1 /* 2 * Copyright 2012 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 21 * DEALINGS IN THE SOFTWARE. 22 */ 23 24 /** 25 * \file link_varyings.cpp 26 * 27 * Linker functions related specifically to linking varyings between shader 28 * stages. 29 */ 30 31 32 #include "main/mtypes.h" 33 #include "glsl_symbol_table.h" 34 #include "glsl_parser_extras.h" 35 #include "ir_optimization.h" 36 #include "linker.h" 37 #include "link_varyings.h" 38 #include "main/macros.h" 39 #include "util/hash_table.h" 40 #include "program.h" 41 42 43 /** 44 * Get the varying type stripped of the outermost array if we're processing 45 * a stage whose varyings are arrays indexed by a vertex number (such as 46 * geometry shader inputs). 47 */ 48 static const glsl_type * 49 get_varying_type(const ir_variable *var, gl_shader_stage stage) 50 { 51 const glsl_type *type = var->type; 52 53 if (!var->data.patch && 54 ((var->data.mode == ir_var_shader_out && 55 stage == MESA_SHADER_TESS_CTRL) || 56 (var->data.mode == ir_var_shader_in && 57 (stage == MESA_SHADER_TESS_CTRL || stage == MESA_SHADER_TESS_EVAL || 58 stage == MESA_SHADER_GEOMETRY)))) { 59 assert(type->is_array()); 60 type = type->fields.array; 61 } 62 63 return type; 64 } 65 66 static void 67 create_xfb_varying_names(void *mem_ctx, const glsl_type *t, char **name, 68 size_t name_length, unsigned *count, 69 const char *ifc_member_name, 70 const glsl_type *ifc_member_t, char ***varying_names) 71 { 72 if (t->is_interface()) { 73 size_t new_length = name_length; 74 75 assert(ifc_member_name && ifc_member_t); 76 ralloc_asprintf_rewrite_tail(name, &new_length, ".%s", ifc_member_name); 77 78 create_xfb_varying_names(mem_ctx, ifc_member_t, name, new_length, count, 79 NULL, NULL, varying_names); 80 } else if (t->is_record()) { 81 for (unsigned i = 0; i < t->length; i++) { 82 const char *field = t->fields.structure[i].name; 83 size_t new_length = name_length; 84 85 ralloc_asprintf_rewrite_tail(name, &new_length, ".%s", field); 86 87 create_xfb_varying_names(mem_ctx, t->fields.structure[i].type, name, 88 new_length, count, NULL, NULL, 89 varying_names); 90 } 91 } else if (t->without_array()->is_record() || 92 t->without_array()->is_interface() || 93 (t->is_array() && t->fields.array->is_array())) { 94 for (unsigned i = 0; i < t->length; i++) { 95 size_t new_length = name_length; 96 97 /* Append the subscript to the current variable name */ 98 ralloc_asprintf_rewrite_tail(name, &new_length, "[%u]", i); 99 100 create_xfb_varying_names(mem_ctx, t->fields.array, name, new_length, 101 count, ifc_member_name, ifc_member_t, 102 varying_names); 103 } 104 } else { 105 (*varying_names)[(*count)++] = ralloc_strdup(mem_ctx, *name); 106 } 107 } 108 109 static bool 110 process_xfb_layout_qualifiers(void *mem_ctx, const gl_linked_shader *sh, 111 struct gl_shader_program *prog, 112 unsigned *num_tfeedback_decls, 113 char ***varying_names) 114 { 115 bool has_xfb_qualifiers = false; 116 117 /* We still need to enable transform feedback mode even if xfb_stride is 118 * only applied to a global out. Also we don't bother to propagate 119 * xfb_stride to interface block members so this will catch that case also. 120 */ 121 for (unsigned j = 0; j < MAX_FEEDBACK_BUFFERS; j++) { 122 if (prog->TransformFeedback.BufferStride[j]) { 123 has_xfb_qualifiers = true; 124 break; 125 } 126 } 127 128 foreach_in_list(ir_instruction, node, sh->ir) { 129 ir_variable *var = node->as_variable(); 130 if (!var || var->data.mode != ir_var_shader_out) 131 continue; 132 133 /* From the ARB_enhanced_layouts spec: 134 * 135 * "Any shader making any static use (after preprocessing) of any of 136 * these *xfb_* qualifiers will cause the shader to be in a 137 * transform feedback capturing mode and hence responsible for 138 * describing the transform feedback setup. This mode will capture 139 * any output selected by *xfb_offset*, directly or indirectly, to 140 * a transform feedback buffer." 141 */ 142 if (var->data.explicit_xfb_buffer || var->data.explicit_xfb_stride) { 143 has_xfb_qualifiers = true; 144 } 145 146 if (var->data.explicit_xfb_offset) { 147 *num_tfeedback_decls += var->type->varying_count(); 148 has_xfb_qualifiers = true; 149 } 150 } 151 152 if (*num_tfeedback_decls == 0) 153 return has_xfb_qualifiers; 154 155 unsigned i = 0; 156 *varying_names = ralloc_array(mem_ctx, char *, *num_tfeedback_decls); 157 foreach_in_list(ir_instruction, node, sh->ir) { 158 ir_variable *var = node->as_variable(); 159 if (!var || var->data.mode != ir_var_shader_out) 160 continue; 161 162 if (var->data.explicit_xfb_offset) { 163 char *name; 164 const glsl_type *type, *member_type; 165 166 if (var->data.from_named_ifc_block) { 167 type = var->get_interface_type(); 168 169 /* Find the member type before it was altered by lowering */ 170 const glsl_type *type_wa = type->without_array(); 171 member_type = 172 type_wa->fields.structure[type_wa->field_index(var->name)].type; 173 name = ralloc_strdup(NULL, type_wa->name); 174 } else { 175 type = var->type; 176 member_type = NULL; 177 name = ralloc_strdup(NULL, var->name); 178 } 179 create_xfb_varying_names(mem_ctx, type, &name, strlen(name), &i, 180 var->name, member_type, varying_names); 181 ralloc_free(name); 182 } 183 } 184 185 assert(i == *num_tfeedback_decls); 186 return has_xfb_qualifiers; 187 } 188 189 /** 190 * Validate the types and qualifiers of an output from one stage against the 191 * matching input to another stage. 192 */ 193 static void 194 cross_validate_types_and_qualifiers(struct gl_context *ctx, 195 struct gl_shader_program *prog, 196 const ir_variable *input, 197 const ir_variable *output, 198 gl_shader_stage consumer_stage, 199 gl_shader_stage producer_stage) 200 { 201 /* Check that the types match between stages. 202 */ 203 const glsl_type *type_to_match = input->type; 204 205 /* VS -> GS, VS -> TCS, VS -> TES, TES -> GS */ 206 const bool extra_array_level = (producer_stage == MESA_SHADER_VERTEX && 207 consumer_stage != MESA_SHADER_FRAGMENT) || 208 consumer_stage == MESA_SHADER_GEOMETRY; 209 if (extra_array_level) { 210 assert(type_to_match->is_array()); 211 type_to_match = type_to_match->fields.array; 212 } 213 214 if (type_to_match != output->type) { 215 /* There is a bit of a special case for gl_TexCoord. This 216 * built-in is unsized by default. Applications that variable 217 * access it must redeclare it with a size. There is some 218 * language in the GLSL spec that implies the fragment shader 219 * and vertex shader do not have to agree on this size. Other 220 * driver behave this way, and one or two applications seem to 221 * rely on it. 222 * 223 * Neither declaration needs to be modified here because the array 224 * sizes are fixed later when update_array_sizes is called. 225 * 226 * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec: 227 * 228 * "Unlike user-defined varying variables, the built-in 229 * varying variables don't have a strict one-to-one 230 * correspondence between the vertex language and the 231 * fragment language." 232 */ 233 if (!output->type->is_array() || !is_gl_identifier(output->name)) { 234 linker_error(prog, 235 "%s shader output `%s' declared as type `%s', " 236 "but %s shader input declared as type `%s'\n", 237 _mesa_shader_stage_to_string(producer_stage), 238 output->name, 239 output->type->name, 240 _mesa_shader_stage_to_string(consumer_stage), 241 input->type->name); 242 return; 243 } 244 } 245 246 /* Check that all of the qualifiers match between stages. 247 */ 248 249 /* According to the OpenGL and OpenGLES GLSL specs, the centroid qualifier 250 * should match until OpenGL 4.3 and OpenGLES 3.1. The OpenGLES 3.0 251 * conformance test suite does not verify that the qualifiers must match. 252 * The deqp test suite expects the opposite (OpenGLES 3.1) behavior for 253 * OpenGLES 3.0 drivers, so we relax the checking in all cases. 254 */ 255 if (false /* always skip the centroid check */ && 256 prog->data->Version < (prog->IsES ? 310 : 430) && 257 input->data.centroid != output->data.centroid) { 258 linker_error(prog, 259 "%s shader output `%s' %s centroid qualifier, " 260 "but %s shader input %s centroid qualifier\n", 261 _mesa_shader_stage_to_string(producer_stage), 262 output->name, 263 (output->data.centroid) ? "has" : "lacks", 264 _mesa_shader_stage_to_string(consumer_stage), 265 (input->data.centroid) ? "has" : "lacks"); 266 return; 267 } 268 269 if (input->data.sample != output->data.sample) { 270 linker_error(prog, 271 "%s shader output `%s' %s sample qualifier, " 272 "but %s shader input %s sample qualifier\n", 273 _mesa_shader_stage_to_string(producer_stage), 274 output->name, 275 (output->data.sample) ? "has" : "lacks", 276 _mesa_shader_stage_to_string(consumer_stage), 277 (input->data.sample) ? "has" : "lacks"); 278 return; 279 } 280 281 if (input->data.patch != output->data.patch) { 282 linker_error(prog, 283 "%s shader output `%s' %s patch qualifier, " 284 "but %s shader input %s patch qualifier\n", 285 _mesa_shader_stage_to_string(producer_stage), 286 output->name, 287 (output->data.patch) ? "has" : "lacks", 288 _mesa_shader_stage_to_string(consumer_stage), 289 (input->data.patch) ? "has" : "lacks"); 290 return; 291 } 292 293 /* The GLSL 4.30 and GLSL ES 3.00 specifications say: 294 * 295 * "As only outputs need be declared with invariant, an output from 296 * one shader stage will still match an input of a subsequent stage 297 * without the input being declared as invariant." 298 * 299 * while GLSL 4.20 says: 300 * 301 * "For variables leaving one shader and coming into another shader, 302 * the invariant keyword has to be used in both shaders, or a link 303 * error will result." 304 * 305 * and GLSL ES 1.00 section 4.6.4 "Invariance and Linking" says: 306 * 307 * "The invariance of varyings that are declared in both the vertex 308 * and fragment shaders must match." 309 */ 310 if (input->data.invariant != output->data.invariant && 311 prog->data->Version < (prog->IsES ? 300 : 430)) { 312 linker_error(prog, 313 "%s shader output `%s' %s invariant qualifier, " 314 "but %s shader input %s invariant qualifier\n", 315 _mesa_shader_stage_to_string(producer_stage), 316 output->name, 317 (output->data.invariant) ? "has" : "lacks", 318 _mesa_shader_stage_to_string(consumer_stage), 319 (input->data.invariant) ? "has" : "lacks"); 320 return; 321 } 322 323 /* GLSL >= 4.40 removes text requiring interpolation qualifiers 324 * to match cross stage, they must only match within the same stage. 325 * 326 * From page 84 (page 90 of the PDF) of the GLSL 4.40 spec: 327 * 328 * "It is a link-time error if, within the same stage, the interpolation 329 * qualifiers of variables of the same name do not match. 330 * 331 * Section 4.3.9 (Interpolation) of the GLSL ES 3.00 spec says: 332 * 333 * "When no interpolation qualifier is present, smooth interpolation 334 * is used." 335 * 336 * So we match variables where one is smooth and the other has no explicit 337 * qualifier. 