src/compiler/nir/nir_builder.h

   1 /*
   2  * Copyright © 2014-2015 Broadcom
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #ifndef NIR_BUILDER_H
  25 #define NIR_BUILDER_H
  26
  27 #include "nir_control_flow.h"
  28
  29 struct exec_list;
  30
  31 typedef struct nir_builder {
  32    nir_cursor cursor;
  33
  34    /* Whether new ALU instructions will be marked "exact" */
  35    bool exact;
  36
  37    nir_shader *shader;
  38    nir_function_impl *impl;
  39 } nir_builder;
  40
  41 static inline void
  42 nir_builder_init(nir_builder *build, nir_function_impl *impl)
  43 {
  44    memset(build, 0, sizeof(*build));
  45    build->exact = false;
  46    build->impl = impl;
  47    build->shader = impl->function->shader;
  48 }
  49
  50 static inline void
  51 nir_builder_init_simple_shader(nir_builder *build, void *mem_ctx,
  52                                gl_shader_stage stage,
  53                                const nir_shader_compiler_options *options)
  54 {
  55    build->shader = nir_shader_create(mem_ctx, stage, options, NULL);
  56    nir_function *func = nir_function_create(build->shader, "main");
  57    build->exact = false;
  58    build->impl = nir_function_impl_create(func);
  59    build->cursor = nir_after_cf_list(&build->impl->body);
  60 }
  61
  62 static inline void
  63 nir_builder_instr_insert(nir_builder *build, nir_instr *instr)
  64 {
  65    nir_instr_insert(build->cursor, instr);
  66
  67    /* Move the cursor forward. */
  68    build->cursor = nir_after_instr(instr);
  69 }
  70
  71 static inline nir_instr *
  72 nir_builder_last_instr(nir_builder *build)
  73 {
  74    assert(build->cursor.option == nir_cursor_after_instr);
  75    return build->cursor.instr;
  76 }
  77
  78 static inline void
  79 nir_builder_cf_insert(nir_builder *build, nir_cf_node *cf)
  80 {
  81    nir_cf_node_insert(build->cursor, cf);
  82 }
  83
  84 static inline bool
  85 nir_builder_is_inside_cf(nir_builder *build, nir_cf_node *cf_node)
  86 {
  87    nir_block *block = nir_cursor_current_block(build->cursor);
  88    for (nir_cf_node *n = &block->cf_node; n; n = n->parent) {
  89       if (n == cf_node)
  90          return true;
  91    }
  92    return false;
  93 }
  94
  95 static inline nir_if *
  96 nir_push_if(nir_builder *build, nir_ssa_def *condition)
  97 {
  98    nir_if *nif = nir_if_create(build->shader);
  99    nif->condition = nir_src_for_ssa(condition);
 100    nir_builder_cf_insert(build, &nif->cf_node);
 101    build->cursor = nir_before_cf_list(&nif->then_list);
 102    return nif;
 103 }
 104
 105 static inline nir_if *
 106 nir_push_else(nir_builder *build, nir_if *nif)
 107 {
 108    if (nif) {
 109       assert(nir_builder_is_inside_cf(build, &nif->cf_node));
 110    } else {
 111       nir_block *block = nir_cursor_current_block(build->cursor);
 112       nif = nir_cf_node_as_if(block->cf_node.parent);
 113    }
 114    build->cursor = nir_before_cf_list(&nif->else_list);
 115    return nif;
 116 }
 117
 118 static inline void
 119 nir_pop_if(nir_builder *build, nir_if *nif)
 120 {
 121    if (nif) {
 122       assert(nir_builder_is_inside_cf(build, &nif->cf_node));
 123    } else {
 124       nir_block *block = nir_cursor_current_block(build->cursor);
