof(s));
 352         return packed;
 353 }
 354
 355 static void
 356 bi_write_data_register(bi_clause *clause, bi_instruction *ins)
 357 {
 358         assert(ins->dest & BIR_INDEX_REGISTER);
 359         unsigned reg = ins->dest & ~BIR_INDEX_REGISTER;
 360         assert(reg <= 63);
 361         clause->data_register = reg;
 362 }
 363
 364 static enum bifrost_packed_src
 365 bi_get_src_reg_port(struct bi_registers *regs, unsigned src)
 366 {
 367         unsigned reg = src & ~BIR_INDEX_REGISTER;
 368
 369         if (regs->port[0] == reg && regs->enabled[0])
 370                 return BIFROST_SRC_PORT0;
 371         else if (regs->port[1] == reg && regs->enabled[1])
 372                 return BIFROST_SRC_PORT1;
 373         else if (regs->port[3] == reg && regs->read_port3)
 374                 return BIFROST_SRC_PORT3;
 375         else
 376                 unreachable("Tried to access register with no port");
 377 }
 378
 379 static enum bifrost_packed_src
 380 bi_get_src(bi_instruction *ins, struct bi_registers *regs, unsigned s, bool is_fma)
 381 {
 382         unsigned src = ins->src[s];
 383
 384         if (src & BIR_INDEX_REGISTER)
 385                 return bi_get_src_reg_port(regs, src);
 386         else if (src & BIR_INDEX_ZERO && is_fma)
 387                 return BIFROST_SRC_STAGE;
 388         else if (src & BIR_INDEX_PASS)
 389                 return src & ~BIR_INDEX_PASS;
 390         else
 391                 unreachable("Unknown src");
 392 }
 393
 394 static unsigned
 395 bi_pack_fma_fma(bi_instruction *ins, struct bi_registers *regs)
 396 {
 397         /* (-a)(-b) = ab, so we only need one negate bit */
 398         bool negate_mul = ins->src_neg[0] ^ ins->src_neg[1];
 399
 400         struct bifrost_fma_fma pack = {
 401                 .src0 = bi_get_src(ins, regs, 0, true),
 402                 .src1 = bi_get_src(ins, regs, 1, true),
 403                 .src2 = bi_get_src(ins, regs, 2, true),
 404                 .src0_abs = ins->src_abs[0],
 405                 .src1_abs = ins->src_abs[1],
 406                 .src2_abs = ins->src_abs[2],
 407                 .src0_neg = negate_mul,
 408                 .src2_neg = ins->src_neg[2],
 409                 .op = BIFROST_FMA_OP_FMA
 410         };
 411
 412         RETURN_PACKED(pack);
 413 }
 414
 415 static unsigned
 416 bi_pack_fma_add(bi_instruction *ins, struct bi_registers *regs)
 417 {
 418         /* TODO: fadd16 packing is a bit different */
 419         assert(ins->dest_type == nir_type_float32);
 420
 421         struct bifrost_fma_add pack = {
 422                 .src0 = bi_get_src(ins, regs, 0, true),
 423                 .src1 = bi_get_src(ins, regs, 1, true),
 424                 .src0_abs = ins->src_abs[0],
 425                 .src1_abs = ins->src_abs[1],
 426                 .src0_neg = ins->src_neg[0],
 427                 .src1_neg = ins->src_neg[1],
 428                 .unk = 0x0,
 429                 .outmod = ins->outmod,
 430                 .roundmode = ins->roundmode,
 431                 .op = BIFROST_FMA_OP_FADD32
 432         };
 433
 434         RETURN_PACKED(pack);
 435 }
 436
 437 static unsigned
 438 bi_pack_fma_1src(bi_instruction *ins, struct bi_registers *regs, unsigned op)
 439 {
 440         struct bifrost_fma_inst pack = {
 441                 .src0 = bi_get_src(ins, regs, 0, true),
 442                 .op = op
 443         };
 444
 445         RETURN_PACKED(pack);
 446 }
 447
 448 static unsigned
 449 bi_pack_fma(bi_clause *clause, bi_bundle bundle, struct bi_registers *regs)
 450 {
 451         if (!bundle.fma)
 452                 return BIFROST_FMA_NOP;
 453
 454         switch (bundle.fma->type) {
 455         case BI_ADD:
 456                 return bi_pack_fma_add(bundle.fma, regs);
 457         case BI_CMP:
 458         case BI_BITWISE:
 459         case BI_CONVERT:
 460         case BI_CSEL:
 461                 return BIFROST_FMA_NOP;
 462         case BI_FMA:
 463                 return bi_pack_fma_fma(bundle.fma, regs);
 464         case BI_FREXP:
 465         case BI_ISUB:
 466         case BI_MINMAX:
 467                 return BIFROST_FMA_NOP;
 468         case BI_MOV:
 469                 return bi_pack_fma_1src(bundle.fma, regs, BIFROST_FMA_OP_MOV);
 470         case BI_FMOV:
 471         case BI_SHIFT:
 472         case BI_SWIZZLE:
 473         case BI_ROUND:
 474                 return BIFROST_FMA_NOP;
 475         default:
 476                 unreachable("Cannot encode class as FMA");
 477         }
 478 }
 479
 480 static unsigned
 481 bi_pack_add_ld_vary(bi_clause *clause, bi_instruction *ins, struct bi_registers *regs)
 482 {
 483         unsigned size = nir_alu_type_get_type_size(ins->dest_type);
 484         assert(size == 32 || size == 16);
 485
 486         unsigned op = (size == 32) ?
 487                 BIFROST_ADD_OP_LD_VAR_32 :
 488                 BIFROST_ADD_OP_LD_VAR_16;
 489
 490         unsigned cmask = bi_from_bytemask(ins->writemask, size / 8);
 491         unsigned channels = util_bitcount(cmask);
 492         assert(cmask == ((1 << channels) - 1));
 493
 494         unsigned packed_addr = 0;
 495
 496         if (ins->src[0] & BIR_INDEX_CONSTANT) {
 497                 /* Direct uses address field directly */
 498                 packed_addr = ins->src[0] & ~BIR_INDEX_CONSTANT;
 499                 assert(packed_addr < 0b1000);
 500         } else {
 501                 /* Indirect gets an extra source */
 502                 packed_addr = bi_get_src(ins, regs, 0, false) | 0b11000;
 503         }
 504
 505         /* The destination is thrown in the data register */
 506         assert(ins->dest & BIR_INDEX_REGISTER);
 507         clause->data_register = ins->dest & ~BIR_INDEX_REGISTER;
 508
 509         assert(channels >= 1 && channels <= 4);
 510
 511         struct bifrost_ld_var pack = {
 512                 .src0 = bi_get_src(ins, regs, 1, false),
 513                 .addr = packed_addr,
 514                 .channels = MALI_POSITIVE(channels),
 515                 .interp_mode = ins->load_vary.interp_mode,
 516                 .reuse = ins->load_vary.reuse,
 517                 .flat = ins->load_vary.flat,
 518                 .op = op
 519         };
 520
 521         RETURN_PACKED(pack);
 522 }
 523
 524 static unsigned
 525 bi_pack_add_2src(bi_instruction *ins, struct bi_registers *regs, unsigned op)
 526 {
 527         struct bifrost_add_2src pack = {
 528                 .src0 = bi_get_src(ins, regs, 0, true),
 529                 .src1 = bi_get_src(ins, regs, 1, true),
 530                 .op = op
 531         };
 532
 533         RETURN_PACKED(pack);
 534 }
 535
 536 static unsigned
 537 bi_pack_add_ld_ubo(bi_clause *clause, bi_instruction *ins, struct bi_registers *regs)
 538 {
 539         unsigned components = bi_load32_components(ins);
 540
 541         const unsigned ops[4] = {
 542                 BIFROST_ADD_OP_LD_UBO_1,
 543                 BIFROST_ADD_OP_LD_UBO_2,
 544                 BIFROST_ADD_OP_LD_UBO_3,
 545                 BIFROST_ADD_OP_LD_UBO_4
 546         };
 547
 548         bi_write_data_register(clause, ins);
 549         return bi_pack_add_2src(ins, regs, ops[components - 1]);
 550 }
 551
 552 static unsigned
 553 bi_pack_add_atest(bi_clause *clause, bi_instruction *ins, struct bi_registers *regs)
 554 {
 555         /* TODO: fp16 */
 556         assert(ins->src_types[1] == nir_type_float32);
