src/compiler/nir/nir_instr_set.c

   1 /*
   2  * Copyright © 2014 Connor Abbott
   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
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include "nir_instr_set.h"
  25 #include "nir_vla.h"
  26 #include "util/half_float.h"
  27
  28 static bool
  29 src_is_ssa(nir_src *src, void *data)
  30 {
  31    (void) data;
  32    return src->is_ssa;
  33 }
  34
  35 static bool
  36 dest_is_ssa(nir_dest *dest, void *data)
  37 {
  38    (void) data;
  39    return dest->is_ssa;
  40 }
  41
  42 ASSERTED static inline bool
  43 instr_each_src_and_dest_is_ssa(const nir_instr *instr)
  44 {
  45    if (!nir_foreach_dest((nir_instr *)instr, dest_is_ssa, NULL) ||
  46        !nir_foreach_src((nir_instr *)instr, src_is_ssa, NULL))
  47       return false;
  48
  49    return true;
  50 }
  51
  52 /* This function determines if uses of an instruction can safely be rewritten
  53  * to use another identical instruction instead. Note that this function must
  54  * be kept in sync with hash_instr() and nir_instrs_equal() -- only
  55  * instructions that pass this test will be handed on to those functions, and
  56  * conversely they must handle everything that this function returns true for.
  57  */
  58 static bool
  59 instr_can_rewrite(const nir_instr *instr)
  60 {
  61    /* We only handle SSA. */
  62    assert(instr_each_src_and_dest_is_ssa(instr));
  63
  64    switch (instr->type) {
  65    case nir_instr_type_alu:
  66    case nir_instr_type_deref:
  67    case nir_instr_type_tex:
  68    case nir_instr_type_load_const:
  69    case nir_instr_type_phi:
  70       return true;
  71    case nir_instr_type_intrinsic:
  72       return nir_intrinsic_can_reorder(nir_instr_as_intrinsic(instr));
  73    case nir_instr_type_call:
  74    case nir_instr_type_jump:
  75    case nir_instr_type_ssa_undef:
  76       return false;
  77    case nir_instr_type_parallel_copy:
  78    default:
  79       unreachable("Invalid instruction type");
  80    }
  81
  82    return false;
  83 }
  84
  85
  86 #define HASH(hash, data) XXH32(&(data), sizeof(data), hash)
  87
  88 static uint32_t
  89 hash_src(uint32_t hash, const nir_src *src)
  90 {
  91    assert(src->is_ssa);
  92    hash = HASH(hash, src->ssa);
  93    return hash;
  94 }
  95
  96 static uint32_t
  97 hash_alu_src(uint32_t hash, const nir_alu_src *src, unsigned num_components)
  98 {
  99    hash = HASH(hash, src->abs);
 100    hash = HASH(hash, src->negate);
 101
 102    for (unsigned i = 0; i < num_components; i++)
 103       hash = HASH(hash, src->swizzle[i]);
 104
 105    hash = hash_src(hash, &src->src);
 106    return hash;
 107 }
 108
 109 static uint32_t
 110 hash_alu(uint32_t hash, const nir_alu_instr *instr)
 111 {
 112    hash = HASH(hash, instr->op);
 113
 114    /* We explicitly don't hash instr->exact. */
 115    uint8_t flags = instr->no_signed_wrap |
 116                    instr->no_unsigned_wrap << 1;
 117    hash = HASH(hash, flags);
 118
 119    hash = HASH(hash, instr->dest.dest.ssa.num_components);
 120    hash = HASH(hash, instr->dest.dest.ssa.bit_size);
 121
 122    if (nir_op_infos[instr->op].algebraic_properties & NIR_OP_IS_2SRC_COMMUTATIVE) {
 123       assert(nir_op_infos[instr->op].num_inputs >= 2);
 124
 125       uint32_t hash0 = hash_alu_src(hash, &instr->src[0],
 126                                     nir_ssa_alu_instr_src_components(instr, 0));
 127       uint32_t hash1 = hash_alu_src(hash, &instr->src[1],
 128                                     nir_ssa_alu_instr_src_components(instr, 1));
 129       /* For commutative operations, we need some commutative way of
 130        * combining the hashes.  One option would be to XOR them but that
 131        * means that anything with two identical sources will hash to 0 and
 132        * that's common enough we probably don't want the guaranteed
 133        * collision.  Either addition or multiplication will also work.
