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    shader->info = si ? si : rzalloc(shader, shader_info);
  48
  49    exec_list_make_empty(&shader->functions);
  50    exec_list_make_empty(&shader->registers);
  51    exec_list_make_empty(&shader->globals);
  52    exec_list_make_empty(&shader->system_values);
  53    shader->reg_alloc = 0;
  54
  55    shader->num_inputs = 0;
  56    shader->num_outputs = 0;
  57    shader->num_uniforms = 0;
  58    shader->num_shared = 0;
  59
  60    shader->stage = stage;
  61
  62    return shader;
  63 }
  64
  65 static nir_register *
  66 reg_create(void *mem_ctx, struct exec_list *list)
  67 {
  68    nir_register *reg = ralloc(mem_ctx, nir_register);
  69
  70    list_inithead(&reg->uses);
  71    list_inithead(&reg->defs);
  72    list_inithead(&reg->if_uses);
  73
  74    reg->num_components = 0;
  75    reg->bit_size = 32;
  76    reg->num_array_elems = 0;
  77    reg->is_packed = false;
  78    reg->name = NULL;
  79
  80    exec_list_push_tail(list, &reg->node);
  81
  82    return reg;
  83 }
  84
  85 nir_register *
  86 nir_global_reg_create(nir_shader *shader)
  87 {
  88    nir_register *reg = reg_create(shader, &shader->registers);
  89    reg->index = shader->reg_alloc++;
  90    reg->is_global = true;
  91
  92    return reg;
  93 }
  94
  95 nir_register *
  96 nir_local_reg_create(nir_function_impl *impl)
  97 {
  98    nir_register *reg = reg_create(ralloc_parent(impl), &impl->registers);
  99    reg->index = impl->reg_alloc++;
 100    reg->is_global = false;
 101
 102    return reg;
 103 }
 104
 105 void
 106 nir_reg_remove(nir_register *reg)
 107 {
 108    exec_node_remove(&reg->node);
 109 }
 110
 111 void
 112 nir_shader_add_variable(nir_shader *shader, nir_variable *var)
 113 {
 114    switch (var->data.mode) {
 115    case nir_var_all:
 116       assert(!"invalid mode");
 117       break;
 118
 119    case nir_var_local:
 120       assert(!"nir_shader_add_variable cannot be used for local variables");
 121       break;
 122
 123    case nir_var_param:
 124       assert(!"nir_shader_add_variable cannot be used for function parameters");
 125       break;
 126
 127    case nir_var_global:
 128       exec_list_push_tail(&shader->globals, &var->node);
 129       break;
 130
 131    case nir_var_shader_in:
 132       exec_list_push_tail(&shader->inputs, &var->node);
 133       break;
 134
 135    case nir_var_shader_out:
 136       exec_list_push_tail(&shader->outputs, &var->node);
 137       break;
 138
 139    case nir_var_uniform:
 140    case nir_var_shader_storage:
 141       exec_list_push_tail(&shader->uniforms, &var->node);
 142       break;
 143
 144    case nir_var_shared:
 145       assert(shader->stage == MESA_SHADER_COMPUTE);
 146       exec_list_push_tail(&shader->shared, &var->node);
 147       break;
 148
 149    case nir_var_system_value:
 150       exec_list_push_tail(&shader->system_values, &var->node);
 151       break;
 152    }
 153 }
 154
 155 nir_variable *
 156 nir_variable_create(nir_shader *shader, nir_variable_mode mode,
 157                     const struct glsl_type *type, const char *name)
 158 {
 159    nir_variable *var = rzalloc(shader, nir_variable);
 160    var->name = ralloc_strdup(var, name);
 161    var->type = type;
 162    var->data.mode = mode;
 163
 164    if ((mode == nir_var_shader_in && shader->stage != MESA_SHADER_VERTEX) ||
 165        (mode == nir_var_shader_out && shader->stage != MESA_SHADER_FRAGMENT))
 166       var->data.interpolation = INTERP_MODE_SMOOTH;
 167
 168    if (mode == nir_var_shader_in || mode == nir_var_uniform)
 169       var->data.read_only = true;
 170
 171    nir_shader_add_variable(shader, var);
 172
 173    return var;
 174 }
 175
 176 nir_variable *
 177 nir_local_variable_create(nir_function_impl *impl,
 178                           const struct glsl_type *type, const char *name)
 179 {
 180    nir_variable *var = rzalloc(impl->function->shader, nir_variable);
 181    var->name = ralloc_strdup(var, name);
 182    var->type = type;
 183    var->data.mode = nir_var_local;
 184
 185    nir_function_impl_add_variable(impl, var);
 186
 187    return var;
 188 }
 189
 190 nir_function *
 191 nir_function_create(nir_shader *shader, const char *name)
 192 {
 193    nir_function *func = ralloc(shader, nir_function);
 194
 195    exec_list_push_tail(&shader->functions, &func->node);
 196
 197    func->name = ralloc_strdup(func, name);
 198    func->shader = shader;
 199    func->num_params = 0;
 200    func->params = NULL;
 201    func->return_type = glsl_void_type();
 202    func->impl = NULL;
 203
 204    return func;
 205 }
 206
 207 void nir_src_copy(nir_src *dest, const nir_src *src, void *mem_ctx)
 208 {
 209    dest->is_ssa = src->is_ssa;
 210    if (src->is_ssa) {
 211       dest->ssa = src->ssa;
 212    } else {
 213       dest->reg.base_offset = src->reg.base_offset;
 214       dest->reg.reg = src->reg.reg;
 215       if (src->reg.indirect) {
 216          dest->reg.indirect = ralloc(mem_ctx, nir_src);
 217          nir_src_copy(dest->reg.indirect, src->reg.indirect, mem_ctx);
 218       } else {
 219          dest->reg.indirect = NULL;
 220       }
 221    }
 222 }
 223
 224 void nir_dest_copy(nir_dest *dest, const nir_dest *src, nir_instr *instr)
 225 {
 226    /* Copying an SSA definition makes no sense whatsoever. */
 227    assert(!src->is_ssa);
 228
 229    dest->is_ssa = false;
 230
 231    dest->reg.base_offset = src->reg.base_offset;
 232    dest->reg.reg = src->reg.reg;
 233    if (src->reg.indirect) {
 234       dest->reg.indirect = ralloc(instr, nir_src);
 235       nir_src_copy(dest->reg.indirect, src->reg.indirect, instr);
 236    } else {
 237       dest->reg.indirect = NULL;
 238    }
 239 }
 240
 241 void
 242 nir_alu_src_copy(nir_alu_src *dest, const nir_alu_src *src,
 243                  nir_alu_instr *instr)
 244 {
 245    nir_src_copy(&dest->src, &src->src, &instr->instr);
 246    dest->abs = src->abs;
 247    dest->negate = src->negate;
 248    for (unsigned i = 0; i < 4; i++)
 249       dest->swizzle[i] = src->swizzle[i];
 250 }
 251
 252 void
 253 nir_alu_dest_copy(nir_alu_dest *dest, const nir_alu_dest *src,
 254                   nir_alu_instr *instr)
 255 {
 256    nir_dest_copy(&dest->dest, &src->dest, &instr->instr);
 257    dest->write_mask = src->write_mask;
 258    dest->saturate = src->saturate;
 259 }
 260
 261
 262 static void
 263 cf_init(nir_cf_node *node, nir_cf_node_type type)
 264 {
 265    exec_node_init(&node->node);
 266    node->parent = NULL;
 267    node->type = type;
 268 }
 269
 270 nir_function_impl *
 271 nir_function_impl_create_bare(nir_shader *shader)
 272 {
 273    nir_function_impl *impl = ralloc(shader, nir_function_impl);
 274
 275    impl->function = NULL;
 276
 277    cf_init(&impl->cf_node, nir_cf_node_function);
 278
 279    exec_list_make_empty(&impl->body);
 280    exec_list_make_empty(&impl->registers);
 281    exec_list_make_empty(&impl->locals);
 282    impl->num_params = 0;
 283    impl->params = NULL;
 284    impl->return_var = NULL;
 285    impl->reg_alloc = 0;
 286    impl->ssa_alloc = 0;
 287    impl->valid_metadata = nir_metadata_none;
 288
 289    /* create start & end blocks */
 290    nir_block *start_block = nir_block_create(shader);
 291    nir_block *end_block = nir_block_create(shader);
 292    start_block->cf_node.parent = &impl->cf_node;
 293    end_block->cf_node.parent = &impl->cf_node;
 294    impl->end_block = end_block;
 295
 296    exec_list_push_tail(&impl->body, &start_block->cf_node.node);
 297
 298    start_block->successors[0] = end_block;
 299    _mesa_set_add(end_block->predecessors, start_block);
 300    return impl;
 301 }
 302
 303 nir_function_impl *
 304 nir_function_impl_create(nir_function *function)
 305 {
 306    assert(function->impl == NULL);
 307
 308    nir_function_impl *impl = nir_function_impl_create_bare(function->shader);
 309
 310    function->impl = impl;
 311    impl->function = function;
 312
 313    impl->num_params = function->num_params;
 314    impl->params = ralloc_array(function->shader,
 315                                nir_variable *, impl->num_params);
 316
 317    for (unsigned i = 0; i < impl->num_params; i++) {
 318       impl->params[i] = rzalloc(function->shader, nir_variable);
 319       impl->params[i]->type = function->params[i].type;
 320       impl->params[i]->data.mode = nir_var_param;
 321       impl->params[i]->data.location = i;
 322    }
 323
 324    if (!glsl_type_is_void(function->return_type)) {
 325       impl->return_var = rzalloc(function->shader, nir_variable);
 326       impl->return_var->type = function->return_type;
 327       impl->return_var->data.mode = nir_var_param;
 328       impl->return_var->data.location = -1;
 329    } else {
 330       impl->return_var = NULL;
 331    }
 332
 333    return impl;
 334 }
 335
 336 nir_block *
 337 nir_block_create(nir_shader *shader)
 338 {
 339    nir_block *block = rzalloc(shader, nir_block);
 340
 341    cf_init(&block->cf_node, nir_cf_node_block);
 342
 343    block->successors[0] = block->successors[1] = NULL;
 344    block->predecessors = _mesa_set_create(block, _mesa_hash_pointer,
 345                                           _mesa_key_pointer_equal);
 346    block->imm_dom = NULL;
 347    /* XXX maybe it would be worth it to defer allocation?  This
 348     * way it doesn't get allocated for shader refs that never run
 349     * nir_calc_dominance?  For example, state-tracker creates an
 350     * initial IR, clones that, runs appropriate lowering pass, passes
 351     * to driver which does common lowering/opt, and then stores ref
 352     * which is later used to do state specific lowering and futher
 353     * opt.  Do any of the references not need dominance metadata?
