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Member "mesa-20.1.8/src/compiler/glsl/ir_reader.cpp" (16 Sep 2020, 34867 Bytes) of package /linux/misc/mesa-20.1.8.tar.xz:


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    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.get_head_raw()->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.get_head_raw()->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(), "explicit_invariant") == 0) {
  423          var->data.explicit_invariant = true;
  424       } else if (strcmp(qualifier->value(), "invariant") == 0) {
  425          var->data.invariant = true;
  426       } else if (strcmp(qualifier->value(), "uniform") == 0) {
  427      var->data.mode = ir_var_uniform;
  428       } else if (strcmp(qualifier->value(), "shader_storage") == 0) {
  429      var->data.mode = ir_var_shader_storage;
  430       } else if (strcmp(qualifier->value(), "auto") == 0) {
  431      var->data.mode = ir_var_auto;
  432       } else if (strcmp(qualifier->value(), "in") == 0) {
  433      var->data.mode = ir_var_function_in;
  434       } else if (strcmp(qualifier->value(), "shader_in") == 0) {
  435          var->data.mode = ir_var_shader_in;
  436       } else if (strcmp(qualifier->value(), "const_in") == 0) {
  437      var->data.mode = ir_var_const_in;
  438       } else if (strcmp(qualifier->value(), "out") == 0) {
  439      var->data.mode = ir_var_function_out;
  440       } else if (strcmp(qualifier->value(), "shader_out") == 0) {
  441      var->data.mode = ir_var_shader_out;
  442       } else if (strcmp(qualifier->value(), "inout") == 0) {
  443      var->data.mode = ir_var_function_inout;
  444       } else if (strcmp(qualifier->value(), "temporary") == 0) {
  445      var->data.mode = ir_var_temporary;
  446       } else if (strcmp(qualifier->value(), "stream1") == 0) {
  447      var->data.stream = 1;
  448       } else if (strcmp(qualifier->value(), "stream2") == 0) {
  449      var->data.stream = 2;
  450       } else if (strcmp(qualifier->value(), "stream3") == 0) {
  451      var->data.stream = 3;
  452       } else if (strcmp(qualifier->value(), "smooth") == 0) {
  453      var->data.interpolation = INTERP_MODE_SMOOTH;
  454       } else if (strcmp(qualifier->value(), "flat") == 0) {
  455      var->data.interpolation = INTERP_MODE_FLAT;
  456       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
  457      var->data.interpolation = INTERP_MODE_NOPERSPECTIVE;
  458       } else {
  459      ir_read_error(expr, "unknown qualifier: %s", qualifier->value());
  460      return NULL;
  461       }
  462    }
  463 
  464    // Add the variable to the symbol table
  465    state->symbols->add_variable(var);
  466 
  467    return var;
  468 }
  469 
  470 
  471 ir_if *
  472 ir_reader::read_if(s_expression *expr, ir_loop *loop_ctx)
  473 {
  474    s_expression *s_cond;
  475    s_expression *s_then;
  476    s_expression *s_else;
  477 
  478    s_pattern pat[] = { "if", s_cond, s_then, s_else };
  479    if (!MATCH(expr, pat)) {
  480       ir_read_error(expr, "expected (if <condition> (<then>...) (<else>...))");
  481       return NULL;
  482    }
  483 
  484    ir_rvalue *condition = read_rvalue(s_cond);
  485    if (condition == NULL) {
  486       ir_read_error(NULL, "when reading condition of (if ...)");
  487       return NULL;
  488    }
  489 
  490    ir_if *iff = new(mem_ctx) ir_if(condition);
  491 
  492    read_instructions(&iff->then_instructions, s_then, loop_ctx);
  493    read_instructions(&iff->else_instructions, s_else, loop_ctx);
  494    if (state->error) {
  495       delete iff;
  496       iff = NULL;
  497    }
  498    return iff;
  499 }
  500 
  501 
  502 ir_loop *
  503 ir_reader::read_loop(s_expression *expr)
