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 ref's 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 = ralloc(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 static nir_deref_var *
 628 copy_deref_var(void *mem_ctx, nir_deref_var *deref)
 629 {
 630    nir_deref_var *ret = nir_deref_var_create(mem_ctx, deref->var);
 631    ret->deref.type = deref->deref.type;
 632    if (deref->deref.child)
 633       ret->deref.child = nir_copy_deref(ret, deref->deref.child);
 634    return ret;
 635 }
 636
 637 static nir_deref_array *
 638 copy_deref_array(void *mem_ctx, nir_deref_array *deref)
 639 {
 640    nir_deref_array *ret = nir_deref_array_create(mem_ctx);
 641    ret->base_offset = deref->base_offset;
 642    ret->deref_array_type = deref->deref_array_type;
 643    if (deref->deref_array_type == nir_deref_array_type_indirect) {
 644       nir_src_copy(&ret->indirect, &deref->indirect, mem_ctx);
 645    }
 646    ret->deref.type = deref->deref.type;
 647    if (deref->deref.child)
 648       ret->deref.child = nir_copy_deref(ret, deref->deref.child);
 649    return ret;
 650 }
 651
 652 static nir_deref_struct *
 653 copy_deref_struct(void *mem_ctx, nir_deref_struct *deref)
 654 {
 655    nir_deref_struct *ret = nir_deref_struct_create(mem_ctx, deref->index);
 656    ret->deref.type = deref->deref.type;
 657    if (deref->deref.child)
 658       ret->deref.child = nir_copy_deref(ret, deref->deref.child);
 659    return ret;
 660 }
 661
 662 nir_deref *
 663 nir_copy_deref(void *mem_ctx, nir_deref *deref)
 664 {
 665    if (deref == NULL)
 666       return NULL;
 667
 668    switch (deref->deref_type) {
 669    case nir_deref_type_var:
 670       return &copy_deref_var(mem_ctx, nir_deref_as_var(deref))->deref;
 671    case nir_deref_type_array:
 672       return &copy_deref_array(mem_ctx, nir_deref_as_array(deref))->deref;
 673    case nir_deref_type_struct:
 674       return &copy_deref_struct(mem_ctx, nir_deref_as_struct(deref))->deref;
 675    default:
 676       unreachable("Invalid dereference type");
 677    }
 678
 679    return NULL;
 680 }
 681
 682 /* This is the second step in the recursion.  We've found the tail and made a
 683  * copy.  Now we need to iterate over all possible leaves and call the
 684  * callback on each one.
 685  */
 686 static bool
 687 deref_foreach_leaf_build_recur(nir_deref_var *deref, nir_deref *tail,
 688                                nir_deref_foreach_leaf_cb cb, void *state)
 689 {
 690    unsigned length;
 691    union {
 692       nir_deref_array arr;
 693       nir_deref_struct str;
 694    } tmp;
 695
 696    assert(tail->child == NULL);
 697    switch (glsl_get_base_type(tail->type)) {
 698    case GLSL_TYPE_UINT:
 699    case GLSL_TYPE_INT:
 700    case GLSL_TYPE_FLOAT:
 701    case GLSL_TYPE_DOUBLE:
 702    case GLSL_TYPE_BOOL:
 703       if (glsl_type_is_vector_or_scalar(tail->type))
 704          return cb(deref, state);
 705       /* Fall Through */
 706
 707    case GLSL_TYPE_ARRAY:
 708       tmp.arr.deref.deref_type = nir_deref_type_array;
 709       tmp.arr.deref.type = glsl_get_array_element(tail->type);
 710       tmp.arr.deref_array_type = nir_deref_array_type_direct;
 711       tmp.arr.indirect = NIR_SRC_INIT;
 712       tail->child = &tmp.arr.deref;
 713
 714       length = glsl_get_length(tail->type);
 715       for (unsigned i = 0; i < length; i++) {
