src/compiler/glsl/ir_reader.cpp

   1 /*
   2  * Copyright © 2010 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 #include "ir_reader.h"
  25 #include "glsl_parser_extras.h"
  26 #include "compiler/glsl_types.h"
  27 #include "s_expression.h"
  28
  29 static const bool debug = false;
  30
  31 namespace {
  32
  33 class ir_reader {
  34 public:
  35    ir_reader(_mesa_glsl_parse_state *);
  36
  37    void read(exec_list *instructions, const char *src, bool scan_for_protos);
  38
  39 private:
  40    void *mem_ctx;
  41    _mesa_glsl_parse_state *state;
  42
  43    void ir_read_error(s_expression *, const char *fmt, ...);
  44
  45    const glsl_type *read_type(s_expression *);
  46
  47    void scan_for_prototypes(exec_list *, s_expression *);
  48    ir_function *read_function(s_expression *, bool skip_body);
  49    void read_function_sig(ir_function *, s_expression *, bool skip_body);
  50
  51    void read_instructions(exec_list *, s_expression *, ir_loop *);
  52    ir_instruction *read_instruction(s_expression *, ir_loop *);
  53    ir_variable *read_declaration(s_expression *);
  54    ir_if *read_if(s_expression *, ir_loop *);
  55    ir_loop *read_loop(s_expression *);
  56    ir_call *read_call(s_expression *);
  57    ir_return *read_return(s_expression *);
  58    ir_rvalue *read_rvalue(s_expression *);
  59    ir_assignment *read_assignment(s_expression *);
  60    ir_expression *read_expression(s_expression *);
  61    ir_swizzle *read_swizzle(s_expression *);
  62    ir_constant *read_constant(s_expression *);
  63    ir_texture *read_texture(s_expression *);
  64    ir_emit_vertex *read_emit_vertex(s_expression *);
  65    ir_end_primitive *read_end_primitive(s_expression *);
  66    ir_barrier *read_barrier(s_expression *);
  67
  68    ir_dereference *read_dereference(s_expression *);
  69    ir_dereference_variable *read_var_ref(s_expression *);
  70 };
  71
  72 } /* anonymous namespace */
  73
  74 ir_reader::ir_reader(_mesa_glsl_parse_state *state) : state(state)
  75 {
  76    this->mem_ctx = state;
  77 }
  78
  79 void
  80 _mesa_glsl_read_ir(_mesa_glsl_parse_state *state, exec_list *instructions,
  81                    const char *src, bool scan_for_protos)
  82 {
  83    ir_reader r(state);
  84    r.read(instructions, src, scan_for_protos);
  85 }
  86
  87 void
  88 ir_reader::read(exec_list *instructions, const char *src, bool scan_for_protos)
  89 {
  90    void *sx_mem_ctx = ralloc_context(NULL);
  91    s_expression *expr = s_expression::read_expression(sx_mem_ctx, src);
  92    if (expr == NULL) {
  93       ir_read_error(NULL, "couldn't parse S-Expression.");
  94       return;
  95    }
  96
  97    if (scan_for_protos) {
  98       scan_for_prototypes(instructions, expr);
  99       if (state->error)
 100          return;
 101    }
 102
 103    read_instructions(instructions, expr, NULL);
 104    ralloc_free(sx_mem_ctx);
 105
 106    if (debug)
 107       validate_ir_tree(instructions);
 108 }
 109
 110 void
 111 ir_reader::ir_read_error(s_expression *expr, const char *fmt, ...)
 112 {
 113    va_list ap;
 114
 115    state->error = true;
 116
 117    if (state->current_function != NULL)
 118       ralloc_asprintf_append(&state->info_log, "In function %s:\n",
 119                              state->current_function->function_name());
 120    ralloc_strcat(&state->info_log, "error: ");
 121
 122    va_start(ap, fmt);
 123    ralloc_vasprintf_append(&state->info_log, fmt, ap);
 124    va_end(ap);
 125    ralloc_strcat(&state->info_log, "\n");
 126
 127    if (expr != NULL) {
 128       ralloc_strcat(&state->info_log, "...in this context:\n   ");
 129       expr->print();
 130       ralloc_strcat(&state->info_log, "\n\n");
 131    }
 132 }
 133
 134 const glsl_type *
 135 ir_reader::read_type(s_expression *expr)
 136 {
 137    s_expression *s_base_type;
 138    s_int *s_size;
 139
 140    s_pattern pat[] = { "array", s_base_type, s_size };
 141    if (MATCH(expr, pat)) {
 142       const glsl_type *base_type = read_type(s_base_type);
 143       if (base_type == NULL) {
 144          ir_read_error(NULL, "when reading base type of array type");
 145          return NULL;
 146       }
 147
 148       return glsl_type::get_array_instance(base_type, s_size->value());
 149    }
 150
 151    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 152    if (type_sym == NULL) {
 153       ir_read_error(expr, "expected <type>");
 154       return NULL;
 155    }
 156
 157    const glsl_type *type = state->symbols->get_type(type_sym->value());
 158    if (type == NULL)
 159       ir_read_error(expr, "invalid type: %s", type_sym->value());
 160
 161    return type;
 162 }
 163
 164
 165 void
 166 ir_reader::scan_for_prototypes(exec_list *instructions, s_expression *expr)
 167 {
 168    s_list *list = SX_AS_LIST(expr);
 169    if (list == NULL) {
 170       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 171       return;
 172    }
 173
 174    foreach_in_list(s_list, sub, &list->subexpressions) {
 175       if (!sub->is_list())
 176          continue; // not a (function ...); ignore it.
