src/compiler/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                   shader_info *si)
  37 {
  38    nir_shader *shader = rzalloc(mem_ctx, nir_shader);
  39
  40    exec_list_make_empty(&shader->uniforms);
  41    exec_list_make_empty(&shader->inputs);
  42    exec_list_make_empty(&shader->outputs);
  43    exec_list_make_empty(&shader->shared);
  44
  45    shader->options = options;
  46
  47    if (si)
  48       shader->info = *si;
  49
  50    exec_list_make_empty(&shader->functions);
  51    exec_list_make_empty(&shader->registers);
  52    exec_list_make_empty(&shader->globals);
  53    exec_list_make_empty(&shader->system_values);
  54    shader->reg_alloc = 0;
  55
  56    shader->num_inputs = 0;
  57    shader->num_outputs = 0;
  58    shader->num_uniforms = 0;
  59    shader->num_shared = 0;
  60
  61    shader->stage = stage;
  62
  63    return shader;
  64 }
  65
  66 static nir_register *
  67 reg_create(void *mem_ctx, struct exec_list *list)
  68 {
  69    nir_register *reg = ralloc(mem_ctx, nir_register);
  70
  71    list_inithead(&reg->uses);
  72    list_inithead(&reg->defs);
  73    list_inithead(&reg->if_uses);
  74
  75    reg->num_components = 0;
  76    reg->bit_size = 32;
  77    reg->num_array_elems = 0;
  78    reg->is_packed = false;
  79    reg->name = NULL;
  80
  81    exec_list_push_tail(list, &reg->node);
  82
  83    return reg;
  84 }
  85
  86 nir_register *
  87 nir_global_reg_create(nir_shader *shader)
  88 {
  89    nir_register *reg = reg_create(shader, &shader->registers);
  90    reg->index = shader->reg_alloc++;
  91    reg->is_global = true;
  92
  93    return reg;
  94 }
  95
  96 nir_register *
  97 nir_local_reg_create(nir_function_impl *impl)
  98 {
  99    nir_register *reg = reg_create(ralloc_parent(impl), &impl->registers);
 100    reg->index = impl->reg_alloc++;
 101    reg->is_global = false;
 102
 103    return reg;
 104 }
 105
 106 void
 107 nir_reg_remove(nir_register *reg)
 108 {
 109    exec_node_remove(&reg->node);
 110 }
 111
 112 void
 113 nir_shader_add_variable(nir_shader *shader, nir_variable *var)
 114 {
 115    switch (var->data.mode) {
 116    case nir_var_all:
 117       assert(!"invalid mode");
 118       break;
 119
 120    case nir_var_local:
 121       assert(!"nir_shader_add_variable cannot be used for local variables");
 122       break;
 123
 124    case nir_var_param:
 125       assert(!"nir_shader_add_variable cannot be used for function parameters");
 126       break;
 127
 128    case nir_var_global:
 129       exec_list_push_tail(&shader->globals, &var->node);
 130       break;
 131
 132    case nir_var_shader_in:
 133       exec_list_push_tail(&shader->inputs, &var->node);
 134       break;
 135
 136    case nir_var_shader_out:
 137       exec_list_push_tail(&shader->outputs, &var->node);
 138       break;
 139
 140    case nir_var_uniform:
 141    case nir_var_shader_storage:
 142       exec_list_push_tail(&shader->uniforms, &var->node);
 143       break;
 144
 145    case nir_var_shared:
 146       assert(shader->stage == MESA_SHADER_COMPUTE);
 147       exec_list_push_tail(&shader->shared, &var->node);
 148       break;
 149
 150    case nir_var_system_value:
 151       exec_list_push_tail(&shader->system_values, &var->node);
 152       break;
 153    }
 154 }
 155
 156 nir_variable *
 157 nir_variable_create(nir_shader *shader, nir_variable_mode mode,
 158                     const struct glsl_type *type, const char *name)
 159 {
 160    nir_variable *var = rzalloc(shader, nir_variable);
 161    var->name = ralloc_strdup(var, name);
 162    var->type = type;
 163    var->data.mode = mode;
 164
 165    if ((mode == nir_var_shader_in && shader->stage != MESA_SHADER_VERTEX) ||
 166        (mode == nir_var_shader_out && shader->stage != MESA_SHADER_FRAGMENT))
 167       var->data.interpolation = INTERP_MODE_SMOOTH;
 168
 169    if (mode == nir_var_shader_in || mode == nir_var_uniform)
 170       var->data.read_only = true;
 171
 172    nir_shader_add_variable(shader, var);
 173
 174    return var;
 175 }
 176
 177 nir_variable *
 178 nir_local_variable_create(nir_function_impl *impl,
 179                           const struct glsl_type *type, const char *name)
 180 {
 181    nir_variable *var = rzalloc(impl->function->shader, nir_variable);
 182    var->name = ralloc_strdup(var, name);
 183    var->type = type;
 184    var->data.mode = nir_var_local;
 185
 186    nir_function_impl_add_variable(impl, var);
 187
 188    return var;
 189 }
 190
 191 nir_function *
 192 nir_function_create(nir_shader *shader, const char *name)
 193 {
 194    nir_function *func = ralloc(shader, nir_function);
 195
 196    exec_list_push_tail(&shader->functions, &func->node);
 197
 198    func->name = ralloc_strdup(func, name);
 199    func->shader = shader;
 200    func->num_params = 0;
 201    func->params = NULL;
 202    func->return_type = glsl_void_type();
 203    func->impl = NULL;
 204
 205    return func;
 206 }
 207
 208 void nir_src_copy(nir_src *dest, const nir_src *src, void *mem_ctx)
 209 {
 210    dest->is_ssa = src->is_ssa;
 211    if (src->is_ssa) {
 212       dest->ssa = src->ssa;
 213    } else {
 214       dest->reg.base_offset = src->reg.base_offset;
 215       dest->reg.reg = src->reg.reg;
 216       if (src->reg.indirect) {
 217          dest->reg.indirect = ralloc(mem_ctx, nir_src);
 218          nir_src_copy(dest->reg.indirect, src->reg.indirect, mem_ctx);
 219       } else {
 220          dest->reg.indirect = NULL;
 221       }
 222    }
 223 }
 224
 225 void nir_dest_copy(nir_dest *dest, const nir_dest *src, nir_instr *instr)
 226 {
 227    /* Copying an SSA definition makes no sense whatsoever. */
 228    assert(!src->is_ssa);
 229
 230    dest->is_ssa = false;
 231
 232    dest->reg.base_offset = src->reg.base_offset;
 233    dest->reg.reg = src->reg.reg;
 234    if (src->reg.indirect) {
 235       dest->reg.indirect = ralloc(instr, nir_src);
 236       nir_src_copy(dest->reg.indirect, src->reg.indirect, instr);
 237    } else {
 238       dest->reg.indirect = NULL;
 239    }
 240 }
 241
 242 void
 243 nir_alu_src_copy(nir_alu_src *dest, const nir_alu_src *src,
 244                  nir_alu_instr *instr)
 245 {
 246    nir_src_copy(&dest->src, &src->src, &instr->instr);
 247    dest->abs = src->abs;
 248    dest->negate = src->negate;
 249    for (unsigned i = 0; i < 4; i++)
 250       dest->swizzle[i] = src->swizzle[i];
 251 }
 252
 253 void
 254 nir_alu_dest_copy(nir_alu_dest *dest, const nir_alu_dest *src,
 255                   nir_alu_instr *instr)
 256 {
 257    nir_dest_copy(&dest->dest, &src->dest, &instr->instr);
 258    dest->write_mask = src->write_mask;
 259    dest->saturate = src->saturate;
 260 }
 261
 262
 263 static void
 264 cf_init(nir_cf_node *node, nir_cf_node_type type)
 265 {
 266    exec_node_init(&node->node);
 267    node->parent = NULL;
 268    node->type = type;
 269 }
 270
 271 nir_function_impl *
 272 nir_function_impl_create_bare(nir_shader *shader)
 273 {
 274    nir_function_impl *impl = ralloc(shader, nir_function_impl);
 275
 276    impl->function = NULL;
 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(shader);
 292    nir_block *end_block = nir_block_create(shader);
 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_function_impl *
 305 nir_function_impl_create(nir_function *function)
 306 {
 307    assert(function->impl == NULL);
 308
 309    nir_function_impl *impl = nir_function_impl_create_bare(function->shader);
 310
 311    function->impl = impl;
 312    impl->function = function;
 313
 314    impl->num_params = function->num_params;
 315    impl->params = ralloc_array(function->shader,
 316                                nir_variable *, impl->num_params);
 317
 318    for (unsigned i = 0; i < impl->num_params; i++) {
 319       impl->params[i] = rzalloc(function->shader, nir_variable);
 320       impl->params[i]->type = function->params[i].type;
 321       impl->params[i]->data.mode = nir_var_param;
 322       impl->params[i]->data.location = i;
 323    }
 324
 325    if (!glsl_type_is_void(function->return_type)) {
 326       impl->return_var = rzalloc(function->shader, nir_variable);
 327       impl->return_var->type = function->return_type;
 328       impl->return_var->data.mode = nir_var_param;
 329       impl->return_var->data.location = -1;
 330    } else {
 331       impl->return_var = NULL;
 332    }
 333
 334    return impl;
 335 }
 336
 337 nir_block *
 338 nir_block_create(nir_shader *shader)
 339 {
 340    nir_block *block = rzalloc(shader, nir_block);
 341
 342    cf_init(&block->cf_node, nir_cf_node_block);
 343
 344    block->successors[0] = block->successors[1] = NULL;
 345    block->predecessors = _mesa_set_create(block, _mesa_hash_pointer,
 346                                           _mesa_key_pointer_equal);
 347    block->imm_dom = NULL;
 348    /* XXX maybe it would be worth it to defer allocation?  This
 349     * way it doesn't get allocated for shader refs that never run
 350     * nir_calc_dominance?  For example, state-tracker creates an
 351     * initial IR, clones that, runs appropriate lowering pass, passes
 352     * to driver which does common lowering/opt, and then stores ref
 353     * which is later used to do state specific lowering and futher
 354     * opt.  Do any of the references not need dominance metadata?