338 */ 339 unsigned input_interpolation = input->data.interpolation; 340 unsigned output_interpolation = output->data.interpolation; 341 if (prog->IsES) { 342 if (input_interpolation == INTERP_MODE_NONE) 343 input_interpolation = INTERP_MODE_SMOOTH; 344 if (output_interpolation == INTERP_MODE_NONE) 345 output_interpolation = INTERP_MODE_SMOOTH; 346 } 347 if (input_interpolation != output_interpolation && 348 prog->data->Version < 440) { 349 if (!ctx->Const.AllowGLSLCrossStageInterpolationMismatch) { 350 linker_error(prog, 351 "%s shader output `%s' specifies %s " 352 "interpolation qualifier, " 353 "but %s shader input specifies %s " 354 "interpolation qualifier\n", 355 _mesa_shader_stage_to_string(producer_stage), 356 output->name, 357 interpolation_string(output->data.interpolation), 358 _mesa_shader_stage_to_string(consumer_stage), 359 interpolation_string(input->data.interpolation)); 360 return; 361 } else { 362 linker_warning(prog, 363 "%s shader output `%s' specifies %s " 364 "interpolation qualifier, " 365 "but %s shader input specifies %s " 366 "interpolation qualifier\n", 367 _mesa_shader_stage_to_string(producer_stage), 368 output->name, 369 interpolation_string(output->data.interpolation), 370 _mesa_shader_stage_to_string(consumer_stage), 371 interpolation_string(input->data.interpolation)); 372 } 373 } 374 } 375 376 /** 377 * Validate front and back color outputs against single color input 378 */ 379 static void 380 cross_validate_front_and_back_color(struct gl_context *ctx, 381 struct gl_shader_program *prog, 382 const ir_variable *input, 383 const ir_variable *front_color, 384 const ir_variable *back_color, 385 gl_shader_stage consumer_stage, 386 gl_shader_stage producer_stage) 387 { 388 if (front_color != NULL && front_color->data.assigned) 389 cross_validate_types_and_qualifiers(ctx, prog, input, front_color, 390 consumer_stage, producer_stage); 391 392 if (back_color != NULL && back_color->data.assigned) 393 cross_validate_types_and_qualifiers(ctx, prog, input, back_color, 394 consumer_stage, producer_stage); 395 } 396 397 static unsigned 398 compute_variable_location_slot(ir_variable *var, gl_shader_stage stage) 399 { 400 unsigned location_start = VARYING_SLOT_VAR0; 401 402 switch (stage) { 403 case MESA_SHADER_VERTEX: 404 if (var->data.mode == ir_var_shader_in) 405 location_start = VERT_ATTRIB_GENERIC0; 406 break; 407 case MESA_SHADER_TESS_CTRL: 408 case MESA_SHADER_TESS_EVAL: 409 if (var->data.patch) 410 location_start = VARYING_SLOT_PATCH0; 411 break; 412 case MESA_SHADER_FRAGMENT: 413 if (var->data.mode == ir_var_shader_out) 414 location_start = FRAG_RESULT_DATA0; 415 break; 416 default: 417 break; 418 } 419 420 return var->data.location - location_start; 421 } 422 423 struct explicit_location_info { 424 ir_variable *var; 425 unsigned numerical_type; 426 unsigned interpolation; 427 bool centroid; 428 bool sample; 429 bool patch; 430 }; 431 432 static inline unsigned 433 get_numerical_type(const glsl_type *type) 434 { 435 /* From the OpenGL 4.6 spec, section 4.4.1 Input Layout Qualifiers, Page 68, 436 * (Location aliasing): 437 * 438 * "Further, when location aliasing, the aliases sharing the location 439 * must have the same underlying numerical type (floating-point or 440 * integer) 441 */ 442 if (type->is_float() || type->is_double()) 443 return GLSL_TYPE_FLOAT; 444 return GLSL_TYPE_INT; 445 } 446 447 static bool 448 check_location_aliasing(struct explicit_location_info explicit_locations[][4], 449 ir_variable *var, 450 unsigned location, 451 unsigned component, 452 unsigned location_limit, 453 const glsl_type *type, 454 unsigned interpolation, 455 bool centroid, 456 bool sample, 457 bool patch, 458 gl_shader_program *prog, 459 gl_shader_stage stage) 460 { 461 unsigned last_comp; 462 if (type->without_array()->is_record()) { 463 /* The component qualifier can't be used on structs so just treat 464 * all component slots as used. 465 */ 466 last_comp = 4; 467 } else { 468 unsigned dmul = type->without_array()->is_64bit() ? 2 : 1; 469 last_comp = component + type->without_array()->vector_elements * dmul; 470 } 471 472 while (location < location_limit) { 473 unsigned comp = 0; 474 while (comp < 4) { 475 struct explicit_location_info *info = 476 &explicit_locations[location][comp]; 477 478 if (info->var) { 479 /* Component aliasing is not alloed */ 480 if (comp >= component && comp < last_comp) { 481 linker_error(prog, 482 "%s shader has multiple outputs explicitly " 483 "assigned to location %d and component %d\n", 484 _mesa_shader_stage_to_string(stage), 485 location, comp); 486 return false; 487 } else { 488 /* For all other used components we need to have matching 489 * types, interpolation and auxiliary storage 490 */ 491 if (info->numerical_type != 492 get_numerical_type(type->without_array())) { 493 linker_error(prog, 494 "Varyings sharing the same location must " 495 "have the same underlying numerical type. " 496 "Location %u component %u\n", 497 location, comp); 498 return false; 499 } 500 501 if (info->interpolation != interpolation) { 502 linker_error(prog, 503 "%s shader has multiple outputs at explicit " 504 "location %u with different interpolation " 505 "settings\n", 506 _mesa_shader_stage_to_string(stage), location); 507 return false; 508 } 509 510 if (info->centroid != centroid || 511 info->sample != sample || 512 info->patch != patch) { 513 linker_error(prog, 514 "%s shader has multiple outputs at explicit " 515 "location %u with different aux storage\n", 516 _mesa_shader_stage_to_string(stage), location); 517 return false; 518 } 519 } 520 } else if (comp >= component && comp < last_comp) { 521 info->var = var; 522 info->numerical_type = get_numerical_type(type->without_array()); 523 info->interpolation = interpolation; 524 info->centroid = centroid; 525 info->sample = sample; 526 info->patch = patch; 527 } 528 529 comp++; 530 531 /* We need to do some special handling for doubles as dvec3 and 532 * dvec4 consume two consecutive locations. We don't need to 533 * worry about components beginning at anything other than 0 as 534 * the spec does not allow this for dvec3 and dvec4. 535 */ 536 if (comp == 4 && last_comp > 4) { 537 last_comp = last_comp - 4; 538 /* Bump location index and reset the component index */ 539 location++; 540 comp = 0; 541 component = 0; 542 } 543 } 544 545 location++; 546 } 547 548 return true; 549 } 550 551 static bool 552 validate_explicit_variable_location(struct gl_context *ctx, 553 struct explicit_location_info explicit_locations[][4], 554 ir_variable *var, 555 gl_shader_program *prog, 556 gl_linked_shader *sh) 557 { 558 const glsl_type *type = get_varying_type(var, sh->Stage); 559 unsigned num_elements = type->count_attribute_slots(false); 560 unsigned idx = compute_variable_location_slot(var, sh->Stage); 561 unsigned slot_limit = idx + num_elements; 562 563 /* Vertex shader inputs and fragment shader outputs are validated in 564 * assign_attribute_or_color_locations() so we should not attempt to 565 * validate them again here. 566 */ 567 unsigned slot_max; 568 if (var->data.mode == ir_var_shader_out) { 569 assert(sh->Stage != MESA_SHADER_FRAGMENT); 570 slot_max = 571 ctx->Const.Program[sh->Stage].MaxOutputComponents / 4; 572 } else { 573 assert(var->data.mode == ir_var_shader_in); 574 assert(sh->Stage != MESA_SHADER_VERTEX); 575 slot_max = 576 ctx->Const.Program[sh->Stage].MaxInputComponents / 4; 577 } 578 579 if (slot_limit > slot_max) { 580 linker_error(prog, 581 "Invalid location %u in %s shader\n", 582 idx, _mesa_shader_stage_to_string(sh->Stage)); 583 return false; 584 } 585 586 const glsl_type *type_without_array = type->without_array(); 587 if (type_without_array->is_interface()) { 588 for (unsigned i = 0; i < type_without_array->length; i++) { 589 glsl_struct_field *field = &type_without_array->fields.structure[i]; 590 unsigned field_location = field->location - 591 (field->patch ? VARYING_SLOT_PATCH0 : VARYING_SLOT_VAR0); 592 if (!check_location_aliasing(explicit_locations, var, 593 field_location, 594 0, field_location + 1, 595 field->type, 596 field->interpolation, 597 field->centroid, 598 field->sample, 599 field->patch, 600 prog, sh->Stage)) { 601 return false; 602 } 603 } 604 } else if (!check_location_aliasing(explicit_locations, var, 605 idx, var->data.location_frac, 606 slot_limit, type, 607 var->data.interpolation, 608 var->data.centroid, 609 var->data.sample, 610 var->data.patch, 611 prog, sh->Stage)) { 612 return false; 613 } 614 615 return true; 616 } 617 618 /** 619 * Validate explicit locations for the inputs to the first stage and the 620 * outputs of the last stage in an SSO program (everything in between is 621 * validated in cross_validate_outputs_to_inputs). 622 */ 623 void 624 validate_sso_explicit_locations(struct gl_context *ctx, 625 struct gl_shader_program *prog, 626 gl_shader_stage first_stage, 627 gl_shader_stage last_stage) 628 { 629 assert(prog->SeparateShader); 630 631 /* VS inputs and FS outputs are validated in 632 * assign_attribute_or_color_locations() 633 */ 634 bool validate_first_stage = first_stage != MESA_SHADER_VERTEX; 635 bool validate_last_stage = last_stage != MESA_SHADER_FRAGMENT; 636 if (!validate_first_stage && !validate_last_stage) 637 return; 638 639 struct explicit_location_info explicit_locations[MAX_VARYING][4]; 640 641 gl_shader_stage stages[2] = { first_stage, last_stage }; 642 bool validate_stage[2] = { validate_first_stage, validate_last_stage }; 643 ir_variable_mode var_direction[2] = { ir_var_shader_in, ir_var_shader_out }; 644 645 for (unsigned i = 0; i < 2; i++) { 646 if (!validate_stage[i]) 647 continue; 648 649 gl_shader_stage stage = stages[i]; 650 651 gl_linked_shader *sh = prog->_LinkedShaders[stage]; 652 assert(sh); 653 654 memset(explicit_locations, 0, sizeof(explicit_locations)); 655 656 foreach_in_list(ir_instruction, node, sh->ir) { 657 ir_variable *const var = node->as_variable(); 658 659 if (var == NULL || 660 !var->data.explicit_location || 661 var->data.location < VARYING_SLOT_VAR0 || 662 var->data.mode != var_direction[i]) 663 continue; 664 665 if (!validate_explicit_variable_location( 666 ctx, explicit_locations, var, prog, sh)) { 667 return; 668 } 669 } 670 } 671 } 672 673 /** 674 * Validate that outputs from one stage match inputs of another 675 */ 676 void 677 cross_validate_outputs_to_inputs(struct gl_context *ctx, 678 struct gl_shader_program *prog, 679 gl_linked_shader *producer, 680 gl_linked_shader *consumer) 681 { 682 glsl_symbol_table parameters; 683 struct explicit_location_info explicit_locations[MAX_VARYING][4] = { 0 }; 684 685 /* Find all shader outputs in the "producer" stage. 686 */ 687 foreach_in_list(ir_instruction, node, producer->ir) { 688 ir_variable *const var = node->as_variable(); 689 690 if (var == NULL || var->data.mode != ir_var_shader_out) 691 continue; 692 693 if (!var->data.explicit_location 694 || var->data.location < VARYING_SLOT_VAR0) 695 parameters.add_variable(var); 696 else { 697 /* User-defined varyings with explicit locations are handled 698 * differently because they do not need to have matching names. 699 */ 700 if (!validate_explicit_variable_location(ctx, 701 explicit_locations, 702 var, prog, producer)) { 703 return; 704 } 705 } 706 } 707 708 709 /* Find all shader inputs in the "consumer" stage. Any variables that have 710 * matching outputs already in the symbol table must have the same type and 711 * qualifiers. 712 * 713 * Exception: if the consumer is the geometry shader, then the inputs 714 * should be arrays and the type of the array element should match the type 715 * of the corresponding producer output. 716 */ 717 foreach_in_list(ir_instruction, node, consumer->ir) { 718 ir_variable *const input = node->as_variable(); 719 720 if (input == NULL || input->data.mode != ir_var_shader_in) 721 continue; 722 723 if (strcmp(input->name, "gl_Color") == 0 && input->data.used) { 724 const ir_variable *const front_color = 725 parameters.get_variable("gl_FrontColor"); 726 727 const ir_variable *const back_color = 728 parameters.get_variable("gl_BackColor"); 729 730 cross_validate_front_and_back_color(ctx, prog, input, 731 front_color, back_color, 732 consumer->Stage, producer->Stage); 733 } else if (strcmp(input->name, "gl_SecondaryColor") == 0 && input->data.used) { 734 const ir_variable *const front_color = 735 parameters.get_variable("gl_FrontSecondaryColor"); 736 737 const ir_variable *const back_color = 738 parameters.get_variable("gl_BackSecondaryColor"); 739 740 cross_validate_front_and_back_color(ctx, prog, input, 741 front_color, back_color, 742 consumer->Stage, producer->Stage); 743 } else { 744 /* The rules for connecting inputs and outputs change in the presence 745 * of explicit locations. In this case, we no longer care about the 746 * names of the variables. Instead, we care only about the 747 * explicitly assigned location. 748 */ 749 ir_variable *output = NULL; 750 if (input->data.explicit_location 751 && input->data.location >= VARYING_SLOT_VAR0) { 752 753 const glsl_type *type = get_varying_type(input, consumer->Stage); 754 unsigned num_elements = type->count_attribute_slots(false); 755 unsigned idx = 756 compute_variable_location_slot(input, consumer->Stage); 757 unsigned slot_limit = idx + num_elements; 758 759 while (idx < slot_limit) { 760 if (idx >= MAX_VARYING) { 761 linker_error(prog, 762 "Invalid location %u in %s shader\n", idx, 763 _mesa_shader_stage_to_string(consumer->Stage)); 764 return; 765 } 766 767 output = explicit_locations[idx][input->data.location_frac].var; 768 769 if (output == NULL || 770 input->data.location != output->data.location) { 771 linker_error(prog, 772 "%s shader input `%s' with explicit location " 773 "has no matching output\n", 774 _mesa_shader_stage_to_string(consumer->Stage), 775 input->name); 776 break; 777 } 778 idx++; 779 } 780 } else { 781 output = parameters.get_variable(input->name); 782 } 783 784 if (output != NULL) { 785 /* Interface blocks have their own validation elsewhere so don't 786 * try validating them here. 787 */ 788 if (!