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_ivec2(nir_builder *build, int x, int y)
 259 {
 260    nir_const_value v;
 261
 262    memset(&v, 0, sizeof(v));
 263    v.i32[0] = x;
 264    v.i32[1] = y;
 265
 266    return nir_build_imm(build, 2, 32, v);
 267 }
 268
 269 static inline nir_ssa_def *
 270 nir_imm_int(nir_builder *build, int x)
 271 {
 272    nir_const_value v;
 273
 274    memset(&v, 0, sizeof(v));
 275    v.i32[0] = x;
 276
 277    return nir_build_imm(build, 1, 32, v);
 278 }
 279
 280 static inline nir_ssa_def *
 281 nir_imm_int64(nir_builder *build, int64_t x)
 282 {
 283    nir_const_value v;
 284
 285    memset(&v, 0, sizeof(v));
 286    v.i64[0] = x;
 287
 288    return nir_build_imm(build, 1, 64, v);
 289 }
 290
 291 static inline nir_ssa_def *
 292 nir_imm_intN_t(nir_builder *build, uint64_t x, unsigned bit_size)
 293 {
 294    nir_const_value v;
 295
 296    memset(&v, 0, sizeof(v));
 297    assert(bit_size <= 64);
 298    v.i64[0] = x & (~0ull >> (64 - bit_size));
 299
 300    return nir_build_imm(build, 1, bit_size, v);
 301 }
 302
 303 static inline nir_ssa_def *
 304 nir_imm_ivec4(nir_builder *build, int x, int y, int z, int w)
 305 {
 306    nir_const_value v;
 307
 308    memset(&v, 0, sizeof(v));
 309    v.i32[0] = x;
 310    v.i32[1] = y;
 311    v.i32[2] = z;
 312    v.i32[3] = w;
 313
 314    return nir_build_imm(build, 4, 32, v);
 315 }
 316
 317 static inline nir_ssa_def *
 318 nir_build_alu(nir_builder *build, nir_op op, nir_ssa_def *src0,
 319               nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)
 320 {
 321    const nir_op_info *op_info = &nir_op_infos[op];
 322    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
 323    if (!instr)
 324       return NULL;
 325
 326    instr->exact = build->exact;
 327
 328    instr->src[0].src = nir_src_for_ssa(src0);
 329    if (src1)
 330       instr->src[1].src = nir_src_for_ssa(src1);
 331    if (src2)
 332       instr->src[2].src = nir_src_for_ssa(src2);
 333    if (src3)
 334       instr->src[3].src = nir_src_for_ssa(src3);
 335
 336    /* Guess the number of components the destination temporary should have
 337     * based on our input sizes, if it's not fixed for the op.
 338     */
 339    unsigned num_components = op_info->output_size;
 340    if (num_components == 0) {
 341       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 342          if (op_info->input_sizes[i] == 0)
 343             num_components = MAX2(num_components,
 344                                   instr->src[i].src.ssa->num_components);
 345       }
 346    }
 347    assert(num_components != 0);
 348
 349    /* Figure out the bitwidth based on the source bitwidth if the instruction
 350     * is variable-width.
 351     */
 352    unsigned bit_size = nir_alu_type_get_type_size(op_info->output_type);
 353    if (bit_size == 0) {
 354       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 355          unsigned src_bit_size = instr->src[i].src.ssa->bit_size;
 356          if (nir_alu_type_get_type_size(op_info->input_types[i]) == 0) {
 357             if (bit_size)
 358                assert(src_bit_size == bit_size);
 359             else
 360                bit_size = src_bit_size;
 361          } else {
 362             assert(src_bit_size ==
 363                nir_alu_type_get_type_size(op_info->input_types[i]));
 364          }
 365       }
 366    }
 367
 368    /* When in doubt, assume 32. */
 369    if (bit_size == 0)
 370       bit_size = 32;
 371
 372    /* Make sure we don't swizzle from outside of our source vector (like if a
 373     * scalar value was passed into a multiply with a vector).