 177
 178       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 179       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 180          continue; // not a (function ...); ignore it.
 181
 182       ir_function *f = read_function(sub, true);
 183       if (f == NULL)
 184          return;
 185       instructions->push_tail(f);
 186    }
 187 }
 188
 189 ir_function *
 190 ir_reader::read_function(s_expression *expr, bool skip_body)
 191 {
 192    bool added = false;
 193    s_symbol *name;
 194
 195    s_pattern pat[] = { "function", name };
 196    if (!PARTIAL_MATCH(expr, pat)) {
 197       ir_read_error(expr, "Expected (function <name> (signature ...) ...)");
 198       return NULL;
 199    }
 200
 201    ir_function *f = state->symbols->get_function(name->value());
 202    if (f == NULL) {
 203       f = new(mem_ctx) ir_function(name->value());
 204       added = state->symbols->add_function(f);
 205       assert(added);
 206    }
 207
 208    /* Skip over "function" tag and function name (which are guaranteed to be
 209     * present by the above PARTIAL_MATCH call).
 210     */
 211    exec_node *node = ((s_list *) expr)->subexpressions.head->next->next;
 212    for (/* nothing */; !node->is_tail_sentinel(); node = node->next) {
 213       s_expression *s_sig = (s_expression *) node;
 214       read_function_sig(f, s_sig, skip_body);
 215    }
 216    return added ? f : NULL;
 217 }
 218
 219 static bool
 220 always_available(const _mesa_glsl_parse_state *)
 221 {
 222    return true;
 223 }
 224
 225 void
 226 ir_reader::read_function_sig(ir_function *f, s_expression *expr, bool skip_body)
 227 {
 228    s_expression *type_expr;
 229    s_list *paramlist;
 230    s_list *body_list;
 231
 232    s_pattern pat[] = { "signature", type_expr, paramlist, body_list };
 233    if (!MATCH(expr, pat)) {
 234       ir_read_error(expr, "Expected (signature <type> (parameters ...) "
 235                           "(<instruction> ...))");
 236       return;
 237    }
 238
 239    const glsl_type *return_type = read_type(type_expr);
 240    if (return_type == NULL)
 241       return;
 242
 243    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 244    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 245       ir_read_error(paramlist, "Expected (parameters ...)");
 246       return;
 247    }
 248
 249    // Read the parameters list into a temporary place.
 250    exec_list hir_parameters;
 251    state->symbols->push_scope();
 252
 253    /* Skip over the "parameters" tag. */
 254    exec_node *node = paramlist->subexpressions.head->next;
 255    for (/* nothing */; !node->is_tail_sentinel(); node = node->next) {
 256       ir_variable *var = read_declaration((s_expression *) node);
 257       if (var == NULL)
 258          return;
 259
 260       hir_parameters.push_tail(var);
 261    }
 262
 263    ir_function_signature *sig =
 264       f->exact_matching_signature(state, &hir_parameters);
 265    if (sig == NULL && skip_body) {
 266       /* If scanning for prototypes, generate a new signature. */
 267       /* ir_reader doesn't know what languages support a given built-in, so
 268        * just say that they're always available.  For now, other mechanisms
 269        * guarantee the right built-ins are available.
 270        */
 271       sig = new(mem_ctx) ir_function_signature(return_type, always_available);
 272       f->add_signature(sig);
 273    } else if (sig != NULL) {
 274       const char *badvar = sig->qualifiers_match(&hir_parameters);
 275       if (badvar != NULL) {
 276          ir_read_error(expr, "function `%s' parameter `%s' qualifiers "
 277                        "don't match prototype", f->name, badvar);
 278          return;
 279       }
 280
 281       if (sig->return_type != return_type) {
 282          ir_read_error(expr, "function `%s' return type doesn't "
 283                        "match prototype", f->name);
 284          return;
 285       }
 286    } else {
 287       /* No prototype for this body exists - skip it. */
 288       state->symbols->pop_scope();
 289       return;
 290    }
 291    assert(sig != NULL);
 292
 293    sig->replace_parameters(&hir_parameters);
 294
 295    if (!skip_body && !body_list->subexpressions.is_empty()) {
 296       if (sig->is_defined) {
 297          ir_read_error(expr, "function %s redefined", f->name);
 298          return;
 299       }
 300       state->current_function = sig;
 301       read_instructions(&sig->body, body_list, NULL);
 302       state->current_function = NULL;
 303       sig->is_defined = true;
 304    }
 305
 306    state->symbols->pop_scope();
 307 }
 308
 309 void
 310 ir_reader::read_instructions(exec_list *instructions, s_expression *expr,
 311                              ir_loop *loop_ctx)
 312 {
 313    // Read in a list of instructions
 314    s_list *list = SX_AS_LIST(expr);
 315    if (list == NULL) {
 316       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 317       return;
 318    }
 319
 320    foreach_in_list(s_expression, sub, &list->subexpressions) {
 321       ir_instruction *ir = read_instruction(sub, loop_ctx);
 322       if (ir != NULL) {
 323          /* Global variable declarations should be moved to the top, before
 324           * any functions that might use them.  Functions are added to the
 325           * instruction stream when scanning for prototypes, so without this
 326           * hack, they always appear before variable declarations.