  504 {
  505    s_expression *s_body;
  506 
  507    s_pattern loop_pat[] = { "loop", s_body };
  508    if (!MATCH(expr, loop_pat)) {
  509       ir_read_error(expr, "expected (loop <body>)");
  510       return NULL;
  511    }
  512 
  513    ir_loop *loop = new(mem_ctx) ir_loop;
  514 
  515    read_instructions(&loop->body_instructions, s_body, loop);
  516    if (state->error) {
  517       delete loop;
  518       loop = NULL;
  519    }
  520    return loop;
  521 }
  522 
  523 
  524 ir_return *
  525 ir_reader::read_return(s_expression *expr)
  526 {
  527    s_expression *s_retval;
  528 
  529    s_pattern return_value_pat[] = { "return", s_retval};
  530    s_pattern return_void_pat[] = { "return" };
  531    if (MATCH(expr, return_value_pat)) {
  532       ir_rvalue *retval = read_rvalue(s_retval);
  533       if (retval == NULL) {
  534          ir_read_error(NULL, "when reading return value");
  535          return NULL;
  536       }
  537       return new(mem_ctx) ir_return(retval);
  538    } else if (MATCH(expr, return_void_pat)) {
  539       return new(mem_ctx) ir_return;
  540    } else {
  541       ir_read_error(expr, "expected (return <rvalue>) or (return)");
  542       return NULL;
  543    }
  544 }
  545 
  546 
  547 ir_rvalue *
  548 ir_reader::read_rvalue(s_expression *expr)
  549 {
  550    s_list *list = SX_AS_LIST(expr);
  551    if (list == NULL || list->subexpressions.is_empty())
  552       return NULL;
  553 
  554    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
  555    if (tag == NULL) {
  556       ir_read_error(expr, "expected rvalue tag");
  557       return NULL;
  558    }
  559 
  560    ir_rvalue *rvalue = read_dereference(list);
  561    if (rvalue != NULL || state->error)
  562       return rvalue;
  563    else if (strcmp(tag->value(), "swiz") == 0) {
  564       rvalue = read_swizzle(list);
  565    } else if (strcmp(tag->value(), "expression") == 0) {
  566       rvalue = read_expression(list);
  567    } else if (strcmp(tag->value(), "constant") == 0) {
  568       rvalue = read_constant(list);
  569    } else {
  570       rvalue = read_texture(list);
  571       if (rvalue == NULL && !state->error)
  572      ir_read_error(expr, "unrecognized rvalue tag: %s", tag->value());
  573    }
  574 
  575    return rvalue;
  576 }
  577 
  578 ir_assignment *
  579 ir_reader::read_assignment(s_expression *expr)
  580 {
  581    s_expression *cond_expr = NULL;
  582    s_expression *lhs_expr, *rhs_expr;
  583    s_list       *mask_list;
  584 
  585    s_pattern pat4[] = { "assign",            mask_list, lhs_expr, rhs_expr };
  586    s_pattern pat5[] = { "assign", cond_expr, mask_list, lhs_expr, rhs_expr };
  587    if (!MATCH(expr, pat4) && !MATCH(expr, pat5)) {
  588       ir_read_error(expr, "expected (assign [<condition>] (<write mask>) "
  589               "<lhs> <rhs>)");
  590       return NULL;
  591    }
  592 
  593    ir_rvalue *condition = NULL;
  594    if (cond_expr != NULL) {
  595       condition = read_rvalue(cond_expr);
  596       if (condition == NULL) {
  597      ir_read_error(NULL, "when reading condition of assignment");
  598      return NULL;
  599       }
  600    }
  601 
  602    unsigned mask = 0;
  603 
  604    s_symbol *mask_symbol;
  605    s_pattern mask_pat[] = { mask_symbol };
  606    if (MATCH(mask_list, mask_pat)) {
  607       const char *mask_str = mask_symbol->value();
  608       unsigned mask_length = strlen(mask_str);
  609       if (mask_length > 4) {
  610      ir_read_error(expr, "invalid write mask: %s", mask_str);
  611      return NULL;
  612       }
  613 
  614       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
  615 
  616       for (unsigned i = 0; i < mask_length; i++) {