 374     */
 375    for (unsigned i = 0; i < op_info->num_inputs; i++) {
 376       for (unsigned j = instr->src[i].src.ssa->num_components;
 377            j < NIR_MAX_VEC_COMPONENTS; j++) {
 378          instr->src[i].swizzle[j] = instr->src[i].src.ssa->num_components - 1;
 379       }
 380    }
 381
 382    nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components,
 383                      bit_size, NULL);
 384    instr->dest.write_mask = (1 << num_components) - 1;
 385
 386    nir_builder_instr_insert(build, &instr->instr);
 387
 388    return &instr->dest.dest.ssa;
 389 }
 390
 391 #include "nir_builder_opcodes.h"
 392
 393 static inline nir_ssa_def *
 394 nir_vec(nir_builder *build, nir_ssa_def **comp, unsigned num_components)
 395 {
 396    switch (num_components) {
 397    case 4:
 398       return nir_vec4(build, comp[0], comp[1], comp[2], comp[3]);
 399    case 3:
 400       return nir_vec3(build, comp[0], comp[1], comp[2]);
 401    case 2:
 402       return nir_vec2(build, comp[0], comp[1]);
 403    case 1:
 404       return comp[0];
 405    default:
 406       unreachable("bad component count");
 407       return NULL;
 408    }
 409 }
 410
 411 /**
 412  * Similar to nir_fmov, but takes a nir_alu_src instead of a nir_ssa_def.
 413  */
 414 static inline nir_ssa_def *
 415 nir_fmov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 416 {
 417    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_fmov);
 418    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components,
 419                      nir_src_bit_size(src.src), NULL);
 420    mov->exact = build->exact;
 421    mov->dest.write_mask = (1 << num_components) - 1;
 422    mov->src[0] = src;
 423    nir_builder_instr_insert(build, &mov->instr);
 424
 425    return &mov->dest.dest.ssa;
 426 }
 427
 428 static inline nir_ssa_def *
 429 nir_imov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 430 {
 431    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_imov);
 432    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components,
 433                      nir_src_bit_size(src.src), NULL);
 434    mov->exact = build->exact;
 435    mov->dest.write_mask = (1 << num_components) - 1;
 436    mov->src[0] = src;
 437    nir_builder_instr_insert(build, &mov->instr);
 438
 439    return &mov->dest.dest.ssa;
 440 }
 441
 442 /**
 443  * Construct an fmov or imov that reswizzles the source's components.
 444  */
 445 static inline nir_ssa_def *
 446 nir_swizzle(nir_builder *build, nir_ssa_def *src, const unsigned *swiz,
 447             unsigned num_components, bool use_fmov)
 448 {
 449    assert(num_components <= NIR_MAX_VEC_COMPONENTS);
 450    nir_alu_src alu_src = { NIR_SRC_INIT };
 451    alu_src.src = nir_src_for_ssa(src);
 452    for (unsigned i = 0; i < num_components && i < NIR_MAX_VEC_COMPONENTS; i++)
 453       alu_src.swizzle[i] = swiz[i];
 454
 455    return use_fmov ? nir_fmov_alu(build, alu_src, num_components) :
 456                      nir_imov_alu(build, alu_src, num_components);
 457 }
 458
 459 /* Selects the right fdot given the number of components in each source. */
 460 static inline nir_ssa_def *
 461 nir_fdot(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)
 462 {
 463    assert(src0->num_components == src1->num_components);
 464    switch (src0->num_components) {
 465    case 1: return nir_fmul(build, src0, src1);
 466    case 2: return nir_fdot2(build, src0, src1);
 467    case 3: return nir_fdot3(build, src0, src1);
 468    case 4: return nir_fdot4(build, src0, src1);
 469    default:
 470       unreachable("bad component size");
 471    }
 472
 473    return NULL;
 474 }
 475
 476 static inline nir_ssa_def *
 477 nir_bany_inequal(nir_builder *b, nir_ssa_def *src0, nir_ssa_def *src1)
 478 {
 479    switch (src0->num_components) {
 480    case 1: return nir_ine(b, src0, src1);
 481    case 2: return nir_bany_inequal2(b, src0, src1);
 482    case 3: return nir_bany_inequal3(b, src0, src1);
 483    case 4: return nir_bany_inequal4(b, src0, src1);
 484    default:
 485       unreachable("bad component size");
 486    }
 487 }
 488
 489 static inline nir_ssa_def *
 490 nir_bany(nir_builder *b, nir_ssa_def *src)
 491 {
 492    return nir_bany_inequal(b, src, nir_imm_int(b, 0));
 493 }
 494
 495 static inline nir_ssa_def *
 496 nir_channel(nir_builder *b, nir_ssa_def *def, unsigned c)
 497 {
 498    return nir_swizzle(b, def, &c, 1, false);
 499 }
 500
 501 static inline nir_ssa_def *
 502 nir_channels(nir_builder *b, nir_ssa_def *def, nir_component_mask_t mask)
 503 {
 504    unsigned num_channels = 0, swizzle[NIR_MAX_VEC_COMPONENTS] = { 0 };
 505
 506    for (unsigned i = 0; i < NIR_MAX_VEC_COMPONENTS; i++) {
 507       if ((mask & (1 << i)) == 0)
 508          continue;
 509       swizzle[num_channels++] = i;
 510    }
 511
 512    return nir_swizzle(b, def, swizzle, num_channels, false);
 513 }
 514
 515 /**
 516  * Turns a nir_src into a nir_ssa_def * so it can be passed to
 517  * nir_build_alu()-based builder calls.