 355     */
 356    block->dom_frontier = _mesa_set_create(block, _mesa_hash_pointer,
 357                                           _mesa_key_pointer_equal);
 358
 359    exec_list_make_empty(&block->instr_list);
 360
 361    return block;
 362 }
 363
 364 static inline void
 365 src_init(nir_src *src)
 366 {
 367    src->is_ssa = false;
 368    src->reg.reg = NULL;
 369    src->reg.indirect = NULL;
 370    src->reg.base_offset = 0;
 371 }
 372
 373 nir_if *
 374 nir_if_create(nir_shader *shader)
 375 {
 376    nir_if *if_stmt = ralloc(shader, nir_if);
 377
 378    cf_init(&if_stmt->cf_node, nir_cf_node_if);
 379    src_init(&if_stmt->condition);
 380
 381    nir_block *then = nir_block_create(shader);
 382    exec_list_make_empty(&if_stmt->then_list);
 383    exec_list_push_tail(&if_stmt->then_list, &then->cf_node.node);
 384    then->cf_node.parent = &if_stmt->cf_node;
 385
 386    nir_block *else_stmt = nir_block_create(shader);
 387    exec_list_make_empty(&if_stmt->else_list);
 388    exec_list_push_tail(&if_stmt->else_list, &else_stmt->cf_node.node);
 389    else_stmt->cf_node.parent = &if_stmt->cf_node;
 390
 391    return if_stmt;
 392 }
 393
 394 nir_loop *
 395 nir_loop_create(nir_shader *shader)
 396 {
 397    nir_loop *loop = rzalloc(shader, nir_loop);
 398
 399    cf_init(&loop->cf_node, nir_cf_node_loop);
 400
 401    nir_block *body = nir_block_create(shader);
 402    exec_list_make_empty(&loop->body);
 403    exec_list_push_tail(&loop->body, &body->cf_node.node);
 404    body->cf_node.parent = &loop->cf_node;
 405
 406    body->successors[0] = body;
 407    _mesa_set_add(body->predecessors, body);
 408
 409    return loop;
 410 }
 411
 412 static void
 413 instr_init(nir_instr *instr, nir_instr_type type)
 414 {
 415    instr->type = type;
 416    instr->block = NULL;
 417    exec_node_init(&instr->node);
 418 }
 419
 420 static void
 421 dest_init(nir_dest *dest)
 422 {
 423    dest->is_ssa = false;
 424    dest->reg.reg = NULL;
 425    dest->reg.indirect = NULL;
 426    dest->reg.base_offset = 0;
 427 }
 428
 429 static void
 430 alu_dest_init(nir_alu_dest *dest)
 431 {
 432    dest_init(&dest->dest);
 433    dest->saturate = false;
 434    dest->write_mask = 0xf;
 435 }
 436
 437 static void
 438 alu_src_init(nir_alu_src *src)
 439 {
 440    src_init(&src->src);
 441    src->abs = src->negate = false;
 442    src->swizzle[0] = 0;
 443    src->swizzle[1] = 1;
 444    src->swizzle[2] = 2;
 445    src->swizzle[3] = 3;
 446 }
 447
 448 nir_alu_instr *
 449 nir_alu_instr_create(nir_shader *shader, nir_op op)
 450 {
 451    unsigned num_srcs = nir_op_infos[op].num_inputs;
 452    /* TODO: don't use rzalloc */
 453    nir_alu_instr *instr =
 454       rzalloc_size(shader,
 455                    sizeof(nir_alu_instr) + num_srcs * sizeof(nir_alu_src));
 456
 457    instr_init(&instr->instr, nir_instr_type_alu);
 458    instr->op = op;
 459    alu_dest_init(&instr->dest);
 460    for (unsigned i = 0; i < num_srcs; i++)
 461       alu_src_init(&instr->src[i]);
 462
 463    return instr;
 464 }
 465
 466 nir_jump_instr *
 467 nir_jump_instr_create(nir_shader *shader, nir_jump_type type)
 468 {
 469    nir_jump_instr *instr = ralloc(shader, nir_jump_instr);
 470    instr_init(&instr->instr, nir_instr_type_jump);
 471    instr->type = type;
 472    return instr;
 473 }
 474
 475 nir_load_const_instr *
 476 nir_load_const_instr_create(nir_shader *shader, unsigned num_components,
 477                             unsigned bit_size)
 478 {
 479    nir_load_const_instr *instr = ralloc(shader, nir_load_const_instr);
 480    instr_init(&instr->instr, nir_instr_type_load_const);
 481
 482    nir_ssa_def_init(&instr->instr, &instr->def, num_components, bit_size, NULL);
 483
 484    return instr;
 485 }
 486
 487 nir_intrinsic_instr *
 488 nir_intrinsic_instr_create(nir_shader *shader, nir_intrinsic_op op)
 489 {
 490    unsigned num_srcs = nir_intrinsic_infos[op].num_srcs;
 491    /* TODO: don't use rzalloc */
 492    nir_intrinsic_instr *instr =
 493       rzalloc_size(shader,
 494                   sizeof(nir_intrinsic_instr) + num_srcs * sizeof(nir_src));
 495
 496    instr_init(&instr->instr, nir_instr_type_intrinsic);
 497    instr->intrinsic = op;
 498
 499    if (nir_intrinsic_infos[op].has_dest)
 500       dest_init(&instr->dest);
 501
 502    for (unsigned i = 0; i < num_srcs; i++)
 503       src_init(&instr->src[i]);
 504
 505    return instr;
 506 }
 507
 508 nir_call_instr *
 509 nir_call_instr_create(nir_shader *shader, nir_function *callee)
 510 {
 511    nir_call_instr *instr = ralloc(shader, nir_call_instr);
 512    instr_init(&instr->instr, nir_instr_type_call);
 513
 514    instr->callee = callee;
 515    instr->num_params = callee->num_params;
 516    instr->params = ralloc_array(instr, nir_deref_var *, instr->num_params);
 517    instr->return_deref = NULL;
 518
 519    return instr;
 520 }
 521
 522 nir_tex_instr *
 523 nir_tex_instr_create(nir_shader *shader, unsigned num_srcs)
 524 {
 525    nir_tex_instr *instr = rzalloc(shader, nir_tex_instr);
 526    instr_init(&instr->instr, nir_instr_type_tex);
 527
 528    dest_init(&instr->dest);
 529
 530    instr->num_srcs = num_srcs;
 531    instr->src = ralloc_array(instr, nir_tex_src, num_srcs);
 532    for (unsigned i = 0; i < num_srcs; i++)
 533       src_init(&instr->src[i].src);
 534
 535    instr->texture_index = 0;
 536    instr->texture_array_size = 0;
 537    instr->texture = NULL;
 538    instr->sampler_index = 0;
 539    instr->sampler = NULL;
 540
 541    return instr;
 542 }
 543
 544 void
 545 nir_tex_instr_remove_src(nir_tex_instr *tex, unsigned src_idx)
 546 {
 547    assert(src_idx < tex->num_srcs);
 548
 549    /* First rewrite the source to NIR_SRC_INIT */
 550    nir_instr_rewrite_src(&tex->instr, &tex->src[src_idx].src, NIR_SRC_INIT);
 551
 552    /* Now, move all of the other sources down */
 553    for (unsigned i = src_idx + 1; i < tex->num_srcs; i++) {
 554       tex->src[i-1].src_type = tex->src[i].src_type;
 555       nir_instr_move_src(&tex->instr, &tex->src[i-1].src, &tex->src[i].src);
 556    }
 557    tex->num_srcs--;
 558 }
 559
 560 nir_phi_instr *
 561 nir_phi_instr_create(nir_shader *shader)
 562 {
 563    nir_phi_instr *instr = ralloc(shader, nir_phi_instr);
 564    instr_init(&instr->instr, nir_instr_type_phi);
 565
 566    dest_init(&instr->dest);
 567    exec_list_make_empty(&instr->srcs);
 568    return instr;
 569 }
 570
 571 nir_parallel_copy_instr *
 572 nir_parallel_copy_instr_create(nir_shader *shader)
 573 {
 574    nir_parallel_copy_instr *instr = ralloc(shader, nir_parallel_copy_instr);
 575    instr_init(&instr->instr, nir_instr_type_parallel_copy);
 576
 577    exec_list_make_empty(&instr->entries);
 578
 579    return instr;
 580 }
 581
 582 nir_ssa_undef_instr *
 583 nir_ssa_undef_instr_create(nir_shader *shader,
 584                            unsigned num_components,
 585                            unsigned bit_size)
 586 {
 587    nir_ssa_undef_instr *instr = ralloc(shader, nir_ssa_undef_instr);
 588    instr_init(&instr->instr, nir_instr_type_ssa_undef);
 589
 590    nir_ssa_def_init(&instr->instr, &instr->def, num_components, bit_size, NULL);
