src/glsl/nir/nir.c

   1 /*
   2  * Copyright © 2014 Intel Corporation
   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  * Authors:
  24  *    Connor Abbott (cwabbott0@gmail.com)
  25  *
  26  */
  27
  28 #include "nir.h"
  29 #include "nir_control_flow_private.h"
  30 #include <assert.h>
  31
  32 nir_shader *
  33 nir_shader_create(void *mem_ctx,
  34                   gl_shader_stage stage,
  35                   const nir_shader_compiler_options *options)
  36 {
  37    nir_shader *shader = ralloc(mem_ctx, nir_shader);
  38
  39    exec_list_make_empty(&shader->uniforms);
  40    exec_list_make_empty(&shader->inputs);
  41    exec_list_make_empty(&shader->outputs);
  42
  43    shader->options = options;
  44    memset(&shader->info, 0, sizeof(shader->info));
  45
  46    exec_list_make_empty(&shader->functions);
  47    exec_list_make_empty(&shader->registers);
  48    exec_list_make_empty(&shader->globals);
  49    exec_list_make_empty(&shader->system_values);
  50    shader->reg_alloc = 0;
  51
  52    shader->num_inputs = 0;
  53    shader->num_outputs = 0;
  54    shader->num_uniforms = 0;
  55
  56    shader->stage = stage;
  57
  58    return shader;
  59 }
  60
  61 static nir_register *
  62 reg_create(void *mem_ctx, struct exec_list *list)
  63 {
  64    nir_register *reg = ralloc(mem_ctx, nir_register);
  65
  66    list_inithead(&reg->uses);
  67    list_inithead(&reg->defs);
  68    list_inithead(&reg->if_uses);
  69
  70    reg->num_components = 0;
  71    reg->num_array_elems = 0;
  72    reg->is_packed = false;
  73    reg->name = NULL;
  74
  75    exec_list_push_tail(list, &reg->node);
  76
  77    return reg;
  78 }
  79
  80 nir_register *
  81 nir_global_reg_create(nir_shader *shader)
  82 {
  83    nir_register *reg = reg_create(shader, &shader->registers);
  84    reg->index = shader->reg_alloc++;
  85    reg->is_global = true;
  86
  87    return reg;
  88 }
  89
  90 nir_register *
  91 nir_local_reg_create(nir_function_impl *impl)
  92 {
  93    nir_register *reg = reg_create(ralloc_parent(impl), &impl->registers);
  94    reg->index = impl->reg_alloc++;
  95    reg->is_global = false;
  96
  97    return reg;
  98 }
  99
 100 void
 101 nir_reg_remove(nir_register *reg)
 102 {
 103    exec_node_remove(&reg->node);
 104 }
 105
 106 void
 107 nir_shader_add_variable(nir_shader *shader, nir_variable *var)
 108 {
 109    switch (var->data.mode) {
 110    case nir_var_local:
 111       assert(!"nir_shader_add_variable cannot be used for local variables");
 112       break;
 113
 114    case nir_var_global:
 115       exec_list_push_tail(&shader->globals, &var->node);
 116       break;
 117
 118    case nir_var_shader_in:
 119       exec_list_push_tail(&shader->inputs, &var->node);
 120       break;
 121
 122    case nir_var_shader_out:
 123       exec_list_push_tail(&shader->outputs, &var->node);
 124       break;
 125
 126    case nir_var_uniform:
 127    case nir_var_shader_storage:
 128       exec_list_push_tail(&shader->uniforms, &var->node);
 129       break;
 130
 131    case nir_var_system_value:
 132       exec_list_push_tail(&shader->system_values, &var->node);
 133       break;
 134    }
 135 }
 136
 137 nir_variable *
 138 nir_variable_create(nir_shader *shader, nir_variable_mode mode,
 139                     const struct glsl_type *type, const char *name)
 140 {
 141    nir_variable *var = rzalloc(shader, nir_variable);
 142    var->name = ralloc_strdup(var, name);
 143    var->type = type;
 144    var->data.mode = mode;
 145
 146    if ((mode == nir_var_shader_in && shader->stage != MESA_SHADER_VERTEX) ||
 147        (mode == nir_var_shader_out && shader->stage != MESA_SHADER_FRAGMENT))
 148       var->data.interpolation = INTERP_QUALIFIER_SMOOTH;
 149
 150    if (mode == nir_var_shader_in || mode == nir_var_uniform)
 151       var->data.read_only = true;
 152
 153    nir_shader_add_variable(shader, var);
 154
 155    return var;
 156 }
 157
 158 nir_variable *
 159 nir_local_variable_create(nir_function_impl *impl,
 160                           const struct glsl_type *type, const char *name)
 161 {
 162    nir_variable *var = rzalloc(impl->overload->function->shader, nir_variable);
 163    var->name = ralloc_strdup(var, name);
 164    var->type = type;
 165    var->data.mode = nir_var_local;
 166
 167    nir_function_impl_add_variable(impl, var);
 168
 169    return var;
 170 }
 171
 172 nir_function *
 173 nir_function_create(nir_shader *shader, const char *name)
 174 {
 175    nir_function *func = ralloc(shader, nir_function);
 176
 177    exec_list_push_tail(&shader->functions, &func->node);
 178    exec_list_make_empty(&func->overload_list);
 179    func->name = ralloc_strdup(func, name);
 180    func->shader = shader;
 181
 182    return func;
 183 }
 184
 185 nir_function_overload *
 186 nir_function_overload_create(nir_function *func)
 187 {
 188    void *mem_ctx = ralloc_parent(func);
 189
 190    nir_function_overload *overload = ralloc(mem_ctx, nir_function_overload);
 191
 192    overload->num_params = 0;
 193    overload->params = NULL;
 194    overload->return_type = glsl_void_type();
 195    overload->impl = NULL;
 196
 197    exec_list_push_tail(&func->overload_list, &overload->node);
 198    overload->function = func;
 199
 200    return overload;
 201 }
 202
 203 void nir_src_copy(nir_src *dest, const nir_src *src, void *mem_ctx)
 204 {
 205    dest->is_ssa = src->is_ssa;
 206    if (src->is_ssa) {
 207       dest->ssa = src->ssa;
 208    } else {
 209       dest->reg.base_offset = src->reg.base_offset;
 210       dest->reg.reg = src->reg.reg;
 211       if (src->reg.indirect) {
 212          dest->reg.indirect = ralloc(mem_ctx, nir_src);
 213          nir_src_copy(dest->reg.indirect, src->reg.indirect, mem_ctx);
 214       } else {
 215          dest->reg.indirect = NULL;
 216       }
 217    }
 218 }
 219
 220 void nir_dest_copy(nir_dest *dest, const nir_dest *src, nir_instr *instr)
 221 {
 222    /* Copying an SSA definition makes no sense whatsoever. */
 223    assert(!src->is_ssa);
 224
 225    dest->is_ssa = false;
 226
 227    dest->reg.base_offset = src->reg.base_offset;