 327           */
 328          if (state->current_function == NULL && ir->as_variable() != NULL)
 329             instructions->push_head(ir);
 330          else
 331             instructions->push_tail(ir);
 332       }
 333    }
 334 }
 335
 336
 337 ir_instruction *
 338 ir_reader::read_instruction(s_expression *expr, ir_loop *loop_ctx)
 339 {
 340    s_symbol *symbol = SX_AS_SYMBOL(expr);
 341    if (symbol != NULL) {
 342       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 343          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
 344       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 345          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 346    }
 347
 348    s_list *list = SX_AS_LIST(expr);
 349    if (list == NULL || list->subexpressions.is_empty()) {
 350       ir_read_error(expr, "Invalid instruction.\n");
 351       return NULL;
 352    }
 353
 354    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 355    if (tag == NULL) {
 356       ir_read_error(expr, "expected instruction tag");
 357       return NULL;
 358    }
 359
 360    ir_instruction *inst = NULL;
 361    if (strcmp(tag->value(), "declare") == 0) {
 362       inst = read_declaration(list);
 363    } else if (strcmp(tag->value(), "assign") == 0) {
 364       inst = read_assignment(list);
 365    } else if (strcmp(tag->value(), "if") == 0) {
 366       inst = read_if(list, loop_ctx);
 367    } else if (strcmp(tag->value(), "loop") == 0) {
 368       inst = read_loop(list);
 369    } else if (strcmp(tag->value(), "call") == 0) {
 370       inst = read_call(list);
 371    } else if (strcmp(tag->value(), "return") == 0) {
 372       inst = read_return(list);
 373    } else if (strcmp(tag->value(), "function") == 0) {
 374       inst = read_function(list, false);
 375    } else if (strcmp(tag->value(), "emit-vertex") == 0) {
 376       inst = read_emit_vertex(list);
 377    } else if (strcmp(tag->value(), "end-primitive") == 0) {
 378       inst = read_end_primitive(list);
 379    } else if (strcmp(tag->value(), "barrier") == 0) {
 380       inst = read_barrier(list);
 381    } else {
 382       inst = read_rvalue(list);
 383       if (inst == NULL)
 384          ir_read_error(NULL, "when reading instruction");
 385    }
 386    return inst;
 387 }
 388
 389 ir_variable *
 390 ir_reader::read_declaration(s_expression *expr)
 391 {
 392    s_list *s_quals;
 393    s_expression *s_type;
 394    s_symbol *s_name;
 395
 396    s_pattern pat[] = { "declare", s_quals, s_type, s_name };
 397    if (!MATCH(expr, pat)) {
 398       ir_read_error(expr, "expected (declare (<qualifiers>) <type> <name>)");
 399       return NULL;
 400    }
 401
 402    const glsl_type *type = read_type(s_type);
 403    if (type == NULL)
 404       return NULL;
 405
 406    ir_variable *var = new(mem_ctx) ir_variable(type, s_name->value(),
 407                                                ir_var_auto);
 408
 409    foreach_in_list(s_symbol, qualifier, &s_quals->subexpressions) {
 410       if (!qualifier->is_symbol()) {
 411          ir_read_error(expr, "qualifier list must contain only symbols");
 412          return NULL;
 413       }
 414
 415       // FINISHME: Check for duplicate/conflicting qualifiers.
 416       if (strcmp(qualifier->value(), "centroid") == 0) {
 417          var->data.centroid = 1;
 418       } else if (strcmp(qualifier->value(), "sample") == 0) {
 419          var->data.sample = 1;
 420       } else if (strcmp(qualifier->value(), "patch") == 0) {
 421          var->data.patch = 1;
 422       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 423          var->data.invariant = 1;
 424       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 425          var->data.mode = ir_var_uniform;
 426       } else if (strcmp(qualifier->value(), "shader_storage") == 0) {
 427          var->data.mode = ir_var_shader_storage;
 428       } else if (strcmp(qualifier->value(), "auto") == 0) {
 429          var->data.mode = ir_var_auto;
 430       } else if (strcmp(qualifier->value(), "in") == 0) {
 431          var->data.mode = ir_var_function_in;
 432       } else if (strcmp(qualifier->value(), "shader_in") == 0) {
 433          var->data.mode = ir_var_shader_in;
 434       } else if (strcmp(qualifier->value(), "const_in") == 0) {
 435          var->data.mode = ir_var_const_in;
 436       } else if (strcmp(qualifier->value(), "out") == 0) {
 437          var->data.mode = ir_var_function_out;
 438       } else if (strcmp(qualifier->value(), "shader_out") == 0) {
 439          var->data.mode = ir_var_shader_out;
 440       } else if (strcmp(qualifier->value(), "inout") == 0) {
 441          var->data.mode = ir_var_function_inout;
 442       } else if (strcmp(qualifier->value(), "temporary") == 0) {
 443          var->data.mode = ir_var_temporary;
 444       } else if (strcmp(qualifier->value(), "stream1") == 0) {
 445          var->data.stream = 1;