 557
 558         struct bifrost_add_atest pack = {
 559                 .src0 = bi_get_src(ins, regs, 0, false),
 560                 .src1 = bi_get_src(ins, regs, 1, false),
 561                 .component = 1, /* Set for fp32 */
 562                 .op = BIFROST_ADD_OP_ATEST,
 563         };
 564
 565         /* Despite *also* writing with the usual mechanism... quirky and
 566          * perhaps unnecessary, but let's match the blob */
 567         clause->data_register = ins->dest & ~BIR_INDEX_REGISTER;
 568
 569         RETURN_PACKED(pack);
 570 }
 571
 572 static unsigned
 573 bi_pack_add_blend(bi_instruction *ins, struct bi_registers *regs)
 574 {
 575         struct bifrost_add_inst pack = {
 576                 .src0 = bi_get_src(ins, regs, 0, false),
 577                 .op = BIFROST_ADD_OP_BLEND
 578         };
 579
 580         /* TODO: Pack location in uniform_const */
 581         assert(ins->blend_location == 0);
 582
 583         RETURN_PACKED(pack);
 584 }
 585
 586 static unsigned
 587 bi_pack_add(bi_clause *clause, bi_bundle bundle, struct bi_registers *regs)
 588 {
 589         if (!bundle.add)
 590                 return BIFROST_ADD_NOP;
 591
 592         switch (bundle.add->type) {
 593         case BI_ADD:
 594                 return BIFROST_ADD_NOP;
 595         case BI_ATEST:
 596                 return bi_pack_add_atest(clause, bundle.add, regs);
 597         case BI_BRANCH:
 598         case BI_CMP:
 599                 return BIFROST_ADD_NOP;
 600         case BI_BLEND:
 601                 return bi_pack_add_blend(bundle.add, regs);
 602         case BI_BITWISE:
 603         case BI_CONVERT:
 604         case BI_DISCARD:
 605         case BI_FREXP:
 606         case BI_ISUB:
 607         case BI_LOAD:
 608                 return BIFROST_ADD_NOP;
 609         case BI_LOAD_UNIFORM:
 610                 return bi_pack_add_ld_ubo(clause, bundle.add, regs);
 611         case BI_LOAD_ATTR:
 612                 return BIFROST_ADD_NOP;
 613         case BI_LOAD_VAR:
 614                 return bi_pack_add_ld_vary(clause, bundle.add, regs);
 615         case BI_LOAD_VAR_ADDRESS:
 616         case BI_MINMAX:
 617         case BI_MOV:
 618         case BI_FMOV:
 619         case BI_SHIFT:
 620         case BI_STORE:
 621         case BI_STORE_VAR:
 622         case BI_SPECIAL:
 623         case BI_SWIZZLE:
 624         case BI_TEX:
 625         case BI_ROUND:
 626                 return BIFROST_ADD_NOP;
 627         default:
 628                 unreachable("Cannot encode class as ADD");
 629         }
 630 }
 631
 632 struct bi_packed_bundle {
 633         uint64_t lo;
 634         uint64_t hi;
 635 };
 636
 637 static struct bi_packed_bundle
 638 bi_pack_bundle(bi_clause *clause, bi_bundle bundle, bi_bundle prev, bool first_bundle)
 639 {
 640         struct bi_registers regs = bi_assign_ports(bundle, prev);
 641         bi_assign_uniform_constant(clause, &regs, bundle);
 642         regs.first_instruction = first_bundle;
 643
 644         uint64_t reg = bi_pack_registers(regs);
 645         uint64_t fma = bi_pack_fma(clause, bundle, &regs);
 646         uint64_t add = bi_pack_add(clause, bundle, &regs);
 647
 648         struct bi_packed_bundle packed = {
 649                 .lo = reg | (fma << 35) | ((add & 0b111111) << 58),
 650                 .hi = add >> 6
 651         };
 652
 653         return packed;
 654 }
 655
 656 /* Packs the next two constants as a dedicated constant quadword at the end of
 657  * the clause, returning the number packed. */
 658
 659 static unsigned
 660 bi_pack_constants(bi_context *ctx, bi_clause *clause,
 661                 unsigned index,