 591
 592    return instr;
 593 }
 594
 595 nir_deref_var *
 596 nir_deref_var_create(void *mem_ctx, nir_variable *var)
 597 {
 598    nir_deref_var *deref = ralloc(mem_ctx, nir_deref_var);
 599    deref->deref.deref_type = nir_deref_type_var;
 600    deref->deref.child = NULL;
 601    deref->deref.type = var->type;
 602    deref->var = var;
 603    return deref;
 604 }
 605
 606 nir_deref_array *
 607 nir_deref_array_create(void *mem_ctx)
 608 {
 609    nir_deref_array *deref = ralloc(mem_ctx, nir_deref_array);
 610    deref->deref.deref_type = nir_deref_type_array;
 611    deref->deref.child = NULL;
 612    deref->deref_array_type = nir_deref_array_type_direct;
 613    src_init(&deref->indirect);
 614    deref->base_offset = 0;
 615    return deref;
 616 }
 617
 618 nir_deref_struct *
 619 nir_deref_struct_create(void *mem_ctx, unsigned field_index)
 620 {
 621    nir_deref_struct *deref = ralloc(mem_ctx, nir_deref_struct);
 622    deref->deref.deref_type = nir_deref_type_struct;
 623    deref->deref.child = NULL;
 624    deref->index = field_index;
 625    return deref;
 626 }
 627
 628 nir_deref_var *
 629 nir_deref_var_clone(const nir_deref_var *deref, void *mem_ctx)
 630 {
 631    if (deref == NULL)
 632       return NULL;
 633
 634    nir_deref_var *ret = nir_deref_var_create(mem_ctx, deref->var);
 635    ret->deref.type = deref->deref.type;
 636    if (deref->deref.child)
 637       ret->deref.child = nir_deref_clone(deref->deref.child, ret);
 638    return ret;
 639 }
 640
 641 static nir_deref_array *
 642 deref_array_clone(const nir_deref_array *deref, void *mem_ctx)
 643 {
 644    nir_deref_array *ret = nir_deref_array_create(mem_ctx);
 645    ret->base_offset = deref->base_offset;
 646    ret->deref_array_type = deref->deref_array_type;
 647    if (deref->deref_array_type == nir_deref_array_type_indirect) {
 648       nir_src_copy(&ret->indirect, &deref->indirect, mem_ctx);
 649    }
 650    ret->deref.type = deref->deref.type;
 651    if (deref->deref.child)
 652       ret->deref.child = nir_deref_clone(deref->deref.child, ret);
 653    return ret;
 654 }
 655
 656 static nir_deref_struct *
 657 deref_struct_clone(const nir_deref_struct *deref, void *mem_ctx)
 658 {
 659    nir_deref_struct *ret = nir_deref_struct_create(mem_ctx, deref->index);
 660    ret->deref.type = deref->deref.type;
 661    if (deref->deref.child)
 662       ret->deref.child = nir_deref_clone(deref->deref.child, ret);
 663    return ret;
 664 }
 665
 666 nir_deref *
 667 nir_deref_clone(const nir_deref *deref, void *mem_ctx)
 668 {
 669    if (deref == NULL)
 670       return NULL;
 671
 672    switch (deref->deref_type) {
 673    case nir_deref_type_var:
 674       return &nir_deref_var_clone(nir_deref_as_var(deref), mem_ctx)->deref;
 675    case nir_deref_type_array:
 676       return &deref_array_clone(nir_deref_as_array(deref), mem_ctx)->deref;
 677    case nir_deref_type_struct:
 678       return &deref_struct_clone(nir_deref_as_struct(deref), mem_ctx)->deref;
 679    default:
 680       unreachable("Invalid dereference type");
 681    }
 682
 683    return NULL;
 684 }
 685
 686 /* This is the second step in the recursion.  We've found the tail and made a
 687  * copy.  Now we need to iterate over all possible leaves and call the
 688  * callback on each one.
 689  */
 690 static bool
 691 deref_foreach_leaf_build_recur(nir_deref_var *deref, nir_deref *tail,
 692                                nir_deref_foreach_leaf_cb cb, void *state)
 693 {
 694    unsigned length;
 695    union {
 696       nir_deref_array arr;
 697       nir_deref_struct str;
 698    } tmp;
 699
 700    assert(tail->child == NULL);
 701    switch (glsl_get_base_type(tail->type)) {
 702    case GLSL_TYPE_UINT:
 703    case GLSL_TYPE_UINT64:
 704    case GLSL_TYPE_INT:
 705    case GLSL_TYPE_INT64:
 706    case GLSL_TYPE_FLOAT:
 707    case GLSL_TYPE_DOUBLE:
 708    case GLSL_TYPE_BOOL:
 709       if (glsl_type_is_vector_or_scalar(tail->type))
 710          return cb(deref, state);
 711       /* Fall Through */
 712
 713    case GLSL_TYPE_ARRAY:
 714       tmp.arr.deref.deref_type = nir_deref_type_array;
 715       tmp.arr.deref.type = glsl_get_array_element(tail->type);
 716       tmp.arr.deref_array_type = nir_deref_array_type_direct;
 717       tmp.arr.indirect = NIR_SRC_INIT;
 718       tail->child = &tmp.arr.deref;
 719
 720       length = glsl_get_length(tail->type);
 721       for (unsigned i = 0; i < length; i++) {
 722          tmp.arr.deref.child = NULL;
 723          tmp.arr.base_offset = i;
 724          if (!deref_foreach_leaf_build_recur(deref, &tmp.arr.deref, cb, state))
 725             return false;
 726       }
 727       return true;
 728
 729    case GLSL_TYPE_STRUCT:
 730       tmp.str.deref.deref_type = nir_deref_type_struct;
 731       tail->child = &tmp.str.deref;
 732
 733       length = glsl_get_length(tail->type);
 734       for (unsigned i = 0; i < length; i++) {
 735          tmp.arr.deref.child = NULL;
 736          tmp.str.deref.type = glsl_get_struct_field(tail->type, i);
 737          tmp.str.index = i;
 738          if (!deref_foreach_leaf_build_recur(deref, &tmp.arr.deref, cb, state))
 739             return false;
 740       }
 741       return true;
 742
 743    default:
 744       unreachable("Invalid type for dereference");
 745    }
 746 }
 747
 748 /* This is the first step of the foreach_leaf recursion.  In this step we are
 749  * walking to the end of the deref chain and making a copy in the stack as we
 750  * go.  This is because we don't want to mutate the deref chain that was
 751  * passed in by the caller.  The downside is that this deref chain is on the
 752  * stack and , if the caller wants to do anything with it, they will have to
 753  * make their own copy because this one will go away.
 754  */
 755 static bool
 756 deref_foreach_leaf_copy_recur(nir_deref_var *deref, nir_deref *tail,
 757                               nir_deref_foreach_leaf_cb cb, void *state)
 758 {
 759    union {
 760       nir_deref_array arr;
 761       nir_deref_struct str;
 762    } c;
 763
 764    if (tail->child) {
 765       switch (tail->child->deref_type) {
 766       case nir_deref_type_array:
 767          c.arr = *nir_deref_as_array(tail->child);
 768          tail->child = &c.arr.deref;
 769          return deref_foreach_leaf_copy_recur(deref, &c.arr.deref, cb, state);
 770
 771       case nir_deref_type_struct:
 772          c.str = *nir_deref_as_struct(tail->child);
 773          tail->child = &c.str.deref;
 774          return deref_foreach_leaf_copy_recur(deref, &c.str.deref, cb, state);
 775
 776       case nir_deref_type_var:
 777       default:
 778          unreachable("Invalid deref type for a child");
 779       }
 780    } else {
 781       /* We've gotten to the end of the original deref.  Time to start
 782        * building our own derefs.
 783        */
 784       return deref_foreach_leaf_build_recur(deref, tail, cb, state);
 785    }
 786 }
 787
 788 /**
 789  * This function iterates over all of the possible derefs that can be created
 790  * with the given deref as the head.  It then calls the provided callback with
 791  * a full deref for each one.