(input->get_interface_type() && 789 output->get_interface_type())) 790 cross_validate_types_and_qualifiers(ctx, prog, input, output, 791 consumer->Stage, 792 producer->Stage); 793 } else { 794 /* Check for input vars with unmatched output vars in prev stage 795 * taking into account that interface blocks could have a matching 796 * output but with different name, so we ignore them. 797 */ 798 assert(!input->data.assigned); 799 if (input->data.used && !input->get_interface_type() && 800 !input->data.explicit_location && !prog->SeparateShader) 801 linker_error(prog, 802 "%s shader input `%s' " 803 "has no matching output in the previous stage\n", 804 _mesa_shader_stage_to_string(consumer->Stage), 805 input->name); 806 } 807 } 808 } 809 } 810 811 /** 812 * Demote shader inputs and outputs that are not used in other stages, and 813 * remove them via dead code elimination. 814 */ 815 static void 816 remove_unused_shader_inputs_and_outputs(bool is_separate_shader_object, 817 gl_linked_shader *sh, 818 enum ir_variable_mode mode) 819 { 820 if (is_separate_shader_object) 821 return; 822 823 foreach_in_list(ir_instruction, node, sh->ir) { 824 ir_variable *const var = node->as_variable(); 825 826 if (var == NULL || var->data.mode != int(mode)) 827 continue; 828 829 /* A shader 'in' or 'out' variable is only really an input or output if 830 * its value is used by other shader stages. This will cause the 831 * variable to have a location assigned. 832 */ 833 if (var->data.is_unmatched_generic_inout && !var->data.is_xfb_only) { 834 assert(var->data.mode != ir_var_temporary); 835 836 /* Assign zeros to demoted inputs to allow more optimizations. */ 837 if (var->data.mode == ir_var_shader_in && !var->constant_value) 838 var->constant_value = ir_constant::zero(var, var->type); 839 840 var->data.mode = ir_var_auto; 841 } 842 } 843 844 /* Eliminate code that is now dead due to unused inputs/outputs being 845 * demoted. 846 */ 847 while (do_dead_code(sh->ir, false)) 848 ; 849 850 } 851 852 /** 853 * Initialize this object based on a string that was passed to 854 * glTransformFeedbackVaryings. 855 * 856 * If the input is mal-formed, this call still succeeds, but it sets 857 * this->var_name to a mal-formed input, so tfeedback_decl::find_output_var() 858 * will fail to find any matching variable. 859 */ 860 void 861 tfeedback_decl::init(struct gl_context *ctx, const void *mem_ctx, 862 const char *input) 863 { 864 /* We don't have to be pedantic about what is a valid GLSL variable name, 865 * because any variable with an invalid name can't exist in the IR anyway. 866 */ 867 868 this->location = -1; 869 this->orig_name = input; 870 this->lowered_builtin_array_variable = none; 871 this->skip_components = 0; 872 this->next_buffer_separator = false; 873 this->matched_candidate = NULL; 874 this->stream_id = 0; 875 this->buffer = 0; 876 this->offset = 0; 877 878 if (ctx->Extensions.ARB_transform_feedback3) { 879 /* Parse gl_NextBuffer. */ 880 if (strcmp(input, "gl_NextBuffer") == 0) { 881 this->next_buffer_separator = true; 882 return; 883 } 884 885 /* Parse gl_SkipComponents. */ 886 if (strcmp(input, "gl_SkipComponents1") == 0) 887 this->skip_components = 1; 888 else if (strcmp(input, "gl_SkipComponents2") == 0) 889 this->skip_components = 2; 890 else if (strcmp(input, "gl_SkipComponents3") == 0) 891 this->skip_components = 3; 892 else if (strcmp(input, "gl_SkipComponents4") == 0) 893 this->skip_components = 4; 894 895 if (this->skip_components) 896 return; 897 } 898 899 /* Parse a declaration. */ 900 const char *base_name_end; 901 long subscript = parse_program_resource_name(input, &base_name_end); 902 this->var_name = ralloc_strndup(mem_ctx, input, base_name_end - input); 903 if (this->var_name == NULL) { 904 _mesa_error_no_memory(__func__); 905 return; 906 } 907 908 if (subscript >= 0) { 909 this->array_subscript = subscript; 910 this->is_subscripted = true; 911 } else { 912 this->is_subscripted = false; 913 } 914 915 /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this 916 * class must behave specially to account for the fact that gl_ClipDistance 917 * is converted from a float[8] to a vec4[2]. 918 */ 919 if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerCombinedClipCullDistance && 920 strcmp(this->var_name, "gl_ClipDistance") == 0) { 921 this->lowered_builtin_array_variable = clip_distance; 922 } 923 if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerCombinedClipCullDistance && 924 strcmp(this->var_name, "gl_CullDistance") == 0) { 925 this->lowered_builtin_array_variable = cull_distance; 926 } 927 928 if (ctx->Const.LowerTessLevel && 929 (strcmp(this->var_name, "gl_TessLevelOuter") == 0)) 930 this->lowered_builtin_array_variable = tess_level_outer; 931 if (ctx->Const.LowerTessLevel && 932 (strcmp(this->var_name, "gl_TessLevelInner") == 0)) 933 this->lowered_builtin_array_variable = tess_level_inner; 934 } 935 936 937 /** 938 * Determine whether two tfeedback_decl objects refer to the same variable and 939 * array index (if applicable). 940 */ 941 bool 942 tfeedback_decl::is_same(const tfeedback_decl &x, const tfeedback_decl &y) 943 { 944 assert(x.is_varying() && y.is_varying()); 945 946 if (strcmp(x.var_name, y.var_name) != 0) 947 return false; 948 if (x.is_subscripted != y.is_subscripted) 949 return false; 950 if (x.is_subscripted && x.array_subscript != y.array_subscript) 951 return false; 952 return true; 953 } 954 955 956 /** 957 * Assign a location and stream ID for this tfeedback_decl object based on the 958 * transform feedback candidate found by find_candidate. 959 * 960 * If an error occurs, the error is reported through linker_error() and false 961 * is returned. 962 */ 963 bool 964 tfeedback_decl::assign_location(struct gl_context *ctx, 965 struct gl_shader_program *prog) 966 { 967 assert(this->is_varying()); 968 969 unsigned fine_location 970 = this->matched_candidate->toplevel_var->data.location * 4 971 + this->matched_candidate->toplevel_var->data.location_frac 972 + this->matched_candidate->offset; 973 const unsigned dmul = 974 this->matched_candidate->type->without_array()->is_64bit() ? 2 : 1; 975 976 if (this->matched_candidate->type->is_array()) { 977 /* Array variable */ 978 const unsigned matrix_cols = 979 this->matched_candidate->type->fields.array->matrix_columns; 980 const unsigned vector_elements = 981 this->matched_candidate->type->fields.array->vector_elements; 982 unsigned actual_array_size; 983 switch (this->lowered_builtin_array_variable) { 984 case clip_distance: 985 actual_array_size = prog->last_vert_prog ? 986 prog->last_vert_prog->info.clip_distance_array_size : 0; 987 break; 988 case cull_distance: 989 actual_array_size = prog->last_vert_prog ? 990 prog->last_vert_prog->info.cull_distance_array_size : 0; 991 break; 992 case tess_level_outer: 993 actual_array_size = 4; 994 break; 995 case tess_level_inner: 996 actual_array_size = 2; 997 break; 998 case none: 999 default: 1000 actual_array_size = this->matched_candidate->type->array_size(); 1001 break; 1002 } 1003 1004 if (this->is_subscripted) { 1005 /* Check array bounds. */ 1006 if (this->array_subscript >= actual_array_size) { 1007 linker_error(prog, "Transform feedback varying %s has index " 1008 "%i, but the array size is %u.", 1009 this->orig_name, this->array_subscript, 1010 actual_array_size); 1011 return false; 1012 } 1013 unsigned array_elem_size = this->lowered_builtin_array_variable ? 1014 1 : vector_elements * matrix_cols * dmul; 1015 fine_location += array_elem_size * this->array_subscript; 1016 this->size = 1; 1017 } else { 1018 this->size = actual_array_size; 1019 } 1020 this->vector_elements = vector_elements; 1021 this->matrix_columns = matrix_cols; 1022 if (this->lowered_builtin_array_variable) 1023 this->type = GL_FLOAT; 1024 else 1025 this->type = this->matched_candidate->type->fields.array->gl_type; 1026 } else { 1027 /* Regular variable (scalar, vector, or matrix) */ 1028 if (this->is_subscripted) { 1029 linker_error(prog, "Transform feedback varying %s requested, " 1030 "but %s is not an array.", 1031 this->orig_name, this->var_name); 1032 return false; 1033 } 1034 this->size = 1; 1035 this->vector_elements = this->matched_candidate->type->vector_elements; 1036 this->matrix_columns = this->matched_candidate->type->matrix_columns; 1037 this->type = this->matched_candidate->type->gl_type; 1038 } 1039 this->location = fine_location / 4; 1040 this->location_frac = fine_location % 4; 1041 1042 /* From GL_EXT_transform_feedback: 1043 * A program will fail to link if: 1044 * 1045 * * the total number of components to capture in any varying 1046 * variable in <varyings> is greater than the constant 1047 * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the 1048 * buffer mode is SEPARATE_ATTRIBS_EXT; 1049 */ 1050 if (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS && 1051 this->num_components() > 1052 ctx->Const.MaxTransformFeedbackSeparateComponents) { 1053 linker_error(prog, "Transform feedback varying %s exceeds " 1054 "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.", 1055 this->orig_name); 1056 return false; 1057 } 1058 1059 /* Only transform feedback varyings can be assigned to non-zero streams, 1060 * so assign the stream id here. 1061 */ 1062 this->stream_id = this->matched_candidate->toplevel_var->data.stream; 1063 1064 unsigned array_offset = this->array_subscript * 4 * dmul; 1065 unsigned struct_offset = this->matched_candidate->offset * 4 * dmul; 1066 this->buffer = this->matched_candidate->toplevel_var->data.xfb_buffer; 1067 this->offset = this->matched_candidate->toplevel_var->data.offset + 1068 array_offset + struct_offset; 1069 1070 return true; 1071 } 1072 1073 1074 unsigned 1075 tfeedback_decl::get_num_outputs() const 1076 { 1077 if (!this->is_varying()) { 1078 return 0; 1079 } 1080 return (this->num_components() + this->location_frac + 3)/4; 1081 } 1082 1083 1084 /** 1085 * Update gl_transform_feedback_info to reflect this tfeedback_decl. 1086 * 1087 * If an error occurs, the error is reported through linker_error() and false 1088 * is returned. 1089 */ 1090 bool 1091 tfeedback_decl::store(struct gl_context *ctx, struct gl_shader_program *prog, 1092 struct gl_transform_feedback_info *info, 1093 unsigned buffer, unsigned buffer_index, 1094 const unsigned max_outputs, bool *explicit_stride, 1095 bool has_xfb_qualifiers) const 1096 { 1097 unsigned xfb_offset = 0; 1098 unsigned size = this->size; 1099 /* Handle gl_SkipComponents. */ 1100 if (this->skip_components) { 1101 info->Buffers[buffer].Stride += this->skip_components; 1102 size = this->skip_components; 1103 goto store_varying; 1104 } 1105 1106 if (this->next_buffer_separator) { 1107 size = 0; 1108 goto store_varying; 1109 } 1110 1111 if (has_xfb_qualifiers) { 1112 xfb_offset = this->offset / 4; 1113 } else { 1114 xfb_offset = info->Buffers[buffer].Stride; 1115 } 1116 info->Varyings[info->NumVarying].Offset = xfb_offset * 4; 1117 1118 { 1119 unsigned location = this->location; 1120 unsigned location_frac = this->location_frac; 1121 unsigned num_components = this->num_components(); 1122 while (num_components > 0) { 1123 unsigned output_size = MIN2(num_components, 4 - location_frac); 1124 assert((info->NumOutputs == 0 && max_outputs == 0) || 1125 info->NumOutputs < max_outputs); 1126 1127 /* From the ARB_enhanced_layouts spec: 1128 * 1129 * "If such a block member or variable is not written during a shader 1130 * invocation, the buffer contents at the assigned offset will be 1131 * undefined. Even if there are no static writes to a variable or 1132 * member that is assigned a transform feedback offset, the space is 1133 * still allocated in the buffer and still affects the stride." 