 662                 struct util_dynarray *emission)
 663 {
 664         /* After these two, are we done? Determines tag */
 665         bool done = clause->constant_count <= (index + 2);
 666         bool only = clause->constant_count <= (index + 1);
 667
 668         /* TODO: Pos */
 669         assert(index == 0 && clause->bundle_count == 1);
 670
 671         struct bifrost_fmt_constant quad = {
 672                 .pos = 0, /* TODO */
 673                 .tag = done ? BIFROST_FMTC_FINAL : BIFROST_FMTC_CONSTANTS,
 674                 .imm_1 = clause->constants[index + 0] >> 4,
 675                 .imm_2 = only ? 0 : clause->constants[index + 1] >> 4
 676         };
 677
 678         /* XXX: On G71, Connor observed that the difference of the top 4 bits
 679          * of the second constant with the first must be less than 8, otherwise
 680          * we have to swap them. I am not able to reproduce this on G52,
 681          * further investigation needed. Possibly an errata. XXX */
 682
 683         util_dynarray_append(emission, struct bifrost_fmt_constant, quad);
 684
 685         return 2;
 686 }
 687
 688 static void
 689 bi_pack_clause(bi_context *ctx, bi_clause *clause, bi_clause *next,
 690                 struct util_dynarray *emission)
 691 {
 692         struct bi_packed_bundle ins_1 = bi_pack_bundle(clause, clause->bundles[0], clause->bundles[0], true);
 693         assert(clause->bundle_count == 1);
 694
 695         /* Used to decide if we elide writes */
 696         bool is_fragment = ctx->stage == MESA_SHADER_FRAGMENT;
 697
 698         /* State for packing constants throughout */
 699         unsigned constant_index = 0;
 700
 701         struct bifrost_fmt1 quad_1 = {
 702                 .tag = clause->constant_count ? BIFROST_FMT1_CONSTANTS : BIFROST_FMT1_FINAL,
 703                 .header = bi_pack_header(clause, next, is_fragment),
 704                 .ins_1 = ins_1.lo,
 705                 .ins_2 = ins_1.hi & ((1 << 11) - 1),
 706                 .ins_0 = (ins_1.hi >> 11) & 0b111,
 707         };
 708
 709         util_dynarray_append(emission, struct bifrost_fmt1, quad_1);
 710
 711         /* Pack the remaining constants */
 712
 713         while (constant_index < clause->constant_count) {
 714                 constant_index += bi_pack_constants(ctx, clause,
 715                                 constant_index, emission);
 716         }
 717 }
 718
 719 static bi_clause *
 720 bi_next_clause(bi_context *ctx, pan_block *block, bi_clause *clause)
 721 {
 722         /* Try the next clause in this block */
 723         if (clause->link.next != &((bi_block *) block)->clauses)
 724                 return list_first_entry(&(clause->link), bi_clause, link);
 725
 726         /* Try the next block, or the one after that if it's empty, etc .*/
 727         pan_block *next_block = pan_next_block(block);
 728
 729         bi_foreach_block_from(ctx, next_block, block) {
 730                 bi_block *blk = (bi_block *) block;
 731
 732                 if (!list_is_empty(&blk->clauses))
 733                         return list_first_entry(&(blk->clauses), bi_clause, link);
 734         }
 735
 736         return NULL;
 737 }
 738
 739 void
 740 bi_pack(bi_context *ctx, struct util_dynarray *emission)
 741 {
 742         util_dynarray_init(emission, NULL);
 743
 744         bi_foreach_block(ctx, _block) {
 745                 bi_block *block = (bi_block *) _block;
 746
 747                 bi_foreach_clause_in_block(block, clause) {
 748                         bi_clause *next = bi_next_clause(ctx, _block, clause);
 749                         bi_pack_clause(ctx, clause, next, emission);
 750                 }
 751         }
 752 }