 228    dest->reg.reg = src->reg.reg;
 229    if (src->reg.indirect) {
 230       dest->reg.indirect = ralloc(instr, nir_src);
 231       nir_src_copy(dest->reg.indirect, src->reg.indirect, instr);
 232    } else {
 233       dest->reg.indirect = NULL;
 234    }
 235 }
 236
 237 void
 238 nir_alu_src_copy(nir_alu_src *dest, const nir_alu_src *src,
 239                  nir_alu_instr *instr)
 240 {
 241    nir_src_copy(&dest->src, &src->src, &instr->instr);
 242    dest->abs = src->abs;
 243    dest->negate = src->negate;
 244    for (unsigned i = 0; i < 4; i++)
 245       dest->swizzle[i] = src->swizzle[i];
 246 }
 247
 248 void
 249 nir_alu_dest_copy(nir_alu_dest *dest, const nir_alu_dest *src,
 250                   nir_alu_instr *instr)
 251 {
 252    nir_dest_copy(&dest->dest, &src->dest, &instr->instr);
 253    dest->write_mask = src->write_mask;
 254    dest->saturate = src->saturate;
 255 }
 256
 257
 258 static void
 259 cf_init(nir_cf_node *node, nir_cf_node_type type)
 260 {
 261    exec_node_init(&node->node);
 262    node->parent = NULL;
 263    node->type = type;
 264 }
 265
 266 nir_function_impl *
 267 nir_function_impl_create(nir_function_overload *overload)
 268 {
 269    assert(overload->impl == NULL);
 270
 271    void *mem_ctx = ralloc_parent(overload);
 272
 273    nir_function_impl *impl = ralloc(mem_ctx, nir_function_impl);
 274
 275    overload->impl = impl;
 276    impl->overload = overload;
 277
 278    cf_init(&impl->cf_node, nir_cf_node_function);
 279
 280    exec_list_make_empty(&impl->body);
 281    exec_list_make_empty(&impl->registers);
 282    exec_list_make_empty(&impl->locals);
 283    impl->num_params = 0;
 284    impl->params = NULL;
 285    impl->return_var = NULL;
 286    impl->reg_alloc = 0;
 287    impl->ssa_alloc = 0;
 288    impl->valid_metadata = nir_metadata_none;
 289
 290    /* create start & end blocks */
 291    nir_block *start_block = nir_block_create(mem_ctx);
 292    nir_block *end_block = nir_block_create(mem_ctx);
 293    start_block->cf_node.parent = &impl->cf_node;
 294    end_block->cf_node.parent = &impl->cf_node;
 295    impl->end_block = end_block;
 296
 297    exec_list_push_tail(&impl->body, &start_block->cf_node.node);
 298
 299    start_block->successors[0] = end_block;
 300    _mesa_set_add(end_block->predecessors, start_block);
 301    return impl;
 302 }
 303
 304 nir_block *
 305 nir_block_create(void *mem_ctx)
 306 {
 307    nir_block *block = ralloc(mem_ctx, nir_block);
 308
 309    cf_init(&block->cf_node, nir_cf_node_block);
 310
 311    block->successors[0] = block->successors[1] = NULL;
 312    block->predecessors = _mesa_set_create(block, _mesa_hash_pointer,
 313                                           _mesa_key_pointer_equal);
 314    block->imm_dom = NULL;
 315    block->dom_frontier = _mesa_set_create(block, _mesa_hash_pointer,
 316                                           _mesa_key_pointer_equal);
 317
 318    exec_list_make_empty(&block->instr_list);
 319
 320    return block;
 321 }
 322
 323 static inline void
 324 src_init(nir_src *src)
 325 {
 326    src->is_ssa = false;
 327    src->reg.reg = NULL;
 328    src->reg.indirect = NULL;
 329    src->reg.base_offset = 0;
 330 }
 331
 332 nir_if *
 333 nir_if_create(void *mem_ctx)
 334 {
 335    nir_if *if_stmt = ralloc(mem_ctx, nir_if);
 336
 337    cf_init(&if_stmt->cf_node, nir_cf_node_if);
 338    src_init(&if_stmt->condition);
 339
 340    nir_block *then = nir_block_create(mem_ctx);
 341    exec_list_make_empty(&if_stmt->then_list);
 342    exec_list_push_tail(&if_stmt->then_list, &then->cf_node.node);
 343    then->cf_node.parent = &if_stmt->cf_node;
 344
 345    nir_block *else_stmt = nir_block_create(mem_ctx);
 346    exec_list_make_empty(&if_stmt->else_list);
 347    exec_list_push_tail(&if_stmt->else_list, &else_stmt->cf_node.node);
 348    else_stmt->cf_node.parent = &if_stmt->cf_node;
 349
 350    return if_stmt;
 351 }
 352
 353 nir_loop *
 354 nir_loop_create(void *mem_ctx)
 355 {
 356    nir_loop *loop = ralloc(mem_ctx, nir_loop);
 357
 358    cf_init(&loop->cf_node, nir_cf_node_loop);
 359
 360    nir_block *body = nir_block_create(mem_ctx);
 361    exec_list_make_empty(&loop->body);
 362    exec_list_push_tail(&loop->body, &body->cf_node.node);
 363    body->cf_node.parent = &loop->cf_node;
 364
 365    body->successors[0] = body;
 366    _mesa_set_add(body->predecessors, body);
 367
 368    return loop;
 369 }
 370
 371 static void
 372 instr_init(nir_instr *instr, nir_instr_type type)
 373 {
 374    instr->type = type;
 375    instr->block = NULL;
 376    exec_node_init(&instr->node);
 377 }
 378
 379 static void
 380 dest_init(nir_dest *dest)
 381 {
 382    dest->is_ssa = false;
 383    dest->reg.reg = NULL;
 384    dest->reg.indirect = NULL;
 385    dest->reg.base_offset = 0;
 386 }
 387
 388 static void
 389 alu_dest_init(nir_alu_dest *dest)
 390 {
 391    dest_init(&dest->dest);
 392    dest->saturate = false;
 393    dest->write_mask = 0xf;
 394 }
 395
 396 static void
 397 alu_src_init(nir_alu_src *src)
 398 {
 399    src_init(&src->src);
 400    src->abs = src->negate = false;
 401    src->swizzle[0] = 0;
 402    src->swizzle[1] = 1;
 403    src->swizzle[2] = 2;
 404    src->swizzle[3] = 3;
 405 }
 406
 407 nir_alu_instr *
 408 nir_alu_instr_create(nir_shader *shader, nir_op op)
 409 {
 410    unsigned num_srcs = nir_op_infos[op].num_inputs;
 411    nir_alu_instr *instr =
 412       ralloc_size(shader,
 413                   sizeof(nir_alu_instr) + num_srcs * sizeof(nir_alu_src));
 414
 415    instr_init(&instr->instr, nir_instr_type_alu);
 416    instr->op = op;
 417    alu_dest_init(&instr->dest);
 418    for (unsigned i = 0; i < num_srcs; i++)
 419       alu_src_init(&instr->src[i]);
 420
 421    return instr;
 422 }
 423
 424 nir_jump_instr *
 425 nir_jump_instr_create(nir_shader *shader, nir_jump_type type)
 426 {
 427    nir_jump_instr *instr = ralloc(shader, nir_jump_instr);
 428    instr_init(&instr->instr, nir_instr_type_jump);
 429    instr->type = type;
 430    return instr;
 431 }
 432
 433 nir_load_const_instr *
 434 nir_load_const_instr_create(nir_shader *shader, unsigned num_components)
