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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 "glsl_symbol_table.h"
     25 #include "ast.h"
     26 #include "glsl_types.h"
     27 #include "ir.h"
     28 #include "main/core.h" /* for MIN2 */
     29 
     30 static ir_rvalue *
     31 convert_component(ir_rvalue *src, const glsl_type *desired_type);
     32 
     33 bool
     34 apply_implicit_conversion(const glsl_type *to, ir_rvalue * &from,
     35                           struct _mesa_glsl_parse_state *state);
     36 
     37 static unsigned
     38 process_parameters(exec_list *instructions, exec_list *actual_parameters,
     39 		   exec_list *parameters,
     40 		   struct _mesa_glsl_parse_state *state)
     41 {
     42    unsigned count = 0;
     43 
     44    foreach_list (n, parameters) {
     45       ast_node *const ast = exec_node_data(ast_node, n, link);
     46       ir_rvalue *result = ast->hir(instructions, state);
     47 
     48       ir_constant *const constant = result->constant_expression_value();
     49       if (constant != NULL)
     50 	 result = constant;
     51 
     52       actual_parameters->push_tail(result);
     53       count++;
     54    }
     55 
     56    return count;
     57 }
     58 
     59 
     60 /**
     61  * Generate a source prototype for a function signature
     62  *
     63  * \param return_type Return type of the function.  May be \c NULL.
     64  * \param name        Name of the function.
     65  * \param parameters  List of \c ir_instruction nodes representing the
     66  *                    parameter list for the function.  This may be either a
     67  *                    formal (\c ir_variable) or actual (\c ir_rvalue)
     68  *                    parameter list.  Only the type is used.
     69  *
     70  * \return
     71  * A ralloced string representing the prototype of the function.
     72  */
     73 char *
     74 prototype_string(const glsl_type *return_type, const char *name,
     75 		 exec_list *parameters)
     76 {
     77    char *str = NULL;
     78 
     79    if (return_type != NULL)
     80       str = ralloc_asprintf(NULL, "%s ", return_type->name);
     81 
     82    ralloc_asprintf_append(&str, "%s(", name);
     83 
     84    const char *comma = "";
     85    foreach_list(node, parameters) {
     86       const ir_variable *const param = (ir_variable *) node;
     87 
     88       ralloc_asprintf_append(&str, "%s%s", comma, param->type->name);
     89       comma = ", ";
     90    }
     91 
     92    ralloc_strcat(&str, ")");
     93    return str;
     94 }
     95 
     96 /**
     97  * Verify that 'out' and 'inout' actual parameters are lvalues.  Also, verify
     98  * that 'const_in' formal parameters (an extension in our IR) correspond to
     99  * ir_constant actual parameters.
    100  */
    101 static bool
    102 verify_parameter_modes(_mesa_glsl_parse_state *state,
    103 		       ir_function_signature *sig,
    104 		       exec_list &actual_ir_parameters,
    105 		       exec_list &actual_ast_parameters)
    106 {
    107    exec_node *actual_ir_node  = actual_ir_parameters.head;
    108    exec_node *actual_ast_node = actual_ast_parameters.head;
    109 
    110    foreach_list(formal_node, &sig->parameters) {
    111       /* The lists must be the same length. */
    112       assert(!actual_ir_node->is_tail_sentinel());
    113       assert(!actual_ast_node->is_tail_sentinel());
    114 
    115       const ir_variable *const formal = (ir_variable *) formal_node;
    116       const ir_rvalue *const actual = (ir_rvalue *) actual_ir_node;
    117       const ast_expression *const actual_ast =
    118 	 exec_node_data(ast_expression, actual_ast_node, link);
    119 
    120       /* FIXME: 'loc' is incorrect (as of 2011-01-21). It is always
    121        * FIXME: 0:0(0).
    122        */
    123       YYLTYPE loc = actual_ast->get_location();
    124 
    125       /* Verify that 'const_in' parameters are ir_constants. */
    126       if (formal->mode == ir_var_const_in &&
    127 	  actual->ir_type != ir_type_constant) {
    128 	 _mesa_glsl_error(&loc, state,
    129 			  "parameter `in %s' must be a constant expression",
    130 			  formal->name);
    131 	 return false;
    132       }
    133 
    134       /* Verify that 'out' and 'inout' actual parameters are lvalues. */
    135       if (formal->mode == ir_var_out || formal->mode == ir_var_inout) {
    136 	 const char *mode = NULL;
    137 	 switch (formal->mode) {
    138 	 case ir_var_out:   mode = "out";   break;
    139 	 case ir_var_inout: mode = "inout"; break;
    140 	 default:           assert(false);  break;
    141 	 }
    142 
    143 	 /* This AST-based check catches errors like f(i++).  The IR-based
    144 	  * is_lvalue() is insufficient because the actual parameter at the
    145 	  * IR-level is just a temporary value, which is an l-value.