 125       nif = nir_cf_node_as_if(block->cf_node.parent);
 126    }
 127    build->cursor = nir_after_cf_node(&nif->cf_node);
 128 }
 129
 130 static inline nir_ssa_def *
 131 nir_if_phi(nir_builder *build, nir_ssa_def *then_def, nir_ssa_def *else_def)
 132 {
 133    nir_block *block = nir_cursor_current_block(build->cursor);
 134    nir_if *nif = nir_cf_node_as_if(nir_cf_node_prev(&block->cf_node));
 135
 136    nir_phi_instr *phi = nir_phi_instr_create(build->shader);
 137
 138    nir_phi_src *src = ralloc(phi, nir_phi_src);
 139    src->pred = nir_if_last_then_block(nif);
 140    src->src = nir_src_for_ssa(then_def);
 141    exec_list_push_tail(&phi->srcs, &src->node);
 142
 143    src = ralloc(phi, nir_phi_src);
 144    src->pred = nir_if_last_else_block(nif);
 145    src->src = nir_src_for_ssa(else_def);
 146    exec_list_push_tail(&phi->srcs, &src->node);
 147
 148    assert(then_def->num_components == else_def->num_components);
 149    assert(then_def->bit_size == else_def->bit_size);
 150    nir_ssa_dest_init(&phi->instr, &phi->dest,
 151                      then_def->num_components, then_def->bit_size, NULL);
 152
 153    nir_builder_instr_insert(build, &phi->instr);
 154
 155    return &phi->dest.ssa;
 156 }
 157
 158 static inline nir_loop *
 159 nir_push_loop(nir_builder *build)
 160 {
 161    nir_loop *loop = nir_loop_create(build->shader);
 162    nir_builder_cf_insert(build, &loop->cf_node);
 163    build->cursor = nir_before_cf_list(&loop->body);
 164    return loop;
 165 }
 166
 167 static inline void
 168 nir_pop_loop(nir_builder *build, nir_loop *loop)
 169 {
 170    if (loop) {
 171       assert(nir_builder_is_inside_cf(build, &loop->cf_node));
 172    } else {
 173       nir_block *block = nir_cursor_current_block(build->cursor);
 174       loop = nir_cf_node_as_loop(block->cf_node.parent);
 175    }
 176    build->cursor = nir_after_cf_node(&loop->cf_node);
 177 }
 178
 179 static inline nir_ssa_def *
 180 nir_ssa_undef(nir_builder *build, unsigned num_components, unsigned bit_size)
 181 {
 182    nir_ssa_undef_instr *undef =
 183       nir_ssa_undef_instr_create(build->shader, num_components, bit_size);
 184    if (!undef)
 185       return NULL;
 186
 187    nir_instr_insert(nir_before_cf_list(&build->impl->body), &undef->instr);
 188
 189    return &undef->def;
 190 }
 191
 192 static inline nir_ssa_def *
 193 nir_build_imm(nir_builder *build, unsigned num_components,
 194               unsigned bit_size, nir_const_value value)
 195 {
 196    nir_load_const_instr *load_const =
 197       nir_load_const_instr_create(build->shader, num_components, bit_size);
 198    if (!load_const)
 199       return NULL;
 200
 201    load_const->value = value;
 202
 203    nir_builder_instr_insert(build, &load_const->instr);
 204
 205    return &load_const->def;
 206 }
 207
 208 static inline nir_ssa_def *
 209 nir_imm_float(nir_builder *build, float x)
 210 {
 211    nir_const_value v;
 212
 213    memset(&v, 0, sizeof(v));
 214    v.f32[0] = x;
 215
 216    return nir_build_imm(build, 1, 32, v);
 217 }
 218
 219 static inline nir_ssa_def *
 220 nir_imm_double(nir_builder *build, double x)
 221 {
 222    nir_const_value v;
 223
 224    memset(&v, 0, sizeof(v));