 446       } else if (strcmp(qualifier->value(), "stream2") == 0) {
 447          var->data.stream = 2;
 448       } else if (strcmp(qualifier->value(), "stream3") == 0) {
 449          var->data.stream = 3;
 450       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 451          var->data.interpolation = INTERP_QUALIFIER_SMOOTH;
 452       } else if (strcmp(qualifier->value(), "flat") == 0) {
 453          var->data.interpolation = INTERP_QUALIFIER_FLAT;
 454       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 455          var->data.interpolation = INTERP_QUALIFIER_NOPERSPECTIVE;
 456       } else {
 457          ir_read_error(expr, "unknown qualifier: %s", qualifier->value());
 458          return NULL;
 459       }
 460    }
 461
 462    // Add the variable to the symbol table
 463    state->symbols->add_variable(var);
 464
 465    return var;
 466 }
 467
 468
 469 ir_if *
 470 ir_reader::read_if(s_expression *expr, ir_loop *loop_ctx)
 471 {
 472    s_expression *s_cond;
 473    s_expression *s_then;
 474    s_expression *s_else;
 475
 476    s_pattern pat[] = { "if", s_cond, s_then, s_else };
 477    if (!MATCH(expr, pat)) {
 478       ir_read_error(expr, "expected (if <condition> (<then>...) (<else>...))");
 479       return NULL;
 480    }
 481
 482    ir_rvalue *condition = read_rvalue(s_cond);
 483    if (condition == NULL) {
 484       ir_read_error(NULL, "when reading condition of (if ...)");
 485       return NULL;
 486    }
 487
 488    ir_if *iff = new(mem_ctx) ir_if(condition);
 489
 490    read_instructions(&iff->then_instructions, s_then, loop_ctx);
 491    read_instructions(&iff->else_instructions, s_else, loop_ctx);
 492    if (state->error) {
 493       delete iff;
 494       iff = NULL;
 495    }
 496    return iff;
 497 }
 498
 499
 500 ir_loop *
 501 ir_reader::read_loop(s_expression *expr)
 502 {
 503    s_expression *s_body;
 504
 505    s_pattern loop_pat[] = { "loop", s_body };
 506    if (!MATCH(expr, loop_pat)) {
 507       ir_read_error(expr, "expected (loop <body>)");
 508       return NULL;
 509    }
 510
 511    ir_loop *loop = new(mem_ctx) ir_loop;
 512
 513    read_instructions(&loop->body_instructions, s_body, loop);
 514    if (state->error) {
 515       delete loop;
 516       loop = NULL;
 517    }
 518    return loop;
 519 }
 520
 521
 522 ir_return *
 523 ir_reader::read_return(s_expression *expr)
 524 {
 525    s_expression *s_retval;
 526
 527    s_pattern return_value_pat[] = { "return", s_retval};
 528    s_pattern return_void_pat[] = { "return" };
 529    if (MATCH(expr, return_value_pat)) {
 530       ir_rvalue *retval = read_rvalue(s_retval);
 531       if (retval == NULL) {
 532          ir_read_error(NULL, "when reading return value");
 533          return NULL;
 534       }
 535       return new(mem_ctx) ir_return(retval);
 536    } else if (MATCH(expr, return_void_pat)) {
 537       return new(mem_ctx) ir_return;
 538    } else {
 539       ir_read_error(expr, "expected (return <rvalue>) or (return)");
 540       return NULL;
 541    }
 542 }
 543
 544
 545 ir_rvalue *
 546 ir_reader::read_rvalue(s_expression *expr)
 547 {
 548    s_list *list = SX_AS_LIST(expr);
 549    if (list == NULL || list->subexpressions.is_empty())
 550       return NULL;
 551
 552    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 553    if (tag == NULL) {
 554       ir_read_error(expr, "expected rvalue tag");
 555       return NULL;
 556    }
 557
 558    ir_rvalue *rvalue = read_dereference(list);
 559    if (rvalue != NULL || state->error)
 560       return rvalue;
 561    else if (strcmp(tag->value(), "swiz") == 0) {
 562       rvalue = read_swizzle(list);
 563    } else if (strcmp(tag->value(), "expression") == 0) {
 564       rvalue = read_expression(list);
 565    } else if (strcmp(tag->value(), "constant") == 0) {
 566       rvalue = read_constant(list);
 567    } else {
 568       rvalue = read_texture(list);
 569       if (rvalue == NULL && !state->error)
 570          ir_read_error(expr, "unrecognized rvalue tag: %s", tag->value());
 571    }
 572
 573    return rvalue;
 574 }
 575
 576 ir_assignment *
 577 ir_reader::read_assignment(s_expression *expr)
 578 {
 579    s_expression *cond_expr = NULL;
 580    s_expression *lhs_expr, *rhs_expr;
 581    s_list       *mask_list;
 582
 583    s_pattern pat4[] = { "assign",            mask_list, lhs_expr, rhs_expr };
 584    s_pattern pat5[] = { "assign", cond_expr, mask_list, lhs_expr, rhs_expr };
 585    if (!MATCH(expr, pat4) && !MATCH(expr, pat5)) {
 586       ir_read_error(expr, "expected (assign [<condition>] (<write mask>) "
 587                           "<lhs> <rhs>)");
 588       return NULL;
 589    }
 590
 591    ir_rvalue *condition = NULL;
 592    if (cond_expr != NULL) {
 593       condition = read_rvalue(cond_expr);
 594       if (condition == NULL) {
 595          ir_read_error(NULL, "when reading condition of assignment");
 596          return NULL;
 597       }
 598    }
 599