  617      if (mask_str[i] < 'w' || mask_str[i] > 'z') {
  618         ir_read_error(expr, "write mask contains invalid character: %c",
  619               mask_str[i]);
  620         return NULL;
  621      }
  622      mask |= 1 << idx_map[mask_str[i] - 'w'];
  623       }
  624    } else if (!mask_list->subexpressions.is_empty()) {
  625       ir_read_error(mask_list, "expected () or (<write mask>)");
  626       return NULL;
  627    }
  628 
  629    ir_dereference *lhs = read_dereference(lhs_expr);
  630    if (lhs == NULL) {
  631       ir_read_error(NULL, "when reading left-hand side of assignment");
  632       return NULL;
  633    }
  634 
  635    ir_rvalue *rhs = read_rvalue(rhs_expr);
  636    if (rhs == NULL) {
  637       ir_read_error(NULL, "when reading right-hand side of assignment");
  638       return NULL;
  639    }
  640 
  641    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
  642       ir_read_error(expr, "non-zero write mask required.");
  643       return NULL;
  644    }
  645 
  646    return new(mem_ctx) ir_assignment(lhs, rhs, condition, mask);
  647 }
  648 
  649 ir_call *
  650 ir_reader::read_call(s_expression *expr)
  651 {
  652    s_symbol *name;
  653    s_list *params;
  654    s_list *s_return = NULL;
  655 
  656    ir_dereference_variable *return_deref = NULL;
  657 
  658    s_pattern void_pat[] = { "call", name, params };
  659    s_pattern non_void_pat[] = { "call", name, s_return, params };
  660    if (MATCH(expr, non_void_pat)) {
  661       return_deref = read_var_ref(s_return);
  662       if (return_deref == NULL) {
  663      ir_read_error(s_return, "when reading a call's return storage");
  664      return NULL;
  665       }
  666    } else if (!MATCH(expr, void_pat)) {
  667       ir_read_error(expr, "expected (call <name> [<deref>] (<param> ...))");
  668       return NULL;
  669    }
  670 
  671    exec_list parameters;
  672 
  673    foreach_in_list(s_expression, e, &params->subexpressions) {
  674       ir_rvalue *param = read_rvalue(e);
  675       if (param == NULL) {
  676      ir_read_error(e, "when reading parameter to function call");
  677      return NULL;
  678       }
  679       parameters.push_tail(param);
  680    }
  681 
  682    ir_function *f = state->symbols->get_function(name->value());
  683    if (f == NULL) {
  684       ir_read_error(expr, "found call to undefined function %s",
  685             name->value());
  686       return NULL;
  687    }
  688 
  689    ir_function_signature *callee =
  690       f->matching_signature(state, &parameters, true);
  691    if (callee == NULL) {
  692       ir_read_error(expr, "couldn't find matching signature for function "
  693                     "%s", name->value());
  694       return NULL;
  695    }
  696 
  697    if (callee->return_type == glsl_type::void_type && return_deref) {
  698       ir_read_error(expr, "call has return value storage but void type");
  699       return NULL;
  700    } else if (callee->return_type != glsl_type::void_type && !return_deref) {
  701       ir_read_error(expr, "call has non-void type but no return value storage");
  702       return NULL;
  703    }
  704 
  705    return new(mem_ctx) ir_call(callee, return_deref, &parameters);
  706 }
  707 
  708 ir_expression *
  709 ir_reader::read_expression(s_expression *expr)
  710 {
  711    s_expression *s_type;
  712    s_symbol *s_op;
  713    s_expression *s_arg[4] = {NULL};
  714 
  715    s_pattern pat[] = { "expression", s_type, s_op, s_arg[0] };
  716    if (!PARTIAL_MATCH(expr, pat)) {
  717       ir_read_error(expr, "expected (expression <type> <operator> "
  718               "<operand> [<operand>] [<operand>] [<operand>])");
  719       return NULL;
  720    }