 134        */
 135       hash = hash0 * hash1;
 136
 137       for (unsigned i = 2; i < nir_op_infos[instr->op].num_inputs; i++) {
 138          hash = hash_alu_src(hash, &instr->src[i],
 139                              nir_ssa_alu_instr_src_components(instr, i));
 140       }
 141    } else {
 142       for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
 143          hash = hash_alu_src(hash, &instr->src[i],
 144                              nir_ssa_alu_instr_src_components(instr, i));
 145       }
 146    }
 147
 148    return hash;
 149 }
 150
 151 static uint32_t
 152 hash_deref(uint32_t hash, const nir_deref_instr *instr)
 153 {
 154    hash = HASH(hash, instr->deref_type);
 155    hash = HASH(hash, instr->mode);
 156    hash = HASH(hash, instr->type);
 157
 158    if (instr->deref_type == nir_deref_type_var)
 159       return HASH(hash, instr->var);
 160
 161    hash = hash_src(hash, &instr->parent);
 162
 163    switch (instr->deref_type) {
 164    case nir_deref_type_struct:
 165       hash = HASH(hash, instr->strct.index);
 166       break;
 167
 168    case nir_deref_type_array:
 169    case nir_deref_type_ptr_as_array:
 170       hash = hash_src(hash, &instr->arr.index);
 171       break;
 172
 173    case nir_deref_type_cast:
 174       hash = HASH(hash, instr->cast.ptr_stride);
 175       break;
 176
 177    case nir_deref_type_var:
 178    case nir_deref_type_array_wildcard:
 179       /* Nothing to do */
 180       break;
 181
 182    default:
 183       unreachable("Invalid instruction deref type");
 184    }
 185
 186    return hash;
 187 }
 188
 189 static uint32_t
 190 hash_load_const(uint32_t hash, const nir_load_const_instr *instr)
 191 {
 192    hash = HASH(hash, instr->def.num_components);
 193
 194    if (instr->def.bit_size == 1) {
 195       for (unsigned i = 0; i < instr->def.num_components; i++) {
 196          uint8_t b = instr->value[i].b;
 197          hash = HASH(hash, b);
 198       }
 199    } else {
 200       unsigned size = instr->def.num_components * sizeof(*instr->value);
 201       hash = XXH32(instr->value, size, hash);
 202    }
 203
 204    return hash;
 205 }
 206
 207 static int
 208 cmp_phi_src(const void *data1, const void *data2)
 209 {
 210    nir_phi_src *src1 = *(nir_phi_src **)data1;
 211    nir_phi_src *src2 = *(nir_phi_src **)data2;
 212    return src1->pred - src2->pred;
 213 }
 214
 215 static uint32_t
 216 hash_phi(uint32_t hash, const nir_phi_instr *instr)
 217 {
 218    hash = HASH(hash, instr->instr.block);
 219
 220    /* sort sources by predecessor, since the order shouldn't matter */
 221    unsigned num_preds = instr->instr.block->predecessors->entries;
 222    NIR_VLA(nir_phi_src *, srcs, num_preds);
 223    unsigned i = 0;
 224    nir_foreach_phi_src(src, instr) {
 225       srcs[i++] = src;
 226    }
 227
 228    qsort(srcs, num_preds, sizeof(nir_phi_src *), cmp_phi_src);
 229
 230    for (i = 0; i < num_preds; i++) {
 231       hash = hash_src(hash, &srcs[i]->src);
 232       hash = HASH(hash, srcs[i]->pred);
 233    }
 234
 235    return hash;
 236 }
 237
 238 static uint32_t
 239 hash_intrinsic(uint32_t hash, const nir_intrinsic_instr *instr)
 240 {
 241    const nir_intrinsic_info *info = &nir_intrinsic_infos[instr->intrinsic];
 242    hash = HASH(hash, instr->intrinsic);
 243
 244    if (info->has_dest) {
 245       hash = HASH(hash, instr->dest.ssa.num_components);
 246       hash = HASH(hash, instr->dest.ssa.bit_size);