1134 */ 1135 if (this->is_varying_written()) { 1136 info->Outputs[info->NumOutputs].ComponentOffset = location_frac; 1137 info->Outputs[info->NumOutputs].OutputRegister = location; 1138 info->Outputs[info->NumOutputs].NumComponents = output_size; 1139 info->Outputs[info->NumOutputs].StreamId = stream_id; 1140 info->Outputs[info->NumOutputs].OutputBuffer = buffer; 1141 info->Outputs[info->NumOutputs].DstOffset = xfb_offset; 1142 ++info->NumOutputs; 1143 } 1144 info->Buffers[buffer].Stream = this->stream_id; 1145 xfb_offset += output_size; 1146 1147 num_components -= output_size; 1148 location++; 1149 location_frac = 0; 1150 } 1151 } 1152 1153 if (explicit_stride && explicit_stride[buffer]) { 1154 if (this->is_64bit() && info->Buffers[buffer].Stride % 2) { 1155 linker_error(prog, "invalid qualifier xfb_stride=%d must be a " 1156 "multiple of 8 as its applied to a type that is or " 1157 "contains a double.", 1158 info->Buffers[buffer].Stride * 4); 1159 return false; 1160 } 1161 1162 if ((this->offset / 4) / info->Buffers[buffer].Stride != 1163 (xfb_offset - 1) / info->Buffers[buffer].Stride) { 1164 linker_error(prog, "xfb_offset (%d) overflows xfb_stride (%d) for " 1165 "buffer (%d)", xfb_offset * 4, 1166 info->Buffers[buffer].Stride * 4, buffer); 1167 return false; 1168 } 1169 } else { 1170 info->Buffers[buffer].Stride = xfb_offset; 1171 } 1172 1173 /* From GL_EXT_transform_feedback: 1174 * A program will fail to link if: 1175 * 1176 * * the total number of components to capture is greater than 1177 * the constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT 1178 * and the buffer mode is INTERLEAVED_ATTRIBS_EXT. 1179 * 1180 * From GL_ARB_enhanced_layouts: 1181 * 1182 * "The resulting stride (implicit or explicit) must be less than or 1183 * equal to the implementation-dependent constant 1184 * gl_MaxTransformFeedbackInterleavedComponents." 1185 */ 1186 if ((prog->TransformFeedback.BufferMode == GL_INTERLEAVED_ATTRIBS || 1187 has_xfb_qualifiers) && 1188 info->Buffers[buffer].Stride > 1189 ctx->Const.MaxTransformFeedbackInterleavedComponents) { 1190 linker_error(prog, "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS " 1191 "limit has been exceeded."); 1192 return false; 1193 } 1194 1195 store_varying: 1196 info->Varyings[info->NumVarying].Name = ralloc_strdup(prog, 1197 this->orig_name); 1198 info->Varyings[info->NumVarying].Type = this->type; 1199 info->Varyings[info->NumVarying].Size = size; 1200 info->Varyings[info->NumVarying].BufferIndex = buffer_index; 1201 info->NumVarying++; 1202 info->Buffers[buffer].NumVaryings++; 1203 1204 return true; 1205 } 1206 1207 1208 const tfeedback_candidate * 1209 tfeedback_decl::find_candidate(gl_shader_program *prog, 1210 hash_table *tfeedback_candidates) 1211 { 1212 const char *name = this->var_name; 1213 switch (this->lowered_builtin_array_variable) { 1214 case none: 1215 name = this->var_name; 1216 break; 1217 case clip_distance: 1218 name = "gl_ClipDistanceMESA"; 1219 break; 1220 case cull_distance: 1221 name = "gl_CullDistanceMESA"; 1222 break; 1223 case tess_level_outer: 1224 name = "gl_TessLevelOuterMESA"; 1225 break; 1226 case tess_level_inner: 1227 name = "gl_TessLevelInnerMESA"; 1228 break; 1229 } 1230 hash_entry *entry = _mesa_hash_table_search(tfeedback_candidates, name); 1231 1232 this->matched_candidate = entry ? 1233 (const tfeedback_candidate *) entry->data : NULL; 1234 1235 if (!this->matched_candidate) { 1236 /* From GL_EXT_transform_feedback: 1237 * A program will fail to link if: 1238 * 1239 * * any variable name specified in the <varyings> array is not 1240 * declared as an output in the geometry shader (if present) or 1241 * the vertex shader (if no geometry shader is present); 1242 */ 1243 linker_error(prog, "Transform feedback varying %s undeclared.", 1244 this->orig_name); 1245 } 1246 1247 return this->matched_candidate; 1248 } 1249 1250 1251 /** 1252 * Parse all the transform feedback declarations that were passed to 1253 * glTransformFeedbackVaryings() and store them in tfeedback_decl objects. 1254 * 1255 * If an error occurs, the error is reported through linker_error() and false 1256 * is returned. 1257 */ 1258 static bool 1259 parse_tfeedback_decls(struct gl_context *ctx, struct gl_shader_program *prog, 1260 const void *mem_ctx, unsigned num_names, 1261 char **varying_names, tfeedback_decl *decls) 1262 { 1263 for (unsigned i = 0; i < num_names; ++i) { 1264 decls[i].init(ctx, mem_ctx, varying_names[i]); 1265 1266 if (!decls[i].is_varying()) 1267 continue; 1268 1269 /* From GL_EXT_transform_feedback: 1270 * A program will fail to link if: 1271 * 1272 * * any two entries in the <varyings> array specify the same varying 1273 * variable; 1274 * 1275 * We interpret this to mean "any two entries in the <varyings> array 1276 * specify the same varying variable and array index", since transform 1277 * feedback of arrays would be useless otherwise. 1278 */ 1279 for (unsigned j = 0; j < i; ++j) { 1280 if (decls[j].is_varying()) { 1281 if (tfeedback_decl::is_same(decls[i], decls[j])) { 1282 linker_error(prog, "Transform feedback varying %s specified " 1283 "more than once.", varying_names[i]); 1284 return false; 1285 } 1286 } 1287 } 1288 } 1289 return true; 1290 } 1291 1292 1293 static int 1294 cmp_xfb_offset(const void * x_generic, const void * y_generic) 1295 { 1296 tfeedback_decl *x = (tfeedback_decl *) x_generic; 1297 tfeedback_decl *y = (tfeedback_decl *) y_generic; 1298 1299 if (x->get_buffer() != y->get_buffer()) 1300 return x->get_buffer() - y->get_buffer(); 1301 return x->get_offset() - y->get_offset(); 1302 } 1303 1304 /** 1305 * Store transform feedback location assignments into 1306 * prog->sh.LinkedTransformFeedback based on the data stored in 1307 * tfeedback_decls. 1308 * 1309 * If an error occurs, the error is reported through linker_error() and false 1310 * is returned. 1311 */ 1312 static bool 1313 store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog, 1314 unsigned num_tfeedback_decls, 1315 tfeedback_decl *tfeedback_decls, bool has_xfb_qualifiers) 1316 { 1317 if (!prog->last_vert_prog) 1318 return true; 1319 1320 /* Make sure MaxTransformFeedbackBuffers is less than 32 so the bitmask for 1321 * tracking the number of buffers doesn't overflow. 1322 */ 1323 assert(ctx->Const.MaxTransformFeedbackBuffers < 32); 1324 1325 bool separate_attribs_mode = 1326 prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS; 1327 1328 struct gl_program *xfb_prog = prog->last_vert_prog; 1329 xfb_prog->sh.LinkedTransformFeedback = 1330 rzalloc(xfb_prog, struct gl_transform_feedback_info); 1331 1332 /* The xfb_offset qualifier does not have to be used in increasing order 1333 * however some drivers expect to receive the list of transform feedback 1334 * declarations in order so sort it now for convenience. 1335 */ 1336 if (has_xfb_qualifiers) { 1337 qsort(tfeedback_decls, num_tfeedback_decls, sizeof(*tfeedback_decls), 1338 cmp_xfb_offset); 1339 } else { 1340 xfb_prog->sh.LinkedTransformFeedback->api_enabled = true; 1341 } 1342 1343 xfb_prog->sh.LinkedTransformFeedback->Varyings = 1344 rzalloc_array(xfb_prog, struct gl_transform_feedback_varying_info, 1345 num_tfeedback_decls); 1346 1347 unsigned num_outputs = 0; 1348 for (unsigned i = 0; i < num_tfeedback_decls; ++i) { 1349 if (tfeedback_decls[i].is_varying_written()) 1350 num_outputs += tfeedback_decls[i].get_num_outputs(); 1351 } 1352 1353 xfb_prog->sh.LinkedTransformFeedback->Outputs = 1354 rzalloc_array(xfb_prog, struct gl_transform_feedback_output, 1355 num_outputs); 1356 1357 unsigned num_buffers = 0; 1358 unsigned buffers = 0; 1359 1360 if (!has_xfb_qualifiers && separate_attribs_mode) { 1361 /* GL_SEPARATE_ATTRIBS */ 1362 for (unsigned i = 0; i < num_tfeedback_decls; ++i) { 1363 if (!tfeedback_decls[i].store(ctx, prog, 1364 xfb_prog->sh.LinkedTransformFeedback, 1365 num_buffers, num_buffers, num_outputs, 1366 NULL, has_xfb_qualifiers)) 1367 return false; 1368 1369 buffers |= 1 << num_buffers; 1370 num_buffers++; 1371 } 1372 } 1373 else { 1374 /* GL_INVERLEAVED_ATTRIBS */ 1375 int buffer_stream_id = -1; 1376 unsigned buffer = 1377 num_tfeedback_decls ? tfeedback_decls[0].get_buffer() : 0; 1378 bool explicit_stride[MAX_FEEDBACK_BUFFERS] = { false }; 1379 1380 /* Apply any xfb_stride global qualifiers */ 1381 if (has_xfb_qualifiers) { 1382 for (unsigned j = 0; j < MAX_FEEDBACK_BUFFERS; j++) { 1383 if (prog->TransformFeedback.BufferStride[j]) { 1384 explicit_stride[j] = true; 1385 xfb_prog->sh.LinkedTransformFeedback->Buffers[j].Stride = 1386 prog->TransformFeedback.BufferStride[j] / 4; 1387 } 1388 } 1389 } 1390 1391 for (unsigned i = 0; i < num_tfeedback_decls; ++i) { 1392 if (has_xfb_qualifiers && 1393 buffer != tfeedback_decls[i].get_buffer()) { 1394 /* we have moved to the next buffer so reset stream id */ 1395 buffer_stream_id = -1; 1396 num_buffers++; 1397 } 1398 1399 if (tfeedback_decls[i].is_next_buffer_separator()) { 1400 if (!tfeedback_decls[i].store(ctx, prog, 1401 xfb_prog->sh.LinkedTransformFeedback, 1402 buffer, num_buffers, num_outputs, 1403 explicit_stride, has_xfb_qualifiers)) 1404 return false; 1405 num_buffers++; 1406 buffer_stream_id = -1; 1407 continue; 1408 } 1409 1410 if (has_xfb_qualifiers) { 1411 buffer = tfeedback_decls[i].get_buffer(); 1412 } else { 1413 buffer = num_buffers; 1414 } 1415 1416 if (tfeedback_decls[i].is_varying()) { 1417 if (buffer_stream_id == -1) { 1418 /* First varying writing to this buffer: remember its stream */ 1419 buffer_stream_id = (int) tfeedback_decls[i].get_stream_id(); 1420 1421 /* Only mark a buffer as active when there is a varying 1422 * attached to it. This behaviour is based on a revised version 1423 * of section 13.2.2 of the GL 4.6 spec. 1424 */ 1425 buffers |= 1 << buffer; 1426 } else if (buffer_stream_id != 1427 (int) tfeedback_decls[i].get_stream_id()) { 1428 /* Varying writes to the same buffer from a different stream */ 1429 linker_error(prog, 1430 "Transform feedback can't capture varyings belonging " 1431 "to different vertex streams in a single buffer. " 1432 "Varying %s writes to buffer from stream %u, other " 1433 "varyings in the same buffer write from stream %u.", 1434 tfeedback_decls[i].name(), 1435 tfeedback_decls[i].get_stream_id(), 1436 buffer_stream_id); 1437 return false; 1438 } 1439 } 1440 1441 if (!tfeedback_decls[i].store(ctx, prog, 1442 xfb_prog->sh.LinkedTransformFeedback, 1443 buffer, num_buffers, num_outputs, 1444 explicit_stride, has_xfb_qualifiers)) 1445 return false; 1446 } 1447 } 1448 1449 assert(xfb_prog->sh.LinkedTransformFeedback->NumOutputs == num_outputs); 1450 1451 xfb_prog->sh.LinkedTransformFeedback->ActiveBuffers = buffers; 1452 return true; 1453 } 1454 1455 namespace { 1456 1457 /** 1458 * Data structure recording the relationship between outputs of one shader 1459 * stage (the "producer") and inputs of another (the "consumer"). 1460 */ 1461 class varying_matches 1462 { 1463 public: 1464 varying_matches(bool disable_varying_packing, bool xfb_enabled, 1465 bool enhanced_layouts_enabled, 1466 gl_shader_stage producer_stage, 1467 gl_shader_stage consumer_stage); 1468 ~varying_matches(); 1469 void record(ir_variable *producer_var, ir_variable *consumer_var); 1470 unsigned assign_locations(struct gl_shader_program *prog, 1471 uint8_t components[], 1472 uint64_t reserved_slots); 1473 void store_locations() const; 1474 1475 private: 1476 bool is_varying_packing_safe(const glsl_type *type, 1477 const ir_variable *var) const; 1478 1479 /** 1480 * If true, this driver disables varying packing, so all varyings need to 1481 * be aligned on slot boundaries, and take up a number of slots equal to 1482 * their number of matrix columns times their array size. 1483 * 1484 * Packing may also be disabled because our current packing method is not 1485 * safe in SSO or versions of OpenGL where interpolation qualifiers are not 1486 * guaranteed to match across stages. 1487 */ 1488 const bool disable_varying_packing; 1489 1490 /** 1491 * If true, this driver has transform feedback enabled. The transform 1492 * feedback code requires at least some packing be done even when varying 1493 * packing is disabled, fortunately where transform feedback requires 1494 * packing it's safe to override the disabled setting. See 1495 * is_varying_packing_safe(). 1496 */ 1497 const bool xfb_enabled; 1498 1499 const bool enhanced_layouts_enabled; 1500 1501 /** 1502 * Enum representing the order in which varyings are packed within a 1503 * packing class. 