 354     */
 355    block->dom_frontier = _mesa_set_create(block, _mesa_hash_pointer,
 356                                           _mesa_key_pointer_equal);
 357
 358    exec_list_make_empty(&block->instr_list);
 359
 360    return block;
 361 }
 362
 363 static inline void
 364 src_init(nir_src *src)
 365 {
 366    src->is_ssa = false;
 367    src->reg.reg = NULL;
 368    src->reg.indirect = NULL;
 369    src->reg.base_offset = 0;
 370 }
 371
 372 nir_if *
 373 nir_if_create(nir_shader *shader)
 374 {
 375    nir_if *if_stmt = ralloc(shader, nir_if);
 376
 377    cf_init(&if_stmt->cf_node, nir_cf_node_if);
 378    src_init(&if_stmt->condition);
 379
 380    nir_block *then = nir_block_create(shader);
 381    exec_list_make_empty(&if_stmt->then_list);
 382    exec_list_push_tail(&if_stmt->then_list, &then->cf_node.node);
 383    then->cf_node.parent = &if_stmt->cf_node;
 384
 385    nir_block *else_stmt = nir_block_create(shader);
 386    exec_list_make_empty(&if_stmt->else_list);
 387    exec_list_push_tail(&if_stmt->else_list, &else_stmt->cf_node.node);
 388    else_stmt->cf_node.parent = &if_stmt->cf_node;
 389
 390    return if_stmt;
 391 }
 392
 393 nir_loop *
 394 nir_loop_create(nir_shader *shader)
 395 {
 396    nir_loop *loop = rzalloc(shader, nir_loop);
 397
 398    cf_init(&loop->cf_node, nir_cf_node_loop);
 399
 400    nir_block *body = nir_block_create(shader);
 401    exec_list_make_empty(&loop->body);
 402    exec_list_push_tail(&loop->body, &body->cf_node.node);
 403    body->cf_node.parent = &loop->cf_node;
 404
 405    body->successors[0] = body;
 406    _mesa_set_add(body->predecessors, body);
 407
 408    return loop;
 409 }
 410
 411 static void
 412 instr_init(nir_instr *instr, nir_instr_type type)
 413 {
 414    instr->type = type;
 415    instr->block = NULL;
 416    exec_node_init(&instr->node);
 417 }
 418
 419 static void
 420 dest_init(nir_dest *dest)
 421 {
 422    dest->is_ssa = false;
 423    dest->reg.reg = NULL;
 424    dest->reg.indirect = NULL;
 425    dest->reg.base_offset = 0;
 426 }
 427
 428 static void
 429 alu_dest_init(nir_alu_dest *dest)
 430 {
 431    dest_init(&dest->dest);
 432    dest->saturate = false;
 433    dest->write_mask = 0xf;
 434 }
 435
 436 static void
 437 alu_src_init(nir_alu_src *src)
 438 {
 439    src_init(&src->src);
 440    src->abs = src->negate = false;
 441    src->swizzle[0] = 0;
 442    src->swizzle[1] = 1;
 443    src->swizzle[2] = 2;
 444    src->swizzle[3] = 3;
 445 }
 446
 447 nir_alu_instr *
 448 nir_alu_instr_create(nir_shader *shader, nir_op op)
 449 {
 450    unsigned num_srcs = nir_op_infos[op].num_inputs;
 451    /* TODO: don't use rzalloc */
 452    nir_alu_instr *instr =
 453       rzalloc_size(shader,
 454                    sizeof(nir_alu_instr) + num_srcs * sizeof(nir_alu_src));
 455
 456    instr_init(&instr->instr, nir_instr_type_alu);
 457    instr->op = op;
 458    alu_dest_init(&instr->dest);
 459    for (unsigned i = 0; i < num_srcs; i++)
 460       alu_src_init(&instr->src[i]);
 461
 462    return instr;
 463 }
 464
 465 nir_jump_instr *
 466 nir_jump_instr_create(nir_shader *shader, nir_jump_type type)
 467 {
 468    nir_jump_instr *instr = ralloc(shader, nir_jump_instr);
 469    instr_init(&instr->instr, nir_instr_type_jump);
 470    instr->type = type;
 471    return instr;
 472 }
 473
 474 nir_load_const_instr *
 475 nir_load_const_instr_create(nir_shader *shader, unsigned num_components,
 476                             unsigned bit_size)
 477 {
 478    nir_load_const_instr *instr = ralloc(shader, nir_load_const_instr);
 479    instr_init(&instr->instr, nir_instr_type_load_const);
 480
 481    nir_ssa_def_init(&instr->instr, &instr->def, num_components, bit_size, NULL);
 482
 483    return instr;
 484 }
 485
 486 nir_intrinsic_instr *
 487 nir_intrinsic_instr_create(nir_shader *shader, nir_intrinsic_op op)
 488 {
 489    unsigned num_srcs = nir_intrinsic_infos[op].num_srcs;
 490    /* TODO: don't use rzalloc */
 491    nir_intrinsic_instr *instr =
 492       rzalloc_size(shader,
 493                   sizeof(nir_intrinsic_instr) + num_srcs * sizeof(nir_src));
 494
 495    instr_init(&instr->instr, nir_instr_type_intrinsic);
 496    instr->intrinsic = op;
 497
 498    if (nir_intrinsic_infos[op].has_dest)
 499       dest_init(&instr->dest);
 500
 501    for (unsigned i = 0; i < num_srcs; i++)
 502       src_init(&instr->src[i]);
 503
 504    return instr;
 505 }
 506
 507 nir_call_instr *
 508 nir_call_instr_create(nir_shader *shader, nir_function *callee)
 509 {
 510    nir_call_instr *instr = ralloc(shader, nir_call_instr);
 511    instr_init(&instr->instr, nir_instr_type_call);
 512
 513    instr->callee = callee;
 514    instr->num_params = callee->num_params;
 515    instr->params = ralloc_array(instr, nir_deref_var *, instr->num_params);
 516    instr->return_deref = NULL;
 517
 518    return instr;
 519 }
 520
 521 nir_tex_instr *
 522 nir_tex_instr_create(nir_shader *shader, unsigned num_srcs)
 523 {
 524    nir_tex_instr *instr = rzalloc(shader, nir_tex_instr);
 525    instr_init(&instr->instr, nir_instr_type_tex);
 526
 527    dest_init(&instr->dest);
 528
 529    instr->num_srcs = num_srcs;
 530    instr->src = ralloc_array(instr, nir_tex_src, num_srcs);
 531    for (unsigned i = 0; i < num_srcs; i++)
 532       src_init(&instr->src[i].src);
 533
 534    instr->texture_index = 0;
 535    instr->texture_array_size = 0;
 536    instr->texture = NULL;
 537    instr->sampler_index = 0;
 538    instr->sampler = NULL;
 539
 540    return instr;
 541 }
 542
 543 void
 544 nir_tex_instr_remove_src(nir_tex_instr *tex, unsigned src_idx)
 545 {
 546    assert(src_idx < tex->num_srcs);
 547
 548    /* First rewrite the source to NIR_SRC_INIT */
 549    nir_instr_rewrite_src(&tex->instr, &tex->src[src_idx].src, NIR_SRC_INIT);
 550
 551    /* Now, move all of the other sources down */
 552    for (unsigned i = src_idx + 1; i < tex->num_srcs; i++) {
 553       tex->src[i-1].src_type = tex->src[i].src_type;
 554       nir_instr_move_src(&tex->instr, &tex->src[i-1].src, &tex->src[i].src);
 555    }
 556    tex->num_srcs--;
 557 }
 558
 559 nir_phi_instr *
 560 nir_phi_instr_create(nir_shader *shader)
 561 {
 562    nir_phi_instr *instr = ralloc(shader, nir_phi_instr);
 563    instr_init(&instr->instr, nir_instr_type_phi);
 564
 565    dest_init(&instr->dest);
 566    exec_list_make_empty(&instr->srcs);
 567    return instr;
 568 }
 569
 570 nir_parallel_copy_instr *