 518  *
 519  * See nir_ssa_for_alu_src() for alu instructions.
 520  */
 521 static inline nir_ssa_def *
 522 nir_ssa_for_src(nir_builder *build, nir_src src, int num_components)
 523 {
 524    if (src.is_ssa && src.ssa->num_components == num_components)
 525       return src.ssa;
 526
 527    nir_alu_src alu = { NIR_SRC_INIT };
 528    alu.src = src;
 529    for (int j = 0; j < 4; j++)
 530       alu.swizzle[j] = j;
 531
 532    return nir_imov_alu(build, alu, num_components);
 533 }
 534
 535 /**
 536  * Similar to nir_ssa_for_src(), but for alu srcs, respecting the
 537  * nir_alu_src's swizzle.
 538  */
 539 static inline nir_ssa_def *
 540 nir_ssa_for_alu_src(nir_builder *build, nir_alu_instr *instr, unsigned srcn)
 541 {
 542    static uint8_t trivial_swizzle[NIR_MAX_VEC_COMPONENTS];
 543    for (int i = 0; i < NIR_MAX_VEC_COMPONENTS; ++i)
 544       trivial_swizzle[i] = i;
 545    nir_alu_src *src = &instr->src[srcn];
 546    unsigned num_components = nir_ssa_alu_instr_src_components(instr, srcn);
 547
 548    if (src->src.is_ssa && (src->src.ssa->num_components == num_components) &&
 549        !src->abs && !src->negate &&
 550        (memcmp(src->swizzle, trivial_swizzle, num_components) == 0))
 551       return src->src.ssa;
 552
 553    return nir_imov_alu(build, *src, num_components);
 554 }
 555
 556 static inline nir_deref_instr *
 557 nir_build_deref_var(nir_builder *build, nir_variable *var)
 558 {
 559    nir_deref_instr *deref =
 560       nir_deref_instr_create(build->shader, nir_deref_type_var);
 561
 562    deref->mode = var->data.mode;
 563    deref->type = var->type;
 564    deref->var = var;
 565
 566    nir_ssa_dest_init(&deref->instr, &deref->dest, 1, 32, NULL);
 567
 568    nir_builder_instr_insert(build, &deref->instr);
 569
 570    return deref;
 571 }
 572
 573 static inline nir_deref_instr *
 574 nir_build_deref_array(nir_builder *build, nir_deref_instr *parent,
 575                       nir_ssa_def *index)
 576 {
 577    assert(glsl_type_is_array(parent->type) ||
 578           glsl_type_is_matrix(parent->type) ||
 579           glsl_type_is_vector(parent->type));
 580
 581    nir_deref_instr *deref =
 582       nir_deref_instr_create(build->shader, nir_deref_type_array);
 583
 584    deref->mode = parent->mode;
 585    deref->type = glsl_get_array_element(parent->type);
 586    deref->parent = nir_src_for_ssa(&parent->dest.ssa);
 587    deref->arr.index = nir_src_for_ssa(index);
 588
 589    nir_ssa_dest_init(&deref->instr, &deref->dest,
 590                      parent->dest.ssa.num_components,
 591                      parent->dest.ssa.bit_size, NULL);
 592
 593    nir_builder_instr_insert(build, &deref->instr);
 594
 595    return deref;
 596 }
 597
 598 static inline nir_deref_instr *
 599 nir_build_deref_array_wildcard(nir_builder *build, nir_deref_instr *parent)
 600 {
 601    assert(glsl_type_is_array(parent->type) ||
 602           glsl_type_is_matrix(parent->type));
 603
 604    nir_deref_instr *deref =
 605       nir_deref_instr_create(build->shader, nir_deref_type_array_wildcard);
 606
 607    deref->mode = parent->mode;
 608    deref->type = glsl_get_array_element(parent->type);
 609    deref->parent = nir_src_for_ssa(&parent->dest.ssa);
 610
 611    nir_ssa_dest_init(&deref->instr, &deref->dest,
 612                      parent->dest.ssa.num_components,
 613                      parent->dest.ssa.bit_size, NULL);
 614
 615    nir_builder_instr_insert(build, &deref->instr);
 616
 617    return deref;
 618 }
 619
 620 static inline nir_deref_instr *
 621 nir_build_deref_struct(nir_builder *build, nir_deref_instr *parent,
 622                        unsigned index)
 623 {
 624    assert(glsl_type_is_struct(parent->type));
 625
 626    nir_deref_instr *deref =
 627       nir_deref_instr_create(build->shader, nir_deref_type_struct);
 628
 629    deref->mode = parent->mode;