 792  *
 793  * The deref passed to the callback will be allocated on the stack.  You will
 794  * need to make a copy if you want it to hang around.
 795  */
 796 bool
 797 nir_deref_foreach_leaf(nir_deref_var *deref,
 798                        nir_deref_foreach_leaf_cb cb, void *state)
 799 {
 800    nir_deref_var copy = *deref;
 801    return deref_foreach_leaf_copy_recur(&copy, &copy.deref, cb, state);
 802 }
 803
 804 /* Returns a load_const instruction that represents the constant
 805  * initializer for the given deref chain.  The caller is responsible for
 806  * ensuring that there actually is a constant initializer.
 807  */
 808 nir_load_const_instr *
 809 nir_deref_get_const_initializer_load(nir_shader *shader, nir_deref_var *deref)
 810 {
 811    nir_constant *constant = deref->var->constant_initializer;
 812    assert(constant);
 813
 814    const nir_deref *tail = &deref->deref;
 815    unsigned matrix_col = 0;
 816    while (tail->child) {
 817       switch (tail->child->deref_type) {
 818       case nir_deref_type_array: {
 819          nir_deref_array *arr = nir_deref_as_array(tail->child);
 820          assert(arr->deref_array_type == nir_deref_array_type_direct);
 821          if (glsl_type_is_matrix(tail->type)) {
 822             assert(arr->deref.child == NULL);
 823             matrix_col = arr->base_offset;
 824          } else {
 825             constant = constant->elements[arr->base_offset];
 826          }
 827          break;
 828       }
 829
 830       case nir_deref_type_struct: {
 831          constant = constant->elements[nir_deref_as_struct(tail->child)->index];
 832          break;
 833       }
 834
 835       default:
 836          unreachable("Invalid deref child type");
 837       }
 838
 839       tail = tail->child;
 840    }
 841
 842    unsigned bit_size = glsl_get_bit_size(tail->type);
 843    nir_load_const_instr *load =
 844       nir_load_const_instr_create(shader, glsl_get_vector_elements(tail->type),
 845                                   bit_size);
 846
 847    switch (glsl_get_base_type(tail->type)) {
 848    case GLSL_TYPE_FLOAT:
 849    case GLSL_TYPE_INT:
 850    case GLSL_TYPE_UINT:
 851    case GLSL_TYPE_DOUBLE:
 852    case GLSL_TYPE_UINT64:
 853    case GLSL_TYPE_INT64:
 854    case GLSL_TYPE_BOOL:
 855       load->value = constant->values[matrix_col];
 856       break;
 857    default:
 858       unreachable("Invalid immediate type");
 859    }
 860
 861    return load;
 862 }
 863
 864 nir_function_impl *
 865 nir_cf_node_get_function(nir_cf_node *node)
 866 {
 867    while (node->type != nir_cf_node_function) {
 868       node = node->parent;
 869    }
 870
 871    return nir_cf_node_as_function(node);
 872 }
 873
 874 /* Reduces a cursor by trying to convert everything to after and trying to
 875  * go up to block granularity when possible.
 876  */
 877 static nir_cursor
 878 reduce_cursor(nir_cursor cursor)
 879 {
 880    switch (cursor.option) {
 881    case nir_cursor_before_block:
 882       assert(nir_cf_node_prev(&cursor.block->cf_node) == NULL ||
 883              nir_cf_node_prev(&cursor.block->cf_node)->type != nir_cf_node_block);
 884       if (exec_list_is_empty(&cursor.block->instr_list)) {
 885          /* Empty block.  After is as good as before. */
 886          cursor.option = nir_cursor_after_block;
 887       }
 888       return cursor;
 889
 890    case nir_cursor_after_block:
 891       return cursor;
 892
 893    case nir_cursor_before_instr: {
 894       nir_instr *prev_instr = nir_instr_prev(cursor.instr);
 895       if (prev_instr) {
 896          /* Before this instruction is after the previous */
 897          cursor.instr = prev_instr;
 898          cursor.option = nir_cursor_after_instr;
 899       } else {
 900          /* No previous instruction.  Switch to before block */
 901          cursor.block = cursor.instr->block;
 902          cursor.option = nir_cursor_before_block;
 903       }
 904       return reduce_cursor(cursor);
 905    }
 906
 907    case nir_cursor_after_instr:
 908       if (nir_instr_next(cursor.instr) == NULL) {
 909          /* This is the last instruction, switch to after block */
 910          cursor.option = nir_cursor_after_block;
 911          cursor.block = cursor.instr->block;
 912       }
 913       return cursor;
 914
 915    default:
 916       unreachable("Inavlid cursor option");
 917    }
 918 }
 919
 920 bool
 921 nir_cursors_equal(nir_cursor a, nir_cursor b)
 922 {
 923    /* Reduced cursors should be unique */
 924    a = reduce_cursor(a);
 925    b = reduce_cursor(b);
 926
 927    return a.block == b.block && a.option == b.option;
 928 }
 929
 930 static bool
 931 add_use_cb(nir_src *src, void *state)
 932 {
 933    nir_instr *instr = state;
 934
 935    src->parent_instr = instr;
 936    list_addtail(&src->use_link,
 937                 src->is_ssa ? &src->ssa->uses : &src->reg.reg->uses);
 938
 939    return true;
 940 }
 941
 942 static bool
 943 add_ssa_def_cb(nir_ssa_def *def, void *state)
 944 {
 945    nir_instr *instr = state;
 946
 947    if (instr->block && def->index == UINT_MAX) {
 948       nir_function_impl *impl =
 949          nir_cf_node_get_function(&instr->block->cf_node);
 950
 951       def->index = impl->ssa_alloc++;
 952    }
 953
 954    return true;
 955 }
 956
 957 static bool
 958 add_reg_def_cb(nir_dest *dest, void *state)
 959 {
 960    nir_instr *instr = state;
 961
 962    if (!dest->is_ssa) {
 963       dest->reg.parent_instr = instr;
 964       list_addtail(&dest->reg.def_link, &dest->reg.reg->defs);
 965    }
 966
 967    return true;
 968 }
 969
 970 static void
 971 add_defs_uses(nir_instr *instr)
 972 {
 973    nir_foreach_src(instr, add_use_cb, instr);
 974    nir_foreach_dest(instr, add_reg_def_cb, instr);
 975    nir_foreach_ssa_def(instr, add_ssa_def_cb, instr);
 976 }
 977
 978 void
 979 nir_instr_insert(nir_cursor cursor, nir_instr *instr)
 980 {
 981    switch (cursor.option) {
 982    case nir_cursor_before_block:
 983       /* Only allow inserting jumps into empty blocks. */
 984       if (instr->type == nir_instr_type_jump)
 985          assert(exec_list_is_empty(&cursor.block->instr_list));
 986
 987       instr->block = cursor.block;
 988       add_defs_uses(instr);
 989       exec_list_push_head(&cursor.block->instr_list, &instr->node);
 990       break;
 991    case nir_cursor_after_block: {
 992       /* Inserting instructions after a jump is illegal. */
 993       nir_instr *last = nir_block_last_instr(cursor.block);
 994       assert(last == NULL || last->type != nir_instr_type_jump);
 995       (void) last;
 996
 997       instr->block = cursor.block;
 998       add_defs_uses(instr);
 999       exec_list_push_tail(&cursor.block->instr_list, &instr->node);
1000       break;
1001    }
1002    case nir_cursor_before_instr:
1003       assert(instr->type != nir_instr_type_jump);
1004       instr->block = cursor.instr->block;
1005       add_defs_uses(instr);
1006       exec_node_insert_node_before(&cursor.instr->node, &instr->node);
1007       break;
1008    case nir_cursor_after_instr:
1009       /* Inserting instructions after a jump is illegal. */
1010       assert(cursor.instr->type != nir_instr_type_jump);
1011
1012       /* Only allow inserting jumps at the end of the block. */
1013       if (instr->type == nir_instr_type_jump)
1014          assert(cursor.instr == nir_block_last_instr(cursor.instr->block));
1015
1016       instr->block = cursor.instr->block;
1017       add_defs_uses(instr);
1018       exec_node_insert_after(&cursor.instr->node, &instr->node);
1019       break;
1020    }
1021
1022    if (instr->type == nir_instr_type_jump)
1023       nir_handle_add_jump(instr->block);
1024 }
1025
1026 static bool
1027 src_is_valid(const nir_src *src)
1028 {
1029    return src->is_ssa ? (src->ssa != NULL) : (src->reg.reg != NULL);
1030 }
1031
1032 static bool
1033 remove_use_cb(nir_src *src, void *state)
1034 {
1035    (void) state;
1036
1037    if (src_is_valid(src))
1038       list_del(&src->use_link);
1039
1040    return true;
1041 }
1042
1043 static bool
1044 remove_def_cb(nir_dest *dest, void *state)
1045 {
1046    (void) state;
1047
1048    if (!dest->is_ssa)
1049       list_del(&dest->reg.def_link);
1050
1051    return true;
1052 }
1053
1054 static void
1055 remove_defs_uses(nir_instr *instr)
1056 {
1057    nir_foreach_dest(instr, remove_def_cb, instr);
1058    nir_foreach_src(instr, remove_use_cb, instr);
1059 }
1060
1061 void nir_instr_remove(nir_instr *instr)
1062 {
1063    remove_defs_uses(instr);
1064    exec_node_remove(&instr->node);
1065
1066    if (instr->type == nir_instr_type_jump) {
1067       nir_jump_instr *jump_instr = nir_instr_as_jump(instr);
1068       nir_handle_remove_jump(instr->block, jump_instr->type);
1069    }
1070 }
1071
1072 /*@}*/
1073
1074 void
1075 nir_index_local_regs(nir_function_impl *impl)
1076 {
1077    unsigned index = 0;
1078    foreach_list_typed(nir_register, reg, node, &impl->registers) {
1079       reg->index = index++;
1080    }
1081    impl->reg_alloc = index;
1082 }
1083
1084 void
1085 nir_index_global_regs(nir_shader *shader)
1086 {
1087    unsigned index = 0;
1088    foreach_list_typed(nir_register, reg, node, &shader->registers) {