  721    s_arg[1] = (s_expression *) s_arg[0]->next; // may be tail sentinel
  722    s_arg[2] = (s_expression *) s_arg[1]->next; // may be tail sentinel or NULL
  723    if (s_arg[2])
  724       s_arg[3] = (s_expression *) s_arg[2]->next; // may be tail sentinel or NULL
  725 
  726    const glsl_type *type = read_type(s_type);
  727    if (type == NULL)
  728       return NULL;
  729 
  730    /* Read the operator */
  731    ir_expression_operation op = ir_expression::get_operator(s_op->value());
  732    if (op == (ir_expression_operation) -1) {
  733       ir_read_error(expr, "invalid operator: %s", s_op->value());
  734       return NULL;
  735    }
  736 
  737    /* Skip "expression" <type> <operation> by subtracting 3. */
  738    int num_operands = (int) ((s_list *) expr)->subexpressions.length() - 3;
  739 
  740    int expected_operands = ir_expression::get_num_operands(op);
  741    if (num_operands != expected_operands) {
  742       ir_read_error(expr, "found %d expression operands, expected %d",
  743                     num_operands, expected_operands);
  744       return NULL;
  745    }
  746 
  747    ir_rvalue *arg[4] = {NULL};
  748    for (int i = 0; i < num_operands; i++) {
  749       arg[i] = read_rvalue(s_arg[i]);
  750       if (arg[i] == NULL) {
  751          ir_read_error(NULL, "when reading operand #%d of %s", i, s_op->value());
  752          return NULL;
  753       }
  754    }
  755 
  756    return new(mem_ctx) ir_expression(op, type, arg[0], arg[1], arg[2], arg[3]);
  757 }
  758 
  759 ir_swizzle *
  760 ir_reader::read_swizzle(s_expression *expr)
  761 {
  762    s_symbol *swiz;
  763    s_expression *sub;
  764 
  765    s_pattern pat[] = { "swiz", swiz, sub };
  766    if (!MATCH(expr, pat)) {
  767       ir_read_error(expr, "expected (swiz <swizzle> <rvalue>)");
  768       return NULL;
  769    }
  770 
  771    if (strlen(swiz->value()) > 4) {
  772       ir_read_error(expr, "expected a valid swizzle; found %s", swiz->value());
  773       return NULL;
  774    }
  775 
  776    ir_rvalue *rvalue = read_rvalue(sub);
  777    if (rvalue == NULL)
  778       return NULL;
  779 
  780    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
  781                        rvalue->type->vector_elements);
  782    if (ir == NULL)
  783       ir_read_error(expr, "invalid swizzle");
  784 
  785    return ir;
  786 }
  787 
  788 ir_constant *
  789 ir_reader::read_constant(s_expression *expr)
  790 {
  791    s_expression *type_expr;
  792    s_list *values;
  793 
  794    s_pattern pat[] = { "constant", type_expr, values };
  795    if (!MATCH(expr, pat)) {
  796       ir_read_error(expr, "expected (constant <type> (...))");
  797       return NULL;
  798    }
  799 
  800    const glsl_type *type = read_type(type_expr);
  801    if (type == NULL)
  802       return NULL;
  803 
  804    if (values == NULL) {
  805       ir_read_error(expr, "expected (constant <type> (...))");
  806       return NULL;
  807    }
  808 
  809    if (type->is_array()) {
  810       unsigned elements_supplied = 0;
  811       exec_list elements;
  812       foreach_in_list(s_expression, elt, &values->subexpressions) {
  813      ir_constant *ir_elt = read_constant(elt);
  814      if (ir_elt == NULL)
  815         return NULL;
  816      elements.push_tail(ir_elt);
  817      elements_supplied++;
  818       }
  819 
  820       if (elements_supplied != type->length) {
  821      ir_read_error(values, "expected exactly %u array elements, "
  822                "given %u", type->length, elements_supplied);
  823      return NULL;
  824       }
  825       return new(mem_ctx) ir_constant(type, &elements);
  826    }
  827 
  828    ir_constant_data data = { { 0 } };
  829 
  830    // Read in list of values (at most 16).