1504 * 1505 * Currently we pack vec4's first, then vec2's, then scalar values, then 1506 * vec3's. This order ensures that the only vectors that are at risk of 1507 * having to be "double parked" (split between two adjacent varying slots) 1508 * are the vec3's. 1509 */ 1510 enum packing_order_enum { 1511 PACKING_ORDER_VEC4, 1512 PACKING_ORDER_VEC2, 1513 PACKING_ORDER_SCALAR, 1514 PACKING_ORDER_VEC3, 1515 }; 1516 1517 static unsigned compute_packing_class(const ir_variable *var); 1518 static packing_order_enum compute_packing_order(const ir_variable *var); 1519 static int match_comparator(const void *x_generic, const void *y_generic); 1520 static int xfb_comparator(const void *x_generic, const void *y_generic); 1521 1522 /** 1523 * Structure recording the relationship between a single producer output 1524 * and a single consumer input. 1525 */ 1526 struct match { 1527 /** 1528 * Packing class for this varying, computed by compute_packing_class(). 1529 */ 1530 unsigned packing_class; 1531 1532 /** 1533 * Packing order for this varying, computed by compute_packing_order(). 1534 */ 1535 packing_order_enum packing_order; 1536 unsigned num_components; 1537 1538 /** 1539 * The output variable in the producer stage. 1540 */ 1541 ir_variable *producer_var; 1542 1543 /** 1544 * The input variable in the consumer stage. 1545 */ 1546 ir_variable *consumer_var; 1547 1548 /** 1549 * The location which has been assigned for this varying. This is 1550 * expressed in multiples of a float, with the first generic varying 1551 * (i.e. the one referred to by VARYING_SLOT_VAR0) represented by the 1552 * value 0. 1553 */ 1554 unsigned generic_location; 1555 } *matches; 1556 1557 /** 1558 * The number of elements in the \c matches array that are currently in 1559 * use. 1560 */ 1561 unsigned num_matches; 1562 1563 /** 1564 * The number of elements that were set aside for the \c matches array when 1565 * it was allocated. 1566 */ 1567 unsigned matches_capacity; 1568 1569 gl_shader_stage producer_stage; 1570 gl_shader_stage consumer_stage; 1571 }; 1572 1573 } /* anonymous namespace */ 1574 1575 varying_matches::varying_matches(bool disable_varying_packing, 1576 bool xfb_enabled, 1577 bool enhanced_layouts_enabled, 1578 gl_shader_stage producer_stage, 1579 gl_shader_stage consumer_stage) 1580 : disable_varying_packing(disable_varying_packing), 1581 xfb_enabled(xfb_enabled), 1582 enhanced_layouts_enabled(enhanced_layouts_enabled), 1583 producer_stage(producer_stage), 1584 consumer_stage(consumer_stage) 1585 { 1586 /* Note: this initial capacity is rather arbitrarily chosen to be large 1587 * enough for many cases without wasting an unreasonable amount of space. 1588 * varying_matches::record() will resize the array if there are more than 1589 * this number of varyings. 1590 */ 1591 this->matches_capacity = 8; 1592 this->matches = (match *) 1593 malloc(sizeof(*this->matches) * this->matches_capacity); 1594 this->num_matches = 0; 1595 } 1596 1597 1598 varying_matches::~varying_matches() 1599 { 1600 free(this->matches); 1601 } 1602 1603 1604 /** 1605 * Packing is always safe on individual arrays, structures, and matrices. It 1606 * is also safe if the varying is only used for transform feedback. 1607 */ 1608 bool 1609 varying_matches::is_varying_packing_safe(const glsl_type *type, 1610 const ir_variable *var) const 1611 { 1612 if (consumer_stage == MESA_SHADER_TESS_EVAL || 1613 consumer_stage == MESA_SHADER_TESS_CTRL || 1614 producer_stage == MESA_SHADER_TESS_CTRL) 1615 return false; 1616 1617 return xfb_enabled && (type->is_array() || type->is_record() || 1618 type->is_matrix() || var->data.is_xfb_only); 1619 } 1620 1621 1622 /** 1623 * Record the given producer/consumer variable pair in the list of variables 1624 * that should later be assigned locations. 1625 * 1626 * It is permissible for \c consumer_var to be NULL (this happens if a 1627 * variable is output by the producer and consumed by transform feedback, but 1628 * not consumed by the consumer). 1629 * 1630 * If \c producer_var has already been paired up with a consumer_var, or 1631 * producer_var is part of fixed pipeline functionality (and hence already has 1632 * a location assigned), this function has no effect. 1633 * 1634 * Note: as a side effect this function may change the interpolation type of 1635 * \c producer_var, but only when the change couldn't possibly affect 1636 * rendering. 1637 */ 1638 void 1639 varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var) 1640 { 1641 assert(producer_var != NULL || consumer_var != NULL); 1642 1643 if ((producer_var && (!producer_var->data.is_unmatched_generic_inout || 1644 producer_var->data.explicit_location)) || 1645 (consumer_var && (!consumer_var->data.is_unmatched_generic_inout || 1646 consumer_var->data.explicit_location))) { 1647 /* Either a location already exists for this variable (since it is part 1648 * of fixed functionality), or it has already been recorded as part of a 1649 * previous match. 1650 */ 1651 return; 1652 } 1653 1654 bool needs_flat_qualifier = consumer_var == NULL && 1655 (producer_var->type->contains_integer() || 1656 producer_var->type->contains_double()); 1657 1658 if (!disable_varying_packing && 1659 (needs_flat_qualifier || 1660 (consumer_stage != MESA_SHADER_NONE && consumer_stage != MESA_SHADER_FRAGMENT))) { 1661 /* Since this varying is not being consumed by the fragment shader, its 1662 * interpolation type varying cannot possibly affect rendering. 1663 * Also, this variable is non-flat and is (or contains) an integer 1664 * or a double. 1665 * If the consumer stage is unknown, don't modify the interpolation 1666 * type as it could affect rendering later with separate shaders. 1667 * 1668 * lower_packed_varyings requires all integer varyings to flat, 1669 * regardless of where they appear. We can trivially satisfy that 1670 * requirement by changing the interpolation type to flat here. 1671 */ 1672 if (producer_var) { 1673 producer_var->data.centroid = false; 1674 producer_var->data.sample = false; 1675 producer_var->data.interpolation = INTERP_MODE_FLAT; 1676 } 1677 1678 if (consumer_var) { 1679 consumer_var->data.centroid = false; 1680 consumer_var->data.sample = false; 1681 consumer_var->data.interpolation = INTERP_MODE_FLAT; 1682 } 1683 } 1684 1685 if (this->num_matches == this->matches_capacity) { 1686 this->matches_capacity *= 2; 1687 this->matches = (match *) 1688 realloc(this->matches, 1689 sizeof(*this->matches) * this->matches_capacity); 1690 } 1691 1692 /* We must use the consumer to compute the packing class because in GL4.4+ 1693 * there is no guarantee interpolation qualifiers will match across stages. 1694 * 1695 * From Section 4.5 (Interpolation Qualifiers) of the GLSL 4.30 spec: 1696 * 1697 * "The type and presence of interpolation qualifiers of variables with 1698 * the same name declared in all linked shaders for the same cross-stage 1699 * interface must match, otherwise the link command will fail. 1700 * 1701 * When comparing an output from one stage to an input of a subsequent 1702 * stage, the input and output don't match if their interpolation 1703 * qualifiers (or lack thereof) are not the same." 1704 * 1705 * This text was also in at least revison 7 of the 4.40 spec but is no 1706 * longer in revision 9 and not in the 4.50 spec. 1707 */ 1708 const ir_variable *const var = (consumer_var != NULL) 1709 ? consumer_var : producer_var; 1710 const gl_shader_stage stage = (consumer_var != NULL) 1711 ? consumer_stage : producer_stage; 1712 const glsl_type *type = get_varying_type(var, stage); 1713 1714 if (producer_var && consumer_var && 1715 consumer_var->data.must_be_shader_input) { 1716 producer_var->data.must_be_shader_input = 1; 1717 } 1718 1719 this->matches[this->num_matches].packing_class 1720 = this->compute_packing_class(var); 1721 this->matches[this->num_matches].packing_order 1722 = this->compute_packing_order(var); 1723 if ((this->disable_varying_packing && !is_varying_packing_safe(type, var)) || 1724 var->data.must_be_shader_input) { 1725 unsigned slots = type->count_attribute_slots(false); 1726 this->matches[this->num_matches].num_components = slots * 4; 1727 } else { 1728 this->matches[this->num_matches].num_components 1729 = type->component_slots(); 1730 } 1731 1732 this->matches[this->num_matches].producer_var = producer_var; 1733 this->matches[this->num_matches].consumer_var = consumer_var; 1734 this->num_matches++; 1735 if (producer_var) 1736 producer_var->data.is_unmatched_generic_inout = 0; 1737 if (consumer_var) 1738 consumer_var->data.is_unmatched_generic_inout = 0; 1739 } 1740 1741 1742 /** 1743 * Choose locations for all of the variable matches that were previously 1744 * passed to varying_matches::record(). 1745 * \param components returns array[slot] of number of components used 1746 * per slot (1, 2, 3 or 4) 1747 * \param reserved_slots bitmask indicating which varying slots are already 1748 * allocated 1749 * \return number of slots (4-element vectors) allocated 1750 */ 1751 unsigned 1752 varying_matches::assign_locations(struct gl_shader_program *prog, 1753 uint8_t components[], 1754 uint64_t reserved_slots) 1755 { 1756 /* If packing has been disabled then we cannot safely sort the varyings by 1757 * class as it may mean we are using a version of OpenGL where 1758 * interpolation qualifiers are not guaranteed to be matching across 1759 * shaders, sorting in this case could result in mismatching shader 1760 * interfaces. 1761 * When packing is disabled the sort orders varyings used by transform 1762 * feedback first, but also depends on *undefined behaviour* of qsort to 1763 * reverse the order of the varyings. See: xfb_comparator(). 1764 */ 1765 if (!this->disable_varying_packing) { 1766 /* Sort varying matches into an order that makes them easy to pack. */ 1767 qsort(this->matches, this->num_matches, sizeof(*this->matches), 1768 &varying_matches::match_comparator); 1769 } else { 1770 /* Only sort varyings that are only used by transform feedback. */ 1771 qsort(this->matches, this->num_matches, sizeof(*this->matches), 1772 &varying_matches::xfb_comparator); 1773 } 1774 1775 unsigned generic_location = 0; 1776 unsigned generic_patch_location = MAX_VARYING*4; 1777 bool previous_var_xfb_only = false; 1778 unsigned previous_packing_class = ~0u; 1779 1780 /* For tranform feedback separate mode, we know the number of attributes 1781 * is <= the number of buffers. So packing isn't critical. In fact, 1782 * packing vec3 attributes can cause trouble because splitting a vec3 1783 * effectively creates an additional transform feedback output. The 1784 * extra TFB output may exceed device driver limits. 1785 */ 1786 const bool dont_pack_vec3 = 1787 (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS && 1788 prog->TransformFeedback.NumVarying > 0); 1789 1790 for (unsigned i = 0; i < this->num_matches; i++) { 1791 unsigned *location = &generic_location; 1792 const ir_variable *var; 1793 const glsl_type *type; 1794 bool is_vertex_input = false; 1795 1796 if (matches[i].consumer_var) { 1797 var = matches[i].consumer_var; 1798 type = get_varying_type(var, consumer_stage); 1799 if (consumer_stage == MESA_SHADER_VERTEX) 1800 is_vertex_input = true; 1801 } else { 1802 var = matches[i].producer_var; 1803 type = get_varying_type(var, producer_stage); 1804 } 1805 1806 if (var->data.patch) 1807 location = &generic_patch_location; 1808 1809 /* Advance to the next slot if this varying has a different packing 1810 * class than the previous one, and we're not already on a slot 1811 * boundary. 1812 * 1813 * Also advance to the next slot if packing is disabled. This makes sure 1814 * we don't assign varyings the same locations which is possible 1815 * because we still pack individual arrays, records and matrices even 1816 * when packing is disabled. Note we don't advance to the next slot if 1817 * we can pack varyings together that are only used for transform 1818 * feedback. 1819 */ 1820 if (var->data.must_be_shader_input || 1821 (this->disable_varying_packing && 1822 !(previous_var_xfb_only && var->data.is_xfb_only)) || 1823 (previous_packing_class != this->matches[i].packing_class) || 1824 (this->matches[i].packing_order == PACKING_ORDER_VEC3 && 1825 dont_pack_vec3)) { 1826 *location = ALIGN(*location, 4); 1827 } 1828 1829 previous_var_xfb_only = var->data.is_xfb_only; 1830 previous_packing_class = this->matches[i].packing_class; 1831 1832 /* The number of components taken up by this variable. For vertex shader 1833 * inputs, we use the number of slots * 4, as they have different 1834 * counting rules. 1835 */ 1836 unsigned num_components = is_vertex_input ? 