 247    }
 248
 249    hash = XXH32(instr->const_index, info->num_indices * sizeof(instr->const_index[0]), hash);
 250    return hash;
 251 }
 252
 253 static uint32_t
 254 hash_tex(uint32_t hash, const nir_tex_instr *instr)
 255 {
 256    hash = HASH(hash, instr->op);
 257    hash = HASH(hash, instr->num_srcs);
 258
 259    for (unsigned i = 0; i < instr->num_srcs; i++) {
 260       hash = HASH(hash, instr->src[i].src_type);
 261       hash = hash_src(hash, &instr->src[i].src);
 262    }
 263
 264    hash = HASH(hash, instr->coord_components);
 265    hash = HASH(hash, instr->sampler_dim);
 266    hash = HASH(hash, instr->is_array);
 267    hash = HASH(hash, instr->is_shadow);
 268    hash = HASH(hash, instr->is_new_style_shadow);
 269    unsigned component = instr->component;
 270    hash = HASH(hash, component);
 271    for (unsigned i = 0; i < 4; ++i)
 272       for (unsigned j = 0; j < 2; ++j)
 273          hash = HASH(hash, instr->tg4_offsets[i][j]);
 274    hash = HASH(hash, instr->texture_index);
 275    hash = HASH(hash, instr->sampler_index);
 276    hash = HASH(hash, instr->texture_non_uniform);
 277    hash = HASH(hash, instr->sampler_non_uniform);
 278
 279    return hash;
 280 }
 281
 282 /* Computes a hash of an instruction for use in a hash table. Note that this
 283  * will only work for instructions where instr_can_rewrite() returns true, and
 284  * it should return identical hashes for two instructions that are the same
 285  * according nir_instrs_equal().
 286  */
 287
 288 static uint32_t
 289 hash_instr(const void *data)
 290 {
 291    const nir_instr *instr = data;
 292    uint32_t hash = 0;
 293
 294    switch (instr->type) {
 295    case nir_instr_type_alu:
 296       hash = hash_alu(hash, nir_instr_as_alu(instr));
 297       break;
 298    case nir_instr_type_deref:
 299       hash = hash_deref(hash, nir_instr_as_deref(instr));
 300       break;
 301    case nir_instr_type_load_const:
 302       hash = hash_load_const(hash, nir_instr_as_load_const(instr));
 303       break;
 304    case nir_instr_type_phi:
 305       hash = hash_phi(hash, nir_instr_as_phi(instr));
 306       break;
 307    case nir_instr_type_intrinsic:
 308       hash = hash_intrinsic(hash, nir_instr_as_intrinsic(instr));
 309       break;
 310    case nir_instr_type_tex:
 311       hash = hash_tex(hash, nir_instr_as_tex(instr));
 312       break;
 313    default:
 314       unreachable("Invalid instruction type");
 315    }
 316
 317    return hash;
 318 }
 319
 320 bool
 321 nir_srcs_equal(nir_src src1, nir_src src2)
 322 {
 323    if (src1.is_ssa) {
 324       if (src2.is_ssa) {
 325          return src1.ssa == src2.ssa;
 326       } else {
 327          return false;
 328       }
 329    } else {
 330       if (src2.is_ssa) {
 331          return false;
 332       } else {
 333          if ((src1.reg.indirect == NULL) != (src2.reg.indirect == NULL))
 334             return false;
 335
 336          if (src1.reg.indirect) {
 337             if (!nir_srcs_equal(*src1.reg.indirect, *src2.reg.indirect))
 338                return false;
 339          }
 340
 341          return src1.reg.reg == src2.reg.reg &&
 342                 src1.reg.base_offset == src2.reg.base_offset;
 343       }
 344    }
 345 }
 346
 347 /**
 348  * If the \p s is an SSA value that was generated by a negation instruction,
 349  * that instruction is returned as a \c nir_alu_instr.  Otherwise \c NULL is
 350  * returned.