  831    unsigned k = 0;
  832    foreach_in_list(s_expression, expr, &values->subexpressions) {
  833       if (k >= 16) {
  834      ir_read_error(values, "expected at most 16 numbers");
  835      return NULL;
  836       }
  837 
  838       if (type->is_float()) {
  839      s_number *value = SX_AS_NUMBER(expr);
  840      if (value == NULL) {
  841         ir_read_error(values, "expected numbers");
  842         return NULL;
  843      }
  844      data.f[k] = value->fvalue();
  845       } else {
  846      s_int *value = SX_AS_INT(expr);
  847      if (value == NULL) {
  848         ir_read_error(values, "expected integers");
  849         return NULL;
  850      }
  851 
  852      switch (type->base_type) {
  853      case GLSL_TYPE_UINT: {
  854         data.u[k] = value->value();
  855         break;
  856      }
  857      case GLSL_TYPE_INT: {
  858         data.i[k] = value->value();
  859         break;
  860      }
  861      case GLSL_TYPE_BOOL: {
  862         data.b[k] = value->value();
  863         break;
  864      }
  865      default:
  866         ir_read_error(values, "unsupported constant type");
  867         return NULL;
  868      }
  869       }
  870       ++k;
  871    }
  872    if (k != type->components()) {
  873       ir_read_error(values, "expected %u constant values, found %u",
  874             type->components(), k);
  875       return NULL;
  876    }
  877 
  878    return new(mem_ctx) ir_constant(type, &data);
  879 }
  880 
  881 ir_dereference_variable *
  882 ir_reader::read_var_ref(s_expression *expr)
  883 {
  884    s_symbol *s_var;
  885    s_pattern var_pat[] = { "var_ref", s_var };
  886 
  887    if (MATCH(expr, var_pat)) {
  888       ir_variable *var = state->symbols->get_variable(s_var->value());
  889       if (var == NULL) {
  890      ir_read_error(expr, "undeclared variable: %s", s_var->value());
  891      return NULL;
  892       }
  893       return new(mem_ctx) ir_dereference_variable(var);
  894    }
  895    return NULL;
  896 }
  897 
  898 ir_dereference *
  899 ir_reader::read_dereference(s_expression *expr)
  900 {
  901    s_expression *s_subject;
  902    s_expression *s_index;
  903    s_symbol *s_field;
  904 
  905    s_pattern array_pat[] = { "array_ref", s_subject, s_index };
  906    s_pattern record_pat[] = { "record_ref", s_subject, s_field };
  907 
  908    ir_dereference_variable *var_ref = read_var_ref(expr);
  909    if (var_ref != NULL) {
  910       return var_ref;
  911    } else if (MATCH(expr, array_pat)) {
  912       ir_rvalue *subject = read_rvalue(s_subject);
  913       if (subject == NULL) {
  914      ir_read_error(NULL, "when reading the subject of an array_ref");
  915      return NULL;
  916       }
  917 
  918       ir_rvalue *idx = read_rvalue(s_index);
  919       if (idx == NULL) {
  920      ir_read_error(NULL, "when reading the index of an array_ref");
  921      return NULL;
  922       }
  923       return new(mem_ctx) ir_dereference_array(subject, idx);
  924    } else if (MATCH(expr, record_pat)) {
  925       ir_rvalue *subject = read_rvalue(s_subject);
  926       if (subject == NULL) {
  927      ir_read_error(NULL, "when reading the subject of a record_ref");
  928      return NULL;
  929       }
  930       return new(mem_ctx) ir_dereference_record(subject, s_field->value());
  931    }
  932    return NULL;
  933 }
  934 
  935 ir_texture *
  936 ir_reader::read_texture(s_expression *expr)
  937 {
  938    s_symbol *tag = NULL;
  939    s_expression *s_type = NULL;
  940    s_expression *s_sampler = NULL;
  941    s_expression *s_coord = NULL;
  942    s_expression *s_offset = NULL;
  943    s_expression *s_proj = NULL;
  944    s_list *s_shadow = NULL;
  945    s_expression *s_lod = NULL;
  946    s_expression *s_sample_index = NULL;
  947    s_expression *s_component = NULL;
  948 
  949    ir_texture_opcode op = ir_tex; /* silence warning */
  950 
  951    s_pattern tex_pattern[] =