 600    unsigned mask = 0;
 601
 602    s_symbol *mask_symbol;
 603    s_pattern mask_pat[] = { mask_symbol };
 604    if (MATCH(mask_list, mask_pat)) {
 605       const char *mask_str = mask_symbol->value();
 606       unsigned mask_length = strlen(mask_str);
 607       if (mask_length > 4) {
 608          ir_read_error(expr, "invalid write mask: %s", mask_str);
 609          return NULL;
 610       }
 611
 612       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
 613
 614       for (unsigned i = 0; i < mask_length; i++) {
 615          if (mask_str[i] < 'w' || mask_str[i] > 'z') {
 616             ir_read_error(expr, "write mask contains invalid character: %c",
 617                           mask_str[i]);
 618             return NULL;
 619          }
 620          mask |= 1 << idx_map[mask_str[i] - 'w'];
 621       }
 622    } else if (!mask_list->subexpressions.is_empty()) {
 623       ir_read_error(mask_list, "expected () or (<write mask>)");
 624       return NULL;
 625    }
 626
 627    ir_dereference *lhs = read_dereference(lhs_expr);
 628    if (lhs == NULL) {
 629       ir_read_error(NULL, "when reading left-hand side of assignment");
 630       return NULL;
 631    }
 632
 633    ir_rvalue *rhs = read_rvalue(rhs_expr);
 634    if (rhs == NULL) {
 635       ir_read_error(NULL, "when reading right-hand side of assignment");
 636       return NULL;
 637    }
 638
 639    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
 640       ir_read_error(expr, "non-zero write mask required.");
 641       return NULL;
 642    }
 643
 644    return new(mem_ctx) ir_assignment(lhs, rhs, condition, mask);
 645 }
 646
 647 ir_call *
 648 ir_reader::read_call(s_expression *expr)
 649 {
 650    s_symbol *name;
 651    s_list *params;
 652    s_list *s_return = NULL;
 653
 654    ir_dereference_variable *return_deref = NULL;
 655
 656    s_pattern void_pat[] = { "call", name, params };
 657    s_pattern non_void_pat[] = { "call", name, s_return, params };
 658    if (MATCH(expr, non_void_pat)) {
 659       return_deref = read_var_ref(s_return);
 660       if (return_deref == NULL) {
 661          ir_read_error(s_return, "when reading a call's return storage");
 662          return NULL;
 663       }
 664    } else if (!MATCH(expr, void_pat)) {
 665       ir_read_error(expr, "expected (call <name> [<deref>] (<param> ...))");
 666       return NULL;
 667    }
 668
 669    exec_list parameters;
 670
 671    foreach_in_list(s_expression, e, &params->subexpressions) {
 672       ir_rvalue *param = read_rvalue(e);
 673       if (param == NULL) {
 674          ir_read_error(e, "when reading parameter to function call");
 675          return NULL;
 676       }
 677       parameters.push_tail(param);
 678    }
 679
 680    ir_function *f = state->symbols->get_function(name->value());
 681    if (f == NULL) {
 682       ir_read_error(expr, "found call to undefined function %s",
 683                     name->value());
 684       return NULL;
 685    }
 686
 687    ir_function_signature *callee =
 688       f->matching_signature(state, &parameters, true);
 689    if (callee == NULL) {
 690       ir_read_error(expr, "couldn't find matching signature for function "
 691                     "%s", name->value());
 692       return NULL;
 693    }
 694
 695    if (callee->return_type == glsl_type::void_type && return_deref) {
 696       ir_read_error(expr, "call has return value storage but void type");
 697       return NULL;
 698    } else if (callee->return_type != glsl_type::void_type && !return_deref) {
 699       ir_read_error(expr, "call has non-void type but no return value storage");
 700       return NULL;
 701    }
 702
 703    return new(mem_ctx) ir_call(callee, return_deref, &parameters);
 704 }
 705
 706 ir_expression *
 707 ir_reader::read_expression(s_expression *expr)
 708 {
 709    s_expression *s_type;
 710    s_symbol *s_op;
 711    s_expression *s_arg[4] = {NULL};
 712
 713    s_pattern pat[] = { "expression", s_type, s_op, s_arg[0] };
 714    if (!PARTIAL_MATCH(expr, pat)) {
 715       ir_read_error(expr, "expected (expression <type> <operator> "
 716                           "<operand> [<operand>] [<operand>] [<operand>])");
 717       return NULL;
 718    }
 719    s_arg[1] = (s_expression *) s_arg[0]->next; // may be tail sentinel
 720    s_arg[2] = (s_expression *) s_arg[1]->next; // may be tail sentinel or NULL
 721    if (s_arg[2])
 722       s_arg[3] = (s_expression *) s_arg[2]->next; // may be tail sentinel or NULL
 723
 724    const glsl_type *type = read_type(s_type);
 725    if (type == NULL)
 726       return NULL;
 727
 728    /* Read the operator */
 729    ir_expression_operation op = ir_expression::get_operator(s_op->value());
 730    if (op == (ir_expression_operation) -1) {
 731       ir_read_error(expr, "invalid operator: %s", s_op->value());
 732       return NULL;
 733    }
 734
 735    /* Skip "expression" <type> <operation> by subtracting 3. */