 351  */
 352 static nir_alu_instr *
 353 get_neg_instr(nir_src s)
 354 {
 355    nir_alu_instr *alu = nir_src_as_alu_instr(s);
 356
 357    return alu != NULL && (alu->op == nir_op_fneg || alu->op == nir_op_ineg)
 358           ? alu : NULL;
 359 }
 360
 361 bool
 362 nir_const_value_negative_equal(nir_const_value c1,
 363                                nir_const_value c2,
 364                                nir_alu_type full_type)
 365 {
 366    assert(nir_alu_type_get_base_type(full_type) != nir_type_invalid);
 367    assert(nir_alu_type_get_type_size(full_type) != 0);
 368
 369    switch (full_type) {
 370    case nir_type_float16:
 371       return _mesa_half_to_float(c1.u16) == -_mesa_half_to_float(c2.u16);
 372
 373    case nir_type_float32:
 374       return c1.f32 == -c2.f32;
 375
 376    case nir_type_float64:
 377       return c1.f64 == -c2.f64;
 378
 379    case nir_type_int8:
 380    case nir_type_uint8:
 381       return c1.i8 == -c2.i8;
 382
 383    case nir_type_int16:
 384    case nir_type_uint16:
 385       return c1.i16 == -c2.i16;
 386
 387    case nir_type_int32:
 388    case nir_type_uint32:
 389       return c1.i32 == -c2.i32;
 390
 391    case nir_type_int64:
 392    case nir_type_uint64:
 393       return c1.i64 == -c2.i64;
 394
 395    default:
 396       break;
 397    }
 398
 399    return false;
 400 }
 401
 402 /**
 403  * Shallow compare of ALU srcs to determine if one is the negation of the other
 404  *
 405  * This function detects cases where \p alu1 is a constant and \p alu2 is a
 406  * constant that is its negation.  It will also detect cases where \p alu2 is
 407  * an SSA value that is a \c nir_op_fneg applied to \p alu1 (and vice versa).
 408  *
 409  * This function does not detect the general case when \p alu1 and \p alu2 are
 410  * SSA values that are the negations of each other (e.g., \p alu1 represents
 411  * (a * b) and \p alu2 represents (-a * b)).
 412  *
 413  * \warning
 414  * It is the responsibility of the caller to ensure that the component counts,
 415  * write masks, and base types of the sources being compared are compatible.
 416  */
 417 bool
 418 nir_alu_srcs_negative_equal(const nir_alu_instr *alu1,
 419                             const nir_alu_instr *alu2,
 420                             unsigned src1, unsigned src2)
 421 {
 422 #ifndef NDEBUG
 423    for (unsigned i = 0; i < NIR_MAX_VEC_COMPONENTS; i++) {
 424       assert(nir_alu_instr_channel_used(alu1, src1, i) ==
 425              nir_alu_instr_channel_used(alu2, src2, i));
 426    }
 427
 428    if (nir_op_infos[alu1->op].input_types[src1] == nir_type_float) {
 429       assert(nir_op_infos[alu1->op].input_types[src1] ==
 430              nir_op_infos[alu2->op].input_types[src2]);
 431    } else {
 432       assert(nir_op_infos[alu1->op].input_types[src1] == nir_type_int);
 433       assert(nir_op_infos[alu2->op].input_types[src2] == nir_type_int);
 434    }
 435 #endif
 436
 437    if (alu1->src[src1].abs != alu2->src[src2].abs)
 438       return false;
 439
 440    bool parity = alu1->src[src1].negate != alu2->src[src2].negate;
 441
 442    /* Handling load_const instructions is tricky. */
 443
 444    const nir_const_value *const const1 =
 445       nir_src_as_const_value(alu1->src[src1].src);
 446
 447    if (const1 != NULL) {
 448       /* Assume that constant folding will eliminate source mods and unary
 449        * ops.