 630    deref->type = glsl_get_struct_field(parent->type, index);
 631    deref->parent = nir_src_for_ssa(&parent->dest.ssa);
 632    deref->strct.index = index;
 633
 634    nir_ssa_dest_init(&deref->instr, &deref->dest,
 635                      parent->dest.ssa.num_components,
 636                      parent->dest.ssa.bit_size, NULL);
 637
 638    nir_builder_instr_insert(build, &deref->instr);
 639
 640    return deref;
 641 }
 642
 643 static inline nir_deref_instr *
 644 nir_build_deref_cast(nir_builder *build, nir_ssa_def *parent,
 645                      nir_variable_mode mode, const struct glsl_type *type)
 646 {
 647    nir_deref_instr *deref =
 648       nir_deref_instr_create(build->shader, nir_deref_type_cast);
 649
 650    deref->mode = mode;
 651    deref->type = type;
 652    deref->parent = nir_src_for_ssa(parent);
 653
 654    nir_ssa_dest_init(&deref->instr, &deref->dest,
 655                      parent->num_components, parent->bit_size, NULL);
 656
 657    nir_builder_instr_insert(build, &deref->instr);
 658
 659    return deref;
 660 }
 661
 662 /** Returns a deref that follows another but starting from the given parent
 663  *
 664  * The new deref will be the same type and take the same array or struct index
 665  * as the leader deref but it may have a different parent.  This is very
 666  * useful for walking deref paths.
 667  */
 668 static inline nir_deref_instr *
 669 nir_build_deref_follower(nir_builder *b, nir_deref_instr *parent,
 670                          nir_deref_instr *leader)
 671 {
 672    /* If the derefs would have the same parent, don't make a new one */
 673    assert(leader->parent.is_ssa);
 674    if (leader->parent.ssa == &parent->dest.ssa)
 675       return leader;
 676
 677    UNUSED nir_deref_instr *leader_parent = nir_src_as_deref(leader->parent);
 678
 679    switch (leader->deref_type) {
 680    case nir_deref_type_var:
 681       unreachable("A var dereference cannot have a parent");
 682       break;
 683
 684    case nir_deref_type_array:
 685    case nir_deref_type_array_wildcard:
 686       assert(glsl_type_is_matrix(parent->type) ||
 687              glsl_type_is_array(parent->type));
 688       assert(glsl_get_length(parent->type) ==
 689              glsl_get_length(leader_parent->type));
 690
 691       if (leader->deref_type == nir_deref_type_array) {
 692          assert(leader->arr.index.is_ssa);
 693          return nir_build_deref_array(b, parent, leader->arr.index.ssa);
 694       } else {
 695          return nir_build_deref_array_wildcard(b, parent);
 696       }
 697
 698    case nir_deref_type_struct:
 699       assert(glsl_type_is_struct(parent->type));
 700       assert(glsl_get_length(parent->type) ==
 701              glsl_get_length(leader_parent->type));
 702
 703       return nir_build_deref_struct(b, parent, leader->strct.index);
 704
 705    default:
 706       unreachable("Invalid deref instruction type");
 707    }
 708 }
 709
 710 static inline nir_ssa_def *
 711 nir_load_reg(nir_builder *build, nir_register *reg)
 712 {
 713    return nir_ssa_for_src(build, nir_src_for_reg(reg), reg->num_components);
 714 }
 715
 716 static inline nir_ssa_def *
 717 nir_load_deref(nir_builder *build, nir_deref_instr *deref)
 718 {
 719    nir_intrinsic_instr *load =
 720       nir_intrinsic_instr_create(build->shader, nir_intrinsic_load_deref);
 721    load->num_components = glsl_get_vector_elements(deref->type);
 722    load->src[0] = nir_src_for_ssa(&deref->dest.ssa);
 723    nir_ssa_dest_init(&load->instr, &load->dest, load->num_components,
 724                      glsl_get_bit_size(deref->type), NULL);
 725    nir_builder_instr_insert(build, &load->instr);
 726    return &load->dest.ssa;
 727 }
 728
 729 static inline void
 730 nir_store_deref(nir_builder *build, nir_deref_instr *deref,
 731                 nir_ssa_def *value, unsigned writemask)