 736    int num_operands = (int) ((s_list *) expr)->subexpressions.length() - 3;
 737
 738    int expected_operands = ir_expression::get_num_operands(op);
 739    if (num_operands != expected_operands) {
 740       ir_read_error(expr, "found %d expression operands, expected %d",
 741                     num_operands, expected_operands);
 742       return NULL;
 743    }
 744
 745    ir_rvalue *arg[4] = {NULL};
 746    for (int i = 0; i < num_operands; i++) {
 747       arg[i] = read_rvalue(s_arg[i]);
 748       if (arg[i] == NULL) {
 749          ir_read_error(NULL, "when reading operand #%d of %s", i, s_op->value());
 750          return NULL;
 751       }
 752    }
 753
 754    return new(mem_ctx) ir_expression(op, type, arg[0], arg[1], arg[2], arg[3]);
 755 }
 756
 757 ir_swizzle *
 758 ir_reader::read_swizzle(s_expression *expr)
 759 {
 760    s_symbol *swiz;
 761    s_expression *sub;
 762
 763    s_pattern pat[] = { "swiz", swiz, sub };
 764    if (!MATCH(expr, pat)) {
 765       ir_read_error(expr, "expected (swiz <swizzle> <rvalue>)");
 766       return NULL;
 767    }
 768
 769    if (strlen(swiz->value()) > 4) {
 770       ir_read_error(expr, "expected a valid swizzle; found %s", swiz->value());
 771       return NULL;
 772    }
 773
 774    ir_rvalue *rvalue = read_rvalue(sub);
 775    if (rvalue == NULL)
 776       return NULL;
 777
 778    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 779                                        rvalue->type->vector_elements);
 780    if (ir == NULL)
 781       ir_read_error(expr, "invalid swizzle");
 782
 783    return ir;
 784 }
 785
 786 ir_constant *
 787 ir_reader::read_constant(s_expression *expr)
 788 {
 789    s_expression *type_expr;
 790    s_list *values;
 791
 792    s_pattern pat[] = { "constant", type_expr, values };
 793    if (!MATCH(expr, pat)) {
 794       ir_read_error(expr, "expected (constant <type> (...))");
 795       return NULL;
 796    }
 797
 798    const glsl_type *type = read_type(type_expr);
 799    if (type == NULL)
 800       return NULL;
 801
 802    if (values == NULL) {
 803       ir_read_error(expr, "expected (constant <type> (...))");
 804       return NULL;
 805    }
 806
 807    if (type->is_array()) {
 808       unsigned elements_supplied = 0;
 809       exec_list elements;
 810       foreach_in_list(s_expression, elt, &values->subexpressions) {
 811          ir_constant *ir_elt = read_constant(elt);
 812          if (ir_elt == NULL)
 813             return NULL;
 814          elements.push_tail(ir_elt);
 815          elements_supplied++;
 816       }
 817
 818       if (elements_supplied != type->length) {
 819          ir_read_error(values, "expected exactly %u array elements, "
 820                        "given %u", type->length, elements_supplied);
 821          return NULL;
 822       }
 823       return new(mem_ctx) ir_constant(type, &elements);
 824    }
 825
 826    ir_constant_data data = { { 0 } };
 827
 828    // Read in list of values (at most 16).
 829    unsigned k = 0;
 830    foreach_in_list(s_expression, expr, &values->subexpressions) {
 831       if (k >= 16) {
 832          ir_read_error(values, "expected at most 16 numbers");
 833          return NULL;
 834       }
 835
 836       if (type->base_type == GLSL_TYPE_FLOAT) {
 837          s_number *value = SX_AS_NUMBER(expr);
 838          if (value == NULL) {
 839             ir_read_error(values, "expected numbers");
 840             return NULL;
 841          }
 842          data.f[k] = value->fvalue();
 843       } else {
 844          s_int *value = SX_AS_INT(expr);
 845          if (value == NULL) {
 846             ir_read_error(values, "expected integers");
 847             return NULL;
 848          }
 849
 850          switch (type->base_type) {
 851          case GLSL_TYPE_UINT: {
 852             data.u[k] = value->value();
 853             break;
 854          }
 855          case GLSL_TYPE_INT: {
 856             data.i[k] = value->value();
 857             break;
 858          }
 859          case GLSL_TYPE_BOOL: {
 860             data.b[k] = value->value();
 861             break;
 862          }
 863          default:
 864             ir_read_error(values, "unsupported constant type");
 865             return NULL;
 866          }
 867       }
 868       ++k;
 869    }
 870    if (k != type->components()) {
 871       ir_read_error(values, "expected %u constant values, found %u",
 872                     type->components(), k);
 873       return NULL;
 874    }
 875
 876    return new(mem_ctx) ir_constant(type, &data);
 877 }
 878
 879 ir_dereference_variable *
 880 ir_reader::read_var_ref(s_expression *expr)
 881 {
 882    s_symbol *s_var;
 883    s_pattern var_pat[] = { "var_ref", s_var };
 884
 885    if (MATCH(expr, var_pat)) {
 886       ir_variable *var = state->symbols->get_variable(s_var->value());
 887       if (var == NULL) {
 888          ir_read_error(expr, "undeclared variable: %s", s_var->value());