 435 {
 436    nir_load_const_instr *instr = ralloc(shader, nir_load_const_instr);
 437    instr_init(&instr->instr, nir_instr_type_load_const);
 438
 439    nir_ssa_def_init(&instr->instr, &instr->def, num_components, NULL);
 440
 441    return instr;
 442 }
 443
 444 nir_intrinsic_instr *
 445 nir_intrinsic_instr_create(nir_shader *shader, nir_intrinsic_op op)
 446 {
 447    unsigned num_srcs = nir_intrinsic_infos[op].num_srcs;
 448    nir_intrinsic_instr *instr =
 449       ralloc_size(shader,
 450                   sizeof(nir_intrinsic_instr) + num_srcs * sizeof(nir_src));
 451
 452    instr_init(&instr->instr, nir_instr_type_intrinsic);
 453    instr->intrinsic = op;
 454
 455    if (nir_intrinsic_infos[op].has_dest)
 456       dest_init(&instr->dest);
 457
 458    for (unsigned i = 0; i < num_srcs; i++)
 459       src_init(&instr->src[i]);
 460
 461    return instr;
 462 }
 463
 464 nir_call_instr *
 465 nir_call_instr_create(nir_shader *shader, nir_function_overload *callee)
 466 {
 467    nir_call_instr *instr = ralloc(shader, nir_call_instr);
 468    instr_init(&instr->instr, nir_instr_type_call);
 469
 470    instr->callee = callee;
 471    instr->num_params = callee->num_params;
 472    instr->params = ralloc_array(instr, nir_deref_var *, instr->num_params);
 473    instr->return_deref = NULL;
 474
 475    return instr;
 476 }
 477
 478 nir_tex_instr *
 479 nir_tex_instr_create(nir_shader *shader, unsigned num_srcs)
 480 {
 481    nir_tex_instr *instr = rzalloc(shader, nir_tex_instr);
 482    instr_init(&instr->instr, nir_instr_type_tex);
 483
 484    dest_init(&instr->dest);
 485
 486    instr->num_srcs = num_srcs;
 487    instr->src = ralloc_array(instr, nir_tex_src, num_srcs);
 488    for (unsigned i = 0; i < num_srcs; i++)
 489       src_init(&instr->src[i].src);
 490
 491    instr->sampler_index = 0;
 492    instr->sampler_array_size = 0;
 493    instr->sampler = NULL;
 494
 495    return instr;
 496 }
 497
 498 nir_phi_instr *
 499 nir_phi_instr_create(nir_shader *shader)
 500 {
 501    nir_phi_instr *instr = ralloc(shader, nir_phi_instr);
 502    instr_init(&instr->instr, nir_instr_type_phi);
 503
 504    dest_init(&instr->dest);
 505    exec_list_make_empty(&instr->srcs);
 506    return instr;
 507 }
 508
 509 nir_parallel_copy_instr *
 510 nir_parallel_copy_instr_create(nir_shader *shader)
 511 {
 512    nir_parallel_copy_instr *instr = ralloc(shader, nir_parallel_copy_instr);
 513    instr_init(&instr->instr, nir_instr_type_parallel_copy);
 514
 515    exec_list_make_empty(&instr->entries);
 516
 517    return instr;
 518 }
 519
 520 nir_ssa_undef_instr *
 521 nir_ssa_undef_instr_create(nir_shader *shader, unsigned num_components)
 522 {
 523    nir_ssa_undef_instr *instr = ralloc(shader, nir_ssa_undef_instr);
 524    instr_init(&instr->instr, nir_instr_type_ssa_undef);
 525
 526    nir_ssa_def_init(&instr->instr, &instr->def, num_components, NULL);
 527
 528    return instr;
 529 }
 530
 531 nir_deref_var *
 532 nir_deref_var_create(void *mem_ctx, nir_variable *var)
 533 {
 534    nir_deref_var *deref = ralloc(mem_ctx, nir_deref_var);
 535    deref->deref.deref_type = nir_deref_type_var;
 536    deref->deref.child = NULL;
 537    deref->deref.type = var->type;
 538    deref->var = var;
 539    return deref;
 540 }
 541
 542 nir_deref_array *
 543 nir_deref_array_create(void *mem_ctx)
 544 {
 545    nir_deref_array *deref = ralloc(mem_ctx, nir_deref_array);
 546    deref->deref.deref_type = nir_deref_type_array;
 547    deref->deref.child = NULL;
 548    deref->deref_array_type = nir_deref_array_type_direct;
 549    src_init(&deref->indirect);
 550    deref->base_offset = 0;
 551    return deref;
 552 }
 553
 554 nir_deref_struct *
 555 nir_deref_struct_create(void *mem_ctx, unsigned field_index)
 556 {
 557    nir_deref_struct *deref = ralloc(mem_ctx, nir_deref_struct);
 558    deref->deref.deref_type = nir_deref_type_struct;
 559    deref->deref.child = NULL;
 560    deref->index = field_index;
 561    return deref;
 562 }
 563
 564 static nir_deref_var *
 565 copy_deref_var(void *mem_ctx, nir_deref_var *deref)
 566 {
 567    nir_deref_var *ret = nir_deref_var_create(mem_ctx, deref->var);
 568    ret->deref.type = deref->deref.type;
 569    if (deref->deref.child)
 570       ret->deref.child = nir_copy_deref(ret, deref->deref.child);
 571    return ret;
 572 }
 573
 574 static nir_deref_array *
 575 copy_deref_array(void *mem_ctx, nir_deref_array *deref)
 576 {
 577    nir_deref_array *ret = nir_deref_array_create(mem_ctx);
 578    ret->base_offset = deref->base_offset;
 579    ret->deref_array_type = deref->deref_array_type;
 580    if (deref->deref_array_type == nir_deref_array_type_indirect) {
 581       nir_src_copy(&ret->indirect, &deref->indirect, mem_ctx);
 582    }
 583    ret->deref.type = deref->deref.type;
 584    if (deref->deref.child)
 585       ret->deref.child = nir_copy_deref(ret, deref->deref.child);
 586    return ret;
 587 }
 588
 589 static nir_deref_struct *
 590 copy_deref_struct(void *mem_ctx, nir_deref_struct *deref)
 591 {
 592    nir_deref_struct *ret = nir_deref_struct_create(mem_ctx, deref->index);
 593    ret->deref.type = deref->deref.type;
 594    if (deref->deref.child)
 595       ret->deref.child = nir_copy_deref(ret, deref->deref.child);
 596    return ret;
 597 }
 598
 599 nir_deref *
 600 nir_copy_deref(void *mem_ctx, nir_deref *deref)
 601 {
 602    switch (deref->deref_type) {
 603    case nir_deref_type_var:
 604       return &copy_deref_var(mem_ctx, nir_deref_as_var(deref))->deref;
 605    case nir_deref_type_array:
 606       return &copy_deref_array(mem_ctx, nir_deref_as_array(deref))->deref;
 607    case nir_deref_type_struct:
 608       return &copy_deref_struct(mem_ctx, nir_deref_as_struct(deref))->deref;
 609    default:
 610       unreachable("Invalid dereference type");
 611    }
 612
 613    return NULL;
 614 }
 615
 616 /* Returns a load_const instruction that represents the constant
 617  * initializer for the given deref chain.  The caller is responsible for
 618  * ensuring that there actually is a constant initializer.