 716          tmp.arr.deref.child = NULL;
 717          tmp.arr.base_offset = i;
 718          if (!deref_foreach_leaf_build_recur(deref, &tmp.arr.deref, cb, state))
 719             return false;
 720       }
 721       return true;
 722
 723    case GLSL_TYPE_STRUCT:
 724       tmp.str.deref.deref_type = nir_deref_type_struct;
 725       tail->child = &tmp.str.deref;
 726
 727       length = glsl_get_length(tail->type);
 728       for (unsigned i = 0; i < length; i++) {
 729          tmp.arr.deref.child = NULL;
 730          tmp.str.deref.type = glsl_get_struct_field(tail->type, i);
 731          tmp.str.index = i;
 732          if (!deref_foreach_leaf_build_recur(deref, &tmp.arr.deref, cb, state))
 733             return false;
 734       }
 735       return true;
 736
 737    default:
 738       unreachable("Invalid type for dereference");
 739    }
 740 }
 741
 742 /* This is the first step of the foreach_leaf recursion.  In this step we are
 743  * walking to the end of the deref chain and making a copy in the stack as we
 744  * go.  This is because we don't want to mutate the deref chain that was
 745  * passed in by the caller.  The downside is that this deref chain is on the
 746  * stack and , if the caller wants to do anything with it, they will have to
 747  * make their own copy because this one will go away.
 748  */
 749 static bool
 750 deref_foreach_leaf_copy_recur(nir_deref_var *deref, nir_deref *tail,
 751                               nir_deref_foreach_leaf_cb cb, void *state)
 752 {
 753    union {
 754       nir_deref_array arr;
 755       nir_deref_struct str;
 756    } c;
 757
 758    if (tail->child) {
 759       switch (tail->child->deref_type) {
 760       case nir_deref_type_array:
 761          c.arr = *nir_deref_as_array(tail->child);
 762          tail->child = &c.arr.deref;
 763          return deref_foreach_leaf_copy_recur(deref, &c.arr.deref, cb, state);
 764
 765       case nir_deref_type_struct:
 766          c.str = *nir_deref_as_struct(tail->child);
 767          tail->child = &c.str.deref;
 768          return deref_foreach_leaf_copy_recur(deref, &c.str.deref, cb, state);
 769
 770       case nir_deref_type_var:
 771       default:
 772          unreachable("Invalid deref type for a child");
 773       }
 774    } else {
 775       /* We've gotten to the end of the original deref.  Time to start
 776        * building our own derefs.
 777        */
 778       return deref_foreach_leaf_build_recur(deref, tail, cb, state);
 779    }
 780 }
 781
 782 /**
 783  * This function iterates over all of the possible derefs that can be created
 784  * with the given deref as the head.  It then calls the provided callback with
 785  * a full deref for each one.
 786  *
 787  * The deref passed to the callback will be allocated on the stack.  You will
 788  * need to make a copy if you want it to hang around.
 789  */
 790 bool
 791 nir_deref_foreach_leaf(nir_deref_var *deref,
 792                        nir_deref_foreach_leaf_cb cb, void *state)
 793 {
 794    nir_deref_var copy = *deref;
 795    return deref_foreach_leaf_copy_recur(&copy, &copy.deref, cb, state);
 796 }
 797
 798 /* Returns a load_const instruction that represents the constant
 799  * initializer for the given deref chain.  The caller is responsible for
 800  * ensuring that there actually is a constant initializer.
