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 nir_ssa_def *
  85 nir_ssa_undef(nir_builder *build, unsigned num_components, unsigned bit_size)
  86 {
  87    nir_ssa_undef_instr *undef =
  88       nir_ssa_undef_instr_create(build->shader, num_components, bit_size);
  89    if (!undef)
  90       return NULL;
  91
  92    nir_instr_insert(nir_before_cf_list(&build->impl->body), &undef->instr);
  93
  94    return &undef->def;
  95 }
  96
  97 static inline nir_ssa_def *
  98 nir_build_imm(nir_builder *build, unsigned num_components,
  99               unsigned bit_size, nir_const_value value)
 100 {
 101    nir_load_const_instr *load_const =
 102       nir_load_const_instr_create(build->shader, num_components, bit_size);
 103    if (!load_const)
 104       return NULL;
 105
 106    load_const->value = value;
 107
 108    nir_builder_instr_insert(build, &load_const->instr);
 109
 110    return &load_const->def;
 111 }
 112
 113 static inline nir_ssa_def *
 114 nir_imm_float(nir_builder *build, float x)
 115 {
 116    nir_const_value v;
 117
 118    memset(&v, 0, sizeof(v));
 119    v.f32[0] = x;
 120
 121    return nir_build_imm(build, 1, 32, v);
 122 }
 123
 124 static inline nir_ssa_def *
 125 nir_imm_double(nir_builder *build, double x)
 126 {
 127    nir_const_value v;
 128
 129    memset(&v, 0, sizeof(v));
 130    v.f64[0] = x;
 131
 132    return nir_build_imm(build, 1, 64, v);
 133 }
 134
 135 static inline nir_ssa_def *
 136 nir_imm_vec4(nir_builder *build, float x, float y, float z, float w)
 137 {
 138    nir_const_value v;
 139
 140    memset(&v, 0, sizeof(v));
 141    v.f32[0] = x;
 142    v.f32[1] = y;
 143    v.f32[2] = z;
 144    v.f32[3] = w;
 145
 146    return nir_build_imm(build, 4, 32, v);
 147 }
 148
 149 static inline nir_ssa_def *
 150 nir_imm_int(nir_builder *build, int x)
 151 {
 152    nir_const_value v;
 153
 154    memset(&v, 0, sizeof(v));
 155    v.i32[0] = x;
 156
 157    return nir_build_imm(build, 1, 32, v);
 158 }
 159
 160 static inline nir_ssa_def *
 161 nir_imm_ivec4(nir_builder *build, int x, int y, int z, int w)
 162 {
 163    nir_const_value v;
 164
 165    memset(&v, 0, sizeof(v));
 166    v.i32[0] = x;
 167    v.i32[1] = y;
 168    v.i32[2] = z;
 169    v.i32[3] = w;
 170
 171    return nir_build_imm(build, 4, 32, v);
 172 }
 173
 174 static inline nir_ssa_def *
 175 nir_build_alu(nir_builder *build, nir_op op, nir_ssa_def *src0,
 176               nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)
 177 {
 178    const nir_op_info *op_info = &nir_op_infos[op];
 179    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
 180    if (!instr)
 181       return NULL;
 182
 183    instr->exact = build->exact;
 184
 185    instr->src[0].src = nir_src_for_ssa(src0);
 186    if (src1)
 187       instr->src[1].src = nir_src_for_ssa(src1);
 188    if (src2)
 189       instr->src[2].src = nir_src_for_ssa(src2);
 190    if (src3)
 191       instr->src[3].src = nir_src_for_ssa(src3);
 192
 193    /* Guess the number of components the destination temporary should have
 194     * based on our input sizes, if it's not fixed for the op.
 195     */
 196    unsigned num_components = op_info->output_size;
 197    if (num_components == 0) {
 198       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 199          if (op_info->input_sizes[i] == 0)
 200             num_components = MAX2(num_components,
 201                                   instr->src[i].src.ssa->num_components);
 202       }
 203    }
 204    assert(num_components != 0);
 205
 206    /* Figure out the bitwidth based on the source bitwidth if the instruction
 207     * is variable-width.
 208     */
 209    unsigned bit_size = nir_alu_type_get_type_size(op_info->output_type);
 210    if (bit_size == 0) {
 211       for (unsigned i = 0; i < op_info->num_inputs; i++) {
 212          unsigned src_bit_size = instr->src[i].src.ssa->bit_size;
 213          if (nir_alu_type_get_type_size(op_info->input_types[i]) == 0) {
 214             if (bit_size)
 215                assert(src_bit_size == bit_size);
 216             else
 217                bit_size = src_bit_size;
 218          } else {
 219             assert(src_bit_size ==
 220                nir_alu_type_get_type_size(op_info->input_types[i]));
 221          }
 222       }
 223    }
 224
 225    /* Make sure we don't swizzle from outside of our source vector (like if a
 226     * scalar value was passed into a multiply with a vector).