 225    v.f64[0] = x;
 226
 227    return nir_build_imm(build, 1, 64, v);
 228 }
 229
 230 static inline nir_ssa_def *
 231 nir_imm_floatN_t(nir_builder *build, double x, unsigned bit_size)
 232 {
 233    switch (bit_size) {
 234    case 32:
 235       return nir_imm_float(build, x);
 236    case 64:
 237       return nir_imm_double(build, x);
 238    }
 239
 240    unreachable("unknown float immediate bit size");
 241 }
 242
 243 static inline nir_ssa_def *
 244 nir_imm_vec4(nir_builder *build, float x, float y, float z, float w)
 245 {
 246    nir_const_value v;
 247
 248    memset(&v, 0, sizeof(v));
 249    v.f32[0] = x;
 250    v.f32[1] = y;
 251    v.f32[2] = z;
 252    v.f32[3] = w;
 253
 254    return nir_build_imm(build, 4, 32, v);
 255 }
 256
 257 static inline nir_ssa_def *
 258 nir_imm_int(nir_builder *build, int x)
 259 {
 260    nir_const_value v;
 261
 262    memset(&v, 0, sizeof(v));
 263    v.i32[0] = x;
 264
 265    return nir_build_imm(build, 1, 32, v);
 266 }
 267
 268 static inline nir_ssa_def *
 269 nir_imm_int64(nir_builder *build, int64_t x)
 270 {
 271    nir_const_value v;
 272
 273    memset(&v, 0, sizeof(v));
 274    v.i64[0] = x;
 275
 276    return nir_build_imm(build, 1, 64, v);
 277 }
 278
 279 static inline nir_ssa_def *
 280 nir_imm_intN_t(nir_builder *build, uint64_t x, unsigned bit_size)
 281 {
 282    nir_const_value v;
 283
 284    memset(&v, 0, sizeof(v));
 285    assert(bit_size <= 64);
 286    v.i64[0] = x & (~0ull >> (64 - bit_size));
 287
 288    return nir_build_imm(build, 1, bit_size, v);
 289 }
 290
 291 static inline nir_ssa_def *
 292 nir_imm_ivec4(nir_builder *build, int x, int y, int z, int w)
 293 {
 294    nir_const_value v;
 295
 296    memset(&v, 0, sizeof(v));
 297    v.i32[0] = x;
 298    v.i32[1] = y;
 299    v.i32[2] = z;
 300    v.i32[3] = w;
 301
 302    return nir_build_imm(build, 4, 32, v);
 303 }
 304
 305 static inline nir_ssa_def *
 306 nir_build_alu(nir_builder *build, nir_op op, nir_ssa_def *src0,
 307               nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)
 308 {
 309    const nir_op_info *op_info = &nir_op_infos[op];
 310    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
 311    if (!instr)
 312       return NULL;
 313
 314    instr->exact = build->exact;
 315
 316    instr->src[0].src = nir_src_for_ssa(src0);
 317    if (src1)
 318       instr->src[1].src = nir_src_for_ssa(src1);
 319    if (src2)
 320       instr->src[2].src = nir_src_for_ssa(src2);
 321    if (src3)
 322       instr->src[3].src = nir_src_for_ssa(src3);
 323
 324    /* Guess the number of components the destination temporary should have
 325     * based on our input sizes, if it's not fixed for the op.
 326     */
 327    unsigned num_components = op_info->output_size;
 328    if (num_components == 0) {
 329       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 330          if (op_info->input_sizes[i] == 0)
 331             num_components = MAX2(num_components,
 332                                   instr->src[i].src.ssa->num_components);
 333       }
 334    }
 335    assert(num_components != 0);
 336
 337    /* Figure out the bitwidth based on the source bitwidth if the instruction
 338     * is variable-width.