1837 type->count_attribute_slots(is_vertex_input) * 4 : 1838 this->matches[i].num_components; 1839 1840 /* The last slot for this variable, inclusive. */ 1841 unsigned slot_end = *location + num_components - 1; 1842 1843 /* FIXME: We could be smarter in the below code and loop back over 1844 * trying to fill any locations that we skipped because we couldn't pack 1845 * the varying between an explicit location. For now just let the user 1846 * hit the linking error if we run out of room and suggest they use 1847 * explicit locations. 1848 */ 1849 while (slot_end < MAX_VARYING * 4u) { 1850 const unsigned slots = (slot_end / 4u) - (*location / 4u) + 1; 1851 const uint64_t slot_mask = ((1ull << slots) - 1) << (*location / 4u); 1852 1853 assert(slots > 0); 1854 1855 if ((reserved_slots & slot_mask) == 0) { 1856 break; 1857 } 1858 1859 *location = ALIGN(*location + 1, 4); 1860 slot_end = *location + num_components - 1; 1861 } 1862 1863 if (!var->data.patch && slot_end >= MAX_VARYING * 4u) { 1864 linker_error(prog, "insufficient contiguous locations available for " 1865 "%s it is possible an array or struct could not be " 1866 "packed between varyings with explicit locations. Try " 1867 "using an explicit location for arrays and structs.", 1868 var->name); 1869 } 1870 1871 if (slot_end < MAX_VARYINGS_INCL_PATCH * 4u) { 1872 for (unsigned j = *location / 4u; j < slot_end / 4u; j++) 1873 components[j] = 4; 1874 components[slot_end / 4u] = (slot_end & 3) + 1; 1875 } 1876 1877 this->matches[i].generic_location = *location; 1878 1879 *location = slot_end + 1; 1880 } 1881 1882 return (generic_location + 3) / 4; 1883 } 1884 1885 1886 /** 1887 * Update the producer and consumer shaders to reflect the locations 1888 * assignments that were made by varying_matches::assign_locations(). 1889 */ 1890 void 1891 varying_matches::store_locations() const 1892 { 1893 /* Check is location needs to be packed with lower_packed_varyings() or if 1894 * we can just use ARB_enhanced_layouts packing. 1895 */ 1896 bool pack_loc[MAX_VARYINGS_INCL_PATCH] = { 0 }; 1897 const glsl_type *loc_type[MAX_VARYINGS_INCL_PATCH][4] = { {NULL, NULL} }; 1898 1899 for (unsigned i = 0; i < this->num_matches; i++) { 1900 ir_variable *producer_var = this->matches[i].producer_var; 1901 ir_variable *consumer_var = this->matches[i].consumer_var; 1902 unsigned generic_location = this->matches[i].generic_location; 1903 unsigned slot = generic_location / 4; 1904 unsigned offset = generic_location % 4; 1905 1906 if (producer_var) { 1907 producer_var->data.location = VARYING_SLOT_VAR0 + slot; 1908 producer_var->data.location_frac = offset; 1909 } 1910 1911 if (consumer_var) { 1912 assert(consumer_var->data.location == -1); 1913 consumer_var->data.location = VARYING_SLOT_VAR0 + slot; 1914 consumer_var->data.location_frac = offset; 1915 } 1916 1917 /* Find locations suitable for native packing via 1918 * ARB_enhanced_layouts. 1919 */ 1920 if (producer_var && consumer_var) { 1921 if (enhanced_layouts_enabled) { 1922 const glsl_type *type = 1923 get_varying_type(producer_var, producer_stage); 1924 if (type->is_array() || type->is_matrix() || type->is_record() || 1925 type->is_double()) { 1926 unsigned comp_slots = type->component_slots() + offset; 1927 unsigned slots = comp_slots / 4; 1928 if (comp_slots % 4) 1929 slots += 1; 1930 1931 for (unsigned j = 0; j < slots; j++) { 1932 pack_loc[slot + j] = true; 1933 } 1934 } else if (offset + type->vector_elements > 4) { 1935 pack_loc[slot] = true; 1936 pack_loc[slot + 1] = true; 1937 } else { 1938 loc_type[slot][offset] = type; 1939 } 1940 } 1941 } 1942 } 1943 1944 /* Attempt to use ARB_enhanced_layouts for more efficient packing if 1945 * suitable. 1946 */ 1947 if (enhanced_layouts_enabled) { 1948 for (unsigned i = 0; i < this->num_matches; i++) { 1949 ir_variable *producer_var = this->matches[i].producer_var; 1950 ir_variable *consumer_var = this->matches[i].consumer_var; 1951 unsigned generic_location = this->matches[i].generic_location; 1952 unsigned slot = generic_location / 4; 1953 1954 if (pack_loc[slot] || !producer_var || !consumer_var) 1955 continue; 1956 1957 const glsl_type *type = 1958 get_varying_type(producer_var, producer_stage); 1959 bool type_match = true; 1960 for (unsigned j = 0; j < 4; j++) { 1961 if (loc_type[slot][j]) { 1962 if (type->base_type != loc_type[slot][j]->base_type) 1963 type_match = false; 1964 } 1965 } 1966 1967 if (type_match) { 1968 producer_var->data.explicit_location = 1; 1969 consumer_var->data.explicit_location = 1; 1970 producer_var->data.explicit_component = 1; 1971 consumer_var->data.explicit_component = 1; 1972 } 1973 } 1974 } 1975 } 1976 1977 1978 /** 1979 * Compute the "packing class" of the given varying. This is an unsigned 1980 * integer with the property that two variables in the same packing class can 1981 * be safely backed into the same vec4. 1982 */ 1983 unsigned 1984 varying_matches::compute_packing_class(const ir_variable *var) 1985 { 1986 /* Without help from the back-end, there is no way to pack together 1987 * variables with different interpolation types, because 1988 * lower_packed_varyings must choose exactly one interpolation type for 1989 * each packed varying it creates. 1990 * 1991 * However, we can safely pack together floats, ints, and uints, because: 1992 * 1993 * - varyings of base type "int" and "uint" must use the "flat" 1994 * interpolation type, which can only occur in GLSL 1.30 and above. 1995 * 1996 * - On platforms that support GLSL 1.30 and above, lower_packed_varyings 1997 * can store flat floats as ints without losing any information (using 1998 * the ir_unop_bitcast_* opcodes). 1999 * 2000 * Therefore, the packing class depends only on the interpolation type. 2001 */ 2002 const unsigned interp = var->is_interpolation_flat() 2003 ? unsigned(INTERP_MODE_FLAT) : var->data.interpolation; 2004 2005 assert(interp < (1 << 3)); 2006 2007 const unsigned packing_class = (interp << 0) | 2008 (var->data.centroid << 3) | 2009 (var->data.sample << 4) | 2010 (var->data.patch << 5) | 2011 (var->data.must_be_shader_input << 6); 2012 2013 return packing_class; 2014 } 2015 2016 2017 /** 2018 * Compute the "packing order" of the given varying. This is a sort key we 2019 * use to determine when to attempt to pack the given varying relative to 2020 * other varyings in the same packing class. 2021 */ 2022 varying_matches::packing_order_enum 2023 varying_matches::compute_packing_order(const ir_variable *var) 2024 { 2025 const glsl_type *element_type = var->type; 2026 2027 while (element_type->is_array()) { 2028 element_type = element_type->fields.array; 2029 } 2030 2031 switch (element_type->component_slots() % 4) { 2032 case 1: return PACKING_ORDER_SCALAR; 2033 case 2: return PACKING_ORDER_VEC2; 2034 case 3: return PACKING_ORDER_VEC3; 2035 case 0: return PACKING_ORDER_VEC4; 2036 default: 2037 assert(!"Unexpected value of vector_elements"); 2038 return PACKING_ORDER_VEC4; 2039 } 2040 } 2041 2042 2043 /** 2044 * Comparison function passed to qsort() to sort varyings by packing_class and 2045 * then by packing_order. 2046 */ 2047 int 2048 varying_matches::match_comparator(const void *x_generic, const void *y_generic) 2049 { 2050 const match *x = (const match *) x_generic; 2051 const match *y = (const match *) y_generic; 2052 2053 if (x->packing_class != y->packing_class) 2054 return x->packing_class - y->packing_class; 2055 return x->packing_order - y->packing_order; 2056 } 2057 2058 2059 /** 2060 * Comparison function passed to qsort() to sort varyings used only by 2061 * transform feedback when packing of other varyings is disabled. 2062 */ 2063 int 2064 varying_matches::xfb_comparator(const void *x_generic, const void *y_generic) 2065 { 2066 const match *x = (const match *) x_generic; 2067 2068 if (x->producer_var != NULL && x->producer_var->data.is_xfb_only) 2069 return match_comparator(x_generic, y_generic); 2070 2071 /* FIXME: When the comparator returns 0 it means the elements being 2072 * compared are equivalent. However the qsort documentation says: 2073 * 2074 * "The order of equivalent elements is undefined." 2075 * 2076 * In practice the sort ends up reversing the order of the varyings which 2077 * means locations are also assigned in this reversed order and happens to 2078 * be what we want. This is also whats happening in 2079 * varying_matches::match_comparator(). 2080 */ 2081 return 0; 2082 } 2083 2084 2085 /** 2086 * Is the given variable a varying variable to be counted against the 2087 * limit in ctx->Const.MaxVarying? 2088 * This includes variables such as texcoords, colors and generic 2089 * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord. 2090 */ 2091 static bool 2092 var_counts_against_varying_limit(gl_shader_stage stage, const ir_variable *var) 2093 { 2094 /* Only fragment shaders will take a varying variable as an input */ 2095 if (stage == MESA_SHADER_FRAGMENT && 2096 var->data.mode == ir_var_shader_in) { 2097 switch (var->data.location) { 2098 case VARYING_SLOT_POS: 2099 case VARYING_SLOT_FACE: 2100 case VARYING_SLOT_PNTC: 2101 return false; 2102 default: 2103 return true; 2104 } 2105 } 2106 return false; 2107 } 2108 2109 2110 /** 2111 * Visitor class that generates tfeedback_candidate structs describing all 2112 * possible targets of transform feedback. 2113 * 2114 * tfeedback_candidate structs are stored in the hash table 2115 * tfeedback_candidates, which is passed to the constructor. This hash table 2116 * maps varying names to instances of the tfeedback_candidate struct. 2117 */ 2118 class tfeedback_candidate_generator : public program_resource_visitor 2119 { 2120 public: 2121 tfeedback_candidate_generator(void *mem_ctx, 2122 hash_table *tfeedback_candidates) 2123 : mem_ctx(mem_ctx), 2124 tfeedback_candidates(tfeedback_candidates), 2125 toplevel_var(NULL), 2126 varying_floats(0) 2127 { 2128 } 2129 2130 void process(ir_variable *var) 2131 { 2132 /* All named varying interface blocks should be flattened by now */ 2133 assert(!var->is_interface_instance()); 2134 2135 this->toplevel_var = var; 2136 this->varying_floats = 0; 2137 program_resource_visitor::process(var, false); 2138 } 2139 2140 private: 2141 virtual void visit_field(const glsl_type *type, const char *name, 2142 bool /* row_major */, 2143 const glsl_type * /* record_type */, 2144 const enum glsl_interface_packing, 2145 bool /* last_field */) 2146 { 2147 assert(!type->without_array()->is_record()); 2148 assert(!type->without_array()->is_interface()); 2149 2150 tfeedback_candidate *candidate 2151 = rzalloc(this->mem_ctx, tfeedback_candidate); 2152 candidate->toplevel_var = this->toplevel_var; 2153 candidate->type = type; 2154 candidate->offset = this->varying_floats; 2155 _mesa_hash_table_insert(this->tfeedback_candidates, 2156 ralloc_strdup(this->mem_ctx, name), 2157 candidate); 2158 this->varying_floats += type->component_slots(); 2159 } 2160 2161 /** 2162 * Memory context used to allocate hash table keys and values. 2163 */ 2164 void * const mem_ctx; 2165 2166 /** 2167 * Hash table in which tfeedback_candidate objects should be stored. 2168 */ 2169 hash_table * const tfeedback_candidates; 2170 2171 /** 2172 * Pointer to the toplevel variable that is being traversed. 2173 */ 2174 ir_variable *toplevel_var; 2175 2176 /** 2177 * Total number of varying floats that have been visited so far. This is 2178 * used to determine the offset to each varying within the toplevel 2179 * variable. 2180 */ 2181 unsigned varying_floats; 2182 }; 2183 2184 2185 namespace linker { 2186 2187 void 2188 populate_consumer_input_sets(void *mem_ctx, exec_list *ir, 2189 hash_table *consumer_inputs, 2190 hash_table *consumer_interface_inputs, 2191 ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX]) 2192 { 2193 memset(consumer_inputs_with_locations, 2194 0, 2195 sizeof(consumer_inputs_with_locations[0]) * VARYING_SLOT_TESS_MAX); 2196 2197 foreach_in_list(ir_instruction, node, ir) { 2198 ir_variable *const input_var = node->as_variable(); 2199 2200 if (input_var != NULL && input_var->data.mode == ir_var_shader_in) { 2201 /* All interface blocks should have been lowered by this point */ 2202 assert(!input_var->type->is_interface()); 2203 2204 if (input_var->data.explicit_location) { 2205 /* assign_varying_locations only cares about finding the 2206 * ir_variable at the start of a contiguous location block. 2207 * 2208 * - For !producer, consumer_inputs_with_locations isn't used. 2209 * 2210 * - For !consumer, consumer_inputs_with_locations is empty. 