 450        */
 451       if (parity)
 452          return false;
 453
 454       const nir_const_value *const const2 =
 455          nir_src_as_const_value(alu2->src[src2].src);
 456
 457       if (const2 == NULL)
 458          return false;
 459
 460       if (nir_src_bit_size(alu1->src[src1].src) !=
 461           nir_src_bit_size(alu2->src[src2].src))
 462          return false;
 463
 464       const nir_alu_type full_type = nir_op_infos[alu1->op].input_types[src1] |
 465                                      nir_src_bit_size(alu1->src[src1].src);
 466       for (unsigned i = 0; i < NIR_MAX_VEC_COMPONENTS; i++) {
 467          if (nir_alu_instr_channel_used(alu1, src1, i) &&
 468              !nir_const_value_negative_equal(const1[alu1->src[src1].swizzle[i]],
 469                                              const2[alu2->src[src2].swizzle[i]],
 470                                              full_type))
 471             return false;
 472       }
 473
 474       return true;
 475    }
 476
 477    uint8_t alu1_swizzle[4] = {0};
 478    nir_src alu1_actual_src;
 479    nir_alu_instr *neg1 = get_neg_instr(alu1->src[src1].src);
 480
 481    if (neg1) {
 482       parity = !parity;
 483       alu1_actual_src = neg1->src[0].src;
 484
 485       for (unsigned i = 0; i < nir_ssa_alu_instr_src_components(neg1, 0); i++)
 486          alu1_swizzle[i] = neg1->src[0].swizzle[i];
 487    } else {
 488       alu1_actual_src = alu1->src[src1].src;
 489
 490       for (unsigned i = 0; i < nir_ssa_alu_instr_src_components(alu1, src1); i++)
 491          alu1_swizzle[i] = i;
 492    }
 493
 494    uint8_t alu2_swizzle[4] = {0};
 495    nir_src alu2_actual_src;
 496    nir_alu_instr *neg2 = get_neg_instr(alu2->src[src2].src);
 497
 498    if (neg2) {
 499       parity = !parity;
 500       alu2_actual_src = neg2->src[0].src;
 501
 502       for (unsigned i = 0; i < nir_ssa_alu_instr_src_components(neg2, 0); i++)
 503          alu2_swizzle[i] = neg2->src[0].swizzle[i];
 504    } else {
 505       alu2_actual_src = alu2->src[src2].src;
 506
 507       for (unsigned i = 0; i < nir_ssa_alu_instr_src_components(alu2, src2); i++)
 508          alu2_swizzle[i] = i;
 509    }
 510
 511    for (unsigned i = 0; i < nir_ssa_alu_instr_src_components(alu1, src1); i++) {
 512       if (alu1_swizzle[alu1->src[src1].swizzle[i]] !=
 513           alu2_swizzle[alu2->src[src2].swizzle[i]])
 514          return false;
 515    }
 516
 517    return parity && nir_srcs_equal(alu1_actual_src, alu2_actual_src);
 518 }
 519
 520 bool
 521 nir_alu_srcs_equal(const nir_alu_instr *alu1, const nir_alu_instr *alu2,
 522                    unsigned src1, unsigned src2)
 523 {
 524    if (alu1->src[src1].abs != alu2->src[src2].abs ||
 525        alu1->src[src1].negate != alu2->src[src2].negate)
 526       return false;
 527
 528    for (unsigned i = 0; i < nir_ssa_alu_instr_src_components(alu1, src1); i++) {
 529       if (alu1->src[src1].swizzle[i] != alu2->src[src2].swizzle[i])
 530          return false;
 531    }
 532
 533    return nir_srcs_equal(alu1->src[src1].src, alu2->src[src2].src);
 534 }
 535
 536 /* Returns "true" if two instructions are equal. Note that this will only
 537  * work for the subset of instructions defined by instr_can_rewrite(). Also,
 538  * it should only return "true" for instructions that hash_instr() will return
 539  * the same hash for (ignoring collisions, of course).