 801  */
 802 nir_load_const_instr *
 803 nir_deref_get_const_initializer_load(nir_shader *shader, nir_deref_var *deref)
 804 {
 805    nir_constant *constant = deref->var->constant_initializer;
 806    assert(constant);
 807
 808    const nir_deref *tail = &deref->deref;
 809    unsigned matrix_offset = 0;
 810    while (tail->child) {
 811       switch (tail->child->deref_type) {
 812       case nir_deref_type_array: {
 813          nir_deref_array *arr = nir_deref_as_array(tail->child);
 814          assert(arr->deref_array_type == nir_deref_array_type_direct);
 815          if (glsl_type_is_matrix(tail->type)) {
 816             assert(arr->deref.child == NULL);
 817             matrix_offset = arr->base_offset;
 818          } else {
 819             constant = constant->elements[arr->base_offset];
 820          }
 821          break;
 822       }
 823
 824       case nir_deref_type_struct: {
 825          constant = constant->elements[nir_deref_as_struct(tail->child)->index];
 826          break;
 827       }
 828
 829       default:
 830          unreachable("Invalid deref child type");
 831       }
 832
 833       tail = tail->child;
 834    }
 835
 836    unsigned bit_size = glsl_get_bit_size(tail->type);
 837    nir_load_const_instr *load =
 838       nir_load_const_instr_create(shader, glsl_get_vector_elements(tail->type),
 839                                   bit_size);
 840
 841    matrix_offset *= load->def.num_components;
 842    for (unsigned i = 0; i < load->def.num_components; i++) {
 843       switch (glsl_get_base_type(tail->type)) {
 844       case GLSL_TYPE_FLOAT:
 845       case GLSL_TYPE_INT:
 846       case GLSL_TYPE_UINT:
 847          load->value.u32[i] = constant->value.u[matrix_offset + i];
 848          break;
 849       case GLSL_TYPE_DOUBLE:
 850          load->value.f64[i] = constant->value.d[matrix_offset + i];
 851          break;
 852       case GLSL_TYPE_BOOL:
 853          load->value.u32[i] = constant->value.b[matrix_offset + i] ?
 854                              NIR_TRUE : NIR_FALSE;
 855          break;
 856       default:
 857          unreachable("Invalid immediate type");
 858       }
 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 /* note: does *not* take ownership of 'name' */
1513 void
1514 nir_ssa_def_init(nir_instr *instr, nir_ssa_def *def,
1515                  unsigned num_components,
1516                  unsigned bit_size, const char *name)
1517 {
1518    def->name = ralloc_strdup(instr, name);
1519    def->parent_instr = instr;
1520    list_inithead(&def->uses);
1521    list_inithead(&def->if_uses);
1522    def->num_components = num_components;
1523    def->bit_size = bit_size;
1524
1525    if (instr->block) {
1526       nir_function_impl *impl =
1527          nir_cf_node_get_function(&instr->block->cf_node);
1528
1529       def->index = impl->ssa_alloc++;
1530    } else {
1531       def->index = UINT_MAX;
1532    }
1533 }
1534
1535 /* note: does *not* take ownership of 'name' */
1536 void
1537 nir_ssa_dest_init(nir_instr *instr, nir_dest *dest,
1538                  unsigned num_components, unsigned bit_size,
1539                  const char *name)
1540 {
1541    dest->is_ssa = true;
1542    nir_ssa_def_init(instr, &dest->ssa, num_components, bit_size, name);
1543 }
1544
1545 void
1546 nir_ssa_def_rewrite_uses(nir_ssa_def *def, nir_src new_src)
1547 {
1548    assert(!new_src.is_ssa || def != new_src.ssa);
1549
1550    nir_foreach_use_safe(use_src, def)
1551       nir_instr_rewrite_src(use_src->parent_instr, use_src, new_src);
1552
1553    nir_foreach_if_use_safe(use_src, def)
1554       nir_if_rewrite_condition(use_src->parent_if, new_src);
1555 }
1556
1557 static bool
1558 is_instr_between(nir_instr *start, nir_instr *end, nir_instr *between)
1559 {
1560    assert(start->block == end->block);
1561
1562    if (between->block != start->block)
1563       return false;
1564
1565    /* Search backwards looking for "between" */
1566    while (start != end) {
1567       if (between == end)
1568          return true;
1569
1570       end = nir_instr_prev(end);
1571       assert(end);
1572    }
1573
1574    return false;
1575 }
1576
1577 /* Replaces all uses of the given SSA def with the given source but only if
1578  * the use comes after the after_me instruction.  This can be useful if you
1579  * are emitting code to fix up the result of some instruction: you can freely
1580  * use the result in that code and then call rewrite_uses_after and pass the
1581  * last fixup instruction as after_me and it will replace all of the uses you
1582  * want without touching the fixup code.