 571 nir_parallel_copy_instr_create(nir_shader *shader)
 572 {
 573    nir_parallel_copy_instr *instr = ralloc(shader, nir_parallel_copy_instr);
 574    instr_init(&instr->instr, nir_instr_type_parallel_copy);
 575
 576    exec_list_make_empty(&instr->entries);
 577
 578    return instr;
 579 }
 580
 581 nir_ssa_undef_instr *
 582 nir_ssa_undef_instr_create(nir_shader *shader,
 583                            unsigned num_components,
 584                            unsigned bit_size)
 585 {
 586    nir_ssa_undef_instr *instr = ralloc(shader, nir_ssa_undef_instr);
 587    instr_init(&instr->instr, nir_instr_type_ssa_undef);
 588
 589    nir_ssa_def_init(&instr->instr, &instr->def, num_components, bit_size, NULL);
 590
 591    return instr;
 592 }
 593
 594 nir_deref_var *
 595 nir_deref_var_create(void *mem_ctx, nir_variable *var)
 596 {
 597    nir_deref_var *deref = ralloc(mem_ctx, nir_deref_var);
 598    deref->deref.deref_type = nir_deref_type_var;
 599    deref->deref.child = NULL;
 600    deref->deref.type = var->type;
 601    deref->var = var;
 602    return deref;
 603 }
 604
 605 nir_deref_array *
 606 nir_deref_array_create(void *mem_ctx)
 607 {
 608    nir_deref_array *deref = ralloc(mem_ctx, nir_deref_array);
 609    deref->deref.deref_type = nir_deref_type_array;
 610    deref->deref.child = NULL;
 611    deref->deref_array_type = nir_deref_array_type_direct;
 612    src_init(&deref->indirect);
 613    deref->base_offset = 0;
 614    return deref;
 615 }
 616
 617 nir_deref_struct *
 618 nir_deref_struct_create(void *mem_ctx, unsigned field_index)
 619 {
 620    nir_deref_struct *deref = ralloc(mem_ctx, nir_deref_struct);
 621    deref->deref.deref_type = nir_deref_type_struct;
 622    deref->deref.child = NULL;
 623    deref->index = field_index;
 624    return deref;
 625 }
 626
 627 nir_deref_var *
 628 nir_deref_var_clone(const nir_deref_var *deref, void *mem_ctx)
 629 {
 630    if (deref == NULL)
 631       return NULL;
 632
 633    nir_deref_var *ret = nir_deref_var_create(mem_ctx, deref->var);
 634    ret->deref.type = deref->deref.type;
 635    if (deref->deref.child)
 636       ret->deref.child = nir_deref_clone(deref->deref.child, ret);
 637    return ret;
 638 }
 639
 640 static nir_deref_array *
 641 deref_array_clone(const nir_deref_array *deref, void *mem_ctx)
 642 {
 643    nir_deref_array *ret = nir_deref_array_create(mem_ctx);
 644    ret->base_offset = deref->base_offset;
 645    ret->deref_array_type = deref->deref_array_type;
 646    if (deref->deref_array_type == nir_deref_array_type_indirect) {
 647       nir_src_copy(&ret->indirect, &deref->indirect, mem_ctx);
 648    }
 649    ret->deref.type = deref->deref.type;
 650    if (deref->deref.child)
 651       ret->deref.child = nir_deref_clone(deref->deref.child, ret);
 652    return ret;
 653 }
 654
 655 static nir_deref_struct *
 656 deref_struct_clone(const nir_deref_struct *deref, void *mem_ctx)
 657 {
 658    nir_deref_struct *ret = nir_deref_struct_create(mem_ctx, deref->index);
 659    ret->deref.type = deref->deref.type;
 660    if (deref->deref.child)
 661       ret->deref.child = nir_deref_clone(deref->deref.child, ret);
 662    return ret;
 663 }
 664
 665 nir_deref *
 666 nir_deref_clone(const nir_deref *deref, void *mem_ctx)
 667 {
 668    if (deref == NULL)
 669       return NULL;
 670
 671    switch (deref->deref_type) {
 672    case nir_deref_type_var:
 673       return &nir_deref_var_clone(nir_deref_as_var(deref), mem_ctx)->deref;
 674    case nir_deref_type_array:
 675       return &deref_array_clone(nir_deref_as_array(deref), mem_ctx)->deref;
 676    case nir_deref_type_struct:
 677       return &deref_struct_clone(nir_deref_as_struct(deref), mem_ctx)->deref;
 678    default:
 679       unreachable("Invalid dereference type");
 680    }
 681
 682    return NULL;
 683 }
 684
 685 /* This is the second step in the recursion.  We've found the tail and made a
 686  * copy.  Now we need to iterate over all possible leaves and call the
 687  * callback on each one.
 688  */
 689 static bool
 690 deref_foreach_leaf_build_recur(nir_deref_var *deref, nir_deref *tail,
 691                                nir_deref_foreach_leaf_cb cb, void *state)
 692 {
 693    unsigned length;
 694    union {
 695       nir_deref_array arr;
 696       nir_deref_struct str;
 697    } tmp;
 698
 699    assert(tail->child == NULL);
 700    switch (glsl_get_base_type(tail->type)) {
 701    case GLSL_TYPE_UINT:
 702    case GLSL_TYPE_UINT64:
 703    case GLSL_TYPE_INT:
 704    case GLSL_TYPE_INT64:
 705    case GLSL_TYPE_FLOAT:
 706    case GLSL_TYPE_DOUBLE:
 707    case GLSL_TYPE_BOOL:
 708       if (glsl_type_is_vector_or_scalar(tail->type))
 709          return cb(deref, state);
 710       /* Fall Through */
 711
 712    case GLSL_TYPE_ARRAY:
 713       tmp.arr.deref.deref_type = nir_deref_type_array;
 714       tmp.arr.deref.type = glsl_get_array_element(tail->type);
 715       tmp.arr.deref_array_type = nir_deref_array_type_direct;
 716       tmp.arr.indirect = NIR_SRC_INIT;
 717       tail->child = &tmp.arr.deref;
 718
 719       length = glsl_get_length(tail->type);
 720       for (unsigned i = 0; i < length; i++) {
 721          tmp.arr.deref.child = NULL;
 722          tmp.arr.base_offset = i;
 723          if (!deref_foreach_leaf_build_recur(deref, &tmp.arr.deref, cb, state))
 724             return false;
 725       }
 726       return true;
 727
 728    case GLSL_TYPE_STRUCT:
 729       tmp.str.deref.deref_type = nir_deref_type_struct;
 730       tail->child = &tmp.str.deref;
 731
 732       length = glsl_get_length(tail->type);
 733       for (unsigned i = 0; i < length; i++) {
 734          tmp.arr.deref.child = NULL;
 735          tmp.str.deref.type = glsl_get_struct_field(tail->type, i);
 736          tmp.str.index = i;
 737          if (!deref_foreach_leaf_build_recur(deref, &tmp.arr.deref, cb, state))
 738             return false;
 739       }
 740       return true;
 741
 742    default:
 743       unreachable("Invalid type for dereference");
 744    }
 745 }
 746
 747 /* This is the first step of the foreach_leaf recursion.  In this step we are
 748  * walking to the end of the deref chain and making a copy in the stack as we
 749  * go.  This is because we don't want to mutate the deref chain that was
 750  * passed in by the caller.  The downside is that this deref chain is on the
 751  * stack and , if the caller wants to do anything with it, they will have to
 752  * make their own copy because this one will go away.