 540  */
 541
 542 bool
 543 nir_instrs_equal(const nir_instr *instr1, const nir_instr *instr2)
 544 {
 545    assert(instr_can_rewrite(instr1) && instr_can_rewrite(instr2));
 546
 547    if (instr1->type != instr2->type)
 548       return false;
 549
 550    switch (instr1->type) {
 551    case nir_instr_type_alu: {
 552       nir_alu_instr *alu1 = nir_instr_as_alu(instr1);
 553       nir_alu_instr *alu2 = nir_instr_as_alu(instr2);
 554
 555       if (alu1->op != alu2->op)
 556          return false;
 557
 558       /* We explicitly don't compare instr->exact. */
 559
 560       if (alu1->no_signed_wrap != alu2->no_signed_wrap)
 561          return false;
 562
 563       if (alu1->no_unsigned_wrap != alu2->no_unsigned_wrap)
 564          return false;
 565
 566       /* TODO: We can probably acutally do something more inteligent such
 567        * as allowing different numbers and taking a maximum or something
 568        * here */
 569       if (alu1->dest.dest.ssa.num_components != alu2->dest.dest.ssa.num_components)
 570          return false;
 571
 572       if (alu1->dest.dest.ssa.bit_size != alu2->dest.dest.ssa.bit_size)
 573          return false;
 574
 575       if (nir_op_infos[alu1->op].algebraic_properties & NIR_OP_IS_2SRC_COMMUTATIVE) {
 576          if ((!nir_alu_srcs_equal(alu1, alu2, 0, 0) ||
 577               !nir_alu_srcs_equal(alu1, alu2, 1, 1)) &&
 578              (!nir_alu_srcs_equal(alu1, alu2, 0, 1) ||
 579               !nir_alu_srcs_equal(alu1, alu2, 1, 0)))
 580             return false;
 581
 582          for (unsigned i = 2; i < nir_op_infos[alu1->op].num_inputs; i++) {
 583             if (!nir_alu_srcs_equal(alu1, alu2, i, i))
 584                return false;
 585          }
 586       } else {
 587          for (unsigned i = 0; i < nir_op_infos[alu1->op].num_inputs; i++) {
 588             if (!nir_alu_srcs_equal(alu1, alu2, i, i))
 589                return false;
 590          }
 591       }
 592       return true;
 593    }
 594    case nir_instr_type_deref: {
 595       nir_deref_instr *deref1 = nir_instr_as_deref(instr1);
 596       nir_deref_instr *deref2 = nir_instr_as_deref(instr2);
 597
 598       if (deref1->deref_type != deref2->deref_type ||
 599           deref1->mode != deref2->mode ||
 600           deref1->type != deref2->type)
 601          return false;
 602
 603       if (deref1->deref_type == nir_deref_type_var)
 604          return deref1->var == deref2->var;
 605
 606       if (!nir_srcs_equal(deref1->parent, deref2->parent))
 607          return false;
 608
 609       switch (deref1->deref_type) {
 610       case nir_deref_type_struct:
 611          if (deref1->strct.index != deref2->strct.index)
 612             return false;
 613          break;
 614
 615       case nir_deref_type_array:
 616       case nir_deref_type_ptr_as_array:
 617          if (!nir_srcs_equal(deref1->arr.index, deref2->arr.index))
 618             return false;
 619          break;
 620
 621       case nir_deref_type_cast:
 622          if (deref1->cast.ptr_stride != deref2->cast.ptr_stride)
 623             return false;
 624          break;
 625
 626       case nir_deref_type_var:
 627       case nir_deref_type_array_wildcard:
 628          /* Nothing to do */
 629          break;
 630
 631       default:
 632          unreachable("Invalid instruction deref type");
 633       }
 634       return true;
 635    }
 636    case nir_instr_type_tex: {
 637       nir_tex_instr *tex1 = nir_instr_as_tex(instr1);