 227     */
 228    for (unsigned i = 0; i < op_info->num_inputs; i++) {
 229       for (unsigned j = instr->src[i].src.ssa->num_components; j < 4; j++) {
 230          instr->src[i].swizzle[j] = instr->src[i].src.ssa->num_components - 1;
 231       }
 232    }
 233
 234    nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components,
 235                      bit_size, NULL);
 236    instr->dest.write_mask = (1 << num_components) - 1;
 237
 238    nir_builder_instr_insert(build, &instr->instr);
 239
 240    return &instr->dest.dest.ssa;
 241 }
 242
 243 #include "nir_builder_opcodes.h"
 244
 245 static inline nir_ssa_def *
 246 nir_vec(nir_builder *build, nir_ssa_def **comp, unsigned num_components)
 247 {
 248    switch (num_components) {
 249    case 4:
 250       return nir_vec4(build, comp[0], comp[1], comp[2], comp[3]);
 251    case 3:
 252       return nir_vec3(build, comp[0], comp[1], comp[2]);
 253    case 2:
 254       return nir_vec2(build, comp[0], comp[1]);
 255    case 1:
 256       return comp[0];
 257    default:
 258       unreachable("bad component count");
 259       return NULL;
 260    }
 261 }
 262
 263 /**
 264  * Similar to nir_fmov, but takes a nir_alu_src instead of a nir_ssa_def.
 265  */
 266 static inline nir_ssa_def *
 267 nir_fmov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 268 {
 269    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_fmov);
 270    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components,
 271                      nir_src_bit_size(src.src), NULL);
 272    mov->exact = build->exact;
 273    mov->dest.write_mask = (1 << num_components) - 1;
 274    mov->src[0] = src;
 275    nir_builder_instr_insert(build, &mov->instr);
 276
 277    return &mov->dest.dest.ssa;
 278 }
 279
 280 static inline nir_ssa_def *
 281 nir_imov_alu(nir_builder *build, nir_alu_src src, unsigned num_components)
 282 {
 283    nir_alu_instr *mov = nir_alu_instr_create(build->shader, nir_op_imov);
 284    nir_ssa_dest_init(&mov->instr, &mov->dest.dest, num_components,
 285                      nir_src_bit_size(src.src), NULL);
 286    mov->exact = build->exact;
 287    mov->dest.write_mask = (1 << num_components) - 1;
 288    mov->src[0] = src;
 289    nir_builder_instr_insert(build, &mov->instr);
 290
 291    return &mov->dest.dest.ssa;
 292 }
 293
 294 /**
 295  * Construct an fmov or imov that reswizzles the source's components.
 296  */
 297 static inline nir_ssa_def *
 298 nir_swizzle(nir_builder *build, nir_ssa_def *src, const unsigned swiz[4],
 299             unsigned num_components, bool use_fmov)
 300 {
 301    nir_alu_src alu_src = { NIR_SRC_INIT };
 302    alu_src.src = nir_src_for_ssa(src);
 303    for (unsigned i = 0; i < num_components; i++)
 304       alu_src.swizzle[i] = swiz[i];
 305
 306    return use_fmov ? nir_fmov_alu(build, alu_src, num_components) :
 307                      nir_imov_alu(build, alu_src, num_components);
 308 }
 309
 310 /* Selects the right fdot given the number of components in each source. */
 311 static inline nir_ssa_def *
 312 nir_fdot(nir_builder *build, nir_ssa_def *src0, nir_ssa_def *src1)
 313 {
 314    assert(src0->num_components == src1->num_components);
 315    switch (src0->num_components) {
 316    case 1: return nir_fmul(build, src0, src1);
 317    case 2: return nir_fdot2(build, src0, src1);
 318    case 3: return nir_fdot3(build, src0, src1);
 319    case 4: return nir_fdot4(build, src0, src1);
 320    default:
 321       unreachable("bad component size");
 322    }
 323
 324    return NULL;
 325 }
 326
 327 static inline nir_ssa_def *
 328 nir_bany_inequal(nir_builder *b, nir_ssa_def *src0, nir_ssa_def *src1)
 329 {
 330    switch (src0->num_components) {
 331    case 1: return nir_ine(b, src0, src1);
 332    case 2: return nir_bany_inequal2(b, src0, src1);
 333    case 3: return nir_bany_inequal3(b, src0, src1);
 334    case 4: return nir_bany_inequal4(b, src0, src1);
 335    default:
 336       unreachable("bad component size");
 337    }
 338 }
 339
 340 static inline nir_ssa_def *
 341 nir_bany(nir_builder *b, nir_ssa_def *src)
 342 {
 343    return nir_bany_inequal(b, src, nir_imm_int(b, 0));
 344 }
 345
 346 static inline nir_ssa_def *
 347 nir_channel(nir_builder *b, nir_ssa_def *def, unsigned c)
 348 {
 349    unsigned swizzle[4] = {c, c, c, c};
 350    return nir_swizzle(b, def, swizzle, 1, false);
 351 }
 352
 353 static inline nir_ssa_def *
 354 nir_channels(nir_builder *b, nir_ssa_def *def, unsigned mask)
 355 {
 356    unsigned num_channels = 0, swizzle[4] = { 0, 0, 0, 0 };
 357
 358    for (unsigned i = 0; i < 4; i++) {
 359       if ((mask & (1 << i)) == 0)
 360          continue;
 361       swizzle[num_channels++] = i;
 362    }
 363
 364    return nir_swizzle(b, def, swizzle, num_channels, false);
 365 }
 366
 367 /**
 368  * Turns a nir_src into a nir_ssa_def * so it can be passed to
 369  * nir_build_alu()-based builder calls.
 370  *
 371  * See nir_ssa_for_alu_src() for alu instructions.
 372  */
 373 static inline nir_ssa_def *
 374 nir_ssa_for_src(nir_builder *build, nir_src src, int num_components)
 375 {
 376    if (src.is_ssa && src.ssa->num_components == num_components)
 377       return src.ssa;
 378
 379    nir_alu_src alu = { NIR_SRC_INIT };
 380    alu.src = src;
 381    for (int j = 0; j < 4; j++)
 382       alu.swizzle[j] = j;
 383
 384    return nir_imov_alu(build, alu, num_components);
 385 }
 386
 387 /**
 388  * Similar to nir_ssa_for_src(), but for alu src's, respecting the
 389  * nir_alu_src's swizzle.
 390  */
 391 static inline nir_ssa_def *
 392 nir_ssa_for_alu_src(nir_builder *build, nir_alu_instr *instr, unsigned srcn)
 393 {
 394    static uint8_t trivial_swizzle[4] = { 0, 1, 2, 3 };
 395    nir_alu_src *src = &instr->src[srcn];
 396    unsigned num_components = nir_ssa_alu_instr_src_components(instr, srcn);
 397
 398    if (src->src.is_ssa && (src->src.ssa->num_components == num_components) &&
 399        !src->abs && !src->negate &&
 400        (memcmp(src->swizzle, trivial_swizzle, num_components) == 0))
 401       return src->src.ssa;
 402
 403    return nir_imov_alu(build, *src, num_components);
 404 }
 405
 406 static inline nir_ssa_def *
 407 nir_load_var(nir_builder *build, nir_variable *var)
 408 {
 409    const unsigned num_components = glsl_get_vector_elements(var->type);
 410
 411    nir_intrinsic_instr *load =
 412       nir_intrinsic_instr_create(build->shader, nir_intrinsic_load_var);
 413    load->num_components = num_components;
 414    load->variables[0] = nir_deref_var_create(load, var);
 415    nir_ssa_dest_init(&load->instr, &load->dest, num_components,
 416                      glsl_get_bit_size(var->type), NULL);
 417    nir_builder_instr_insert(build, &load->instr);
 418    return &load->dest.ssa;
 419 }
 420
 421 static inline nir_ssa_def *
 422 nir_load_deref_var(nir_builder *build, nir_deref_var *deref)
 423 {
 424    const struct glsl_type *type = nir_deref_tail(&deref->deref)->type;
 425    const unsigned num_components = glsl_get_vector_elements(type);
 426
 427    nir_intrinsic_instr *load =
 428       nir_intrinsic_instr_create(build->shader, nir_intrinsic_load_var);
 429    load->num_components = num_components;
 430    load->variables[0] = nir_deref_var_clone(deref, load);
 431    nir_ssa_dest_init(&load->instr, &load->dest, num_components,
 432                      glsl_get_bit_size(type), NULL);
 433    nir_builder_instr_insert(build, &load->instr);
 434    return &load->dest.ssa;
 435 }
 436
 437 static inline void
 438 nir_store_var(nir_builder *build, nir_variable *var, nir_ssa_def *value,
 439               unsigned writemask)
 440 {
 441    const unsigned num_components = glsl_get_vector_elements(var->type);
 442
 443    nir_intrinsic_instr *store =
 444       nir_intrinsic_instr_create(build->shader, nir_intrinsic_store_var);
 445    store->num_components = num_components;