 339     */
 340    unsigned bit_size = nir_alu_type_get_type_size(op_info->output_type);
 341    if (bit_size == 0) {
 342       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 343          unsigned src_bit_size = instr->src[i].src.ssa->bit_size;
 344          if (nir_alu_type_get_type_size(op_info->input_types[i]) == 0) {
 345             if (bit_size)
 346                assert(src_bit_size == bit_size);
 347             else
 348                bit_size = src_bit_size;
 349          } else {
 350             assert(src_bit_size ==
 351                nir_alu_type_get_type_size(op_info->input_types[i]));
 352          }
 353       }
 354    }
 355
 356    /* When in doubt, assume 32. */
 357    if (bit_size == 0)
 358       bit_size = 32;
 359
 360    /* Make sure we don't swizzle from outside of our source vector (like if a
 361     * scalar value was passed into a multiply with a vector).
 362     */
 363    for (unsigned i = 0; i < op_info->num_inputs; i++) {
 364       for (unsigned j = instr->src[i].src.ssa->num_components;
 365            j < NIR_MAX_VEC_COMPONENTS; j++) {
 366          instr->src[i].swizzle[j] = instr->src[i].src.ssa->num_components - 1;
 367       }
 368    }
 369
 370    nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components,
 371                      bit_size, NULL);
 372    instr->dest.write_mask = (1 << num_components) - 1;
 373
 374    nir_builder_instr_insert(build, &instr->instr);
 375
 376    return &instr->dest.dest.ssa;
 377 }
 378
 379 #include "nir_builder_opcodes.h"
 380
 381 static inline nir_ssa_def *
 382 nir_vec(nir_builder *build, nir_ssa_def **comp, unsigned num_components)
 383 {
 384    switch (num_components) {
 385    case 4:
 386       return nir_vec4(build, comp[0], comp[1], comp[2], comp[3]);
 387    case 3:
 388       return nir_vec3(build, comp[0], comp[1], comp[2]);
 389    case 2:
 390       return nir_vec2(build, comp[0], comp[1]);
 391    case 1:
 392       return comp[0];
 393    default:
 394       unreachable("bad component count");
 395       return NULL;
 396    }
 397 }
 398
 399 /**
 400  * Similar to nir_fmov, but takes a nir_alu_src instead of a nir_ssa_def.
 401  */
 402 static inline nir_ssa_def *
 403 nir_fmov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 404 {
 405    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_fmov);
 406    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components,
 407                      nir_src_bit_size(src.src), NULL);
 408    mov->exact = build->exact;
 409    mov->dest.write_mask = (1 << num_components) - 1;
 410    mov->src[0] = src;
 411    nir_builder_instr_insert(build, &mov->instr);
 412
 413    return &mov->dest.dest.ssa;
 414 }
 415
 416 static inline nir_ssa_def *
 417 nir_imov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 418 {
 419    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_imov);
 420    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components,
 421                      nir_src_bit_size(src.src), NULL);
 422    mov->exact = build->exact;
 423    mov->dest.write_mask = (1 << num_components) - 1;
 424    mov->src[0] = src;
 425    nir_builder_instr_insert(build, &mov->instr);
 426
 427    return &mov->dest.dest.ssa;
 428 }
 429
 430 /**
 431  * Construct an fmov or imov that reswizzles the source's components.