 619  */
 620 nir_load_const_instr *
 621 nir_deref_get_const_initializer_load(nir_shader *shader, nir_deref_var *deref)
 622 {
 623    nir_constant *constant = deref->var->constant_initializer;
 624    assert(constant);
 625
 626    const nir_deref *tail = &deref->deref;
 627    unsigned matrix_offset = 0;
 628    while (tail->child) {
 629       switch (tail->child->deref_type) {
 630       case nir_deref_type_array: {
 631          nir_deref_array *arr = nir_deref_as_array(tail->child);
 632          assert(arr->deref_array_type == nir_deref_array_type_direct);
 633          if (glsl_type_is_matrix(tail->type)) {
 634             assert(arr->deref.child == NULL);
 635             matrix_offset = arr->base_offset;
 636          } else {
 637             constant = constant->elements[arr->base_offset];
 638          }
 639          break;
 640       }
 641
 642       case nir_deref_type_struct: {
 643          constant = constant->elements[nir_deref_as_struct(tail->child)->index];
 644          break;
 645       }
 646
 647       default:
 648          unreachable("Invalid deref child type");
 649       }
 650
 651       tail = tail->child;
 652    }
 653
 654    nir_load_const_instr *load =
 655       nir_load_const_instr_create(shader, glsl_get_vector_elements(tail->type));
 656
 657    matrix_offset *= load->def.num_components;
 658    for (unsigned i = 0; i < load->def.num_components; i++) {
 659       switch (glsl_get_base_type(tail->type)) {
 660       case GLSL_TYPE_FLOAT:
 661       case GLSL_TYPE_INT:
 662       case GLSL_TYPE_UINT:
 663          load->value.u[i] = constant->value.u[matrix_offset + i];
 664          break;
 665       case GLSL_TYPE_BOOL:
 666          load->value.u[i] = constant->value.b[matrix_offset + i] ?
 667                              NIR_TRUE : NIR_FALSE;
 668          break;
 669       default:
 670          unreachable("Invalid immediate type");
 671       }
 672    }
 673
 674    return load;
 675 }
 676
 677 nir_function_impl *
 678 nir_cf_node_get_function(nir_cf_node *node)
 679 {
 680    while (node->type != nir_cf_node_function) {
 681       node = node->parent;
 682    }
 683
 684    return nir_cf_node_as_function(node);
 685 }
 686
 687 static bool
 688 add_use_cb(nir_src *src, void *state)
 689 {
 690    nir_instr *instr = state;
 691
 692    src->parent_instr = instr;
 693    list_addtail(&src->use_link,
 694                 src->is_ssa ? &src->ssa->uses : &src->reg.reg->uses);
 695
 696    return true;
 697 }
 698
 699 static bool
 700 add_ssa_def_cb(nir_ssa_def *def, void *state)
 701 {
 702    nir_instr *instr = state;
 703
 704    if (instr->block && def->index == UINT_MAX) {
 705       nir_function_impl *impl =
 706          nir_cf_node_get_function(&instr->block->cf_node);
 707
 708       def->index = impl->ssa_alloc++;
 709    }
 710
 711    return true;
 712 }
 713
 714 static bool
 715 add_reg_def_cb(nir_dest *dest, void *state)
 716 {
 717    nir_instr *instr = state;
 718
 719    if (!dest->is_ssa) {
 720       dest->reg.parent_instr = instr;
 721       list_addtail(&dest->reg.def_link, &dest->reg.reg->defs);
 722    }
 723
 724    return true;
 725 }
 726
 727 static void
 728 add_defs_uses(nir_instr *instr)
 729 {
 730    nir_foreach_src(instr, add_use_cb, instr);
 731    nir_foreach_dest(instr, add_reg_def_cb, instr);
 732    nir_foreach_ssa_def(instr, add_ssa_def_cb, instr);
 733 }
 734
 735 void
 736 nir_instr_insert(nir_cursor cursor, nir_instr *instr)
 737 {
 738    switch (cursor.option) {
 739    case nir_cursor_before_block:
 740       /* Only allow inserting jumps into empty blocks. */
 741       if (instr->type == nir_instr_type_jump)
 742          assert(exec_list_is_empty(&cursor.block->instr_list));
 743
 744       instr->block = cursor.block;
 745       add_defs_uses(instr);
 746       exec_list_push_head(&cursor.block->instr_list, &instr->node);
 747       break;
 748    case nir_cursor_after_block: {
 749       /* Inserting instructions after a jump is illegal. */
 750       nir_instr *last = nir_block_last_instr(cursor.block);
 751       assert(last == NULL || last->type != nir_instr_type_jump);
 752       (void) last;
 753
 754       instr->block = cursor.block;
 755       add_defs_uses(instr);
 756       exec_list_push_tail(&cursor.block->instr_list, &instr->node);
 757       break;
 758    }
 759    case nir_cursor_before_instr:
 760       assert(instr->type != nir_instr_type_jump);
 761       instr->block = cursor.instr->block;
 762       add_defs_uses(instr);
 763       exec_node_insert_node_before(&cursor.instr->node, &instr->node);
 764       break;
 765    case nir_cursor_after_instr:
 766       /* Inserting instructions after a jump is illegal. */
 767       assert(cursor.instr->type != nir_instr_type_jump);
 768
 769       /* Only allow inserting jumps at the end of the block. */
 770       if (instr->type == nir_instr_type_jump)
 771          assert(cursor.instr == nir_block_last_instr(cursor.instr->block));
 772
 773       instr->block = cursor.instr->block;
 774       add_defs_uses(instr);
 775       exec_node_insert_after(&cursor.instr->node, &instr->node);
 776       break;
 777    }
 778
 779    if (instr->type == nir_instr_type_jump)
 780       nir_handle_add_jump(instr->block);
 781 }
 782
 783 static bool
 784 src_is_valid(const nir_src *src)
 785 {
 786    return src->is_ssa ? (src->ssa != NULL) : (src->reg.reg != NULL);
 787 }
 788
 789 static bool
 790 remove_use_cb(nir_src *src, void *state)
 791 {
 792    if (src_is_valid(src))
 793       list_del(&src->use_link);
 794
 795    return true;
 796 }
 797
 798 static bool
 799 remove_def_cb(nir_dest *dest, void *state)
 800 {
 801    if (!dest->is_ssa)
 802       list_del(&dest->reg.def_link);
 803
 804    return true;
 805 }
 806
 807 static void
 808 remove_defs_uses(nir_instr *instr)
 809 {
 810    nir_foreach_dest(instr, remove_def_cb, instr);
 811    nir_foreach_src(instr, remove_use_cb, instr);
 812 }
 813
 814 void nir_instr_remove(nir_instr *instr)
 815 {
 816    remove_defs_uses(instr);
 817    exec_node_remove(&instr->node);
 818
 819    if (instr->type == nir_instr_type_jump) {
 820       nir_jump_instr *jump_instr = nir_instr_as_jump(instr);
 821       nir_handle_remove_jump(instr->block, jump_instr->type);
 822    }
 823 }
 824
 825 /*@}*/
 826
 827 void
 828 nir_index_local_regs(nir_function_impl *impl)
 829 {
 830    unsigned index = 0;
 831    foreach_list_typed(nir_register, reg, node, &impl->registers) {
 832       reg->index = index++;
 833    }
 834    impl->reg_alloc = index;
 835 }
 836
 837 void
 838 nir_index_global_regs(nir_shader *shader)
 839 {