 446    nir_intrinsic_set_write_mask(store, writemask);
 447    store->variables[0] = nir_deref_var_create(store, var);
 448    store->src[0] = nir_src_for_ssa(value);
 449    nir_builder_instr_insert(build, &store->instr);
 450 }
 451
 452 static inline void
 453 nir_store_deref_var(nir_builder *build, nir_deref_var *deref,
 454                     nir_ssa_def *value, unsigned writemask)
 455 {
 456    const unsigned num_components =
 457       glsl_get_vector_elements(nir_deref_tail(&deref->deref)->type);
 458
 459    nir_intrinsic_instr *store =
 460       nir_intrinsic_instr_create(build->shader, nir_intrinsic_store_var);
 461    store->num_components = num_components;
 462    store->const_index[0] = writemask & ((1 << num_components) - 1);
 463    store->variables[0] = nir_deref_var_clone(deref, store);
 464    store->src[0] = nir_src_for_ssa(value);
 465    nir_builder_instr_insert(build, &store->instr);
 466 }
 467
 468 static inline void
 469 nir_copy_deref_var(nir_builder *build, nir_deref_var *dest, nir_deref_var *src)
 470 {
 471    assert(nir_deref_tail(&dest->deref)->type ==
 472           nir_deref_tail(&src->deref)->type);
 473
 474    nir_intrinsic_instr *copy =
 475       nir_intrinsic_instr_create(build->shader, nir_intrinsic_copy_var);
 476    copy->variables[0] = nir_deref_var_clone(dest, copy);
 477    copy->variables[1] = nir_deref_var_clone(src, copy);
 478    nir_builder_instr_insert(build, &copy->instr);
 479 }
 480
 481 static inline void
 482 nir_copy_var(nir_builder *build, nir_variable *dest, nir_variable *src)
 483 {
 484    nir_intrinsic_instr *copy =
 485       nir_intrinsic_instr_create(build->shader, nir_intrinsic_copy_var);
 486    copy->variables[0] = nir_deref_var_create(copy, dest);
 487    copy->variables[1] = nir_deref_var_create(copy, src);
 488    nir_builder_instr_insert(build, &copy->instr);
 489 }
 490
 491 /* Generic builder for system values. */
 492 static inline nir_ssa_def *
 493 nir_load_system_value(nir_builder *build, nir_intrinsic_op op, int index)
 494 {
 495    nir_intrinsic_instr *load = nir_intrinsic_instr_create(build->shader, op);
 496    load->num_components = nir_intrinsic_infos[op].dest_components;
 497    load->const_index[0] = index;
 498    nir_ssa_dest_init(&load->instr, &load->dest,
 499                      nir_intrinsic_infos[op].dest_components, 32, NULL);
 500    nir_builder_instr_insert(build, &load->instr);
 501    return &load->dest.ssa;
 502 }
 503
 504 /* Generate custom builders for system values. */
 505 #define INTRINSIC(name, num_srcs, src_components, has_dest, dest_components, \
 506                   num_variables, num_indices, idx0, idx1, idx2, flags)
 507 #define LAST_INTRINSIC(name)
 508
 509 #define DEFINE_SYSTEM_VALUE(name)                                        \
 510    static inline nir_ssa_def *                                           \
 511    nir_load_##name(nir_builder *build)                                   \
 512    {                                                                     \
 513       return nir_load_system_value(build, nir_intrinsic_load_##name, 0); \
 514    }                                                                     \
 515
 516 #include "nir_intrinsics.h"
 517
 518 static inline nir_ssa_def *
 519 nir_load_barycentric(nir_builder *build, nir_intrinsic_op op,
 520                      unsigned interp_mode)
 521 {
 522    nir_intrinsic_instr *bary = nir_intrinsic_instr_create(build->shader, op);
 523    nir_ssa_dest_init(&bary->instr, &bary->dest, 2, 32, NULL);
 524    nir_intrinsic_set_interp_mode(bary, interp_mode);
 525    nir_builder_instr_insert(build, &bary->instr);
 526    return &bary->dest.ssa;
 527 }
 528
 529 static inline void
 530 nir_jump(nir_builder *build, nir_jump_type jump_type)
 531 {
 532    nir_jump_instr *jump = nir_jump_instr_create(build->shader, jump_type);
 533    nir_builder_instr_insert(build, &jump->instr);
 534 }
 535
 536 #endif /* NIR_BUILDER_H */