 432  */
 433 static inline nir_ssa_def *
 434 nir_swizzle(nir_builder *build, nir_ssa_def *src, const unsigned *swiz,
 435             unsigned num_components, bool use_fmov)
 436 {
 437    assert(num_components <= NIR_MAX_VEC_COMPONENTS);
 438    nir_alu_src alu_src = { NIR_SRC_INIT };
 439    alu_src.src = nir_src_for_ssa(src);
 440    for (unsigned i = 0; i < num_components && i < NIR_MAX_VEC_COMPONENTS; i++)
 441       alu_src.swizzle[i] = swiz[i];
 442
 443    return use_fmov ? nir_fmov_alu(build, alu_src, num_components) :
 444                      nir_imov_alu(build, alu_src, num_components);
 445 }
 446
 447 /* Selects the right fdot given the number of components in each source. */
 448 static inline nir_ssa_def *
 449 nir_fdot(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)
 450 {
 451    assert(src0->num_components == src1->num_components);
 452    switch (src0->num_components) {
 453    case 1: return nir_fmul(build, src0, src1);
 454    case 2: return nir_fdot2(build, src0, src1);
 455    case 3: return nir_fdot3(build, src0, src1);
 456    case 4: return nir_fdot4(build, src0, src1);
 457    default:
 458       unreachable("bad component size");
 459    }
 460
 461    return NULL;
 462 }
 463
 464 static inline nir_ssa_def *
 465 nir_bany_inequal(nir_builder *b, nir_ssa_def *src0, nir_ssa_def *src1)
 466 {
 467    switch (src0->num_components) {
 468    case 1: return nir_ine(b, src0, src1);
 469    case 2: return nir_bany_inequal2(b, src0, src1);
 470    case 3: return nir_bany_inequal3(b, src0, src1);
 471    case 4: return nir_bany_inequal4(b, src0, src1);
 472    default:
 473       unreachable("bad component size");
 474    }
 475 }
 476
 477 static inline nir_ssa_def *
 478 nir_bany(nir_builder *b, nir_ssa_def *src)
 479 {
 480    return nir_bany_inequal(b, src, nir_imm_int(b, 0));
 481 }
 482
 483 static inline nir_ssa_def *
 484 nir_channel(nir_builder *b, nir_ssa_def *def, unsigned c)
 485 {
 486    return nir_swizzle(b, def, &c, 1, false);
 487 }
 488
 489 static inline nir_ssa_def *
 490 nir_channels(nir_builder *b, nir_ssa_def *def, nir_component_mask_t mask)
 491 {
 492    unsigned num_channels = 0, swizzle[NIR_MAX_VEC_COMPONENTS] = { 0 };
 493
 494    for (unsigned i = 0; i < NIR_MAX_VEC_COMPONENTS; i++) {
 495       if ((mask & (1 << i)) == 0)
 496          continue;
 497       swizzle[num_channels++] = i;
 498    }
 499
 500    return nir_swizzle(b, def, swizzle, num_channels, false);
 501 }
 502
 503 /**
 504  * Turns a nir_src into a nir_ssa_def * so it can be passed to
 505  * nir_build_alu()-based builder calls.
 506  *
 507  * See nir_ssa_for_alu_src() for alu instructions.
 508  */
 509 static inline nir_ssa_def *
 510 nir_ssa_for_src(nir_builder *build, nir_src src, int num_components)
 511 {
 512    if (src.is_ssa && src.ssa->num_components == num_components)
 513       return src.ssa;
 514
 515    nir_alu_src alu = { NIR_SRC_INIT };
 516    alu.src = src;
 517    for (int j = 0; j < 4; j++)
 518       alu.swizzle[j] = j;
 519
 520    return nir_imov_alu(build, alu, num_components);
 521 }
 522
 523 /**
 524  * Similar to nir_ssa_for_src(), but for alu srcs, respecting the
 525  * nir_alu_src's swizzle.