 840    unsigned index = 0;
 841    foreach_list_typed(nir_register, reg, node, &shader->registers) {
 842       reg->index = index++;
 843    }
 844    shader->reg_alloc = index;
 845 }
 846
 847 static bool
 848 visit_alu_dest(nir_alu_instr *instr, nir_foreach_dest_cb cb, void *state)
 849 {
 850    return cb(&instr->dest.dest, state);
 851 }
 852
 853 static bool
 854 visit_intrinsic_dest(nir_intrinsic_instr *instr, nir_foreach_dest_cb cb,
 855                      void *state)
 856 {
 857    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
 858       return cb(&instr->dest, state);
 859
 860    return true;
 861 }
 862
 863 static bool
 864 visit_texture_dest(nir_tex_instr *instr, nir_foreach_dest_cb cb,
 865                    void *state)
 866 {
 867    return cb(&instr->dest, state);
 868 }
 869
 870 static bool
 871 visit_phi_dest(nir_phi_instr *instr, nir_foreach_dest_cb cb, void *state)
 872 {
 873    return cb(&instr->dest, state);
 874 }
 875
 876 static bool
 877 visit_parallel_copy_dest(nir_parallel_copy_instr *instr,
 878                          nir_foreach_dest_cb cb, void *state)
 879 {
 880    nir_foreach_parallel_copy_entry(instr, entry) {
 881       if (!cb(&entry->dest, state))
 882          return false;
 883    }
 884
 885    return true;
 886 }
 887
 888 bool
 889 nir_foreach_dest(nir_instr *instr, nir_foreach_dest_cb cb, void *state)
 890 {
 891    switch (instr->type) {
 892    case nir_instr_type_alu:
 893       return visit_alu_dest(nir_instr_as_alu(instr), cb, state);
 894    case nir_instr_type_intrinsic:
 895       return visit_intrinsic_dest(nir_instr_as_intrinsic(instr), cb, state);
 896    case nir_instr_type_tex:
 897       return visit_texture_dest(nir_instr_as_tex(instr), cb, state);
 898    case nir_instr_type_phi:
 899       return visit_phi_dest(nir_instr_as_phi(instr), cb, state);
 900    case nir_instr_type_parallel_copy:
 901       return visit_parallel_copy_dest(nir_instr_as_parallel_copy(instr),
 902                                       cb, state);
 903
 904    case nir_instr_type_load_const:
 905    case nir_instr_type_ssa_undef:
 906    case nir_instr_type_call:
 907    case nir_instr_type_jump:
 908       break;
 909
 910    default:
 911       unreachable("Invalid instruction type");
 912       break;
 913    }
 914
 915    return true;
 916 }
 917
 918 struct foreach_ssa_def_state {
 919    nir_foreach_ssa_def_cb cb;
 920    void *client_state;
 921 };
 922
 923 static inline bool
 924 nir_ssa_def_visitor(nir_dest *dest, void *void_state)
 925 {
 926    struct foreach_ssa_def_state *state = void_state;
 927
 928    if (dest->is_ssa)
 929       return state->cb(&dest->ssa, state->client_state);
 930    else
 931       return true;
 932 }
 933
 934 bool
 935 nir_foreach_ssa_def(nir_instr *instr, nir_foreach_ssa_def_cb cb, void *state)
 936 {
 937    switch (instr->type) {
 938    case nir_instr_type_alu:
 939    case nir_instr_type_tex:
 940    case nir_instr_type_intrinsic:
 941    case nir_instr_type_phi:
 942    case nir_instr_type_parallel_copy: {
 943       struct foreach_ssa_def_state foreach_state = {cb, state};
 944       return nir_foreach_dest(instr, nir_ssa_def_visitor, &foreach_state);
 945    }
 946
 947    case nir_instr_type_load_const:
 948       return cb(&nir_instr_as_load_const(instr)->def, state);
 949    case nir_instr_type_ssa_undef:
 950       return cb(&nir_instr_as_ssa_undef(instr)->def, state);
 951    case nir_instr_type_call:
 952    case nir_instr_type_jump:
 953       return true;
 954    default:
 955       unreachable("Invalid instruction type");
 956    }
 957 }
 958
 959 static bool
 960 visit_src(nir_src *src, nir_foreach_src_cb cb, void *state)
 961 {
 962    if (!cb(src, state))
 963       return false;
 964    if (!src->is_ssa && src->reg.indirect)
 965       return cb(src->reg.indirect, state);
 966    return true;
 967 }
 968
 969 static bool
 970 visit_deref_array_src(nir_deref_array *deref, nir_foreach_src_cb cb,
 971                       void *state)
 972 {
 973    if (deref->deref_array_type == nir_deref_array_type_indirect)
 974       return visit_src(&deref->indirect, cb, state);
 975    return true;
 976 }
 977
 978 static bool
 979 visit_deref_src(nir_deref_var *deref, nir_foreach_src_cb cb, void *state)
 980 {
 981    nir_deref *cur = &deref->deref;
 982    while (cur != NULL) {
 983       if (cur->deref_type == nir_deref_type_array)
 984          if (!visit_deref_array_src(nir_deref_as_array(cur), cb, state))
 985             return false;
 986
 987       cur = cur->child;
 988    }
 989
 990    return true;
 991 }
 992
 993 static bool
 994 visit_alu_src(nir_alu_instr *instr, nir_foreach_src_cb cb, void *state)
 995 {
 996    for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++)
 997       if (!visit_src(&instr->src[i].src, cb, state))
 998          return false;
 999
1000    return true;
1001 }
1002
1003 static bool
1004 visit_tex_src(nir_tex_instr *instr, nir_foreach_src_cb cb, void *state)
1005 {
1006    for (unsigned i = 0; i < instr->num_srcs; i++)
1007       if (!visit_src(&instr->src[i].src, cb, state))
1008          return false;
1009
1010    if (instr->sampler != NULL)
1011       if (!visit_deref_src(instr->sampler, cb, state))
1012          return false;
1013
1014    return true;
1015 }
1016
1017 static bool
1018 visit_intrinsic_src(nir_intrinsic_instr *instr, nir_foreach_src_cb cb,
1019                     void *state)
1020 {
1021    unsigned num_srcs = nir_intrinsic_infos[instr->intrinsic].num_srcs;
1022    for (unsigned i = 0; i < num_srcs; i++)
1023       if (!visit_src(&instr->src[i], cb, state))
1024          return false;
1025
1026    unsigned num_vars =
1027       nir_intrinsic_infos[instr->intrinsic].num_variables;
1028    for (unsigned i = 0; i < num_vars; i++)
1029       if (!visit_deref_src(instr->variables[i], cb, state))
1030          return false;
1031
1032    return true;
1033 }
1034
1035 static bool
1036 visit_call_src(nir_call_instr *instr, nir_foreach_src_cb cb, void *state)
1037 {
1038    return true;
1039 }
1040
1041 static bool
1042 visit_load_const_src(nir_load_const_instr *instr, nir_foreach_src_cb cb,
1043                      void *state)
1044 {
1045    return true;
1046 }
1047
1048 static bool
1049 visit_phi_src(nir_phi_instr *instr, nir_foreach_src_cb cb, void *state)
1050 {
1051    nir_foreach_phi_src(instr, src) {
1052       if (!visit_src(&src->src, cb, state))
1053          return false;
1054    }
1055
1056    return true;
1057 }
1058
1059 static bool
1060 visit_parallel_copy_src(nir_parallel_copy_instr *instr,
1061                         nir_foreach_src_cb cb, void *state)