 889          return NULL;
 890       }
 891       return new(mem_ctx) ir_dereference_variable(var);
 892    }
 893    return NULL;
 894 }
 895
 896 ir_dereference *
 897 ir_reader::read_dereference(s_expression *expr)
 898 {
 899    s_expression *s_subject;
 900    s_expression *s_index;
 901    s_symbol *s_field;
 902
 903    s_pattern array_pat[] = { "array_ref", s_subject, s_index };
 904    s_pattern record_pat[] = { "record_ref", s_subject, s_field };
 905
 906    ir_dereference_variable *var_ref = read_var_ref(expr);
 907    if (var_ref != NULL) {
 908       return var_ref;
 909    } else if (MATCH(expr, array_pat)) {
 910       ir_rvalue *subject = read_rvalue(s_subject);
 911       if (subject == NULL) {
 912          ir_read_error(NULL, "when reading the subject of an array_ref");
 913          return NULL;
 914       }
 915
 916       ir_rvalue *idx = read_rvalue(s_index);
 917       if (idx == NULL) {
 918          ir_read_error(NULL, "when reading the index of an array_ref");
 919          return NULL;
 920       }
 921       return new(mem_ctx) ir_dereference_array(subject, idx);
 922    } else if (MATCH(expr, record_pat)) {
 923       ir_rvalue *subject = read_rvalue(s_subject);
 924       if (subject == NULL) {
 925          ir_read_error(NULL, "when reading the subject of a record_ref");
 926          return NULL;
 927       }
 928       return new(mem_ctx) ir_dereference_record(subject, s_field->value());
 929    }
 930    return NULL;
 931 }
 932
 933 ir_texture *
 934 ir_reader::read_texture(s_expression *expr)
 935 {
 936    s_symbol *tag = NULL;
 937    s_expression *s_type = NULL;
 938    s_expression *s_sampler = NULL;
 939    s_expression *s_coord = NULL;
 940    s_expression *s_offset = NULL;
 941    s_expression *s_proj = NULL;
 942    s_list *s_shadow = NULL;
 943    s_expression *s_lod = NULL;
 944    s_expression *s_sample_index = NULL;
 945    s_expression *s_component = NULL;
 946
 947    ir_texture_opcode op = ir_tex; /* silence warning */
 948
 949    s_pattern tex_pattern[] =
 950       { "tex", s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow };
 951    s_pattern lod_pattern[] =
 952       { "lod", s_type, s_sampler, s_coord };
 953    s_pattern txf_pattern[] =
 954       { "txf", s_type, s_sampler, s_coord, s_offset, s_lod };
 955    s_pattern txf_ms_pattern[] =
 956       { "txf_ms", s_type, s_sampler, s_coord, s_sample_index };
 957    s_pattern txs_pattern[] =
 958       { "txs", s_type, s_sampler, s_lod };
 959    s_pattern tg4_pattern[] =
 960       { "tg4", s_type, s_sampler, s_coord, s_offset, s_component };
 961    s_pattern query_levels_pattern[] =
 962       { "query_levels", s_type, s_sampler };
 963    s_pattern texture_samples_pattern[] =
 964       { "samples", s_type, s_sampler };
 965    s_pattern other_pattern[] =
 966       { tag, s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow, s_lod };
 967
 968    if (MATCH(expr, lod_pattern)) {
 969       op = ir_lod;
 970    } else if (MATCH(expr, tex_pattern)) {
 971       op = ir_tex;
 972    } else if (MATCH(expr, txf_pattern)) {
 973       op = ir_txf;
 974    } else if (MATCH(expr, txf_ms_pattern)) {
 975       op = ir_txf_ms;
 976    } else if (MATCH(expr, txs_pattern)) {
 977       op = ir_txs;
 978    } else if (MATCH(expr, tg4_pattern)) {
 979       op = ir_tg4;
 980    } else if (MATCH(expr, query_levels_pattern)) {
 981       op = ir_query_levels;
 982    } else if (MATCH(expr, texture_samples_pattern)) {
 983       op = ir_texture_samples;
 984    } else if (MATCH(expr, other_pattern)) {
 985       op = ir_texture::get_opcode(tag->value());
 986       if (op == (ir_texture_opcode) -1)
 987          return NULL;
 988    } else {
 989       ir_read_error(NULL, "unexpected texture pattern %s", tag->value());
 990       return NULL;
 991    }
 992
 993    ir_texture *tex = new(mem_ctx) ir_texture(op);
 994
 995    // Read return type
 996    const glsl_type *type = read_type(s_type);
 997    if (type == NULL) {
 998       ir_read_error(NULL, "when reading type in (%s ...)",
 999                     tex->opcode_string());
1000       return NULL;
1001    }
1002
1003    // Read sampler (must be a deref)
1004    ir_dereference *sampler = read_dereference(s_sampler);
1005    if (sampler == NULL) {
1006       ir_read_error(NULL, "when reading sampler in (%s ...)",
1007                     tex->opcode_string());
1008       return NULL;
1009    }
1010    tex->set_sampler(sampler, type);
1011
1012    if (op != ir_txs) {
1013       // Read coordinate (any rvalue)
1014       tex->coordinate = read_rvalue(s_coord);
1015       if (tex->coordinate == NULL) {
1016          ir_read_error(NULL, "when reading coordinate in (%s ...)",
1017                        tex->opcode_string());
1018          return NULL;
1019       }
1020
1021       if (op != ir_txf_ms && op != ir_lod) {
1022          // Read texel offset - either 0 or an rvalue.