 526  */
 527 static inline nir_ssa_def *
 528 nir_ssa_for_alu_src(nir_builder *build, nir_alu_instr *instr, unsigned srcn)
 529 {
 530    static uint8_t trivial_swizzle[NIR_MAX_VEC_COMPONENTS];
 531    for (int i = 0; i < NIR_MAX_VEC_COMPONENTS; ++i)
 532       trivial_swizzle[i] = i;
 533    nir_alu_src *src = &instr->src[srcn];
 534    unsigned num_components = nir_ssa_alu_instr_src_components(instr, srcn);
 535
 536    if (src->src.is_ssa && (src->src.ssa->num_components == num_components) &&
 537        !src->abs && !src->negate &&
 538        (memcmp(src->swizzle, trivial_swizzle, num_components) == 0))
 539       return src->src.ssa;
 540
 541    return nir_imov_alu(build, *src, num_components);
 542 }
 543
 544 static inline nir_deref_instr *
 545 nir_build_deref_var(nir_builder *build, nir_variable *var)
 546 {
 547    nir_deref_instr *deref =
 548       nir_deref_instr_create(build->shader, nir_deref_type_var);
 549
 550    deref->mode = var->data.mode;
 551    deref->type = var->type;
 552    deref->var = var;
 553
 554    nir_ssa_dest_init(&deref->instr, &deref->dest, 1, 32, NULL);
 555
 556    nir_builder_instr_insert(build, &deref->instr);
 557
 558    return deref;
 559 }
 560
 561 static inline nir_deref_instr *
 562 nir_build_deref_array(nir_builder *build, nir_deref_instr *parent,
 563                       nir_ssa_def *index)
 564 {
 565    assert(glsl_type_is_array(parent->type) ||
 566           glsl_type_is_matrix(parent->type) ||
 567           glsl_type_is_vector(parent->type));
 568
 569    nir_deref_instr *deref =
 570       nir_deref_instr_create(build->shader, nir_deref_type_array);
 571
 572    deref->mode = parent->mode;
 573    deref->type = glsl_get_array_element(parent->type);
 574    deref->parent = nir_src_for_ssa(&parent->dest.ssa);
 575    deref->arr.index = nir_src_for_ssa(index);
 576
 577    nir_ssa_dest_init(&deref->instr, &deref->dest,
 578                      parent->dest.ssa.num_components,
 579                      parent->dest.ssa.bit_size, NULL);
 580
 581    nir_builder_instr_insert(build, &deref->instr);
 582
 583    return deref;
 584 }
 585
 586 static inline nir_deref_instr *
 587 nir_build_deref_array_wildcard(nir_builder *build, nir_deref_instr *parent)
 588 {
 589    assert(glsl_type_is_array(parent->type) ||
 590           glsl_type_is_matrix(parent->type));
 591
 592    nir_deref_instr *deref =
 593       nir_deref_instr_create(build->shader, nir_deref_type_array_wildcard);
 594
 595    deref->mode = parent->mode;
 596    deref->type = glsl_get_array_element(parent->type);
 597    deref->parent = nir_src_for_ssa(&parent->dest.ssa);
 598
 599    nir_ssa_dest_init(&deref->instr, &deref->dest,
 600                      parent->dest.ssa.num_components,
 601                      parent->dest.ssa.bit_size, NULL);
 602
 603    nir_builder_instr_insert(build, &deref->instr);
 604
 605    return deref;
 606 }
 607
 608 static inline nir_deref_instr *
 609 nir_build_deref_struct(nir_builder *build, nir_deref_instr *parent,
 610                        unsigned index)
 611 {
 612    assert(glsl_type_is_struct(parent->type));
 613
 614    nir_deref_instr *deref =
 615       nir_deref_instr_create(build->shader, nir_deref_type_struct);
 616
 617    deref->mode = parent->mode;
 618    deref->type = glsl_get_struct_field(parent->type, index);
 619    deref->parent = nir_src_for_ssa(&parent->dest.ssa);
 620    deref->strct.index = index;
 621
 622    nir_ssa_dest_init(&deref->instr, &deref->dest,
 623                      parent->dest.ssa.num_components,
 624                      parent->dest.ssa.bit_size, NULL);
 625
 626    nir_builder_instr_insert(build, &deref->instr);
 627
 628    return deref;
 629 }
 630
 631 static inline nir_deref_instr *
 632 nir_build_deref_cast(nir_builder *build, nir_ssa_def *parent,
 633                      nir_variable_mode mode, const struct glsl_type *type)
 634 {
 635    nir_deref_instr *deref =
 636       nir_deref_instr_create(build->shader, nir_deref_type_cast);
 637
 638    deref->mode = mode;
 639    deref->type = type;
 640    deref->parent = nir_src_for_ssa(parent);
 641
 642    nir_ssa_dest_init(&deref->instr, &deref->dest,
 643                      parent->num_components, parent->bit_size, NULL);
 644
 645    nir_builder_instr_insert(build, &deref->instr);
 646
 647    return deref;
 648 }
 649
 650 /** Returns a deref that follows another but starting from the given parent
 651  *
 652  * The new deref will be the same type and take the same array or struct index
 653  * as the leader deref but it may have a different parent.  This is very
 654  * useful for walking deref paths.