1089       reg->index = index++;
1090    }
1091    shader->reg_alloc = index;
1092 }
1093
1094 static bool
1095 visit_alu_dest(nir_alu_instr *instr, nir_foreach_dest_cb cb, void *state)
1096 {
1097    return cb(&instr->dest.dest, state);
1098 }
1099
1100 static bool
1101 visit_intrinsic_dest(nir_intrinsic_instr *instr, nir_foreach_dest_cb cb,
1102                      void *state)
1103 {
1104    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
1105       return cb(&instr->dest, state);
1106
1107    return true;
1108 }
1109
1110 static bool
1111 visit_texture_dest(nir_tex_instr *instr, nir_foreach_dest_cb cb,
1112                    void *state)
1113 {
1114    return cb(&instr->dest, state);
1115 }
1116
1117 static bool
1118 visit_phi_dest(nir_phi_instr *instr, nir_foreach_dest_cb cb, void *state)
1119 {
1120    return cb(&instr->dest, state);
1121 }
1122
1123 static bool
1124 visit_parallel_copy_dest(nir_parallel_copy_instr *instr,
1125                          nir_foreach_dest_cb cb, void *state)
1126 {
1127    nir_foreach_parallel_copy_entry(entry, instr) {
1128       if (!cb(&entry->dest, state))
1129          return false;
1130    }
1131
1132    return true;
1133 }
1134
1135 bool
1136 nir_foreach_dest(nir_instr *instr, nir_foreach_dest_cb cb, void *state)
1137 {
1138    switch (instr->type) {
1139    case nir_instr_type_alu:
1140       return visit_alu_dest(nir_instr_as_alu(instr), cb, state);
1141    case nir_instr_type_intrinsic:
1142       return visit_intrinsic_dest(nir_instr_as_intrinsic(instr), cb, state);
1143    case nir_instr_type_tex:
1144       return visit_texture_dest(nir_instr_as_tex(instr), cb, state);
1145    case nir_instr_type_phi:
1146       return visit_phi_dest(nir_instr_as_phi(instr), cb, state);
1147    case nir_instr_type_parallel_copy:
1148       return visit_parallel_copy_dest(nir_instr_as_parallel_copy(instr),
1149                                       cb, state);
1150
1151    case nir_instr_type_load_const:
1152    case nir_instr_type_ssa_undef:
1153    case nir_instr_type_call:
1154    case nir_instr_type_jump:
1155       break;
1156
1157    default:
1158       unreachable("Invalid instruction type");
1159       break;
1160    }
1161
1162    return true;
1163 }
1164
1165 struct foreach_ssa_def_state {
1166    nir_foreach_ssa_def_cb cb;
1167    void *client_state;
1168 };
1169
1170 static inline bool
1171 nir_ssa_def_visitor(nir_dest *dest, void *void_state)
1172 {
1173    struct foreach_ssa_def_state *state = void_state;
1174
1175    if (dest->is_ssa)
1176       return state->cb(&dest->ssa, state->client_state);
1177    else
1178       return true;
1179 }
1180
1181 bool
1182 nir_foreach_ssa_def(nir_instr *instr, nir_foreach_ssa_def_cb cb, void *state)
1183 {
1184    switch (instr->type) {
1185    case nir_instr_type_alu:
1186    case nir_instr_type_tex:
1187    case nir_instr_type_intrinsic:
1188    case nir_instr_type_phi:
1189    case nir_instr_type_parallel_copy: {
1190       struct foreach_ssa_def_state foreach_state = {cb, state};
1191       return nir_foreach_dest(instr, nir_ssa_def_visitor, &foreach_state);
1192    }
1193
1194    case nir_instr_type_load_const:
1195       return cb(&nir_instr_as_load_const(instr)->def, state);
1196    case nir_instr_type_ssa_undef:
1197       return cb(&nir_instr_as_ssa_undef(instr)->def, state);
1198    case nir_instr_type_call:
1199    case nir_instr_type_jump:
1200       return true;
1201    default:
1202       unreachable("Invalid instruction type");
1203    }
1204 }
1205
1206 static bool
1207 visit_src(nir_src *src, nir_foreach_src_cb cb, void *state)
1208 {
1209    if (!cb(src, state))
1210       return false;
1211    if (!src->is_ssa && src->reg.indirect)
1212       return cb(src->reg.indirect, state);
1213    return true;
1214 }
1215
1216 static bool
1217 visit_deref_array_src(nir_deref_array *deref, nir_foreach_src_cb cb,
1218                       void *state)
1219 {
1220    if (deref->deref_array_type == nir_deref_array_type_indirect)
1221       return visit_src(&deref->indirect, cb, state);
1222    return true;
1223 }
1224
1225 static bool
1226 visit_deref_src(nir_deref_var *deref, nir_foreach_src_cb cb, void *state)
1227 {
1228    nir_deref *cur = &deref->deref;
1229    while (cur != NULL) {
1230       if (cur->deref_type == nir_deref_type_array) {
1231          if (!visit_deref_array_src(nir_deref_as_array(cur), cb, state))
1232             return false;
1233       }
1234
1235       cur = cur->child;
1236    }
1237
1238    return true;
1239 }
1240
1241 static bool
1242 visit_alu_src(nir_alu_instr *instr, nir_foreach_src_cb cb, void *state)
1243 {
1244    for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++)
1245       if (!visit_src(&instr->src[i].src, cb, state))
1246          return false;
1247
1248    return true;
1249 }
1250
1251 static bool
1252 visit_tex_src(nir_tex_instr *instr, nir_foreach_src_cb cb, void *state)
1253 {
1254    for (unsigned i = 0; i < instr->num_srcs; i++) {
1255       if (!visit_src(&instr->src[i].src, cb, state))
1256          return false;
1257    }
1258
1259    if (instr->texture != NULL) {
1260       if (!visit_deref_src(instr->texture, cb, state))
1261          return false;
1262    }
1263
1264    if (instr->sampler != NULL) {
1265       if (!visit_deref_src(instr->sampler, cb, state))
1266          return false;
1267    }
1268
1269    return true;
1270 }
1271
1272 static bool
1273 visit_intrinsic_src(nir_intrinsic_instr *instr, nir_foreach_src_cb cb,
1274                     void *state)
1275 {
1276    unsigned num_srcs = nir_intrinsic_infos[instr->intrinsic].num_srcs;
1277    for (unsigned i = 0; i < num_srcs; i++) {
1278       if (!visit_src(&instr->src[i], cb, state))
1279          return false;
1280    }
1281
1282    unsigned num_vars =
1283       nir_intrinsic_infos[instr->intrinsic].num_variables;
1284    for (unsigned i = 0; i < num_vars; i++) {
1285       if (!visit_deref_src(instr->variables[i], cb, state))
1286          return false;
1287    }
1288
1289    return true;
1290 }
1291
1292 static bool
1293 visit_phi_src(nir_phi_instr *instr, nir_foreach_src_cb cb, void *state)
1294 {
1295    nir_foreach_phi_src(src, instr) {
1296       if (!visit_src(&src->src, cb, state))
1297          return false;
1298    }
1299
1300    return true;
1301 }
1302
1303 static bool
1304 visit_parallel_copy_src(nir_parallel_copy_instr *instr,
1305                         nir_foreach_src_cb cb, void *state)
1306 {
1307    nir_foreach_parallel_copy_entry(entry, instr) {
1308       if (!visit_src(&entry->src, cb, state))
1309          return false;
1310    }
1311
1312    return true;
1313 }
1314
1315 typedef struct {
1316    void *state;
1317    nir_foreach_src_cb cb;
1318 } visit_dest_indirect_state;
1319
1320 static bool
1321 visit_dest_indirect(nir_dest *dest, void *_state)
1322 {
1323    visit_dest_indirect_state *state = (visit_dest_indirect_state *) _state;
1324
1325    if (!dest->is_ssa && dest->reg.indirect)
1326       return state->cb(dest->reg.indirect, state->state);
1327
1328    return true;
1329 }
1330
1331 bool
1332 nir_foreach_src(nir_instr *instr, nir_foreach_src_cb cb, void *state)
1333 {
1334    switch (instr->type) {
1335    case nir_instr_type_alu:
1336       if (!visit_alu_src(nir_instr_as_alu(instr), cb, state))
1337          return false;
1338       break;
1339    case nir_instr_type_intrinsic:
1340       if (!visit_intrinsic_src(nir_instr_as_intrinsic(instr), cb, state))
1341          return false;
1342       break;
1343    case nir_instr_type_tex:
1344       if (!visit_tex_src(nir_instr_as_tex(instr), cb, state))
1345          return false;
1346       break;
1347    case nir_instr_type_call:
1348       /* Call instructions have no regular sources */
1349       break;
1350    case nir_instr_type_load_const:
1351       /* Constant load instructions have no regular sources */
1352       break;
1353    case nir_instr_type_phi:
1354       if (!visit_phi_src(nir_instr_as_phi(instr), cb, state))
1355          return false;
1356       break;
1357    case nir_instr_type_parallel_copy:
1358       if (!visit_parallel_copy_src(nir_instr_as_parallel_copy(instr),
1359                                    cb, state))
1360          return false;
1361       break;
1362    case nir_instr_type_jump:
1363    case nir_instr_type_ssa_undef:
1364       return true;
1365
1366    default:
1367       unreachable("Invalid instruction type");
1368       break;
1369    }
1370
1371    visit_dest_indirect_state dest_state;
1372    dest_state.state = state;
1373    dest_state.cb = cb;
1374    return nir_foreach_dest(instr, visit_dest_indirect, &dest_state);
1375 }
1376
1377 nir_const_value *
1378 nir_src_as_const_value(nir_src src)
1379 {
1380    if (!src.is_ssa)
1381       return NULL;
1382
1383    if (src.ssa->parent_instr->type != nir_instr_type_load_const)
1384       return NULL;
1385
1386    nir_load_const_instr *load = nir_instr_as_load_const(src.ssa->parent_instr);
1387
1388    return &load->value;
1389 }
1390
1391 /**
1392  * Returns true if the source is known to be dynamically uniform. Otherwise it
1393  * returns false which means it may or may not be dynamically uniform but it
1394  * can't be determined.