1062 {
1063    nir_foreach_parallel_copy_entry(instr, entry) {
1064       if (!visit_src(&entry->src, cb, state))
1065          return false;
1066    }
1067
1068    return true;
1069 }
1070
1071 typedef struct {
1072    void *state;
1073    nir_foreach_src_cb cb;
1074 } visit_dest_indirect_state;
1075
1076 static bool
1077 visit_dest_indirect(nir_dest *dest, void *_state)
1078 {
1079    visit_dest_indirect_state *state = (visit_dest_indirect_state *) _state;
1080
1081    if (!dest->is_ssa && dest->reg.indirect)
1082       return state->cb(dest->reg.indirect, state->state);
1083
1084    return true;
1085 }
1086
1087 bool
1088 nir_foreach_src(nir_instr *instr, nir_foreach_src_cb cb, void *state)
1089 {
1090    switch (instr->type) {
1091    case nir_instr_type_alu:
1092       if (!visit_alu_src(nir_instr_as_alu(instr), cb, state))
1093          return false;
1094       break;
1095    case nir_instr_type_intrinsic:
1096       if (!visit_intrinsic_src(nir_instr_as_intrinsic(instr), cb, state))
1097          return false;
1098       break;
1099    case nir_instr_type_tex:
1100       if (!visit_tex_src(nir_instr_as_tex(instr), cb, state))
1101          return false;
1102       break;
1103    case nir_instr_type_call:
1104       if (!visit_call_src(nir_instr_as_call(instr), cb, state))
1105          return false;
1106       break;
1107    case nir_instr_type_load_const:
1108       if (!visit_load_const_src(nir_instr_as_load_const(instr), cb, state))
1109          return false;
1110       break;
1111    case nir_instr_type_phi:
1112       if (!visit_phi_src(nir_instr_as_phi(instr), cb, state))
1113          return false;
1114       break;
1115    case nir_instr_type_parallel_copy:
1116       if (!visit_parallel_copy_src(nir_instr_as_parallel_copy(instr),
1117                                    cb, state))
1118          return false;
1119       break;
1120    case nir_instr_type_jump:
1121    case nir_instr_type_ssa_undef:
1122       return true;
1123
1124    default:
1125       unreachable("Invalid instruction type");
1126       break;
1127    }
1128
1129    visit_dest_indirect_state dest_state;
1130    dest_state.state = state;
1131    dest_state.cb = cb;
1132    return nir_foreach_dest(instr, visit_dest_indirect, &dest_state);
1133 }
1134
1135 nir_const_value *
1136 nir_src_as_const_value(nir_src src)
1137 {
1138    if (!src.is_ssa)
1139       return NULL;
1140
1141    if (src.ssa->parent_instr->type != nir_instr_type_load_const)
1142       return NULL;
1143
1144    nir_load_const_instr *load = nir_instr_as_load_const(src.ssa->parent_instr);
1145
1146    return &load->value;
1147 }
1148
1149 /**
1150  * Returns true if the source is known to be dynamically uniform. Otherwise it
1151  * returns false which means it may or may not be dynamically uniform but it
1152  * can't be determined.
1153  */
1154 bool
1155 nir_src_is_dynamically_uniform(nir_src src)
1156 {
1157    if (!src.is_ssa)
1158       return false;
1159
1160    /* Constants are trivially dynamically uniform */
1161    if (src.ssa->parent_instr->type == nir_instr_type_load_const)
1162       return true;
1163
1164    /* As are uniform variables */
1165    if (src.ssa->parent_instr->type == nir_instr_type_intrinsic) {
1166       nir_intrinsic_instr *intr = nir_instr_as_intrinsic(src.ssa->parent_instr);
1167
1168       if (intr->intrinsic == nir_intrinsic_load_uniform)
1169          return true;
1170    }
1171
1172    /* XXX: this could have many more tests, such as when a sampler function is
1173     * called with dynamically uniform arguments.
1174     */
1175    return false;
1176 }
1177
1178 static void
1179 src_remove_all_uses(nir_src *src)
1180 {
1181    for (; src; src = src->is_ssa ? NULL : src->reg.indirect) {
1182       if (!src_is_valid(src))
1183          continue;
1184
1185       list_del(&src->use_link);
1186    }
1187 }
1188
1189 static void
1190 src_add_all_uses(nir_src *src, nir_instr *parent_instr, nir_if *parent_if)
1191 {
1192    for (; src; src = src->is_ssa ? NULL : src->reg.indirect) {
1193       if (!src_is_valid(src))
1194          continue;
1195
1196       if (parent_instr) {
1197          src->parent_instr = parent_instr;
1198          if (src->is_ssa)
1199             list_addtail(&src->use_link, &src->ssa->uses);
1200          else
1201             list_addtail(&src->use_link, &src->reg.reg->uses);
1202       } else {
1203          assert(parent_if);
1204          src->parent_if = parent_if;
1205          if (src->is_ssa)
1206             list_addtail(&src->use_link, &src->ssa->if_uses);
1207          else
1208             list_addtail(&src->use_link, &src->reg.reg->if_uses);
1209       }
1210    }
1211 }
1212
1213 void
1214 nir_instr_rewrite_src(nir_instr *instr, nir_src *src, nir_src new_src)
1215 {
1216    assert(!src_is_valid(src) || src->parent_instr == instr);
1217
1218    src_remove_all_uses(src);
1219    *src = new_src;
1220    src_add_all_uses(src, instr, NULL);
1221 }
1222
1223 void
1224 nir_instr_move_src(nir_instr *dest_instr, nir_src *dest, nir_src *src)
1225 {
1226    assert(!src_is_valid(dest) || dest->parent_instr == dest_instr);
1227
1228    src_remove_all_uses(dest);
1229    src_remove_all_uses(src);
1230    *dest = *src;
1231    *src = NIR_SRC_INIT;
1232    src_add_all_uses(dest, dest_instr, NULL);
1233 }
1234
1235 void
1236 nir_if_rewrite_condition(nir_if *if_stmt, nir_src new_src)
1237 {
1238    nir_src *src = &if_stmt->condition;
1239    assert(!src_is_valid(src) || src->parent_if == if_stmt);
1240
1241    src_remove_all_uses(src);
1242    *src = new_src;
1243    src_add_all_uses(src, NULL, if_stmt);
1244 }
1245
1246 void
1247 nir_instr_rewrite_dest(nir_instr *instr, nir_dest *dest, nir_dest new_dest)
1248 {
1249    if (dest->is_ssa) {
1250       /* We can only overwrite an SSA destination if it has no uses. */
1251       assert(list_empty(&dest->ssa.uses) && list_empty(&dest->ssa.if_uses));
1252    } else {
1253       list_del(&dest->reg.def_link);
1254       if (dest->reg.indirect)
1255          src_remove_all_uses(dest->reg.indirect);
1256    }
1257
1258    /* We can't re-write with an SSA def */
1259    assert(!new_dest.is_ssa);
1260
1261    nir_dest_copy(dest, &new_dest, instr);
1262
1263    dest->reg.parent_instr = instr;
1264    list_addtail(&dest->reg.def_link, &new_dest.reg.reg->defs);
1265
1266    if (dest->reg.indirect)
1267       src_add_all_uses(dest->reg.indirect, instr, NULL);
1268 }
1269
1270 void
1271 nir_ssa_def_init(nir_instr *instr, nir_ssa_def *def,
1272                  unsigned num_components, const char *name)
1273 {
1274    def->name = name;
1275    def->parent_instr = instr;