 753  */
 754 static bool
 755 deref_foreach_leaf_copy_recur(nir_deref_var *deref, nir_deref *tail,
 756                               nir_deref_foreach_leaf_cb cb, void *state)
 757 {
 758    union {
 759       nir_deref_array arr;
 760       nir_deref_struct str;
 761    } c;
 762
 763    if (tail->child) {
 764       switch (tail->child->deref_type) {
 765       case nir_deref_type_array:
 766          c.arr = *nir_deref_as_array(tail->child);
 767          tail->child = &c.arr.deref;
 768          return deref_foreach_leaf_copy_recur(deref, &c.arr.deref, cb, state);
 769
 770       case nir_deref_type_struct:
 771          c.str = *nir_deref_as_struct(tail->child);
 772          tail->child = &c.str.deref;
 773          return deref_foreach_leaf_copy_recur(deref, &c.str.deref, cb, state);
 774
 775       case nir_deref_type_var:
 776       default:
 777          unreachable("Invalid deref type for a child");
 778       }
 779    } else {
 780       /* We've gotten to the end of the original deref.  Time to start
 781        * building our own derefs.
 782        */
 783       return deref_foreach_leaf_build_recur(deref, tail, cb, state);
 784    }
 785 }
 786
 787 /**
 788  * This function iterates over all of the possible derefs that can be created
 789  * with the given deref as the head.  It then calls the provided callback with
 790  * a full deref for each one.
 791  *
 792  * The deref passed to the callback will be allocated on the stack.  You will
 793  * need to make a copy if you want it to hang around.
 794  */
 795 bool
 796 nir_deref_foreach_leaf(nir_deref_var *deref,
 797                        nir_deref_foreach_leaf_cb cb, void *state)
 798 {
 799    nir_deref_var copy = *deref;
 800    return deref_foreach_leaf_copy_recur(&copy, &copy.deref, cb, state);
 801 }
 802
 803 /* Returns a load_const instruction that represents the constant
 804  * initializer for the given deref chain.  The caller is responsible for
 805  * ensuring that there actually is a constant initializer.
 806  */
 807 nir_load_const_instr *
 808 nir_deref_get_const_initializer_load(nir_shader *shader, nir_deref_var *deref)
 809 {
 810    nir_constant *constant = deref->var->constant_initializer;
 811    assert(constant);
 812
 813    const nir_deref *tail = &deref->deref;
 814    unsigned matrix_col = 0;
 815    while (tail->child) {
 816       switch (tail->child->deref_type) {
 817       case nir_deref_type_array: {
 818          nir_deref_array *arr = nir_deref_as_array(tail->child);
 819          assert(arr->deref_array_type == nir_deref_array_type_direct);
 820          if (glsl_type_is_matrix(tail->type)) {
 821             assert(arr->deref.child == NULL);
 822             matrix_col = arr->base_offset;
 823          } else {
 824             constant = constant->elements[arr->base_offset];
 825          }
 826          break;
 827       }
 828
 829       case nir_deref_type_struct: {
 830          constant = constant->elements[nir_deref_as_struct(tail->child)->index];
 831          break;
 832       }
 833
 834       default:
 835          unreachable("Invalid deref child type");
 836       }
 837
 838       tail = tail->child;
 839    }
 840
 841    unsigned bit_size = glsl_get_bit_size(tail->type);
 842    nir_load_const_instr *load =
 843       nir_load_const_instr_create(shader, glsl_get_vector_elements(tail->type),
 844                                   bit_size);
 845
 846    switch (glsl_get_base_type(tail->type)) {
 847    case GLSL_TYPE_FLOAT:
 848    case GLSL_TYPE_INT:
 849    case GLSL_TYPE_UINT:
 850    case GLSL_TYPE_DOUBLE:
 851    case GLSL_TYPE_UINT64:
 852    case GLSL_TYPE_INT64:
 853    case GLSL_TYPE_BOOL:
 854       load->value = constant->values[matrix_col];
 855       break;
 856    default:
 857       unreachable("Invalid immediate type");
 858    }
 859
 860    return load;
 861 }
 862
 863 nir_function_impl *
 864 nir_cf_node_get_function(nir_cf_node *node)
 865 {
 866    while (node->type != nir_cf_node_function) {
 867       node = node->parent;
 868    }
 869
 870    return nir_cf_node_as_function(node);
 871 }
 872
 873 /* Reduces a cursor by trying to convert everything to after and trying to
 874  * go up to block granularity when possible.
 875  */
 876 static nir_cursor
 877 reduce_cursor(nir_cursor cursor)
 878 {
 879    switch (cursor.option) {
 880    case nir_cursor_before_block:
 881       assert(nir_cf_node_prev(&cursor.block->cf_node) == NULL ||
 882              nir_cf_node_prev(&cursor.block->cf_node)->type != nir_cf_node_block);
 883       if (exec_list_is_empty(&cursor.block->instr_list)) {
 884          /* Empty block.  After is as good as before. */
 885          cursor.option = nir_cursor_after_block;
 886       }
 887       return cursor;
 888
 889    case nir_cursor_after_block:
 890       return cursor;
 891
 892    case nir_cursor_before_instr: {
 893       nir_instr *prev_instr = nir_instr_prev(cursor.instr);
 894       if (prev_instr) {
 895          /* Before this instruction is after the previous */
 896          cursor.instr = prev_instr;
 897          cursor.option = nir_cursor_after_instr;
 898       } else {
 899          /* No previous instruction.  Switch to before block */
 900          cursor.block = cursor.instr->block;
 901          cursor.option = nir_cursor_before_block;
 902       }
 903       return reduce_cursor(cursor);
 904    }
 905
 906    case nir_cursor_after_instr:
 907       if (nir_instr_next(cursor.instr) == NULL) {
 908          /* This is the last instruction, switch to after block */
 909          cursor.option = nir_cursor_after_block;
 910          cursor.block = cursor.instr->block;
 911       }
 912       return cursor;
 913
 914    default:
 915       unreachable("Inavlid cursor option");
 916    }
 917 }
 918
 919 bool
 920 nir_cursors_equal(nir_cursor a, nir_cursor b)
 921 {
 922    /* Reduced cursors should be unique */
 923    a = reduce_cursor(a);
 924    b = reduce_cursor(b);
 925
 926    return a.block == b.block && a.option == b.option;
 927 }
 928
 929 static bool
 930 add_use_cb(nir_src *src, void *state)
 931 {
 932    nir_instr *instr = state;
 933
 934    src->parent_instr = instr;
 935    list_addtail(&src->use_link,
 936                 src->is_ssa ? &src->ssa->uses : &src->reg.reg->uses);
 937
 938    return true;
 939 }
 940
 941 static bool
 942 add_ssa_def_cb(nir_ssa_def *def, void *state)
 943 {
 944    nir_instr *instr = state;
 945
 946    if (instr->block && def->index == UINT_MAX) {
 947       nir_function_impl *impl =
 948          nir_cf_node_get_function(&instr->block->cf_node);
 949
 950       def->index = impl->ssa_alloc++;
 951    }
 952
 953    return true;
 954 }
 955
 956 static bool
 957 add_reg_def_cb(nir_dest *dest, void *state)
 958 {
 959    nir_instr *instr = state;
 960
 961    if (!dest->is_ssa) {
 962       dest->reg.parent_instr = instr;
 963       list_addtail(&dest->reg.def_link, &dest->reg.reg->defs);
 964    }
 965
 966    return true;
 967 }
 968
 969 static void
 970 add_defs_uses(nir_instr *instr)
 971 {
 972    nir_foreach_src(instr, add_use_cb, instr);
 973    nir_foreach_dest(instr, add_reg_def_cb, instr);
 974    nir_foreach_ssa_def(instr, add_ssa_def_cb, instr);
 975 }
 976
 977 void
 978 nir_instr_insert(nir_cursor cursor, nir_instr *instr)
 979 {
 980    switch (cursor.option) {
 981    case nir_cursor_before_block:
 982       /* Only allow inserting jumps into empty blocks. */
 983       if (instr->type == nir_instr_type_jump)
 984          assert(exec_list_is_empty(&cursor.block->instr_list));
 985
 986       instr->block = cursor.block;
 987       add_defs_uses(instr);
 988       exec_list_push_head(&cursor.block->instr_list, &instr->node);
 989       break;
 990    case nir_cursor_after_block: {
 991       /* Inserting instructions after a jump is illegal. */
 992       nir_instr *last = nir_block_last_instr(cursor.block);
 993       assert(last == NULL || last->type != nir_instr_type_jump);
 994       (void) last;
 995
 996       instr->block = cursor.block;
 997       add_defs_uses(instr);
 998       exec_list_push_tail(&cursor.block->instr_list, &instr->node);
 999       break;
1000    }
1001    case nir_cursor_before_instr:
1002       assert(instr->type != nir_instr_type_jump);
1003       instr->block = cursor.instr->block;
1004       add_defs_uses(instr);
1005       exec_node_insert_node_before(&cursor.instr->node, &instr->node);
1006       break;
1007    case nir_cursor_after_instr:
1008       /* Inserting instructions after a jump is illegal. */
1009       assert(cursor.instr->type != nir_instr_type_jump);