2211 * 2212 * For consumer && producer, if you were trying to set some 2213 * ir_variable to the middle of a location block on the other side 2214 * of producer/consumer, cross_validate_outputs_to_inputs() should 2215 * be link-erroring due to either type mismatch or location 2216 * overlaps. If the variables do match up, then they've got a 2217 * matching data.location and you only looked at 2218 * consumer_inputs_with_locations[var->data.location], not any 2219 * following entries for the array/structure. 2220 */ 2221 consumer_inputs_with_locations[input_var->data.location] = 2222 input_var; 2223 } else if (input_var->get_interface_type() != NULL) { 2224 char *const iface_field_name = 2225 ralloc_asprintf(mem_ctx, "%s.%s", 2226 input_var->get_interface_type()->without_array()->name, 2227 input_var->name); 2228 _mesa_hash_table_insert(consumer_interface_inputs, 2229 iface_field_name, input_var); 2230 } else { 2231 _mesa_hash_table_insert(consumer_inputs, 2232 ralloc_strdup(mem_ctx, input_var->name), 2233 input_var); 2234 } 2235 } 2236 } 2237 } 2238 2239 /** 2240 * Find a variable from the consumer that "matches" the specified variable 2241 * 2242 * This function only finds inputs with names that match. There is no 2243 * validation (here) that the types, etc. are compatible. 2244 */ 2245 ir_variable * 2246 get_matching_input(void *mem_ctx, 2247 const ir_variable *output_var, 2248 hash_table *consumer_inputs, 2249 hash_table *consumer_interface_inputs, 2250 ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX]) 2251 { 2252 ir_variable *input_var; 2253 2254 if (output_var->data.explicit_location) { 2255 input_var = consumer_inputs_with_locations[output_var->data.location]; 2256 } else if (output_var->get_interface_type() != NULL) { 2257 char *const iface_field_name = 2258 ralloc_asprintf(mem_ctx, "%s.%s", 2259 output_var->get_interface_type()->without_array()->name, 2260 output_var->name); 2261 hash_entry *entry = _mesa_hash_table_search(consumer_interface_inputs, iface_field_name); 2262 input_var = entry ? (ir_variable *) entry->data : NULL; 2263 } else { 2264 hash_entry *entry = _mesa_hash_table_search(consumer_inputs, output_var->name); 2265 input_var = entry ? (ir_variable *) entry->data : NULL; 2266 } 2267 2268 return (input_var == NULL || input_var->data.mode != ir_var_shader_in) 2269 ? NULL : input_var; 2270 } 2271 2272 } 2273 2274 static int 2275 io_variable_cmp(const void *_a, const void *_b) 2276 { 2277 const ir_variable *const a = *(const ir_variable **) _a; 2278 const ir_variable *const b = *(const ir_variable **) _b; 2279 2280 if (a->data.explicit_location && b->data.explicit_location) 2281 return b->data.location - a->data.location; 2282 2283 if (a->data.explicit_location && !b->data.explicit_location) 2284 return 1; 2285 2286 if (!a->data.explicit_location && b->data.explicit_location) 2287 return -1; 2288 2289 return -strcmp(a->name, b->name); 2290 } 2291 2292 /** 2293 * Sort the shader IO variables into canonical order 2294 */ 2295 static void 2296 canonicalize_shader_io(exec_list *ir, enum ir_variable_mode io_mode) 2297 { 2298 ir_variable *var_table[MAX_PROGRAM_OUTPUTS * 4]; 2299 unsigned num_variables = 0; 2300 2301 foreach_in_list(ir_instruction, node, ir) { 2302 ir_variable *const var = node->as_variable(); 2303 2304 if (var == NULL || var->data.mode != io_mode) 2305 continue; 2306 2307 /* If we have already encountered more I/O variables that could 2308 * successfully link, bail. 2309 */ 2310 if (num_variables == ARRAY_SIZE(var_table)) 2311 return; 2312 2313 var_table[num_variables++] = var; 2314 } 2315 2316 if (num_variables == 0) 2317 return; 2318 2319 /* Sort the list in reverse order (io_variable_cmp handles this). Later 2320 * we're going to push the variables on to the IR list as a stack, so we 2321 * want the last variable (in canonical order) to be first in the list. 2322 */ 2323 qsort(var_table, num_variables, sizeof(var_table[0]), io_variable_cmp); 2324 2325 /* Remove the variable from it's current location in the IR, and put it at 2326 * the front. 2327 */ 2328 for (unsigned i = 0; i < num_variables; i++) { 2329 var_table[i]->remove(); 2330 ir->push_head(var_table[i]); 2331 } 2332 } 2333 2334 /** 2335 * Generate a bitfield map of the explicit locations for shader varyings. 2336 * 2337 * Note: For Tessellation shaders we are sitting right on the limits of the 2338 * 64 bit map. Per-vertex and per-patch both have separate location domains 2339 * with a max of MAX_VARYING. 2340 */ 2341 static uint64_t 2342 reserved_varying_slot(struct gl_linked_shader *stage, 2343 ir_variable_mode io_mode) 2344 { 2345 assert(io_mode == ir_var_shader_in || io_mode == ir_var_shader_out); 2346 /* Avoid an overflow of the returned value */ 2347 assert(MAX_VARYINGS_INCL_PATCH <= 64); 2348 2349 uint64_t slots = 0; 2350 int var_slot; 2351 2352 if (!stage) 2353 return slots; 2354 2355 foreach_in_list(ir_instruction, node, stage->ir) { 2356 ir_variable *const var = node->as_variable(); 2357 2358 if (var == NULL || var->data.mode != io_mode || 2359 !var->data.explicit_location || 2360 var->data.location < VARYING_SLOT_VAR0) 2361 continue; 2362 2363 var_slot = var->data.location - VARYING_SLOT_VAR0; 2364 2365 unsigned num_elements = get_varying_type(var, stage->Stage) 2366 ->count_attribute_slots(io_mode == ir_var_shader_in && 2367 stage->Stage == MESA_SHADER_VERTEX); 2368 for (unsigned i = 0; i < num_elements; i++) { 2369 if (var_slot >= 0 && var_slot < MAX_VARYINGS_INCL_PATCH) 2370 slots |= UINT64_C(1) << var_slot; 2371 var_slot += 1; 2372 } 2373 } 2374 2375 return slots; 2376 } 2377 2378 2379 /** 2380 * Assign locations for all variables that are produced in one pipeline stage 2381 * (the "producer") and consumed in the next stage (the "consumer"). 2382 * 2383 * Variables produced by the producer may also be consumed by transform 2384 * feedback. 2385 * 2386 * \param num_tfeedback_decls is the number of declarations indicating 2387 * variables that may be consumed by transform feedback. 2388 * 2389 * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects 2390 * representing the result of parsing the strings passed to 2391 * glTransformFeedbackVaryings(). assign_location() will be called for 2392 * each of these objects that matches one of the outputs of the 2393 * producer. 2394 * 2395 * When num_tfeedback_decls is nonzero, it is permissible for the consumer to 2396 * be NULL. In this case, varying locations are assigned solely based on the 2397 * requirements of transform feedback. 2398 */ 2399 static bool 2400 assign_varying_locations(struct gl_context *ctx, 2401 void *mem_ctx, 2402 struct gl_shader_program *prog, 2403 gl_linked_shader *producer, 2404 gl_linked_shader *consumer, 2405 unsigned num_tfeedback_decls, 2406 tfeedback_decl *tfeedback_decls, 2407 const uint64_t reserved_slots) 2408 { 2409 /* Tessellation shaders treat inputs and outputs as shared memory and can 2410 * access inputs and outputs of other invocations. 2411 * Therefore, they can't be lowered to temps easily (and definitely not 2412 * efficiently). 2413 */ 2414 bool unpackable_tess = 2415 (consumer && consumer->Stage == MESA_SHADER_TESS_EVAL) || 2416 (consumer && consumer->Stage == MESA_SHADER_TESS_CTRL) || 2417 (producer && producer->Stage == MESA_SHADER_TESS_CTRL); 2418 2419 /* Transform feedback code assumes varying arrays are packed, so if the 2420 * driver has disabled varying packing, make sure to at least enable 2421 * packing required by transform feedback. 2422 */ 2423 bool xfb_enabled = 2424 ctx->Extensions.EXT_transform_feedback && !unpackable_tess; 2425 2426 /* Disable packing on outward facing interfaces for SSO because in ES we 2427 * need to retain the unpacked varying information for draw time 2428 * validation. 2429 * 2430 * Packing is still enabled on individual arrays, structs, and matrices as 2431 * these are required by the transform feedback code and it is still safe 2432 * to do so. We also enable packing when a varying is only used for 2433 * transform feedback and its not a SSO. 2434 */ 2435 bool disable_varying_packing = 2436 ctx->Const.DisableVaryingPacking || unpackable_tess; 2437 if (prog->SeparateShader && (producer == NULL || consumer == NULL)) 2438 disable_varying_packing = true; 2439 2440 varying_matches matches(disable_varying_packing, xfb_enabled, 2441 ctx->Extensions.ARB_enhanced_layouts, 2442 producer ? producer->Stage : MESA_SHADER_NONE, 2443 consumer ? consumer->Stage : MESA_SHADER_NONE); 2444 hash_table *tfeedback_candidates = 2445 _mesa_hash_table_create(NULL, _mesa_key_hash_string, 2446 _mesa_key_string_equal); 2447 hash_table *consumer_inputs = 2448 _mesa_hash_table_create(NULL, _mesa_key_hash_string, 2449 _mesa_key_string_equal); 2450 hash_table *consumer_interface_inputs = 2451 _mesa_hash_table_create(NULL, _mesa_key_hash_string, 2452 _mesa_key_string_equal); 2453 ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX] = { 2454 NULL, 2455 }; 2456 2457 unsigned consumer_vertices = 0; 2458 if (consumer && consumer->Stage == MESA_SHADER_GEOMETRY) 2459 consumer_vertices = prog->Geom.VerticesIn; 2460 2461 /* Operate in a total of four passes. 2462 * 2463 * 1. Sort inputs / outputs into a canonical order. This is necessary so 2464 * that inputs / outputs of separable shaders will be assigned 2465 * predictable locations regardless of the order in which declarations 2466 * appeared in the shader source. 2467 * 2468 * 2. Assign locations for any matching inputs and outputs. 2469 * 2470 * 3. Mark output variables in the producer that do not have locations as 2471 * not being outputs. This lets the optimizer eliminate them. 2472 * 2473 * 4. Mark input variables in the consumer that do not have locations as 2474 * not being inputs. This lets the optimizer eliminate them. 2475 */ 2476 if (consumer) 2477 canonicalize_shader_io(consumer->ir, ir_var_shader_in); 2478 2479 if (producer) 2480 canonicalize_shader_io(producer->ir, ir_var_shader_out); 2481 2482 if (consumer) 2483 linker::populate_consumer_input_sets(mem_ctx, consumer->ir, 2484 consumer_inputs, 2485 consumer_interface_inputs, 2486 consumer_inputs_with_locations); 2487 2488 if (producer) { 2489 foreach_in_list(ir_instruction, node, producer->ir) { 2490 ir_variable *const output_var = node->as_variable(); 2491 2492 if (output_var == NULL || output_var->data.mode != ir_var_shader_out) 2493 continue; 2494 2495 /* Only geometry shaders can use non-zero streams */ 2496 assert(output_var->data.stream == 0 || 2497 (output_var->data.stream < MAX_VERTEX_STREAMS && 2498 producer->Stage == MESA_SHADER_GEOMETRY)); 2499 2500 if (num_tfeedback_decls > 0) { 2501 tfeedback_candidate_generator g(mem_ctx, tfeedback_candidates); 2502 g.process(output_var); 2503 } 2504 2505 ir_variable *const input_var = 2506 linker::get_matching_input(mem_ctx, output_var, consumer_inputs, 2507 consumer_interface_inputs, 2508 consumer_inputs_with_locations); 2509 2510 /* If a matching input variable was found, add this output (and the 2511 * input) to the set. If this is a separable program and there is no 2512 * consumer stage, add the output. 2513 * 2514 * Always add TCS outputs. They are shared by all invocations 2515 * within a patch and can be used as shared memory. 2516 */ 2517 if (input_var || (prog->SeparateShader && consumer == NULL) || 2518 producer->Stage == MESA_SHADER_TESS_CTRL) { 2519 matches.record(output_var, input_var); 2520 } 2521 2522 /* Only stream 0 outputs can be consumed in the next stage */ 2523 if (input_var && output_var->data.stream != 0) { 2524 linker_error(prog, "output %s is assigned to stream=%d but " 2525 "is linked to an input, which requires stream=0", 2526 output_var->name, output_var->data.stream); 2527 return false; 2528 } 2529 } 2530 } else { 2531 /* If there's no producer stage, then this must be a separable program. 2532 * For example, we may have a program that has just a fragment shader. 2533 * Later this program will be used with some arbitrary vertex (or 2534 * geometry) shader program. This means that locations must be assigned 2535 * for all the inputs. 