1276    list_inithead(&def->uses);
1277    list_inithead(&def->if_uses);
1278    def->num_components = num_components;
1279
1280    if (instr->block) {
1281       nir_function_impl *impl =
1282          nir_cf_node_get_function(&instr->block->cf_node);
1283
1284       def->index = impl->ssa_alloc++;
1285    } else {
1286       def->index = UINT_MAX;
1287    }
1288 }
1289
1290 void
1291 nir_ssa_dest_init(nir_instr *instr, nir_dest *dest,
1292                  unsigned num_components, const char *name)
1293 {
1294    dest->is_ssa = true;
1295    nir_ssa_def_init(instr, &dest->ssa, num_components, name);
1296 }
1297
1298 void
1299 nir_ssa_def_rewrite_uses(nir_ssa_def *def, nir_src new_src)
1300 {
1301    assert(!new_src.is_ssa || def != new_src.ssa);
1302
1303    nir_foreach_use_safe(def, use_src) {
1304       nir_instr *src_parent_instr = use_src->parent_instr;
1305       list_del(&use_src->use_link);
1306       nir_src_copy(use_src, &new_src, src_parent_instr);
1307       src_add_all_uses(use_src, src_parent_instr, NULL);
1308    }
1309
1310    nir_foreach_if_use_safe(def, use_src) {
1311       nir_if *src_parent_if = use_src->parent_if;
1312       list_del(&use_src->use_link);
1313       nir_src_copy(use_src, &new_src, src_parent_if);
1314       src_add_all_uses(use_src, NULL, src_parent_if);
1315    }
1316 }
1317
1318
1319 static bool foreach_cf_node(nir_cf_node *node, nir_foreach_block_cb cb,
1320                             bool reverse, void *state);
1321
1322 static inline bool
1323 foreach_if(nir_if *if_stmt, nir_foreach_block_cb cb, bool reverse, void *state)
1324 {
1325    if (reverse) {
1326       foreach_list_typed_safe_reverse(nir_cf_node, node, node,
1327                                       &if_stmt->else_list) {
1328          if (!foreach_cf_node(node, cb, reverse, state))
1329             return false;
1330       }
1331
1332       foreach_list_typed_safe_reverse(nir_cf_node, node, node,
1333                                       &if_stmt->then_list) {
1334          if (!foreach_cf_node(node, cb, reverse, state))
1335             return false;
1336       }
1337    } else {
1338       foreach_list_typed_safe(nir_cf_node, node, node, &if_stmt->then_list) {
1339          if (!foreach_cf_node(node, cb, reverse, state))
1340             return false;
1341       }
1342
1343       foreach_list_typed_safe(nir_cf_node, node, node, &if_stmt->else_list) {
1344          if (!foreach_cf_node(node, cb, reverse, state))
1345             return false;
1346       }
1347    }
1348
1349    return true;
1350 }
1351
1352 static inline bool
1353 foreach_loop(nir_loop *loop, nir_foreach_block_cb cb, bool reverse, void *state)
1354 {
1355    if (reverse) {
1356       foreach_list_typed_safe_reverse(nir_cf_node, node, node, &loop->body) {
1357          if (!foreach_cf_node(node, cb, reverse, state))
1358             return false;
1359       }
1360    } else {
1361       foreach_list_typed_safe(nir_cf_node, node, node, &loop->body) {
1362          if (!foreach_cf_node(node, cb, reverse, state))
1363             return false;
1364       }
1365    }
1366
1367    return true;
1368 }
1369
1370 static bool
1371 foreach_cf_node(nir_cf_node *node, nir_foreach_block_cb cb,
1372                 bool reverse, void *state)
1373 {
1374    switch (node->type) {
1375    case nir_cf_node_block:
1376       return cb(nir_cf_node_as_block(node), state);
1377    case nir_cf_node_if:
1378       return foreach_if(nir_cf_node_as_if(node), cb, reverse, state);
1379    case nir_cf_node_loop:
1380       return foreach_loop(nir_cf_node_as_loop(node), cb, reverse, state);
1381       break;
1382
1383    default:
1384       unreachable("Invalid CFG node type");
1385       break;
1386    }
1387
1388    return false;
1389 }
1390
1391 bool
1392 nir_foreach_block_in_cf_node(nir_cf_node *node, nir_foreach_block_cb cb,
1393                              void *state)
1394 {
1395    return foreach_cf_node(node, cb, false, state);
1396 }
1397
1398 bool
1399 nir_foreach_block(nir_function_impl *impl, nir_foreach_block_cb cb, void *state)
1400 {
1401    foreach_list_typed_safe(nir_cf_node, node, node, &impl->body) {
1402       if (!foreach_cf_node(node, cb, false, state))
1403          return false;
1404    }
1405
1406    return cb(impl->end_block, state);
1407 }
1408
1409 bool
1410 nir_foreach_block_reverse(nir_function_impl *impl, nir_foreach_block_cb cb,
1411                           void *state)
1412 {
1413    if (!cb(impl->end_block, state))
1414       return false;
1415
1416    foreach_list_typed_safe_reverse(nir_cf_node, node, node, &impl->body) {
1417       if (!foreach_cf_node(node, cb, true, state))
1418          return false;
1419    }
1420
1421    return true;
1422 }
1423
1424 nir_if *
1425 nir_block_get_following_if(nir_block *block)
1426 {
1427    if (exec_node_is_tail_sentinel(&block->cf_node.node))
1428       return NULL;
1429
1430    if (nir_cf_node_is_last(&block->cf_node))
1431       return NULL;
1432
1433    nir_cf_node *next_node = nir_cf_node_next(&block->cf_node);
1434
1435    if (next_node->type != nir_cf_node_if)
1436       return NULL;
1437
1438    return nir_cf_node_as_if(next_node);
1439 }
1440
1441 nir_loop *
1442 nir_block_get_following_loop(nir_block *block)
1443 {
1444    if (exec_node_is_tail_sentinel(&block->cf_node.node))
1445       return NULL;
1446
1447    if (nir_cf_node_is_last(&block->cf_node))
1448       return NULL;
1449
1450    nir_cf_node *next_node = nir_cf_node_next(&block->cf_node);
1451
1452    if (next_node->type != nir_cf_node_loop)
1453       return NULL;
1454
1455    return nir_cf_node_as_loop(next_node);
1456 }
1457 static bool
1458 index_block(nir_block *block, void *state)
1459 {
1460    unsigned *index = state;
1461    block->index = (*index)++;
1462    return true;
1463 }
1464
1465 void
1466 nir_index_blocks(nir_function_impl *impl)
1467 {
1468    unsigned index = 0;
1469
1470    if (impl->valid_metadata & nir_metadata_block_index)
1471       return;
1472
1473    nir_foreach_block(impl, index_block, &index);
1474
1475    impl->num_blocks = index;
1476 }
1477
1478 static bool
1479 index_ssa_def_cb(nir_ssa_def *def, void *state)
1480 {
1481    unsigned *index = (unsigned *) state;
1482    def->index = (*index)++;
1483
1484    return true;
1485 }
1486
1487 static bool
1488 index_ssa_block(nir_block *block, void *state)
1489 {
1490    nir_foreach_instr(block, instr)
1491       nir_foreach_ssa_def(instr, index_ssa_def_cb, state);
1492
1493    return true;
1494 }
1495
1496 /**
1497  * The indices are applied top-to-bottom which has the very nice property
1498  * that, if A dominates B, then A->index <= B->index.