1583  *
1584  * This function assumes that after_me is in the same block as
1585  * def->parent_instr and that after_me comes after def->parent_instr.
1586  */
1587 void
1588 nir_ssa_def_rewrite_uses_after(nir_ssa_def *def, nir_src new_src,
1589                                nir_instr *after_me)
1590 {
1591    assert(!new_src.is_ssa || def != new_src.ssa);
1592
1593    nir_foreach_use_safe(use_src, def) {
1594       assert(use_src->parent_instr != def->parent_instr);
1595       /* Since def already dominates all of its uses, the only way a use can
1596        * not be dominated by after_me is if it is between def and after_me in
1597        * the instruction list.
1598        */
1599       if (!is_instr_between(def->parent_instr, after_me, use_src->parent_instr))
1600          nir_instr_rewrite_src(use_src->parent_instr, use_src, new_src);
1601    }
1602
1603    nir_foreach_if_use_safe(use_src, def)
1604       nir_if_rewrite_condition(use_src->parent_if, new_src);
1605 }
1606
1607 uint8_t
1608 nir_ssa_def_components_read(nir_ssa_def *def)
1609 {
1610    uint8_t read_mask = 0;
1611    nir_foreach_use(use, def) {
1612       if (use->parent_instr->type == nir_instr_type_alu) {
1613          nir_alu_instr *alu = nir_instr_as_alu(use->parent_instr);
1614          nir_alu_src *alu_src = exec_node_data(nir_alu_src, use, src);
1615          int src_idx = alu_src - &alu->src[0];
1616          assert(src_idx >= 0 && src_idx < nir_op_infos[alu->op].num_inputs);
1617
1618          for (unsigned c = 0; c < 4; c++) {
1619             if (!nir_alu_instr_channel_used(alu, src_idx, c))
1620                continue;
1621
1622             read_mask |= (1 << alu_src->swizzle[c]);
1623          }
1624       } else {
1625          return (1 << def->num_components) - 1;
1626       }
1627    }
1628
1629    return read_mask;
1630 }
1631
1632 nir_block *
1633 nir_block_cf_tree_next(nir_block *block)
1634 {
1635    if (block == NULL) {
1636       /* nir_foreach_block_safe() will call this function on a NULL block
1637        * after the last iteration, but it won't use the result so just return
1638        * NULL here.
1639        */
1640       return NULL;
1641    }
1642
1643    nir_cf_node *cf_next = nir_cf_node_next(&block->cf_node);
1644    if (cf_next)
1645       return nir_cf_node_cf_tree_first(cf_next);
1646
1647    nir_cf_node *parent = block->cf_node.parent;
1648
1649    switch (parent->type) {
1650    case nir_cf_node_if: {
1651       /* Are we at the end of the if? Go to the beginning of the else */
1652       nir_if *if_stmt = nir_cf_node_as_if(parent);
1653       if (block == nir_if_last_then_block(if_stmt))
1654          return nir_if_first_else_block(if_stmt);
1655
1656       assert(block == nir_if_last_else_block(if_stmt));
1657       /* fall through */
1658    }
1659
1660    case nir_cf_node_loop:
1661       return nir_cf_node_as_block(nir_cf_node_next(parent));
1662
1663    case nir_cf_node_function:
1664       return NULL;
1665
1666    default:
1667       unreachable("unknown cf node type");
1668    }
1669 }
1670
1671 nir_block *
1672 nir_block_cf_tree_prev(nir_block *block)
1673 {
1674    if (block == NULL) {
1675       /* do this for consistency with nir_block_cf_tree_next() */
1676       return NULL;
1677    }
1678
1679    nir_cf_node *cf_prev = nir_cf_node_prev(&block->cf_node);
1680    if (cf_prev)
1681       return nir_cf_node_cf_tree_last(cf_prev);
1682
1683    nir_cf_node *parent = block->cf_node.parent;
1684
1685    switch (parent->type) {
1686    case nir_cf_node_if: {
1687       /* Are we at the beginning of the else? Go to the end of the if */
1688       nir_if *if_stmt = nir_cf_node_as_if(parent);
1689       if (block == nir_if_first_else_block(if_stmt))
1690          return nir_if_last_then_block(if_stmt);