1395  */
1396 bool
1397 nir_src_is_dynamically_uniform(nir_src src)
1398 {
1399    if (!src.is_ssa)
1400       return false;
1401
1402    /* Constants are trivially dynamically uniform */
1403    if (src.ssa->parent_instr->type == nir_instr_type_load_const)
1404       return true;
1405
1406    /* As are uniform variables */
1407    if (src.ssa->parent_instr->type == nir_instr_type_intrinsic) {
1408       nir_intrinsic_instr *intr = nir_instr_as_intrinsic(src.ssa->parent_instr);
1409
1410       if (intr->intrinsic == nir_intrinsic_load_uniform)
1411          return true;
1412    }
1413
1414    /* XXX: this could have many more tests, such as when a sampler function is
1415     * called with dynamically uniform arguments.
1416     */
1417    return false;
1418 }
1419
1420 static void
1421 src_remove_all_uses(nir_src *src)
1422 {
1423    for (; src; src = src->is_ssa ? NULL : src->reg.indirect) {
1424       if (!src_is_valid(src))
1425          continue;
1426
1427       list_del(&src->use_link);
1428    }
1429 }
1430
1431 static void
1432 src_add_all_uses(nir_src *src, nir_instr *parent_instr, nir_if *parent_if)
1433 {
1434    for (; src; src = src->is_ssa ? NULL : src->reg.indirect) {
1435       if (!src_is_valid(src))
1436          continue;
1437
1438       if (parent_instr) {
1439          src->parent_instr = parent_instr;
1440          if (src->is_ssa)
1441             list_addtail(&src->use_link, &src->ssa->uses);
1442          else
1443             list_addtail(&src->use_link, &src->reg.reg->uses);
1444       } else {
1445          assert(parent_if);
1446          src->parent_if = parent_if;
1447          if (src->is_ssa)
1448             list_addtail(&src->use_link, &src->ssa->if_uses);
1449          else
1450             list_addtail(&src->use_link, &src->reg.reg->if_uses);
1451       }
1452    }
1453 }
1454
1455 void
1456 nir_instr_rewrite_src(nir_instr *instr, nir_src *src, nir_src new_src)
1457 {
1458    assert(!src_is_valid(src) || src->parent_instr == instr);
1459
1460    src_remove_all_uses(src);
1461    *src = new_src;
1462    src_add_all_uses(src, instr, NULL);
1463 }
1464
1465 void
1466 nir_instr_move_src(nir_instr *dest_instr, nir_src *dest, nir_src *src)
1467 {
1468    assert(!src_is_valid(dest) || dest->parent_instr == dest_instr);
1469
1470    src_remove_all_uses(dest);
1471    src_remove_all_uses(src);
1472    *dest = *src;
1473    *src = NIR_SRC_INIT;
1474    src_add_all_uses(dest, dest_instr, NULL);
1475 }
1476
1477 void
1478 nir_if_rewrite_condition(nir_if *if_stmt, nir_src new_src)
1479 {
1480    nir_src *src = &if_stmt->condition;
1481    assert(!src_is_valid(src) || src->parent_if == if_stmt);
1482
1483    src_remove_all_uses(src);
1484    *src = new_src;
1485    src_add_all_uses(src, NULL, if_stmt);
1486 }
1487
1488 void
1489 nir_instr_rewrite_dest(nir_instr *instr, nir_dest *dest, nir_dest new_dest)
1490 {
1491    if (dest->is_ssa) {
1492       /* We can only overwrite an SSA destination if it has no uses. */
1493       assert(list_empty(&dest->ssa.uses) && list_empty(&dest->ssa.if_uses));
1494    } else {
1495       list_del(&dest->reg.def_link);
1496       if (dest->reg.indirect)
1497          src_remove_all_uses(dest->reg.indirect);
1498    }
1499
1500    /* We can't re-write with an SSA def */
1501    assert(!new_dest.is_ssa);
1502
1503    nir_dest_copy(dest, &new_dest, instr);
1504
1505    dest->reg.parent_instr = instr;
1506    list_addtail(&dest->reg.def_link, &new_dest.reg.reg->defs);
1507
1508    if (dest->reg.indirect)
1509       src_add_all_uses(dest->reg.indirect, instr, NULL);
1510 }
1511
1512 void
1513 nir_instr_rewrite_deref(nir_instr *instr, nir_deref_var **deref,
1514                         nir_deref_var *new_deref)
1515 {
1516    if (*deref)
1517       visit_deref_src(*deref, remove_use_cb, NULL);
1518
1519    *deref = new_deref;
1520
1521    if (*deref)
1522       visit_deref_src(*deref, add_use_cb, instr);
1523 }
1524
1525 /* note: does *not* take ownership of 'name' */
1526 void
1527 nir_ssa_def_init(nir_instr *instr, nir_ssa_def *def,
1528                  unsigned num_components,
1529                  unsigned bit_size, const char *name)
1530 {
1531    def->name = ralloc_strdup(instr, name);
1532    def->parent_instr = instr;
1533    list_inithead(&def->uses);
1534    list_inithead(&def->if_uses);
1535    def->num_components = num_components;
1536    def->bit_size = bit_size;
1537
1538    if (instr->block) {
1539       nir_function_impl *impl =
1540          nir_cf_node_get_function(&instr->block->cf_node);
1541
1542       def->index = impl->ssa_alloc++;
1543    } else {
1544       def->index = UINT_MAX;
1545    }
1546 }
1547
1548 /* note: does *not* take ownership of 'name' */
1549 void
1550 nir_ssa_dest_init(nir_instr *instr, nir_dest *dest,
1551                  unsigned num_components, unsigned bit_size,
1552                  const char *name)
1553 {
1554    dest->is_ssa = true;
1555    nir_ssa_def_init(instr, &dest->ssa, num_components, bit_size, name);
1556 }
1557
1558 void
1559 nir_ssa_def_rewrite_uses(nir_ssa_def *def, nir_src new_src)
1560 {
1561    assert(!new_src.is_ssa || def != new_src.ssa);
1562
1563    nir_foreach_use_safe(use_src, def)
1564       nir_instr_rewrite_src(use_src->parent_instr, use_src, new_src);
1565
1566    nir_foreach_if_use_safe(use_src, def)
1567       nir_if_rewrite_condition(use_src->parent_if, new_src);
1568 }
1569
1570 static bool
1571 is_instr_between(nir_instr *start, nir_instr *end, nir_instr *between)
1572 {
1573    assert(start->block == end->block);
1574
1575    if (between->block != start->block)
1576       return false;
1577
1578    /* Search backwards looking for "between" */
1579    while (start != end) {
1580       if (between == end)
1581          return true;
1582
1583       end = nir_instr_prev(end);
1584       assert(end);
1585    }
1586
1587    return false;
1588 }
1589
1590 /* Replaces all uses of the given SSA def with the given source but only if
1591  * the use comes after the after_me instruction.  This can be useful if you
1592  * are emitting code to fix up the result of some instruction: you can freely
1593  * use the result in that code and then call rewrite_uses_after and pass the
1594  * last fixup instruction as after_me and it will replace all of the uses you
1595  * want without touching the fixup code.