2536 */ 2537 foreach_in_list(ir_instruction, node, consumer->ir) { 2538 ir_variable *const input_var = node->as_variable(); 2539 if (input_var && input_var->data.mode == ir_var_shader_in) { 2540 matches.record(NULL, input_var); 2541 } 2542 } 2543 } 2544 2545 for (unsigned i = 0; i < num_tfeedback_decls; ++i) { 2546 if (!tfeedback_decls[i].is_varying()) 2547 continue; 2548 2549 const tfeedback_candidate *matched_candidate 2550 = tfeedback_decls[i].find_candidate(prog, tfeedback_candidates); 2551 2552 if (matched_candidate == NULL) { 2553 _mesa_hash_table_destroy(tfeedback_candidates, NULL); 2554 return false; 2555 } 2556 2557 /* Mark xfb varyings as always active */ 2558 matched_candidate->toplevel_var->data.always_active_io = 1; 2559 2560 /* Mark any corresponding inputs as always active also. We must do this 2561 * because we have a NIR pass that lowers vectors to scalars and another 2562 * that removes unused varyings. 2563 * We don't split varyings marked as always active because there is no 2564 * point in doing so. This means we need to mark both sides of the 2565 * interface as always active otherwise we will have a mismatch and 2566 * start removing things we shouldn't. 2567 */ 2568 ir_variable *const input_var = 2569 linker::get_matching_input(mem_ctx, matched_candidate->toplevel_var, 2570 consumer_inputs, 2571 consumer_interface_inputs, 2572 consumer_inputs_with_locations); 2573 if (input_var) 2574 input_var->data.always_active_io = 1; 2575 2576 if (matched_candidate->toplevel_var->data.is_unmatched_generic_inout) { 2577 matched_candidate->toplevel_var->data.is_xfb_only = 1; 2578 matches.record(matched_candidate->toplevel_var, NULL); 2579 } 2580 } 2581 2582 _mesa_hash_table_destroy(consumer_inputs, NULL); 2583 _mesa_hash_table_destroy(consumer_interface_inputs, NULL); 2584 2585 uint8_t components[MAX_VARYINGS_INCL_PATCH] = {0}; 2586 const unsigned slots_used = matches.assign_locations( 2587 prog, components, reserved_slots); 2588 matches.store_locations(); 2589 2590 for (unsigned i = 0; i < num_tfeedback_decls; ++i) { 2591 if (tfeedback_decls[i].is_varying()) { 2592 if (!tfeedback_decls[i].assign_location(ctx, prog)) { 2593 _mesa_hash_table_destroy(tfeedback_candidates, NULL); 2594 return false; 2595 } 2596 } 2597 } 2598 _mesa_hash_table_destroy(tfeedback_candidates, NULL); 2599 2600 if (consumer && producer) { 2601 foreach_in_list(ir_instruction, node, consumer->ir) { 2602 ir_variable *const var = node->as_variable(); 2603 2604 if (var && var->data.mode == ir_var_shader_in && 2605 var->data.is_unmatched_generic_inout) { 2606 if (!prog->IsES && prog->data->Version <= 120) { 2607 /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec: 2608 * 2609 * Only those varying variables used (i.e. read) in 2610 * the fragment shader executable must be written to 2611 * by the vertex shader executable; declaring 2612 * superfluous varying variables in a vertex shader is 2613 * permissible. 2614 * 2615 * We interpret this text as meaning that the VS must 2616 * write the variable for the FS to read it. See 2617 * "glsl1-varying read but not written" in piglit. 2618 */ 2619 linker_error(prog, "%s shader varying %s not written " 2620 "by %s shader\n.", 2621 _mesa_shader_stage_to_string(consumer->Stage), 2622 var->name, 2623 _mesa_shader_stage_to_string(producer->Stage)); 2624 } else { 2625 linker_warning(prog, "%s shader varying %s not written " 2626 "by %s shader\n.", 2627 _mesa_shader_stage_to_string(consumer->Stage), 2628 var->name, 2629 _mesa_shader_stage_to_string(producer->Stage)); 2630 } 2631 } 2632 } 2633 2634 /* Now that validation is done its safe to remove unused varyings. As 2635 * we have both a producer and consumer its safe to remove unused 2636 * varyings even if the program is a SSO because the stages are being 2637 * linked together i.e. we have a multi-stage SSO. 2638 */ 2639 remove_unused_shader_inputs_and_outputs(false, producer, 2640 ir_var_shader_out); 2641 remove_unused_shader_inputs_and_outputs(false, consumer, 2642 ir_var_shader_in); 2643 } 2644 2645 if (producer) { 2646 lower_packed_varyings(mem_ctx, slots_used, components, ir_var_shader_out, 2647 0, producer, disable_varying_packing, 2648 xfb_enabled); 2649 } 2650 2651 if (consumer) { 2652 lower_packed_varyings(mem_ctx, slots_used, components, ir_var_shader_in, 2653 consumer_vertices, consumer, 2654 disable_varying_packing, xfb_enabled); 2655 } 2656 2657 return true; 2658 } 2659 2660 static bool 2661 check_against_output_limit(struct gl_context *ctx, 2662 struct gl_shader_program *prog, 2663 gl_linked_shader *producer, 2664 unsigned num_explicit_locations) 2665 { 2666 unsigned output_vectors = num_explicit_locations; 2667 2668 foreach_in_list(ir_instruction, node, producer->ir) { 2669 ir_variable *const var = node->as_variable(); 2670 2671 if (var && !var->data.explicit_location && 2672 var->data.mode == ir_var_shader_out && 2673 var_counts_against_varying_limit(producer->Stage, var)) { 2674 /* outputs for fragment shader can't be doubles */ 2675 output_vectors += var->type->count_attribute_slots(false); 2676 } 2677 } 2678 2679 assert(producer->Stage != MESA_SHADER_FRAGMENT); 2680 unsigned max_output_components = 2681 ctx->Const.Program[producer->Stage].MaxOutputComponents; 2682 2683 const unsigned output_components = output_vectors * 4; 2684 if (output_components > max_output_components) { 2685 if (ctx->API == API_OPENGLES2 || prog->IsES) 2686 linker_error(prog, "%s shader uses too many output vectors " 2687 "(%u > %u)\n", 2688 _mesa_shader_stage_to_string(producer->Stage), 2689 output_vectors, 2690 max_output_components / 4); 2691 else 2692 linker_error(prog, "%s shader uses too many output components " 2693 "(%u > %u)\n", 2694 _mesa_shader_stage_to_string(producer->Stage), 2695 output_components, 2696 max_output_components); 2697 2698 return false; 2699 } 2700 2701 return true; 2702 } 2703 2704 static bool 2705 check_against_input_limit(struct gl_context *ctx, 2706 struct gl_shader_program *prog, 2707 gl_linked_shader *consumer, 2708 unsigned num_explicit_locations) 2709 { 2710 unsigned input_vectors = num_explicit_locations; 2711 2712 foreach_in_list(ir_instruction, node, consumer->ir) { 2713 ir_variable *const var = node->as_variable(); 2714 2715 if (var && !var->data.explicit_location && 2716 var->data.mode == ir_var_shader_in && 2717 var_counts_against_varying_limit(consumer->Stage, var)) { 2718 /* vertex inputs aren't varying counted */ 2719 input_vectors += var->type->count_attribute_slots(false); 2720 } 2721 } 2722 2723 assert(consumer->Stage != MESA_SHADER_VERTEX); 2724 unsigned max_input_components = 2725 ctx->Const.Program[consumer->Stage].MaxInputComponents; 2726 2727 const unsigned input_components = input_vectors * 4; 2728 if (input_components > max_input_components) { 2729 if (ctx->API == API_OPENGLES2 || prog->IsES) 2730 linker_error(prog, "%s shader uses too many input vectors " 2731 "(%u > %u)\n", 2732 _mesa_shader_stage_to_string(consumer->Stage), 2733 input_vectors, 2734 max_input_components / 4); 2735 else 2736 linker_error(prog, "%s shader uses too many input components " 2737 "(%u > %u)\n", 2738 _mesa_shader_stage_to_string(consumer->Stage), 2739 input_components, 2740 max_input_components); 2741 2742 return false; 2743 } 2744 2745 return true; 2746 } 2747 2748 bool 2749 link_varyings(struct gl_shader_program *prog, unsigned first, unsigned last, 2750 struct gl_context *ctx, void *mem_ctx) 2751 { 2752 bool has_xfb_qualifiers = false; 2753 unsigned num_tfeedback_decls = 0; 2754 char **varying_names = NULL; 2755 tfeedback_decl *tfeedback_decls = NULL; 2756 2757 /* From the ARB_enhanced_layouts spec: 2758 * 2759 * "If the shader used to record output variables for transform feedback 2760 * varyings uses the "xfb_buffer", "xfb_offset", or "xfb_stride" layout 2761 * qualifiers, the values specified by TransformFeedbackVaryings are 2762 * ignored, and the set of variables captured for transform feedback is 2763 * instead derived from the specified layout qualifiers." 2764 */ 2765 for (int i = MESA_SHADER_FRAGMENT - 1; i >= 0; i--) { 2766 /* Find last stage before fragment shader */ 2767 if (prog->_LinkedShaders[i]) { 2768 has_xfb_qualifiers = 2769 process_xfb_layout_qualifiers(mem_ctx, prog->_LinkedShaders[i], 2770 prog, &num_tfeedback_decls, 2771 &varying_names); 2772 break; 2773 } 2774 } 2775 2776 if (!has_xfb_qualifiers) { 2777 num_tfeedback_decls = prog->TransformFeedback.NumVarying; 2778 varying_names = prog->TransformFeedback.VaryingNames; 2779 } 2780 2781 if (num_tfeedback_decls != 0) { 2782 /* From GL_EXT_transform_feedback: 2783 * A program will fail to link if: 2784 * 2785 * * the <count> specified by TransformFeedbackVaryingsEXT is 2786 * non-zero, but the program object has no vertex or geometry 2787 * shader; 2788 */ 2789 if (first >= MESA_SHADER_FRAGMENT) { 2790 linker_error(prog, "Transform feedback varyings specified, but " 2791 "no vertex, tessellation, or geometry shader is " 2792 "present.\n"); 2793 return false; 2794 } 2795 2796 tfeedback_decls = rzalloc_array(mem_ctx, tfeedback_decl, 2797 num_tfeedback_decls); 2798 if (!parse_tfeedback_decls(ctx, prog, mem_ctx, num_tfeedback_decls, 2799 varying_names, tfeedback_decls)) 2800 return false; 2801 } 2802 2803 /* If there is no fragment shader we need to set transform feedback. 2804 * 2805 * For SSO we also need to assign output locations. We assign them here 2806 * because we need to do it for both single stage programs and multi stage 2807 * programs. 2808 */ 2809 if (last < MESA_SHADER_FRAGMENT && 2810 (num_tfeedback_decls != 0 || prog->SeparateShader)) { 2811 const uint64_t reserved_out_slots = 2812 reserved_varying_slot(prog->_LinkedShaders[last], ir_var_shader_out); 2813 if (!assign_varying_locations(ctx, mem_ctx, prog, 2814 prog->_LinkedShaders[last], NULL, 2815 num_tfeedback_decls, tfeedback_decls, 2816 reserved_out_slots)) 2817 return false; 2818 } 2819 2820 if (last <= MESA_SHADER_FRAGMENT) { 2821 /* Remove unused varyings from the first/last stage unless SSO */ 2822 remove_unused_shader_inputs_and_outputs(prog->SeparateShader, 2823 prog->_LinkedShaders[first], 2824 ir_var_shader_in); 2825 remove_unused_shader_inputs_and_outputs(prog->SeparateShader, 2826 prog->_LinkedShaders[last], 2827 ir_var_shader_out); 2828 2829 /* If the program is made up of only a single stage */ 2830 if (first == last) { 2831 gl_linked_shader *const sh = prog->_LinkedShaders[last]; 2832 2833 do_dead_builtin_varyings(ctx, NULL, sh, 0, NULL); 2834 do_dead_builtin_varyings(ctx, sh, NULL, num_tfeedback_decls, 2835 tfeedback_decls); 2836 2837 if (prog->SeparateShader) { 2838 const uint64_t reserved_slots = 2839 reserved_varying_slot(sh, ir_var_shader_in); 2840 2841 /* Assign input locations for SSO, output locations are already 2842 * assigned. 2843 */ 2844 if (!assign_varying_locations(ctx, mem_ctx, prog, 2845 NULL /* producer */, 2846 sh /* consumer */, 2847 0 /* num_tfeedback_decls */, 2848 NULL /* tfeedback_decls */, 2849 reserved_slots)) 2850 return false; 2851 } 2852 } else { 2853 /* Linking the stages in the opposite order (from fragment to vertex) 2854 * ensures that inter-shader outputs written to in an earlier stage 2855 * are eliminated if they are (transitively) not used in a later 2856 * stage. 2857 */ 2858 int next = last; 2859 for (int i = next - 1; i >= 0; i--) { 2860 if (prog->_LinkedShaders[i] == NULL && i != 0) 2861 continue; 2862 2863 gl_linked_shader *const sh_i = prog->_LinkedShaders[i]; 2864 gl_linked_shader *const sh_next = prog->_LinkedShaders[next]; 2865 2866 const uint64_t reserved_out_slots = 2867 reserved_varying_slot(sh_i, ir_var_shader_out); 2868 const uint64_t reserved_in_slots = 2869 reserved_varying_slot(sh_next, ir_var_shader_in); 2870 2871 do_dead_builtin_varyings(ctx, sh_i, sh_next, 2872 next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0, 2873 tfeedback_decls); 2874 2875 if (!assign_varying_locations(ctx, mem_ctx, prog, sh_i, sh_next, 2876 next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0, 2877 tfeedback_decls, 2878 reserved_out_slots | reserved_in_slots)) 2879 return false; 2880 2881 /* This must be done after all dead varyings are eliminated. */ 2882 if (sh_i != NULL) { 2883 unsigned slots_used = _mesa_bitcount_64(reserved_out_slots); 2884 if (!check_against_output_limit(ctx, prog, sh_i, slots_used)) { 2885 return false; 2886 } 2887 } 2888 2889 unsigned slots_used = _mesa_bitcount_64(reserved_in_slots); 2890 if (!check_against_input_limit(ctx, prog, sh_next, slots_used)) 2891 return false; 2892 2893 next = i; 2894 } 2895 } 2896 } 2897 2898 if (!store_tfeedback_info(ctx, prog, num_tfeedback_decls, tfeedback_decls, 2899 has_xfb_qualifiers)) 2900 return false; 2901 2902 return true; 2903 } 2904