1691
1692       assert(block == nir_if_first_then_block(if_stmt));
1693       /* fall through */
1694    }
1695
1696    case nir_cf_node_loop:
1697       return nir_cf_node_as_block(nir_cf_node_prev(parent));
1698
1699    case nir_cf_node_function:
1700       return NULL;
1701
1702    default:
1703       unreachable("unknown cf node type");
1704    }
1705 }
1706
1707 nir_block *nir_cf_node_cf_tree_first(nir_cf_node *node)
1708 {
1709    switch (node->type) {
1710    case nir_cf_node_function: {
1711       nir_function_impl *impl = nir_cf_node_as_function(node);
1712       return nir_start_block(impl);
1713    }
1714
1715    case nir_cf_node_if: {
1716       nir_if *if_stmt = nir_cf_node_as_if(node);
1717       return nir_if_first_then_block(if_stmt);
1718    }
1719
1720    case nir_cf_node_loop: {
1721       nir_loop *loop = nir_cf_node_as_loop(node);
1722       return nir_loop_first_block(loop);
1723    }
1724
1725    case nir_cf_node_block: {
1726       return nir_cf_node_as_block(node);
1727    }
1728
1729    default:
1730       unreachable("unknown node type");
1731    }
1732 }
1733
1734 nir_block *nir_cf_node_cf_tree_last(nir_cf_node *node)
1735 {
1736    switch (node->type) {
1737    case nir_cf_node_function: {
1738       nir_function_impl *impl = nir_cf_node_as_function(node);
1739       return nir_impl_last_block(impl);
1740    }
1741
1742    case nir_cf_node_if: {
1743       nir_if *if_stmt = nir_cf_node_as_if(node);
1744       return nir_if_last_else_block(if_stmt);
1745    }
1746
1747    case nir_cf_node_loop: {
1748       nir_loop *loop = nir_cf_node_as_loop(node);
1749       return nir_loop_last_block(loop);
1750    }
1751
1752    case nir_cf_node_block: {
1753       return nir_cf_node_as_block(node);
1754    }
1755
1756    default:
1757       unreachable("unknown node type");
1758    }
1759 }
1760
1761 nir_block *nir_cf_node_cf_tree_next(nir_cf_node *node)
1762 {
1763    if (node->type == nir_cf_node_block)
1764       return nir_cf_node_cf_tree_first(nir_cf_node_next(node));
1765    else if (node->type == nir_cf_node_function)
1766       return NULL;
1767    else
1768       return nir_cf_node_as_block(nir_cf_node_next(node));
1769 }
1770
1771 nir_if *
1772 nir_block_get_following_if(nir_block *block)
1773 {
1774    if (exec_node_is_tail_sentinel(&block->cf_node.node))
1775       return NULL;
1776
1777    if (nir_cf_node_is_last(&block->cf_node))
1778       return NULL;
1779
1780    nir_cf_node *next_node = nir_cf_node_next(&block->cf_node);
1781
1782    if (next_node->type != nir_cf_node_if)
1783       return NULL;
1784
1785    return nir_cf_node_as_if(next_node);
1786 }
1787
1788 nir_loop *
1789 nir_block_get_following_loop(nir_block *block)
1790 {
1791    if (exec_node_is_tail_sentinel(&block->cf_node.node))
1792       return NULL;
1793
1794    if (nir_cf_node_is_last(&block->cf_node))
1795       return NULL;
1796
1797    nir_cf_node *next_node = nir_cf_node_next(&block->cf_node);
1798
1799    if (next_node->type != nir_cf_node_loop)
1800       return NULL;
1801
1802    return nir_cf_node_as_loop(next_node);
1803 }
1804
1805 void
1806 nir_index_blocks(nir_function_impl *impl)
1807 {
1808    unsigned index = 0;
1809
1810    if (impl->valid_metadata & nir_metadata_block_index)
1811       return;
1812
1813    nir_foreach_block(block, impl) {
1814       block->index = index++;
1815    }
1816
1817    impl->num_blocks = index;
1818 }
1819
1820 static bool
1821 index_ssa_def_cb(nir_ssa_def *def, void *state)
1822 {
1823    unsigned *index = (unsigned *) state;
1824    def->index = (*index)++;
1825
1826    return true;
1827 }
1828
1829 /**
1830  * The indices are applied top-to-bottom which has the very nice property
1831  * that, if A dominates B, then A->index <= B->index.