 655  */
 656 static inline nir_deref_instr *
 657 nir_build_deref_follower(nir_builder *b, nir_deref_instr *parent,
 658                          nir_deref_instr *leader)
 659 {
 660    /* If the derefs would have the same parent, don't make a new one */
 661    assert(leader->parent.is_ssa);
 662    if (leader->parent.ssa == &parent->dest.ssa)
 663       return leader;
 664
 665    UNUSED nir_deref_instr *leader_parent = nir_src_as_deref(leader->parent);
 666
 667    switch (leader->deref_type) {
 668    case nir_deref_type_var:
 669       unreachable("A var dereference cannot have a parent");
 670       break;
 671
 672    case nir_deref_type_array:
 673    case nir_deref_type_array_wildcard:
 674       assert(glsl_type_is_matrix(parent->type) ||
 675              glsl_type_is_array(parent->type));
 676       assert(glsl_get_length(parent->type) ==
 677              glsl_get_length(leader_parent->type));
 678
 679       if (leader->deref_type == nir_deref_type_array) {
 680          assert(leader->arr.index.is_ssa);
 681          return nir_build_deref_array(b, parent, leader->arr.index.ssa);
 682       } else {
 683          return nir_build_deref_array_wildcard(b, parent);
 684       }
 685
 686    case nir_deref_type_struct:
 687       assert(glsl_type_is_struct(parent->type));
 688       assert(glsl_get_length(parent->type) ==
 689              glsl_get_length(leader_parent->type));
 690
 691       return nir_build_deref_struct(b, parent, leader->strct.index);
 692
 693    default:
 694       unreachable("Invalid deref instruction type");
 695    }
 696 }
 697
 698 static inline nir_ssa_def *
 699 nir_load_reg(nir_builder *build, nir_register *reg)
 700 {
 701    return nir_ssa_for_src(build, nir_src_for_reg(reg), reg->num_components);
 702 }
 703
 704 static inline nir_ssa_def *
 705 nir_load_deref(nir_builder *build, nir_deref_instr *deref)
 706 {
 707    nir_intrinsic_instr *load =
 708       nir_intrinsic_instr_create(build->shader, nir_intrinsic_load_deref);
 709    load->num_components = glsl_get_vector_elements(deref->type);
 710    load->src[0] = nir_src_for_ssa(&deref->dest.ssa);
 711    nir_ssa_dest_init(&load->instr, &load->dest, load->num_components,
 712                      glsl_get_bit_size(deref->type), NULL);
 713    nir_builder_instr_insert(build, &load->instr);
 714    return &load->dest.ssa;
 715 }
 716
 717 static inline void
 718 nir_store_deref(nir_builder *build, nir_deref_instr *deref,
 719                 nir_ssa_def *value, unsigned writemask)
 720 {
 721    nir_intrinsic_instr *store =
 722       nir_intrinsic_instr_create(build->shader, nir_intrinsic_store_deref);
 723    store->num_components = glsl_get_vector_elements(deref->type);
 724    store->src[0] = nir_src_for_ssa(&deref->dest.ssa);
 725    store->src[1] = nir_src_for_ssa(value);
 726    nir_intrinsic_set_write_mask(store,
 727                                 writemask & ((1 << store->num_components) - 1));
 728    nir_builder_instr_insert(build, &store->instr);
 729 }
 730
 731 static inline void
 732 nir_copy_deref(nir_builder *build, nir_deref_instr *dest, nir_deref_instr *src)
 733 {
 734    nir_intrinsic_instr *copy =