1010
1011       /* Only allow inserting jumps at the end of the block. */
1012       if (instr->type == nir_instr_type_jump)
1013          assert(cursor.instr == nir_block_last_instr(cursor.instr->block));
1014
1015       instr->block = cursor.instr->block;
1016       add_defs_uses(instr);
1017       exec_node_insert_after(&cursor.instr->node, &instr->node);
1018       break;
1019    }
1020
1021    if (instr->type == nir_instr_type_jump)
1022       nir_handle_add_jump(instr->block);
1023 }
1024
1025 static bool
1026 src_is_valid(const nir_src *src)
1027 {
1028    return src->is_ssa ? (src->ssa != NULL) : (src->reg.reg != NULL);
1029 }
1030
1031 static bool
1032 remove_use_cb(nir_src *src, void *state)
1033 {
1034    (void) state;
1035
1036    if (src_is_valid(src))
1037       list_del(&src->use_link);
1038
1039    return true;
1040 }
1041
1042 static bool
1043 remove_def_cb(nir_dest *dest, void *state)
1044 {
1045    (void) state;
1046
1047    if (!dest->is_ssa)
1048       list_del(&dest->reg.def_link);
1049
1050    return true;
1051 }
1052
1053 static void
1054 remove_defs_uses(nir_instr *instr)
1055 {
1056    nir_foreach_dest(instr, remove_def_cb, instr);
1057    nir_foreach_src(instr, remove_use_cb, instr);
1058 }
1059
1060 void nir_instr_remove(nir_instr *instr)
1061 {
1062    remove_defs_uses(instr);
1063    exec_node_remove(&instr->node);
1064
1065    if (instr->type == nir_instr_type_jump) {
1066       nir_jump_instr *jump_instr = nir_instr_as_jump(instr);
1067       nir_handle_remove_jump(instr->block, jump_instr->type);
1068    }
1069 }
1070
1071 /*@}*/
1072
1073 void
1074 nir_index_local_regs(nir_function_impl *impl)
1075 {
1076    unsigned index = 0;
1077    foreach_list_typed(nir_register, reg, node, &impl->registers) {
1078       reg->index = index++;
1079    }
1080    impl->reg_alloc = index;
1081 }
1082
1083 void
1084 nir_index_global_regs(nir_shader *shader)
1085 {
1086    unsigned index = 0;
1087    foreach_list_typed(nir_register, reg, node, &shader->registers) {
1088       reg->index = index++;
1089    }
1090    shader->reg_alloc = index;
1091 }
1092
1093 static bool
1094 visit_alu_dest(nir_alu_instr *instr, nir_foreach_dest_cb cb, void *state)
1095 {
1096    return cb(&instr->dest.dest, state);
1097 }
1098
1099 static bool
1100 visit_intrinsic_dest(nir_intrinsic_instr *instr, nir_foreach_dest_cb cb,
1101                      void *state)
1102 {
1103    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
1104       return cb(&instr->dest, state);
1105
1106    return true;
1107 }
1108
1109 static bool
1110 visit_texture_dest(nir_tex_instr *instr, nir_foreach_dest_cb cb,
1111                    void *state)
1112 {
1113    return cb(&instr->dest, state);
1114 }
1115
1116 static bool
1117 visit_phi_dest(nir_phi_instr *instr, nir_foreach_dest_cb cb, void *state)
1118 {
1119    return cb(&instr->dest, state);
1120 }
1121
1122 static bool
1123 visit_parallel_copy_dest(nir_parallel_copy_instr *instr,
1124                          nir_foreach_dest_cb cb, void *state)
1125 {
1126    nir_foreach_parallel_copy_entry(entry, instr) {
1127       if (!cb(&entry->dest, state))
1128          return false;
1129    }
1130
1131    return true;
1132 }
1133
1134 bool
1135 nir_foreach_dest(nir_instr *instr, nir_foreach_dest_cb cb, void *state)
1136 {
1137    switch (instr->type) {
1138    case nir_instr_type_alu:
1139       return visit_alu_dest(nir_instr_as_alu(instr), cb, state);
1140    case nir_instr_type_intrinsic:
1141       return visit_intrinsic_dest(nir_instr_as_intrinsic(instr), cb, state);
1142    case nir_instr_type_tex:
1143       return visit_texture_dest(nir_instr_as_tex(instr), cb, state);
1144    case nir_instr_type_phi:
1145       return visit_phi_dest(nir_instr_as_phi(instr), cb, state);
1146    case nir_instr_type_parallel_copy:
1147       return visit_parallel_copy_dest(nir_instr_as_parallel_copy(instr),
1148                                       cb, state);
1149
1150    case nir_instr_type_load_const:
1151    case nir_instr_type_ssa_undef:
1152    case nir_instr_type_call:
1153    case nir_instr_type_jump:
1154       break;
1155
1156    default:
1157       unreachable("Invalid instruction type");
1158       break;
1159    }
1160
1161    return true;
1162 }
1163
1164 struct foreach_ssa_def_state {
1165    nir_foreach_ssa_def_cb cb;
1166    void *client_state;
1167 };
1168
1169 static inline bool
1170 nir_ssa_def_visitor(nir_dest *dest, void *void_state)
1171 {
1172    struct foreach_ssa_def_state *state = void_state;
1173
1174    if (dest->is_ssa)
1175       return state->cb(&dest->ssa, state->client_state);
1176    else
1177       return true;
1178 }
1179
1180 bool
1181 nir_foreach_ssa_def(nir_instr *instr, nir_foreach_ssa_def_cb cb, void *state)
1182 {
1183    switch (instr->type) {
1184    case nir_instr_type_alu:
1185    case nir_instr_type_tex:
1186    case nir_instr_type_intrinsic:
1187    case nir_instr_type_phi:
1188    case nir_instr_type_parallel_copy: {
1189       struct foreach_ssa_def_state foreach_state = {cb, state};
1190       return nir_foreach_dest(instr, nir_ssa_def_visitor, &foreach_state);
1191    }
1192
1193    case nir_instr_type_load_const:
1194       return cb(&nir_instr_as_load_const(instr)->def, state);
1195    case nir_instr_type_ssa_undef:
1196       return cb(&nir_instr_as_ssa_undef(instr)->def, state);
1197    case nir_instr_type_call:
1198    case nir_instr_type_jump:
1199       return true;
1200    default:
1201       unreachable("Invalid instruction type");
1202    }
1203 }
1204
1205 static bool
1206 visit_src(nir_src *src, nir_foreach_src_cb cb, void *state)
1207 {
1208    if (!cb(src, state))
1209       return false;
1210    if (!src->is_ssa && src->reg.indirect)
1211       return cb(src->reg.indirect, state);
1212    return true;
1213 }
1214
1215 static bool
1216 visit_deref_array_src(nir_deref_array *deref, nir_foreach_src_cb cb,
1217                       void *state)
1218 {
1219    if (deref->deref_array_type == nir_deref_array_type_indirect)
1220       return visit_src(&deref->indirect, cb, state);
1221    return true;
1222 }
1223
1224 static bool
1225 visit_deref_src(nir_deref_var *deref, nir_foreach_src_cb cb, void *state)
1226 {
1227    nir_deref *cur = &deref->deref;
1228    while (cur != NULL) {
1229       if (cur->deref_type == nir_deref_type_array) {
1230          if (!visit_deref_array_src(nir_deref_as_array(cur), cb, state))
1231             return false;
1232       }
1233
1234       cur = cur->child;
1235    }
1236
1237    return true;
1238 }
1239
1240 static bool
1241 visit_alu_src(nir_alu_instr *instr, nir_foreach_src_cb cb, void *state)
1242 {
1243    for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++)
1244       if (!visit_src(&instr->src[i].src, cb, state))
1245          return false;
1246
1247    return true;
1248 }
1249
1250 static bool
1251 visit_tex_src(nir_tex_instr *instr, nir_foreach_src_cb cb, void *state)
1252 {
1253    for (unsigned i = 0; i < instr->num_srcs; i++) {
1254       if (!visit_src(&instr->src[i].src, cb, state))
1255          return false;
1256    }
1257
1258    if (instr->texture != NULL) {
1259       if (!visit_deref_src(instr->texture, cb, state))
1260          return false;
1261    }
1262
1263    if (instr->sampler != NULL) {
1264       if (!visit_deref_src(instr->sampler, cb, state))
1265          return false;
1266    }
1267
1268    return true;
1269 }
1270
1271 static bool
1272 visit_intrinsic_src(nir_intrinsic_instr *instr, nir_foreach_src_cb cb,
1273                     void *state)
1274 {
1275    unsigned num_srcs = nir_intrinsic_infos[instr->intrinsic].num_srcs;
1276    for (unsigned i = 0; i < num_srcs; i++) {
1277       if (!visit_src(&instr->src[i], cb, state))
1278          return false;
1279    }
1280
1281    unsigned num_vars =
1282       nir_intrinsic_infos[instr->intrinsic].num_variables;
1283    for (unsigned i = 0; i < num_vars; i++) {
1284       if (!visit_deref_src(instr->variables[i], cb, state))
1285          return false;
1286    }
1287
1288    return true;
1289 }
1290
1291 static bool
1292 visit_phi_src(nir_phi_instr *instr, nir_foreach_src_cb cb, void *state)
1293 {
1294    nir_foreach_phi_src(src, instr) {
1295       if (!visit_src(&src->src, cb, state))
1296          return false;
1297    }
1298
1299    return true;
1300 }
1301
1302 static bool
1303 visit_parallel_copy_src(nir_parallel_copy_instr *instr,
1304                         nir_foreach_src_cb cb, void *state)
1305 {
1306    nir_foreach_parallel_copy_entry(entry, instr) {
1307       if (!visit_src(&entry->src, cb, state))
1308          return false;