  952       { "tex", s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow };
  953    s_pattern lod_pattern[] =
  954       { "lod", s_type, s_sampler, s_coord };
  955    s_pattern txf_pattern[] =
  956       { "txf", s_type, s_sampler, s_coord, s_offset, s_lod };
  957    s_pattern txf_ms_pattern[] =
  958       { "txf_ms", s_type, s_sampler, s_coord, s_sample_index };
  959    s_pattern txs_pattern[] =
  960       { "txs", s_type, s_sampler, s_lod };
  961    s_pattern tg4_pattern[] =
  962       { "tg4", s_type, s_sampler, s_coord, s_offset, s_component };
  963    s_pattern query_levels_pattern[] =
  964       { "query_levels", s_type, s_sampler };
  965    s_pattern texture_samples_pattern[] =
  966       { "samples", s_type, s_sampler };
  967    s_pattern other_pattern[] =
  968       { tag, s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow, s_lod };
  969 
  970    if (MATCH(expr, lod_pattern)) {
  971       op = ir_lod;
  972    } else if (MATCH(expr, tex_pattern)) {
  973       op = ir_tex;
  974    } else if (MATCH(expr, txf_pattern)) {
  975       op = ir_txf;
  976    } else if (MATCH(expr, txf_ms_pattern)) {
  977       op = ir_txf_ms;
  978    } else if (MATCH(expr, txs_pattern)) {
  979       op = ir_txs;
  980    } else if (MATCH(expr, tg4_pattern)) {
  981       op = ir_tg4;
  982    } else if (MATCH(expr, query_levels_pattern)) {
  983       op = ir_query_levels;
  984    } else if (MATCH(expr, texture_samples_pattern)) {
  985       op = ir_texture_samples;
  986    } else if (MATCH(expr, other_pattern)) {
  987       op = ir_texture::get_opcode(tag->value());
  988       if (op == (ir_texture_opcode) -1)
  989      return NULL;
  990    } else {
  991       ir_read_error(NULL, "unexpected texture pattern %s", tag->value());
  992       return NULL;
  993    }
  994 
  995    ir_texture *tex = new(mem_ctx) ir_texture(op);
  996 
  997    // Read return type
  998    const glsl_type *type = read_type(s_type);
  999    if (type == NULL) {
 1000       ir_read_error(NULL, "when reading type in (%s ...)",
 1001             tex->opcode_string());
 1002       return NULL;
 1003    }
 1004 
 1005    // Read sampler (must be a deref)
 1006    ir_dereference *sampler = read_dereference(s_sampler);
 1007    if (sampler == NULL) {
 1008       ir_read_error(NULL, "when reading sampler in (%s ...)",
 1009             tex->opcode_string());
 1010       return NULL;
 1011    }
 1012    tex->set_sampler(sampler, type);
 1013 
 1014    if (op != ir_txs) {
 1015       // Read coordinate (any rvalue)
 1016       tex->coordinate = read_rvalue(s_coord);
 1017       if (tex->coordinate == NULL) {
 1018      ir_read_error(NULL, "when reading coordinate in (%s ...)",
 1019                tex->opcode_string());
 1020      return NULL;
 1021       }
 1022 
 1023       if (op != ir_txf_ms && op != ir_lod) {
 1024          // Read texel offset - either 0 or an rvalue.
 1025          s_int *si_offset = SX_AS_INT(s_offset);
 1026          if (si_offset == NULL || si_offset->value() != 0) {
 1027             tex->offset = read_rvalue(s_offset);
 1028             if (tex->offset == NULL) {
 1029                ir_read_error(s_offset, "expected 0 or an expression");
 1030                return NULL;
 1031             }
 1032          }
 1033       }
 1034    }
 1035 
 1036    if (op != ir_txf && op != ir_txf_ms &&
 1037        op != ir_txs && op != ir_lod && op != ir_tg4 &&
 1038        op != ir_query_levels && op != ir_texture_samples) {
 1039       s_int *proj_as_int = SX_AS_INT(s_proj);
 1040       if (proj_as_int && proj_as_int->value() == 1) {
 1041      tex->projector = NULL;
 1042       } else {
 1043      tex->projector = read_rvalue(s_proj);
 1044      if (tex->projector == NULL) {
 1045         ir_read_error(NULL, "when reading projective divide in (%s ..)",
 1046                       tex->opcode_string());
 1047         return NULL;
 1048      }
 1049       }
 1050 