 732 {
 733    nir_intrinsic_instr *store =
 734       nir_intrinsic_instr_create(build->shader, nir_intrinsic_store_deref);
 735    store->num_components = glsl_get_vector_elements(deref->type);
 736    store->src[0] = nir_src_for_ssa(&deref->dest.ssa);
 737    store->src[1] = nir_src_for_ssa(value);
 738    nir_intrinsic_set_write_mask(store,
 739                                 writemask & ((1 << store->num_components) - 1));
 740    nir_builder_instr_insert(build, &store->instr);
 741 }
 742
 743 static inline void
 744 nir_copy_deref(nir_builder *build, nir_deref_instr *dest, nir_deref_instr *src)
 745 {
 746    nir_intrinsic_instr *copy =
 747       nir_intrinsic_instr_create(build->shader, nir_intrinsic_copy_deref);
 748    copy->src[0] = nir_src_for_ssa(&dest->dest.ssa);
 749    copy->src[1] = nir_src_for_ssa(&src->dest.ssa);
 750    nir_builder_instr_insert(build, &copy->instr);
 751 }
 752
 753 static inline nir_ssa_def *
 754 nir_load_var(nir_builder *build, nir_variable *var)
 755 {
 756    return nir_load_deref(build, nir_build_deref_var(build, var));
 757 }
 758
 759 static inline void
 760 nir_store_var(nir_builder *build, nir_variable *var, nir_ssa_def *value,
 761               unsigned writemask)
 762 {
 763    nir_store_deref(build, nir_build_deref_var(build, var), value, writemask);
 764 }
 765
 766 static inline void
 767 nir_copy_var(nir_builder *build, nir_variable *dest, nir_variable *src)
 768 {
 769    nir_copy_deref(build, nir_build_deref_var(build, dest),
 770                          nir_build_deref_var(build, src));
 771 }
 772
 773 static inline nir_ssa_def *
 774 nir_load_param(nir_builder *build, uint32_t param_idx)
 775 {
 776    assert(param_idx < build->impl->function->num_params);
 777    nir_parameter *param = &build->impl->function->params[param_idx];
 778
 779    nir_intrinsic_instr *load =
 780       nir_intrinsic_instr_create(build->shader, nir_intrinsic_load_param);
 781    nir_intrinsic_set_param_idx(load, param_idx);
 782    load->num_components = param->num_components;
 783    nir_ssa_dest_init(&load->instr, &load->dest,
 784                      param->num_components, param->bit_size, NULL);
 785    nir_builder_instr_insert(build, &load->instr);
 786    return &load->dest.ssa;
 787 }
 788
 789 #include "nir_builder_opcodes.h"
 790
 791 static inline nir_ssa_def *
 792 nir_load_barycentric(nir_builder *build, nir_intrinsic_op op,
 793                      unsigned interp_mode)
 794 {
 795    nir_intrinsic_instr *bary = nir_intrinsic_instr_create(build->shader, op);
 796    nir_ssa_dest_init(&bary->instr, &bary->dest, 2, 32, NULL);
 797    nir_intrinsic_set_interp_mode(bary, interp_mode);
 798    nir_builder_instr_insert(build, &bary->instr);
 799    return &bary->dest.ssa;
 800 }
 801
 802 static inline void
 803 nir_jump(nir_builder *build, nir_jump_type jump_type)
 804 {
 805    nir_jump_instr *jump = nir_jump_instr_create(build->shader, jump_type);
 806    nir_builder_instr_insert(build, &jump->instr);
 807 }
 808
 809 static inline nir_ssa_def *
 810 nir_compare_func(nir_builder *b, enum compare_func func,
 811                  nir_ssa_def *src0, nir_ssa_def *src1)
 812 {
 813    switch (func) {
 814    case COMPARE_FUNC_NEVER:
 815       return nir_imm_int(b, 0);
 816    case COMPARE_FUNC_ALWAYS:
 817       return nir_imm_int(b, ~0);
 818    case COMPARE_FUNC_EQUAL:
 819       return nir_feq(b, src0, src1);
 820    case COMPARE_FUNC_NOTEQUAL:
 821       return nir_fne(b, src0, src1);
 822    case COMPARE_FUNC_GREATER:
 823       return nir_flt(b, src1, src0);
 824    case COMPARE_FUNC_GEQUAL:
 825       return nir_fge(b, src0, src1);
 826    case COMPARE_FUNC_LESS:
 827       return nir_flt(b, src0, src1);
 828    case COMPARE_FUNC_LEQUAL:
 829       return nir_fge(b, src1, src0);
 830    }
 831    unreachable("bad compare func");
 832 }
 833
 834 #endif /* NIR_BUILDER_H */