1309    }
1310
1311    return true;
1312 }
1313
1314 typedef struct {
1315    void *state;
1316    nir_foreach_src_cb cb;
1317 } visit_dest_indirect_state;
1318
1319 static bool
1320 visit_dest_indirect(nir_dest *dest, void *_state)
1321 {
1322    visit_dest_indirect_state *state = (visit_dest_indirect_state *) _state;
1323
1324    if (!dest->is_ssa && dest->reg.indirect)
1325       return state->cb(dest->reg.indirect, state->state);
1326
1327    return true;
1328 }
1329
1330 bool
1331 nir_foreach_src(nir_instr *instr, nir_foreach_src_cb cb, void *state)
1332 {
1333    switch (instr->type) {
1334    case nir_instr_type_alu:
1335       if (!visit_alu_src(nir_instr_as_alu(instr), cb, state))
1336          return false;
1337       break;
1338    case nir_instr_type_intrinsic:
1339       if (!visit_intrinsic_src(nir_instr_as_intrinsic(instr), cb, state))
1340          return false;
1341       break;
1342    case nir_instr_type_tex:
1343       if (!visit_tex_src(nir_instr_as_tex(instr), cb, state))
1344          return false;
1345       break;
1346    case nir_instr_type_call:
1347       /* Call instructions have no regular sources */
1348       break;
1349    case nir_instr_type_load_const:
1350       /* Constant load instructions have no regular sources */
1351       break;
1352    case nir_instr_type_phi:
1353       if (!visit_phi_src(nir_instr_as_phi(instr), cb, state))
1354          return false;
1355       break;
1356    case nir_instr_type_parallel_copy:
1357       if (!visit_parallel_copy_src(nir_instr_as_parallel_copy(instr),
1358                                    cb, state))
1359          return false;
1360       break;
1361    case nir_instr_type_jump:
1362    case nir_instr_type_ssa_undef:
1363       return true;
1364
1365    default:
1366       unreachable("Invalid instruction type");
1367       break;
1368    }
1369
1370    visit_dest_indirect_state dest_state;
1371    dest_state.state = state;
1372    dest_state.cb = cb;
1373    return nir_foreach_dest(instr, visit_dest_indirect, &dest_state);
1374 }
1375
1376 nir_const_value *
1377 nir_src_as_const_value(nir_src src)
1378 {
1379    if (!src.is_ssa)
1380       return NULL;
1381
1382    if (src.ssa->parent_instr->type != nir_instr_type_load_const)
1383       return NULL;
1384
1385    nir_load_const_instr *load = nir_instr_as_load_const(src.ssa->parent_instr);
1386
1387    return &load->value;
1388 }
1389
1390 /**
1391  * Returns true if the source is known to be dynamically uniform. Otherwise it
1392  * returns false which means it may or may not be dynamically uniform but it
1393  * can't be determined.
1394  */
1395 bool
1396 nir_src_is_dynamically_uniform(nir_src src)
1397 {
1398    if (!src.is_ssa)
1399       return false;
1400
1401    /* Constants are trivially dynamically uniform */
1402    if (src.ssa->parent_instr->type == nir_instr_type_load_const)
1403       return true;
1404
1405    /* As are uniform variables */
1406    if (src.ssa->parent_instr->type == nir_instr_type_intrinsic) {
1407       nir_intrinsic_instr *intr = nir_instr_as_intrinsic(src.ssa->parent_instr);
1408
1409       if (intr->intrinsic == nir_intrinsic_load_uniform)
1410          return true;
1411    }
1412
1413    /* XXX: this could have many more tests, such as when a sampler function is
1414     * called with dynamically uniform arguments.
1415     */
1416    return false;
1417 }
1418
1419 static void
1420 src_remove_all_uses(nir_src *src)
1421 {
1422    for (; src; src = src->is_ssa ? NULL : src->reg.indirect) {
1423       if (!src_is_valid(src))
1424          continue;
1425
1426       list_del(&src->use_link);
1427    }
1428 }
1429
1430 static void
1431 src_add_all_uses(nir_src *src, nir_instr *parent_instr, nir_if *parent_if)
1432 {
1433    for (; src; src = src->is_ssa ? NULL : src->reg.indirect) {
1434       if (!src_is_valid(src))
1435          continue;
1436
1437       if (parent_instr) {
1438          src->parent_instr = parent_instr;
1439          if (src->is_ssa)
1440             list_addtail(&src->use_link, &src->ssa->uses);
1441          else
1442             list_addtail(&src->use_link, &src->reg.reg->uses);
1443       } else {
1444          assert(parent_if);
1445          src->parent_if = parent_if;
1446          if (src->is_ssa)
1447             list_addtail(&src->use_link, &src->ssa->if_uses);
1448          else
1449             list_addtail(&src->use_link, &src->reg.reg->if_uses);
1450       }
1451    }
1452 }
1453
1454 void
1455 nir_instr_rewrite_src(nir_instr *instr, nir_src *src, nir_src new_src)
1456 {
1457    assert(!src_is_valid(src) || src->parent_instr == instr);
1458
1459    src_remove_all_uses(src);
1460    *src = new_src;
1461    src_add_all_uses(src, instr, NULL);
1462 }
1463
1464 void
1465 nir_instr_move_src(nir_instr *dest_instr, nir_src *dest, nir_src *src)
1466 {
1467    assert(!src_is_valid(dest) || dest->parent_instr == dest_instr);
1468
1469    src_remove_all_uses(dest);
1470    src_remove_all_uses(src);
1471    *dest = *src;
1472    *src = NIR_SRC_INIT;
1473    src_add_all_uses(dest, dest_instr, NULL);
1474 }
1475
1476 void
1477 nir_if_rewrite_condition(nir_if *if_stmt, nir_src new_src)
1478 {
1479    nir_src *src = &if_stmt->condition;
1480    assert(!src_is_valid(src) || src->parent_if == if_stmt);
1481
1482    src_remove_all_uses(src);
1483    *src = new_src;
1484    src_add_all_uses(src, NULL, if_stmt);
1485 }
1486
1487 void
1488 nir_instr_rewrite_dest(nir_instr *instr, nir_dest *dest, nir_dest new_dest)
1489 {
1490    if (dest->is_ssa) {
1491       /* We can only overwrite an SSA destination if it has no uses. */
1492       assert(list_empty(&dest->ssa.uses) && list_empty(&dest->ssa.if_uses));
1493    } else {
1494       list_del(&dest->reg.def_link);
1495       if (dest->reg.indirect)
1496          src_remove_all_uses(dest->reg.indirect);
1497    }
1498
1499    /* We can't re-write with an SSA def */
1500    assert(!new_dest.is_ssa);
1501
1502    nir_dest_copy(dest, &new_dest, instr);
1503
1504    dest->reg.parent_instr = instr;
1505    list_addtail(&dest->reg.def_link, &new_dest.reg.reg->defs);
1506
1507    if (dest->reg.indirect)
1508       src_add_all_uses(dest->reg.indirect, instr, NULL);
1509 }
1510
1511 /* note: does *not* take ownership of 'name' */
1512 void
1513 nir_ssa_def_init(nir_instr *instr, nir_ssa_def *def,
1514                  unsigned num_components,
1515                  unsigned bit_size, const char *name)
1516 {
1517    def->name = ralloc_strdup(instr, name);
1518    def->parent_instr = instr;
1519    list_inithead(&def->uses);
1520    list_inithead(&def->if_uses);
1521    def->num_components = num_components;
1522    def->bit_size = bit_size;
1523
1524    if (instr->block) {
1525       nir_function_impl *impl =
1526          nir_cf_node_get_function(&instr->block->cf_node);
1527
1528       def->index = impl->ssa_alloc++;
1529    } else {
1530       def->index = UINT_MAX;
1531    }
1532 }
1533
1534 /* note: does *not* take ownership of 'name' */
1535 void
1536 nir_ssa_dest_init(nir_instr *instr, nir_dest *dest,
1537                  unsigned num_components, unsigned bit_size,
1538                  const char *name)
1539 {
1540    dest->is_ssa = true;
1541    nir_ssa_def_init(instr, &dest->ssa, num_components, bit_size, name);
1542 }
1543
1544 void
1545 nir_ssa_def_rewrite_uses(nir_ssa_def *def, nir_src new_src)
1546 {
1547    assert(!new_src.is_ssa || def != new_src.ssa);
1548
1549    nir_foreach_use_safe(use_src, def)
1550       nir_instr_rewrite_src(use_src->parent_instr, use_src, new_src);
1551
1552    nir_foreach_if_use_safe(use_src, def)
1553       nir_if_rewrite_condition(use_src->parent_if, new_src);
1554 }
1555
1556 static bool
1557 is_instr_between(nir_instr *start, nir_instr *end, nir_instr *between)
1558 {
1559    assert(start->block == end->block);
1560
1561    if (between->block != start->block)
1562       return false;
1563
1564    /* Search backwards looking for "between" */
1565    while (start != end) {
1566       if (between == end)
1567          return true;
1568
1569       end = nir_instr_prev(end);
1570       assert(end);
1571    }
1572
1573    return false;
1574 }
1575
1576 /* Replaces all uses of the given SSA def with the given source but only if
1577  * the use comes after the after_me instruction.  This can be useful if you
1578  * are emitting code to fix up the result of some instruction: you can freely
1579  * use the result in that code and then call rewrite_uses_after and pass the
1580  * last fixup instruction as after_me and it will replace all of the uses you
1581  * want without touching the fixup code.