 1051       if (s_shadow->subexpressions.is_empty()) {
 1052      tex->shadow_comparator = NULL;
 1053       } else {
 1054      tex->shadow_comparator = read_rvalue(s_shadow);
 1055      if (tex->shadow_comparator == NULL) {
 1056         ir_read_error(NULL, "when reading shadow comparator in (%s ..)",
 1057               tex->opcode_string());
 1058         return NULL;
 1059      }
 1060       }
 1061    }
 1062 
 1063    switch (op) {
 1064    case ir_txb:
 1065       tex->lod_info.bias = read_rvalue(s_lod);
 1066       if (tex->lod_info.bias == NULL) {
 1067      ir_read_error(NULL, "when reading LOD bias in (txb ...)");
 1068      return NULL;
 1069       }
 1070       break;
 1071    case ir_txl:
 1072    case ir_txf:
 1073    case ir_txs:
 1074       tex->lod_info.lod = read_rvalue(s_lod);
 1075       if (tex->lod_info.lod == NULL) {
 1076      ir_read_error(NULL, "when reading LOD in (%s ...)",
 1077                tex->opcode_string());
 1078      return NULL;
 1079       }
 1080       break;
 1081    case ir_txf_ms:
 1082       tex->lod_info.sample_index = read_rvalue(s_sample_index);
 1083       if (tex->lod_info.sample_index == NULL) {
 1084          ir_read_error(NULL, "when reading sample_index in (txf_ms ...)");
 1085          return NULL;
 1086       }
 1087       break;
 1088    case ir_txd: {
 1089       s_expression *s_dx, *s_dy;
 1090       s_pattern dxdy_pat[] = { s_dx, s_dy };
 1091       if (!MATCH(s_lod, dxdy_pat)) {
 1092      ir_read_error(s_lod, "expected (dPdx dPdy) in (txd ...)");
 1093      return NULL;
 1094       }
 1095       tex->lod_info.grad.dPdx = read_rvalue(s_dx);
 1096       if (tex->lod_info.grad.dPdx == NULL) {
 1097      ir_read_error(NULL, "when reading dPdx in (txd ...)");
 1098      return NULL;
 1099       }
 1100       tex->lod_info.grad.dPdy = read_rvalue(s_dy);
 1101       if (tex->lod_info.grad.dPdy == NULL) {
 1102      ir_read_error(NULL, "when reading dPdy in (txd ...)");
 1103      return NULL;
 1104       }
 1105       break;
 1106    }
 1107    case ir_tg4:
 1108       tex->lod_info.component = read_rvalue(s_component);
 1109       if (tex->lod_info.component == NULL) {
 1110          ir_read_error(NULL, "when reading component in (tg4 ...)");
 1111          return NULL;
 1112       }
 1113       break;
 1114    default:
 1115       // tex and lod don't have any extra parameters.
 1116       break;
 1117    };
 1118    return tex;
 1119 }
 1120 
 1121 ir_emit_vertex *
 1122 ir_reader::read_emit_vertex(s_expression *expr)
 1123 {
 1124    s_expression *s_stream = NULL;
 1125 
 1126    s_pattern pat[] = { "emit-vertex", s_stream };
 1127 
 1128    if (MATCH(expr, pat)) {
 1129       ir_rvalue *stream = read_dereference(s_stream);
 1130       if (stream == NULL) {
 1131          ir_read_error(NULL, "when reading stream info in emit-vertex");
 1132          return NULL;
 1133       }
 1134       return new(mem_ctx) ir_emit_vertex(stream);
 1135    }
 1136    ir_read_error(NULL, "when reading emit-vertex");
 1137    return NULL;
 1138 }
 1139 
 1140 ir_end_primitive *
 1141 ir_reader::read_end_primitive(s_expression *expr)
 1142 {
 1143    s_expression *s_stream = NULL;
 1144 
 1145    s_pattern pat[] = { "end-primitive", s_stream };
 1146 
 1147    if (MATCH(expr, pat)) {
 1148       ir_rvalue *stream = read_dereference(s_stream);
 1149       if (stream == NULL) {
 1150          ir_read_error(NULL, "when reading stream info in end-primitive");
 1151          return NULL;
 1152       }
 1153       return new(mem_ctx) ir_end_primitive(stream);
 1154    }
 1155    ir_read_error(NULL, "when reading end-primitive");
 1156    return NULL;
 1157 }
 1158 
 1159 ir_barrier *
 1160 ir_reader::read_barrier(s_expression *expr)
 1161 {
 1162    s_pattern pat[] = { "barrier" };
 1163 
 1164    if (MATCH(expr, pat)) {
 1165       return new(mem_ctx) ir_barrier();
 1166    }
 1167    ir_read_error(NULL, "when reading barrier");
 1168    return NULL;
 1169 }