1832  */
1833 void
1834 nir_index_ssa_defs(nir_function_impl *impl)
1835 {
1836    unsigned index = 0;
1837
1838    nir_foreach_block(block, impl) {
1839       nir_foreach_instr(instr, block)
1840          nir_foreach_ssa_def(instr, index_ssa_def_cb, &index);
1841    }
1842
1843    impl->ssa_alloc = index;
1844 }
1845
1846 /**
1847  * The indices are applied top-to-bottom which has the very nice property
1848  * that, if A dominates B, then A->index <= B->index.
1849  */
1850 unsigned
1851 nir_index_instrs(nir_function_impl *impl)
1852 {
1853    unsigned index = 0;
1854
1855    nir_foreach_block(block, impl) {
1856       nir_foreach_instr(instr, block)
1857          instr->index = index++;
1858    }
1859
1860    return index;
1861 }
1862
1863 nir_intrinsic_op
1864 nir_intrinsic_from_system_value(gl_system_value val)
1865 {
1866    switch (val) {
1867    case SYSTEM_VALUE_VERTEX_ID:
1868       return nir_intrinsic_load_vertex_id;
1869    case SYSTEM_VALUE_INSTANCE_ID:
1870       return nir_intrinsic_load_instance_id;
1871    case SYSTEM_VALUE_DRAW_ID:
1872       return nir_intrinsic_load_draw_id;
1873    case SYSTEM_VALUE_BASE_INSTANCE:
1874       return nir_intrinsic_load_base_instance;
1875    case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE:
1876       return nir_intrinsic_load_vertex_id_zero_base;
1877    case SYSTEM_VALUE_BASE_VERTEX:
1878       return nir_intrinsic_load_base_vertex;
1879    case SYSTEM_VALUE_INVOCATION_ID:
1880       return nir_intrinsic_load_invocation_id;
1881    case SYSTEM_VALUE_FRONT_FACE:
1882       return nir_intrinsic_load_front_face;
1883    case SYSTEM_VALUE_SAMPLE_ID:
1884       return nir_intrinsic_load_sample_id;
1885    case SYSTEM_VALUE_SAMPLE_POS:
1886       return nir_intrinsic_load_sample_pos;
1887    case SYSTEM_VALUE_SAMPLE_MASK_IN:
1888       return nir_intrinsic_load_sample_mask_in;
1889    case SYSTEM_VALUE_LOCAL_INVOCATION_ID:
1890       return nir_intrinsic_load_local_invocation_id;
1891    case SYSTEM_VALUE_LOCAL_INVOCATION_INDEX:
1892       return nir_intrinsic_load_local_invocation_index;
1893    case SYSTEM_VALUE_WORK_GROUP_ID:
1894       return nir_intrinsic_load_work_group_id;
1895    case SYSTEM_VALUE_NUM_WORK_GROUPS:
1896       return nir_intrinsic_load_num_work_groups;
1897    case SYSTEM_VALUE_PRIMITIVE_ID:
1898       return nir_intrinsic_load_primitive_id;
1899    case SYSTEM_VALUE_TESS_COORD:
1900       return nir_intrinsic_load_tess_coord;
1901    case SYSTEM_VALUE_TESS_LEVEL_OUTER:
1902       return nir_intrinsic_load_tess_level_outer;
1903    case SYSTEM_VALUE_TESS_LEVEL_INNER:
1904       return nir_intrinsic_load_tess_level_inner;
1905    case SYSTEM_VALUE_VERTICES_IN:
1906       return nir_intrinsic_load_patch_vertices_in;
1907    case SYSTEM_VALUE_HELPER_INVOCATION:
1908       return nir_intrinsic_load_helper_invocation;
1909    default:
1910       unreachable("system value does not directly correspond to intrinsic");
1911    }
1912 }
1913
1914 gl_system_value
1915 nir_system_value_from_intrinsic(nir_intrinsic_op intrin)
1916 {
1917    switch (intrin) {
1918    case nir_intrinsic_load_vertex_id:
1919       return SYSTEM_VALUE_VERTEX_ID;
1920    case nir_intrinsic_load_instance_id:
1921       return SYSTEM_VALUE_INSTANCE_ID;
1922    case nir_intrinsic_load_draw_id:
1923       return SYSTEM_VALUE_DRAW_ID;
1924    case nir_intrinsic_load_base_instance:
1925       return SYSTEM_VALUE_BASE_INSTANCE;
1926    case nir_intrinsic_load_vertex_id_zero_base:
1927       return SYSTEM_VALUE_VERTEX_ID_ZERO_BASE;
1928    case nir_intrinsic_load_base_vertex:
1929       return SYSTEM_VALUE_BASE_VERTEX;
1930    case nir_intrinsic_load_invocation_id:
1931       return SYSTEM_VALUE_INVOCATION_ID;
1932    case nir_intrinsic_load_front_face:
1933       return SYSTEM_VALUE_FRONT_FACE;
1934    case nir_intrinsic_load_sample_id:
1935       return SYSTEM_VALUE_SAMPLE_ID;
1936    case nir_intrinsic_load_sample_pos:
1937       return SYSTEM_VALUE_SAMPLE_POS;
1938    case nir_intrinsic_load_sample_mask_in:
1939       return SYSTEM_VALUE_SAMPLE_MASK_IN;
1940    case nir_intrinsic_load_local_invocation_id:
1941       return SYSTEM_VALUE_LOCAL_INVOCATION_ID;
1942    case nir_intrinsic_load_local_invocation_index:
1943       return SYSTEM_VALUE_LOCAL_INVOCATION_INDEX;
1944    case nir_intrinsic_load_num_work_groups:
1945       return SYSTEM_VALUE_NUM_WORK_GROUPS;
1946    case nir_intrinsic_load_work_group_id:
1947       return SYSTEM_VALUE_WORK_GROUP_ID;
1948    case nir_intrinsic_load_primitive_id:
1949       return SYSTEM_VALUE_PRIMITIVE_ID;
1950    case nir_intrinsic_load_tess_coord:
1951       return SYSTEM_VALUE_TESS_COORD;
1952    case nir_intrinsic_load_tess_level_outer:
1953       return SYSTEM_VALUE_TESS_LEVEL_OUTER;
1954    case nir_intrinsic_load_tess_level_inner:
1955       return SYSTEM_VALUE_TESS_LEVEL_INNER;
1956    case nir_intrinsic_load_patch_vertices_in:
1957       return SYSTEM_VALUE_VERTICES_IN;
1958    case nir_intrinsic_load_helper_invocation:
1959       return SYSTEM_VALUE_HELPER_INVOCATION;
1960    default:
1961       unreachable("intrinsic doesn't produce a system value");
1962    }
1963 }