1582  *
1583  * This function assumes that after_me is in the same block as
1584  * def->parent_instr and that after_me comes after def->parent_instr.
1585  */
1586 void
1587 nir_ssa_def_rewrite_uses_after(nir_ssa_def *def, nir_src new_src,
1588                                nir_instr *after_me)
1589 {
1590    assert(!new_src.is_ssa || def != new_src.ssa);
1591
1592    nir_foreach_use_safe(use_src, def) {
1593       assert(use_src->parent_instr != def->parent_instr);
1594       /* Since def already dominates all of its uses, the only way a use can
1595        * not be dominated by after_me is if it is between def and after_me in
1596        * the instruction list.
1597        */
1598       if (!is_instr_between(def->parent_instr, after_me, use_src->parent_instr))
1599          nir_instr_rewrite_src(use_src->parent_instr, use_src, new_src);
1600    }
1601
1602    nir_foreach_if_use_safe(use_src, def)
1603       nir_if_rewrite_condition(use_src->parent_if, new_src);
1604 }
1605
1606 uint8_t
1607 nir_ssa_def_components_read(nir_ssa_def *def)
1608 {
1609    uint8_t read_mask = 0;
1610    nir_foreach_use(use, def) {
1611       if (use->parent_instr->type == nir_instr_type_alu) {
1612          nir_alu_instr *alu = nir_instr_as_alu(use->parent_instr);
1613          nir_alu_src *alu_src = exec_node_data(nir_alu_src, use, src);
1614          int src_idx = alu_src - &alu->src[0];
1615          assert(src_idx >= 0 && src_idx < nir_op_infos[alu->op].num_inputs);
1616
1617          for (unsigned c = 0; c < 4; c++) {
1618             if (!nir_alu_instr_channel_used(alu, src_idx, c))
1619                continue;
1620
1621             read_mask |= (1 << alu_src->swizzle[c]);
1622          }
1623       } else {
1624          return (1 << def->num_components) - 1;
1625       }
1626    }
1627
1628    return read_mask;
1629 }
1630
1631 nir_block *
1632 nir_block_cf_tree_next(nir_block *block)
1633 {
1634    if (block == NULL) {
1635       /* nir_foreach_block_safe() will call this function on a NULL block
1636        * after the last iteration, but it won't use the result so just return
1637        * NULL here.
1638        */
1639       return NULL;
1640    }
1641
1642    nir_cf_node *cf_next = nir_cf_node_next(&block->cf_node);
1643    if (cf_next)
1644       return nir_cf_node_cf_tree_first(cf_next);
1645
1646    nir_cf_node *parent = block->cf_node.parent;
1647
1648    switch (parent->type) {
1649    case nir_cf_node_if: {
1650       /* Are we at the end of the if? Go to the beginning of the else */
1651       nir_if *if_stmt = nir_cf_node_as_if(parent);
1652       if (block == nir_if_last_then_block(if_stmt))
1653          return nir_if_first_else_block(if_stmt);
1654
1655       assert(block == nir_if_last_else_block(if_stmt));
1656       /* fall through */
1657    }
1658
1659    case nir_cf_node_loop:
1660       return nir_cf_node_as_block(nir_cf_node_next(parent));
1661
1662    case nir_cf_node_function:
1663       return NULL;
1664
1665    default:
1666       unreachable("unknown cf node type");
1667    }
1668 }
1669
1670 nir_block *
1671 nir_block_cf_tree_prev(nir_block *block)
1672 {
1673    if (block == NULL) {
1674       /* do this for consistency with nir_block_cf_tree_next() */
1675       return NULL;
1676    }
1677
1678    nir_cf_node *cf_prev = nir_cf_node_prev(&block->cf_node);
1679    if (cf_prev)
1680       return nir_cf_node_cf_tree_last(cf_prev);
1681
1682    nir_cf_node *parent = block->cf_node.parent;
1683
1684    switch (parent->type) {
1685    case nir_cf_node_if: {
1686       /* Are we at the beginning of the else? Go to the end of the if */
1687       nir_if *if_stmt = nir_cf_node_as_if(parent);
1688       if (block == nir_if_first_else_block(if_stmt))
1689          return nir_if_last_then_block(if_stmt);
1690
1691       assert(block == nir_if_first_then_block(if_stmt));
1692       /* fall through */
1693    }
1694
1695    case nir_cf_node_loop:
1696       return nir_cf_node_as_block(nir_cf_node_prev(parent));
1697
1698    case nir_cf_node_function:
1699       return NULL;
1700
1701    default:
1702       unreachable("unknown cf node type");
1703    }
1704 }
1705
1706 nir_block *nir_cf_node_cf_tree_first(nir_cf_node *node)
1707 {
1708    switch (node->type) {
1709    case nir_cf_node_function: {
1710       nir_function_impl *impl = nir_cf_node_as_function(node);
1711       return nir_start_block(impl);
1712    }
1713
1714    case nir_cf_node_if: {
1715       nir_if *if_stmt = nir_cf_node_as_if(node);
1716       return nir_if_first_then_block(if_stmt);
1717    }
1718
1719    case nir_cf_node_loop: {
1720       nir_loop *loop = nir_cf_node_as_loop(node);
1721       return nir_loop_first_block(loop);
1722    }
1723
1724    case nir_cf_node_block: {
1725       return nir_cf_node_as_block(node);
1726    }
1727
1728    default:
1729       unreachable("unknown node type");
1730    }
1731 }
1732
1733 nir_block *nir_cf_node_cf_tree_last(nir_cf_node *node)
1734 {
1735    switch (node->type) {
1736    case nir_cf_node_function: {
1737       nir_function_impl *impl = nir_cf_node_as_function(node);
1738       return nir_impl_last_block(impl);
1739    }
1740
1741    case nir_cf_node_if: {
1742       nir_if *if_stmt = nir_cf_node_as_if(node);
1743       return nir_if_last_else_block(if_stmt);
1744    }
1745
1746    case nir_cf_node_loop: {
1747       nir_loop *loop = nir_cf_node_as_loop(node);
1748       return nir_loop_last_block(loop);
1749    }
1750
1751    case nir_cf_node_block: {
1752       return nir_cf_node_as_block(node);
1753    }
1754
1755    default:
1756       unreachable("unknown node type");
1757    }
1758 }
1759
1760 nir_block *nir_cf_node_cf_tree_next(nir_cf_node *node)
1761 {
1762    if (node->type == nir_cf_node_block)
1763       return nir_block_cf_tree_next(nir_cf_node_as_block(node));
1764    else if (node->type == nir_cf_node_function)
1765       return NULL;
1766    else
1767       return nir_cf_node_as_block(nir_cf_node_next(node));
1768 }
1769
1770 nir_if *
1771 nir_block_get_following_if(nir_block *block)
1772 {
1773    if (exec_node_is_tail_sentinel(&block->cf_node.node))
1774       return NULL;
1775
1776    if (nir_cf_node_is_last(&block->cf_node))
1777       return NULL;
1778
1779    nir_cf_node *next_node = nir_cf_node_next(&block->cf_node);
1780
1781    if (next_node->type != nir_cf_node_if)
1782       return NULL;
1783
1784    return nir_cf_node_as_if(next_node);
1785 }
1786
1787 nir_loop *
1788 nir_block_get_following_loop(nir_block *block)
1789 {
1790    if (exec_node_is_tail_sentinel(&block->cf_node.node))
1791       return NULL;
1792
1793    if (nir_cf_node_is_last(&block->cf_node))
1794       return NULL;
1795
1796    nir_cf_node *next_node = nir_cf_node_next(&block->cf_node);
1797
1798    if (next_node->type != nir_cf_node_loop)
1799       return NULL;
1800
1801    return nir_cf_node_as_loop(next_node);
1802 }
1803
1804 void
1805 nir_index_blocks(nir_function_impl *impl)
1806 {
1807    unsigned index = 0;
1808
1809    if (impl->valid_metadata & nir_metadata_block_index)
1810       return;
1811
1812    nir_foreach_block(block, impl) {
1813       block->index = index++;
1814    }
1815
1816    impl->num_blocks = index;
1817 }
1818
1819 static bool
1820 index_ssa_def_cb(nir_ssa_def *def, void *state)
1821 {
1822    unsigned *index = (unsigned *) state;
1823    def->index = (*index)++;
1824
1825    return true;
1826 }
1827
1828 /**
1829  * The indices are applied top-to-bottom which has the very nice property
1830  * that, if A dominates B, then A->index <= B->index.