 638       nir_tex_instr *tex2 = nir_instr_as_tex(instr2);
 639
 640       if (tex1->op != tex2->op)
 641          return false;
 642
 643       if (tex1->num_srcs != tex2->num_srcs)
 644          return false;
 645       for (unsigned i = 0; i < tex1->num_srcs; i++) {
 646          if (tex1->src[i].src_type != tex2->src[i].src_type ||
 647              !nir_srcs_equal(tex1->src[i].src, tex2->src[i].src)) {
 648             return false;
 649          }
 650       }
 651
 652       if (tex1->coord_components != tex2->coord_components ||
 653           tex1->sampler_dim != tex2->sampler_dim ||
 654           tex1->is_array != tex2->is_array ||
 655           tex1->is_shadow != tex2->is_shadow ||
 656           tex1->is_new_style_shadow != tex2->is_new_style_shadow ||
 657           tex1->component != tex2->component ||
 658          tex1->texture_index != tex2->texture_index ||
 659          tex1->sampler_index != tex2->sampler_index) {
 660          return false;
 661       }
 662
 663       if (memcmp(tex1->tg4_offsets, tex2->tg4_offsets,
 664                  sizeof(tex1->tg4_offsets)))
 665          return false;
 666
 667       return true;
 668    }
 669    case nir_instr_type_load_const: {
 670       nir_load_const_instr *load1 = nir_instr_as_load_const(instr1);
 671       nir_load_const_instr *load2 = nir_instr_as_load_const(instr2);
 672
 673       if (load1->def.num_components != load2->def.num_components)
 674          return false;
 675
 676       if (load1->def.bit_size != load2->def.bit_size)
 677          return false;
 678
 679       if (load1->def.bit_size == 1) {
 680          for (unsigned i = 0; i < load1->def.num_components; ++i) {
 681             if (load1->value[i].b != load2->value[i].b)
 682                return false;
 683          }
 684       } else {
 685          unsigned size = load1->def.num_components * sizeof(*load1->value);
 686          if (memcmp(load1->value, load2->value, size) != 0)
 687             return false;
 688       }
 689       return true;
 690    }
 691    case nir_instr_type_phi: {
 692       nir_phi_instr *phi1 = nir_instr_as_phi(instr1);
 693       nir_phi_instr *phi2 = nir_instr_as_phi(instr2);
 694
 695       if (phi1->instr.block != phi2->instr.block)
 696          return false;
 697
 698       nir_foreach_phi_src(src1, phi1) {
 699          nir_foreach_phi_src(src2, phi2) {
 700             if (src1->pred == src2->pred) {
 701                if (!nir_srcs_equal(src1->src, src2->src))
 702                   return false;
 703
 704                break;
 705             }
 706          }
 707       }
 708
 709       return true;
 710    }
 711    case nir_instr_type_intrinsic: {
 712       nir_intrinsic_instr *intrinsic1 = nir_instr_as_intrinsic(instr1);
 713       nir_intrinsic_instr *intrinsic2 = nir_instr_as_intrinsic(instr2);
 714       const nir_intrinsic_info *info =
 715          &nir_intrinsic_infos[intrinsic1->intrinsic];
 716
 717       if (intrinsic1->intrinsic != intrinsic2->intrinsic ||
 718           intrinsic1->num_components != intrinsic2->num_components)
 719          return false;
 720
 721       if (info->has_dest && intrinsic1->dest.ssa.num_components !=
 722                             intrinsic2->dest.ssa.num_components)
 723          return false;
 724
 725       if (info->has_dest && intrinsic1->dest.ssa.bit_size !=
 726                             intrinsic2->dest.ssa.bit_size)
 727          return false;
 728