1596  *
1597  * This function assumes that after_me is in the same block as
1598  * def->parent_instr and that after_me comes after def->parent_instr.
1599  */
1600 void
1601 nir_ssa_def_rewrite_uses_after(nir_ssa_def *def, nir_src new_src,
1602                                nir_instr *after_me)
1603 {
1604    assert(!new_src.is_ssa || def != new_src.ssa);
1605
1606    nir_foreach_use_safe(use_src, def) {
1607       assert(use_src->parent_instr != def->parent_instr);
1608       /* Since def already dominates all of its uses, the only way a use can
1609        * not be dominated by after_me is if it is between def and after_me in
1610        * the instruction list.
1611        */
1612       if (!is_instr_between(def->parent_instr, after_me, use_src->parent_instr))
1613          nir_instr_rewrite_src(use_src->parent_instr, use_src, new_src);
1614    }
1615
1616    nir_foreach_if_use_safe(use_src, def)
1617       nir_if_rewrite_condition(use_src->parent_if, new_src);
1618 }
1619
1620 uint8_t
1621 nir_ssa_def_components_read(nir_ssa_def *def)
1622 {
1623    uint8_t read_mask = 0;
1624    nir_foreach_use(use, def) {
1625       if (use->parent_instr->type == nir_instr_type_alu) {
1626          nir_alu_instr *alu = nir_instr_as_alu(use->parent_instr);
1627          nir_alu_src *alu_src = exec_node_data(nir_alu_src, use, src);
1628          int src_idx = alu_src - &alu->src[0];
1629          assert(src_idx >= 0 && src_idx < nir_op_infos[alu->op].num_inputs);
1630
1631          for (unsigned c = 0; c < 4; c++) {
1632             if (!nir_alu_instr_channel_used(alu, src_idx, c))
1633                continue;
1634
1635             read_mask |= (1 << alu_src->swizzle[c]);
1636          }
1637       } else {
1638          return (1 << def->num_components) - 1;
1639       }
1640    }
1641
1642    return read_mask;
1643 }
1644
1645 nir_block *
1646 nir_block_cf_tree_next(nir_block *block)
1647 {
1648    if (block == NULL) {
1649       /* nir_foreach_block_safe() will call this function on a NULL block
1650        * after the last iteration, but it won't use the result so just return
1651        * NULL here.
1652        */
1653       return NULL;
1654    }
1655
1656    nir_cf_node *cf_next = nir_cf_node_next(&block->cf_node);
1657    if (cf_next)
1658       return nir_cf_node_cf_tree_first(cf_next);
1659
1660    nir_cf_node *parent = block->cf_node.parent;
1661
1662    switch (parent->type) {
1663    case nir_cf_node_if: {
1664       /* Are we at the end of the if? Go to the beginning of the else */
1665       nir_if *if_stmt = nir_cf_node_as_if(parent);
1666       if (block == nir_if_last_then_block(if_stmt))
1667          return nir_if_first_else_block(if_stmt);
1668
1669       assert(block == nir_if_last_else_block(if_stmt));
1670       /* fall through */
1671    }
1672
1673    case nir_cf_node_loop:
1674       return nir_cf_node_as_block(nir_cf_node_next(parent));
1675
1676    case nir_cf_node_function:
1677       return NULL;
1678
1679    default:
1680       unreachable("unknown cf node type");
1681    }
1682 }
1683
1684 nir_block *
1685 nir_block_cf_tree_prev(nir_block *block)
1686 {
1687    if (block == NULL) {
1688       /* do this for consistency with nir_block_cf_tree_next() */
1689       return NULL;
1690    }
1691
1692    nir_cf_node *cf_prev = nir_cf_node_prev(&block->cf_node);
1693    if (cf_prev)
1694       return nir_cf_node_cf_tree_last(cf_prev);
1695
1696    nir_cf_node *parent = block->cf_node.parent;
1697
1698    switch (parent->type) {
1699    case nir_cf_node_if: {
1700       /* Are we at the beginning of the else? Go to the end of the if */
1701       nir_if *if_stmt = nir_cf_node_as_if(parent);
1702       if (block == nir_if_first_else_block(if_stmt))
1703          return nir_if_last_then_block(if_stmt);
1704
1705       assert(block == nir_if_first_then_block(if_stmt));
1706       /* fall through */
1707    }
1708
1709    case nir_cf_node_loop:
1710       return nir_cf_node_as_block(nir_cf_node_prev(parent));
1711
1712    case nir_cf_node_function:
1713       return NULL;
1714
1715    default:
1716       unreachable("unknown cf node type");
1717    }
1718 }
1719
1720 nir_block *nir_cf_node_cf_tree_first(nir_cf_node *node)
1721 {
1722    switch (node->type) {
1723    case nir_cf_node_function: {
1724       nir_function_impl *impl = nir_cf_node_as_function(node);
1725       return nir_start_block(impl);
1726    }
1727
1728    case nir_cf_node_if: {
1729       nir_if *if_stmt = nir_cf_node_as_if(node);
1730       return nir_if_first_then_block(if_stmt);
1731    }
1732
1733    case nir_cf_node_loop: {
1734       nir_loop *loop = nir_cf_node_as_loop(node);
1735       return nir_loop_first_block(loop);
1736    }
1737
1738    case nir_cf_node_block: {
1739       return nir_cf_node_as_block(node);
1740    }
1741
1742    default:
1743       unreachable("unknown node type");
1744    }
1745 }
1746
1747 nir_block *nir_cf_node_cf_tree_last(nir_cf_node *node)
1748 {
1749    switch (node->type) {
1750    case nir_cf_node_function: {
1751       nir_function_impl *impl = nir_cf_node_as_function(node);
1752       return nir_impl_last_block(impl);
1753    }
1754
1755    case nir_cf_node_if: {
1756       nir_if *if_stmt = nir_cf_node_as_if(node);
1757       return nir_if_last_else_block(if_stmt);
1758    }
1759
1760    case nir_cf_node_loop: {
1761       nir_loop *loop = nir_cf_node_as_loop(node);
1762       return nir_loop_last_block(loop);
1763    }
1764
1765    case nir_cf_node_block: {
1766       return nir_cf_node_as_block(node);
1767    }
1768
1769    default:
1770       unreachable("unknown node type");
1771    }
1772 }
1773
1774 nir_block *nir_cf_node_cf_tree_next(nir_cf_node *node)
1775 {
1776    if (node->type == nir_cf_node_block)
1777       return nir_block_cf_tree_next(nir_cf_node_as_block(node));
1778    else if (node->type == nir_cf_node_function)
1779       return NULL;
1780    else
1781       return nir_cf_node_as_block(nir_cf_node_next(node));
1782 }
1783
1784 nir_if *
1785 nir_block_get_following_if(nir_block *block)
1786 {
1787    if (exec_node_is_tail_sentinel(&block->cf_node.node))
1788       return NULL;
1789
1790    if (nir_cf_node_is_last(&block->cf_node))
1791       return NULL;
1792
1793    nir_cf_node *next_node = nir_cf_node_next(&block->cf_node);
1794
1795    if (next_node->type != nir_cf_node_if)
1796       return NULL;
1797
1798    return nir_cf_node_as_if(next_node);
1799 }
1800
1801 nir_loop *
1802 nir_block_get_following_loop(nir_block *block)
1803 {
1804    if (exec_node_is_tail_sentinel(&block->cf_node.node))
1805       return NULL;
1806
1807    if (nir_cf_node_is_last(&block->cf_node))
1808       return NULL;
1809
1810    nir_cf_node *next_node = nir_cf_node_next(&block->cf_node);
1811
1812    if (next_node->type != nir_cf_node_loop)
1813       return NULL;
1814
1815    return nir_cf_node_as_loop(next_node);
1816 }
1817
1818 void
1819 nir_index_blocks(nir_function_impl *impl)
1820 {
1821    unsigned index = 0;
1822
1823    if (impl->valid_metadata & nir_metadata_block_index)
1824       return;
1825
1826    nir_foreach_block(block, impl) {
1827       block->index = index++;
1828    }
1829
1830    impl->num_blocks = index;
1831 }
1832
1833 static bool
1834 index_ssa_def_cb(nir_ssa_def *def, void *state)
1835 {
1836    unsigned *index = (unsigned *) state;
1837    def->index = (*index)++;
1838
1839    return true;
1840 }
1841
1842 /**
1843  * The indices are applied top-to-bottom which has the very nice property
1844  * that, if A dominates B, then A->index <= B->index.