1831  */
1832 void
1833 nir_index_ssa_defs(nir_function_impl *impl)
1834 {
1835    unsigned index = 0;
1836
1837    nir_foreach_block(block, impl) {
1838       nir_foreach_instr(instr, block)
1839          nir_foreach_ssa_def(instr, index_ssa_def_cb, &index);
1840    }
1841
1842    impl->ssa_alloc = index;
1843 }
1844
1845 /**
1846  * The indices are applied top-to-bottom which has the very nice property
1847  * that, if A dominates B, then A->index <= B->index.
1848  */
1849 unsigned
1850 nir_index_instrs(nir_function_impl *impl)
1851 {
1852    unsigned index = 0;
1853
1854    nir_foreach_block(block, impl) {
1855       nir_foreach_instr(instr, block)
1856          instr->index = index++;
1857    }
1858
1859    return index;
1860 }
1861
1862 nir_intrinsic_op
1863 nir_intrinsic_from_system_value(gl_system_value val)
1864 {
1865    switch (val) {
1866    case SYSTEM_VALUE_VERTEX_ID:
1867       return nir_intrinsic_load_vertex_id;
1868    case SYSTEM_VALUE_INSTANCE_ID:
1869       return nir_intrinsic_load_instance_id;
1870    case SYSTEM_VALUE_DRAW_ID:
1871       return nir_intrinsic_load_draw_id;
1872    case SYSTEM_VALUE_BASE_INSTANCE:
1873       return nir_intrinsic_load_base_instance;
1874    case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE:
1875       return nir_intrinsic_load_vertex_id_zero_base;
1876    case SYSTEM_VALUE_BASE_VERTEX:
1877       return nir_intrinsic_load_base_vertex;
1878    case SYSTEM_VALUE_INVOCATION_ID:
1879       return nir_intrinsic_load_invocation_id;
1880    case SYSTEM_VALUE_FRONT_FACE:
1881       return nir_intrinsic_load_front_face;
1882    case SYSTEM_VALUE_SAMPLE_ID:
1883       return nir_intrinsic_load_sample_id;
1884    case SYSTEM_VALUE_SAMPLE_POS:
1885       return nir_intrinsic_load_sample_pos;
1886    case SYSTEM_VALUE_SAMPLE_MASK_IN:
1887       return nir_intrinsic_load_sample_mask_in;
1888    case SYSTEM_VALUE_LOCAL_INVOCATION_ID:
1889       return nir_intrinsic_load_local_invocation_id;
1890    case SYSTEM_VALUE_LOCAL_INVOCATION_INDEX:
1891       return nir_intrinsic_load_local_invocation_index;
1892    case SYSTEM_VALUE_WORK_GROUP_ID:
1893       return nir_intrinsic_load_work_group_id;
1894    case SYSTEM_VALUE_NUM_WORK_GROUPS:
1895       return nir_intrinsic_load_num_work_groups;
1896    case SYSTEM_VALUE_PRIMITIVE_ID:
1897       return nir_intrinsic_load_primitive_id;
1898    case SYSTEM_VALUE_TESS_COORD:
1899       return nir_intrinsic_load_tess_coord;
1900    case SYSTEM_VALUE_TESS_LEVEL_OUTER:
1901       return nir_intrinsic_load_tess_level_outer;
1902    case SYSTEM_VALUE_TESS_LEVEL_INNER:
1903       return nir_intrinsic_load_tess_level_inner;
1904    case SYSTEM_VALUE_VERTICES_IN:
1905       return nir_intrinsic_load_patch_vertices_in;
1906    case SYSTEM_VALUE_HELPER_INVOCATION:
1907       return nir_intrinsic_load_helper_invocation;
1908    default:
1909       unreachable("system value does not directly correspond to intrinsic");
1910    }
1911 }
1912
1913 gl_system_value
1914 nir_system_value_from_intrinsic(nir_intrinsic_op intrin)
1915 {
1916    switch (intrin) {
1917    case nir_intrinsic_load_vertex_id:
1918       return SYSTEM_VALUE_VERTEX_ID;
1919    case nir_intrinsic_load_instance_id:
1920       return SYSTEM_VALUE_INSTANCE_ID;
1921    case nir_intrinsic_load_draw_id:
1922       return SYSTEM_VALUE_DRAW_ID;
1923    case nir_intrinsic_load_base_instance:
1924       return SYSTEM_VALUE_BASE_INSTANCE;
1925    case nir_intrinsic_load_vertex_id_zero_base:
1926       return SYSTEM_VALUE_VERTEX_ID_ZERO_BASE;
1927    case nir_intrinsic_load_base_vertex:
1928       return SYSTEM_VALUE_BASE_VERTEX;
1929    case nir_intrinsic_load_invocation_id:
1930       return SYSTEM_VALUE_INVOCATION_ID;
1931    case nir_intrinsic_load_front_face:
1932       return SYSTEM_VALUE_FRONT_FACE;
1933    case nir_intrinsic_load_sample_id:
1934       return SYSTEM_VALUE_SAMPLE_ID;
1935    case nir_intrinsic_load_sample_pos:
1936       return SYSTEM_VALUE_SAMPLE_POS;
1937    case nir_intrinsic_load_sample_mask_in:
1938       return SYSTEM_VALUE_SAMPLE_MASK_IN;
1939    case nir_intrinsic_load_local_invocation_id:
1940       return SYSTEM_VALUE_LOCAL_INVOCATION_ID;
1941    case nir_intrinsic_load_local_invocation_index:
1942       return SYSTEM_VALUE_LOCAL_INVOCATION_INDEX;
1943    case nir_intrinsic_load_num_work_groups:
1944       return SYSTEM_VALUE_NUM_WORK_GROUPS;
1945    case nir_intrinsic_load_work_group_id:
1946       return SYSTEM_VALUE_WORK_GROUP_ID;
1947    case nir_intrinsic_load_primitive_id:
1948       return SYSTEM_VALUE_PRIMITIVE_ID;
1949    case nir_intrinsic_load_tess_coord:
1950       return SYSTEM_VALUE_TESS_COORD;
1951    case nir_intrinsic_load_tess_level_outer:
1952       return SYSTEM_VALUE_TESS_LEVEL_OUTER;
1953    case nir_intrinsic_load_tess_level_inner:
1954       return SYSTEM_VALUE_TESS_LEVEL_INNER;
1955    case nir_intrinsic_load_patch_vertices_in:
1956       return SYSTEM_VALUE_VERTICES_IN;
1957    case nir_intrinsic_load_helper_invocation:
1958       return SYSTEM_VALUE_HELPER_INVOCATION;
1959    default:
1960       unreachable("intrinsic doesn't produce a system value");
1961    }
1962 }