1499  */
1500 void
1501 nir_index_ssa_defs(nir_function_impl *impl)
1502 {
1503    unsigned index = 0;
1504    nir_foreach_block(impl, index_ssa_block, &index);
1505    impl->ssa_alloc = index;
1506 }
1507
1508 static bool
1509 index_instrs_block(nir_block *block, void *state)
1510 {
1511    unsigned *index = state;
1512    nir_foreach_instr(block, instr)
1513       instr->index = (*index)++;
1514
1515    return true;
1516 }
1517
1518 /**
1519  * The indices are applied top-to-bottom which has the very nice property
1520  * that, if A dominates B, then A->index <= B->index.
1521  */
1522 unsigned
1523 nir_index_instrs(nir_function_impl *impl)
1524 {
1525    unsigned index = 0;
1526    nir_foreach_block(impl, index_instrs_block, &index);
1527    return index;
1528 }
1529
1530 nir_intrinsic_op
1531 nir_intrinsic_from_system_value(gl_system_value val)
1532 {
1533    switch (val) {
1534    case SYSTEM_VALUE_VERTEX_ID:
1535       return nir_intrinsic_load_vertex_id;
1536    case SYSTEM_VALUE_INSTANCE_ID:
1537       return nir_intrinsic_load_instance_id;
1538    case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE:
1539       return nir_intrinsic_load_vertex_id_zero_base;
1540    case SYSTEM_VALUE_BASE_VERTEX:
1541       return nir_intrinsic_load_base_vertex;
1542    case SYSTEM_VALUE_INVOCATION_ID:
1543       return nir_intrinsic_load_invocation_id;
1544    case SYSTEM_VALUE_FRONT_FACE:
1545       return nir_intrinsic_load_front_face;
1546    case SYSTEM_VALUE_SAMPLE_ID:
1547       return nir_intrinsic_load_sample_id;
1548    case SYSTEM_VALUE_SAMPLE_POS:
1549       return nir_intrinsic_load_sample_pos;
1550    case SYSTEM_VALUE_SAMPLE_MASK_IN:
1551       return nir_intrinsic_load_sample_mask_in;
1552    case SYSTEM_VALUE_LOCAL_INVOCATION_ID:
1553       return nir_intrinsic_load_local_invocation_id;
1554    case SYSTEM_VALUE_WORK_GROUP_ID:
1555       return nir_intrinsic_load_work_group_id;
1556    case SYSTEM_VALUE_NUM_WORK_GROUPS:
1557       return nir_intrinsic_load_num_work_groups;
1558    case SYSTEM_VALUE_PRIMITIVE_ID:
1559       return nir_intrinsic_load_primitive_id;
1560    case SYSTEM_VALUE_TESS_COORD:
1561       return nir_intrinsic_load_tess_coord;
1562    case SYSTEM_VALUE_TESS_LEVEL_OUTER:
1563       return nir_intrinsic_load_tess_level_outer;
1564    case SYSTEM_VALUE_TESS_LEVEL_INNER:
1565       return nir_intrinsic_load_tess_level_inner;
1566    case SYSTEM_VALUE_VERTICES_IN:
1567       return nir_intrinsic_load_patch_vertices_in;
1568    default:
1569       unreachable("system value does not directly correspond to intrinsic");
1570    }
1571 }
1572
1573 gl_system_value
1574 nir_system_value_from_intrinsic(nir_intrinsic_op intrin)
1575 {
1576    switch (intrin) {
1577    case nir_intrinsic_load_vertex_id:
1578       return SYSTEM_VALUE_VERTEX_ID;
1579    case nir_intrinsic_load_instance_id:
1580       return SYSTEM_VALUE_INSTANCE_ID;
1581    case nir_intrinsic_load_vertex_id_zero_base:
1582       return SYSTEM_VALUE_VERTEX_ID_ZERO_BASE;
1583    case nir_intrinsic_load_base_vertex:
1584       return SYSTEM_VALUE_BASE_VERTEX;
1585    case nir_intrinsic_load_invocation_id:
1586       return SYSTEM_VALUE_INVOCATION_ID;
1587    case nir_intrinsic_load_front_face:
1588       return SYSTEM_VALUE_FRONT_FACE;
1589    case nir_intrinsic_load_sample_id:
1590       return SYSTEM_VALUE_SAMPLE_ID;
1591    case nir_intrinsic_load_sample_pos:
1592       return SYSTEM_VALUE_SAMPLE_POS;
1593    case nir_intrinsic_load_sample_mask_in:
1594       return SYSTEM_VALUE_SAMPLE_MASK_IN;
1595    case nir_intrinsic_load_local_invocation_id:
1596       return SYSTEM_VALUE_LOCAL_INVOCATION_ID;
1597    case nir_intrinsic_load_num_work_groups:
1598       return SYSTEM_VALUE_NUM_WORK_GROUPS;
1599    case nir_intrinsic_load_work_group_id:
1600       return SYSTEM_VALUE_WORK_GROUP_ID;
1601    case nir_intrinsic_load_primitive_id:
1602       return SYSTEM_VALUE_PRIMITIVE_ID;
1603    case nir_intrinsic_load_tess_coord:
1604       return SYSTEM_VALUE_TESS_COORD;
1605    case nir_intrinsic_load_tess_level_outer:
1606       return SYSTEM_VALUE_TESS_LEVEL_OUTER;
1607    case nir_intrinsic_load_tess_level_inner:
1608       return SYSTEM_VALUE_TESS_LEVEL_INNER;
1609    case nir_intrinsic_load_patch_vertices_in:
1610       return SYSTEM_VALUE_VERTICES_IN;
1611    default:
1612       unreachable("intrinsic doesn't produce a system value");
1613    }
1614 }