1023          s_int *si_offset = SX_AS_INT(s_offset);
1024          if (si_offset == NULL || si_offset->value() != 0) {
1025             tex->offset = read_rvalue(s_offset);
1026             if (tex->offset == NULL) {
1027                ir_read_error(s_offset, "expected 0 or an expression");
1028                return NULL;
1029             }
1030          }
1031       }
1032    }
1033
1034    if (op != ir_txf && op != ir_txf_ms &&
1035        op != ir_txs && op != ir_lod && op != ir_tg4 &&
1036        op != ir_query_levels && op != ir_texture_samples) {
1037       s_int *proj_as_int = SX_AS_INT(s_proj);
1038       if (proj_as_int && proj_as_int->value() == 1) {
1039          tex->projector = NULL;
1040       } else {
1041          tex->projector = read_rvalue(s_proj);
1042          if (tex->projector == NULL) {
1043             ir_read_error(NULL, "when reading projective divide in (%s ..)",
1044                           tex->opcode_string());
1045             return NULL;
1046          }
1047       }
1048
1049       if (s_shadow->subexpressions.is_empty()) {
1050          tex->shadow_comparitor = NULL;
1051       } else {
1052          tex->shadow_comparitor = read_rvalue(s_shadow);
1053          if (tex->shadow_comparitor == NULL) {
1054             ir_read_error(NULL, "when reading shadow comparitor in (%s ..)",
1055                           tex->opcode_string());
1056             return NULL;
1057          }
1058       }
1059    }
1060
1061    switch (op) {
1062    case ir_txb:
1063       tex->lod_info.bias = read_rvalue(s_lod);
1064       if (tex->lod_info.bias == NULL) {
1065          ir_read_error(NULL, "when reading LOD bias in (txb ...)");
1066          return NULL;
1067       }
1068       break;
1069    case ir_txl:
1070    case ir_txf:
1071    case ir_txs:
1072       tex->lod_info.lod = read_rvalue(s_lod);
1073       if (tex->lod_info.lod == NULL) {
1074          ir_read_error(NULL, "when reading LOD in (%s ...)",
1075                        tex->opcode_string());
1076          return NULL;
1077       }
1078       break;
1079    case ir_txf_ms:
1080       tex->lod_info.sample_index = read_rvalue(s_sample_index);
1081       if (tex->lod_info.sample_index == NULL) {
1082          ir_read_error(NULL, "when reading sample_index in (txf_ms ...)");
1083          return NULL;
1084       }
1085       break;
1086    case ir_txd: {
1087       s_expression *s_dx, *s_dy;
1088       s_pattern dxdy_pat[] = { s_dx, s_dy };
1089       if (!MATCH(s_lod, dxdy_pat)) {
1090          ir_read_error(s_lod, "expected (dPdx dPdy) in (txd ...)");
1091          return NULL;
1092       }
1093       tex->lod_info.grad.dPdx = read_rvalue(s_dx);
1094       if (tex->lod_info.grad.dPdx == NULL) {
1095          ir_read_error(NULL, "when reading dPdx in (txd ...)");
1096          return NULL;
1097       }
1098       tex->lod_info.grad.dPdy = read_rvalue(s_dy);
1099       if (tex->lod_info.grad.dPdy == NULL) {
1100          ir_read_error(NULL, "when reading dPdy in (txd ...)");
1101          return NULL;
1102       }
1103       break;
1104    }
1105    case ir_tg4:
1106       tex->lod_info.component = read_rvalue(s_component);
1107       if (tex->lod_info.component == NULL) {
1108          ir_read_error(NULL, "when reading component in (tg4 ...)");
1109          return NULL;
1110       }
1111       break;
1112    default:
1113       // tex and lod don't have any extra parameters.
1114       break;
1115    };
1116    return tex;
1117 }
1118
1119 ir_emit_vertex *
1120 ir_reader::read_emit_vertex(s_expression *expr)
1121 {
1122    s_expression *s_stream = NULL;
1123
1124    s_pattern pat[] = { "emit-vertex", s_stream };
1125
1126    if (MATCH(expr, pat)) {
1127       ir_rvalue *stream = read_dereference(s_stream);
1128       if (stream == NULL) {
1129          ir_read_error(NULL, "when reading stream info in emit-vertex");
1130          return NULL;
1131       }
1132       return new(mem_ctx) ir_emit_vertex(stream);
1133    }
1134    ir_read_error(NULL, "when reading emit-vertex");
1135    return NULL;
1136 }
1137
1138 ir_end_primitive *
1139 ir_reader::read_end_primitive(s_expression *expr)
1140 {
1141    s_expression *s_stream = NULL;
1142
1143    s_pattern pat[] = { "end-primitive", s_stream };
1144
1145    if (MATCH(expr, pat)) {
1146       ir_rvalue *stream = read_dereference(s_stream);
1147       if (stream == NULL) {
1148          ir_read_error(NULL, "when reading stream info in end-primitive");
1149          return NULL;
1150       }
1151       return new(mem_ctx) ir_end_primitive(stream);
1152    }
1153    ir_read_error(NULL, "when reading end-primitive");
1154    return NULL;
1155 }
1156
1157 ir_barrier *
1158 ir_reader::read_barrier(s_expression *expr)
1159 {
1160    s_pattern pat[] = { "barrier" };
1161
1162    if (MATCH(expr, pat)) {
1163       return new(mem_ctx) ir_barrier();
1164    }
1165    ir_read_error(NULL, "when reading barrier");
1166    return NULL;
1167 }