1845  */
1846 void
1847 nir_index_ssa_defs(nir_function_impl *impl)
1848 {
1849    unsigned index = 0;
1850
1851    nir_foreach_block(block, impl) {
1852       nir_foreach_instr(instr, block)
1853          nir_foreach_ssa_def(instr, index_ssa_def_cb, &index);
1854    }
1855
1856    impl->ssa_alloc = index;
1857 }
1858
1859 /**
1860  * The indices are applied top-to-bottom which has the very nice property
1861  * that, if A dominates B, then A->index <= B->index.
1862  */
1863 unsigned
1864 nir_index_instrs(nir_function_impl *impl)
1865 {
1866    unsigned index = 0;
1867
1868    nir_foreach_block(block, impl) {
1869       nir_foreach_instr(instr, block)
1870          instr->index = index++;
1871    }
1872
1873    return index;
1874 }
1875
1876 nir_intrinsic_op
1877 nir_intrinsic_from_system_value(gl_system_value val)
1878 {
1879    switch (val) {
1880    case SYSTEM_VALUE_VERTEX_ID:
1881       return nir_intrinsic_load_vertex_id;
1882    case SYSTEM_VALUE_INSTANCE_ID:
1883       return nir_intrinsic_load_instance_id;
1884    case SYSTEM_VALUE_DRAW_ID:
1885       return nir_intrinsic_load_draw_id;
1886    case SYSTEM_VALUE_BASE_INSTANCE:
1887       return nir_intrinsic_load_base_instance;
1888    case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE:
1889       return nir_intrinsic_load_vertex_id_zero_base;
1890    case SYSTEM_VALUE_BASE_VERTEX:
1891       return nir_intrinsic_load_base_vertex;
1892    case SYSTEM_VALUE_INVOCATION_ID:
1893       return nir_intrinsic_load_invocation_id;
1894    case SYSTEM_VALUE_FRAG_COORD:
1895       return nir_intrinsic_load_frag_coord;
1896    case SYSTEM_VALUE_FRONT_FACE:
1897       return nir_intrinsic_load_front_face;
1898    case SYSTEM_VALUE_SAMPLE_ID:
1899       return nir_intrinsic_load_sample_id;
1900    case SYSTEM_VALUE_SAMPLE_POS:
1901       return nir_intrinsic_load_sample_pos;
1902    case SYSTEM_VALUE_SAMPLE_MASK_IN:
1903       return nir_intrinsic_load_sample_mask_in;
1904    case SYSTEM_VALUE_LOCAL_INVOCATION_ID:
1905       return nir_intrinsic_load_local_invocation_id;
1906    case SYSTEM_VALUE_LOCAL_INVOCATION_INDEX:
1907       return nir_intrinsic_load_local_invocation_index;
1908    case SYSTEM_VALUE_WORK_GROUP_ID:
1909       return nir_intrinsic_load_work_group_id;
1910    case SYSTEM_VALUE_NUM_WORK_GROUPS:
1911       return nir_intrinsic_load_num_work_groups;
1912    case SYSTEM_VALUE_PRIMITIVE_ID:
1913       return nir_intrinsic_load_primitive_id;
1914    case SYSTEM_VALUE_TESS_COORD:
1915       return nir_intrinsic_load_tess_coord;
1916    case SYSTEM_VALUE_TESS_LEVEL_OUTER:
1917       return nir_intrinsic_load_tess_level_outer;
1918    case SYSTEM_VALUE_TESS_LEVEL_INNER:
1919       return nir_intrinsic_load_tess_level_inner;
1920    case SYSTEM_VALUE_VERTICES_IN:
1921       return nir_intrinsic_load_patch_vertices_in;
1922    case SYSTEM_VALUE_HELPER_INVOCATION:
1923       return nir_intrinsic_load_helper_invocation;
1924    case SYSTEM_VALUE_VIEW_INDEX:
1925       return nir_intrinsic_load_view_index;
1926    case SYSTEM_VALUE_SUBGROUP_SIZE:
1927       return nir_intrinsic_load_subgroup_size;
1928    case SYSTEM_VALUE_SUBGROUP_INVOCATION:
1929       return nir_intrinsic_load_subgroup_invocation;
1930    case SYSTEM_VALUE_SUBGROUP_EQ_MASK:
1931       return nir_intrinsic_load_subgroup_eq_mask;
1932    case SYSTEM_VALUE_SUBGROUP_GE_MASK:
1933       return nir_intrinsic_load_subgroup_ge_mask;
1934    case SYSTEM_VALUE_SUBGROUP_GT_MASK:
1935       return nir_intrinsic_load_subgroup_gt_mask;
1936    case SYSTEM_VALUE_SUBGROUP_LE_MASK:
1937       return nir_intrinsic_load_subgroup_le_mask;
1938    case SYSTEM_VALUE_SUBGROUP_LT_MASK:
1939       return nir_intrinsic_load_subgroup_lt_mask;
1940    default:
1941       unreachable("system value does not directly correspond to intrinsic");
1942    }
1943 }
1944
1945 gl_system_value
1946 nir_system_value_from_intrinsic(nir_intrinsic_op intrin)
1947 {
1948    switch (intrin) {
1949    case nir_intrinsic_load_vertex_id:
1950       return SYSTEM_VALUE_VERTEX_ID;
1951    case nir_intrinsic_load_instance_id:
1952       return SYSTEM_VALUE_INSTANCE_ID;
1953    case nir_intrinsic_load_draw_id:
1954       return SYSTEM_VALUE_DRAW_ID;
1955    case nir_intrinsic_load_base_instance:
1956       return SYSTEM_VALUE_BASE_INSTANCE;
1957    case nir_intrinsic_load_vertex_id_zero_base:
1958       return SYSTEM_VALUE_VERTEX_ID_ZERO_BASE;
1959    case nir_intrinsic_load_base_vertex:
1960       return SYSTEM_VALUE_BASE_VERTEX;
1961    case nir_intrinsic_load_invocation_id:
1962       return SYSTEM_VALUE_INVOCATION_ID;
1963    case nir_intrinsic_load_frag_coord:
1964       return SYSTEM_VALUE_FRAG_COORD;
1965    case nir_intrinsic_load_front_face:
1966       return SYSTEM_VALUE_FRONT_FACE;
1967    case nir_intrinsic_load_sample_id:
1968       return SYSTEM_VALUE_SAMPLE_ID;
1969    case nir_intrinsic_load_sample_pos:
1970       return SYSTEM_VALUE_SAMPLE_POS;
1971    case nir_intrinsic_load_sample_mask_in:
1972       return SYSTEM_VALUE_SAMPLE_MASK_IN;
1973    case nir_intrinsic_load_local_invocation_id:
1974       return SYSTEM_VALUE_LOCAL_INVOCATION_ID;
1975    case nir_intrinsic_load_local_invocation_index:
1976       return SYSTEM_VALUE_LOCAL_INVOCATION_INDEX;
1977    case nir_intrinsic_load_num_work_groups:
1978       return SYSTEM_VALUE_NUM_WORK_GROUPS;
1979    case nir_intrinsic_load_work_group_id:
1980       return SYSTEM_VALUE_WORK_GROUP_ID;
1981    case nir_intrinsic_load_primitive_id:
1982       return SYSTEM_VALUE_PRIMITIVE_ID;
1983    case nir_intrinsic_load_tess_coord:
1984       return SYSTEM_VALUE_TESS_COORD;
1985    case nir_intrinsic_load_tess_level_outer:
1986       return SYSTEM_VALUE_TESS_LEVEL_OUTER;
1987    case nir_intrinsic_load_tess_level_inner:
1988       return SYSTEM_VALUE_TESS_LEVEL_INNER;
1989    case nir_intrinsic_load_patch_vertices_in:
1990       return SYSTEM_VALUE_VERTICES_IN;
1991    case nir_intrinsic_load_helper_invocation:
1992       return SYSTEM_VALUE_HELPER_INVOCATION;
1993    case nir_intrinsic_load_view_index:
1994       return SYSTEM_VALUE_VIEW_INDEX;
1995    case nir_intrinsic_load_subgroup_size:
1996       return SYSTEM_VALUE_SUBGROUP_SIZE;
1997    case nir_intrinsic_load_subgroup_invocation:
1998       return SYSTEM_VALUE_SUBGROUP_INVOCATION;
1999    case nir_intrinsic_load_subgroup_eq_mask:
2000       return SYSTEM_VALUE_SUBGROUP_EQ_MASK;
2001    case nir_intrinsic_load_subgroup_ge_mask:
2002       return SYSTEM_VALUE_SUBGROUP_GE_MASK;
2003    case nir_intrinsic_load_subgroup_gt_mask:
2004       return SYSTEM_VALUE_SUBGROUP_GT_MASK;
2005    case nir_intrinsic_load_subgroup_le_mask:
2006       return SYSTEM_VALUE_SUBGROUP_LE_MASK;
2007    case nir_intrinsic_load_subgroup_lt_mask:
2008       return SYSTEM_VALUE_SUBGROUP_LT_MASK;
2009    default:
2010       unreachable("intrinsic doesn't produce a system value");
2011    }
2012 }