 735       nir_intrinsic_instr_create(build->shader, nir_intrinsic_copy_deref);
 736    copy->src[0] = nir_src_for_ssa(&dest->dest.ssa);
 737    copy->src[1] = nir_src_for_ssa(&src->dest.ssa);
 738    nir_builder_instr_insert(build, &copy->instr);
 739 }
 740
 741 static inline nir_ssa_def *
 742 nir_load_var(nir_builder *build, nir_variable *var)
 743 {
 744    return nir_load_deref(build, nir_build_deref_var(build, var));
 745 }
 746
 747 static inline void
 748 nir_store_var(nir_builder *build, nir_variable *var, nir_ssa_def *value,
 749               unsigned writemask)
 750 {
 751    nir_store_deref(build, nir_build_deref_var(build, var), value, writemask);
 752 }
 753
 754 static inline void
 755 nir_copy_var(nir_builder *build, nir_variable *dest, nir_variable *src)
 756 {
 757    nir_copy_deref(build, nir_build_deref_var(build, dest),
 758                          nir_build_deref_var(build, src));
 759 }
 760
 761 static inline nir_ssa_def *
 762 nir_load_param(nir_builder *build, uint32_t param_idx)
 763 {
 764    assert(param_idx < build->impl->function->num_params);
 765    nir_parameter *param = &build->impl->function->params[param_idx];
 766
 767    nir_intrinsic_instr *load =
 768       nir_intrinsic_instr_create(build->shader, nir_intrinsic_load_param);
 769    nir_intrinsic_set_param_idx(load, param_idx);
 770    load->num_components = param->num_components;
 771    nir_ssa_dest_init(&load->instr, &load->dest,
 772                      param->num_components, param->bit_size, NULL);
 773    nir_builder_instr_insert(build, &load->instr);
 774    return &load->dest.ssa;
 775 }
 776
 777 #include "nir_builder_opcodes.h"
 778
 779 static inline nir_ssa_def *
 780 nir_load_barycentric(nir_builder *build, nir_intrinsic_op op,
 781                      unsigned interp_mode)
 782 {
 783    nir_intrinsic_instr *bary = nir_intrinsic_instr_create(build->shader, op);
 784    nir_ssa_dest_init(&bary->instr, &bary->dest, 2, 32, NULL);
 785    nir_intrinsic_set_interp_mode(bary, interp_mode);
 786    nir_builder_instr_insert(build, &bary->instr);
 787    return &bary->dest.ssa;
 788 }
 789
 790 static inline void
 791 nir_jump(nir_builder *build, nir_jump_type jump_type)
 792 {
 793    nir_jump_instr *jump = nir_jump_instr_create(build->shader, jump_type);
 794    nir_builder_instr_insert(build, &jump->instr);
 795 }
 796
 797 static inline nir_ssa_def *
 798 nir_compare_func(nir_builder *b, enum compare_func func,
 799                  nir_ssa_def *src0, nir_ssa_def *src1)
 800 {
 801    switch (func) {
 802    case COMPARE_FUNC_NEVER:
 803       return nir_imm_int(b, 0);
 804    case COMPARE_FUNC_ALWAYS:
 805       return nir_imm_int(b, ~0);
 806    case COMPARE_FUNC_EQUAL:
 807       return nir_feq(b, src0, src1);
 808    case COMPARE_FUNC_NOTEQUAL:
 809       return nir_fne(b, src0, src1);
 810    case COMPARE_FUNC_GREATER:
 811       return nir_flt(b, src1, src0);
 812    case COMPARE_FUNC_GEQUAL:
 813       return nir_fge(b, src0, src1);
 814    case COMPARE_FUNC_LESS:
 815       return nir_flt(b, src0, src1);
 816    case COMPARE_FUNC_LEQUAL:
 817       return nir_fge(b, src1, src0);
 818    }
 819    unreachable("bad compare func");
 820 }
 821
 822 #endif /* NIR_BUILDER_H */