 729       for (unsigned i = 0; i < info->num_srcs; i++) {
 730          if (!nir_srcs_equal(intrinsic1->src[i], intrinsic2->src[i]))
 731             return false;
 732       }
 733
 734       for (unsigned i = 0; i < info->num_indices; i++) {
 735          if (intrinsic1->const_index[i] != intrinsic2->const_index[i])
 736             return false;
 737       }
 738
 739       return true;
 740    }
 741    case nir_instr_type_call:
 742    case nir_instr_type_jump:
 743    case nir_instr_type_ssa_undef:
 744    case nir_instr_type_parallel_copy:
 745    default:
 746       unreachable("Invalid instruction type");
 747    }
 748
 749    unreachable("All cases in the above switch should return");
 750 }
 751
 752 static nir_ssa_def *
 753 nir_instr_get_dest_ssa_def(nir_instr *instr)
 754 {
 755    switch (instr->type) {
 756    case nir_instr_type_alu:
 757       assert(nir_instr_as_alu(instr)->dest.dest.is_ssa);
 758       return &nir_instr_as_alu(instr)->dest.dest.ssa;
 759    case nir_instr_type_deref:
 760       assert(nir_instr_as_deref(instr)->dest.is_ssa);
 761       return &nir_instr_as_deref(instr)->dest.ssa;
 762    case nir_instr_type_load_const:
 763       return &nir_instr_as_load_const(instr)->def;
 764    case nir_instr_type_phi:
 765       assert(nir_instr_as_phi(instr)->dest.is_ssa);
 766       return &nir_instr_as_phi(instr)->dest.ssa;
 767    case nir_instr_type_intrinsic:
 768       assert(nir_instr_as_intrinsic(instr)->dest.is_ssa);
 769       return &nir_instr_as_intrinsic(instr)->dest.ssa;
 770    case nir_instr_type_tex:
 771       assert(nir_instr_as_tex(instr)->dest.is_ssa);
 772       return &nir_instr_as_tex(instr)->dest.ssa;
 773    default:
 774       unreachable("We never ask for any of these");
 775    }
 776 }
 777
 778 static bool
 779 cmp_func(const void *data1, const void *data2)
 780 {
 781    return nir_instrs_equal(data1, data2);
 782 }
 783
 784 struct set *
 785 nir_instr_set_create(void *mem_ctx)
 786 {
 787    return _mesa_set_create(mem_ctx, hash_instr, cmp_func);
 788 }
 789
 790 void
 791 nir_instr_set_destroy(struct set *instr_set)
 792 {
 793    _mesa_set_destroy(instr_set, NULL);
 794 }
 795
 796 bool
 797 nir_instr_set_add_or_rewrite(struct set *instr_set, nir_instr *instr)
 798 {
 799    if (!instr_can_rewrite(instr))
 800       return false;
 801
 802    struct set_entry *e = _mesa_set_search_or_add(instr_set, instr);
 803    nir_instr *match = (nir_instr *) e->key;
 804    if (match != instr) {
 805       nir_ssa_def *def = nir_instr_get_dest_ssa_def(instr);
 806       nir_ssa_def *new_def = nir_instr_get_dest_ssa_def(match);
 807
 808       /* It's safe to replace an exact instruction with an inexact one as
 809        * long as we make it exact.  If we got here, the two instructions are
 810        * exactly identical in every other way so, once we've set the exact
 811        * bit, they are the same.
 812        */
 813       if (instr->type == nir_instr_type_alu && nir_instr_as_alu(instr)->exact)
 814          nir_instr_as_alu(match)->exact = true;
 815
 816       nir_ssa_def_rewrite_uses(def, nir_src_for_ssa(new_def));
 817       return true;
 818    }
 819
 820    return false;
 821 }
 822
 823 void
 824 nir_instr_set_remove(struct set *instr_set, nir_instr *instr)
 825 {
 826    if (!instr_can_rewrite(instr))
 827       return;
 828
 829    struct set_entry *entry = _mesa_set_search(instr_set, instr);
 830    if (entry)
 831       _mesa_set_remove(instr_set, entry);
 832 }
 833