    146 	  */
    147 	 if (actual_ast->non_lvalue_description != NULL) {
    148 	    _mesa_glsl_error(&loc, state,
    149 			     "function parameter '%s %s' references a %s",
    150 			     mode, formal->name,
    151 			     actual_ast->non_lvalue_description);
    152 	    return false;
    153 	 }
    154 
    155 	 ir_variable *var = actual->variable_referenced();
    156 	 if (var)
    157 	    var->assigned = true;
    158 
    159 	 if (var && var->read_only) {
    160 	    _mesa_glsl_error(&loc, state,
    161 			     "function parameter '%s %s' references the "
    162 			     "read-only variable '%s'",
    163 			     mode, formal->name,
    164 			     actual->variable_referenced()->name);
    165 	    return false;
    166 	 } else if (!actual->is_lvalue()) {
    167 	    _mesa_glsl_error(&loc, state,
    168 			     "function parameter '%s %s' is not an lvalue",
    169 			     mode, formal->name);
    170 	    return false;
    171 	 }
    172       }
    173 
    174       actual_ir_node  = actual_ir_node->next;
    175       actual_ast_node = actual_ast_node->next;
    176    }
    177    return true;
    178 }
    179 
    180 /**
    181  * If a function call is generated, \c call_ir will point to it on exit.
    182  * Otherwise \c call_ir will be set to \c NULL.
    183  */
    184 static ir_rvalue *
    185 generate_call(exec_list *instructions, ir_function_signature *sig,
    186 	      YYLTYPE *loc, exec_list *actual_parameters,
    187 	      ir_call **call_ir,
    188 	      struct _mesa_glsl_parse_state *state)
    189 {
    190    void *ctx = state;
    191    exec_list post_call_conversions;
    192 
    193    *call_ir = NULL;
    194 
    195    /* Perform implicit conversion of arguments.  For out parameters, we need
    196     * to place them in a temporary variable and do the conversion after the
    197     * call takes place.  Since we haven't emitted the call yet, we'll place
    198     * the post-call conversions in a temporary exec_list, and emit them later.
    199     */
    200    exec_list_iterator actual_iter = actual_parameters->iterator();
    201    exec_list_iterator formal_iter = sig->parameters.iterator();
    202 
    203    while (actual_iter.has_next()) {
    204       ir_rvalue *actual = (ir_rvalue *) actual_iter.get();
    205       ir_variable *formal = (ir_variable *) formal_iter.get();
    206 
    207       assert(actual != NULL);
    208       assert(formal != NULL);
    209 
    210       if (formal->type->is_numeric() || formal->type->is_boolean()) {
    211 	 switch (formal->mode) {
    212 	 case ir_var_const_in:
    213 	 case ir_var_in: {
    214 	    ir_rvalue *converted
    215 	       = convert_component(actual, formal->type);
    216 	    actual->replace_with(converted);
    217 	    break;
    218 	 }
    219 	 case ir_var_out:
    220 	    if (actual->type != formal->type) {
    221 	       /* To convert an out parameter, we need to create a
    222 		* temporary variable to hold the value before conversion,
    223 		* and then perform the conversion after the function call
    224 		* returns.
    225 		*
    226 		* This has the effect of transforming code like this:
    227 		*
    228 		*   void f(out int x);
    229 		*   float value;
    230 		*   f(value);
    231 		*
    232 		* Into IR that's equivalent to this:
    233 		*
    234 		*   void f(out int x);
    235 		*   float value;
    236 		*   int out_parameter_conversion;
    237 		*   f(out_parameter_conversion);
    238 		*   value = float(out_parameter_conversion);
    239 		*/
    240 	       ir_variable *tmp =
    241 		  new(ctx) ir_variable(formal->type,
    242 				       "out_parameter_conversion",
    243 				       ir_var_temporary);
    244 	       instructions->push_tail(tmp);
    245 	       ir_dereference_variable *deref_tmp_1
    246 		  = new(ctx) ir_dereference_variable(tmp);
    247 	       ir_dereference_variable *deref_tmp_2
    248 		  = new(ctx) ir_dereference_variable(tmp);
    249 	       ir_rvalue *converted_tmp
    250 		  = convert_component(deref_tmp_1, actual->type);
    251 	       ir_assignment *assignment
    252 		  = new(ctx) ir_assignment(actual, converted_tmp);
    253 	       post_call_conversions.push_tail(assignment);
    254 	       actual->replace_with(deref_tmp_2);
    255 	    }
    256 	    break;
    257 	 case ir_var_inout:
    258 	    /* Inout parameters should never require conversion, since that
    259 	     * would require an implicit conversion to exist both to and
    260 	     * from the formal parameter type, and there are no
    261 	     * bidirectional implicit conversions.
    262 	     */
    263 	    assert (actual->type == formal->type);
    264 	    break;
    265 	 default:
    266 	    assert (!"Illegal formal parameter mode");
    267 	    break;
    268 	 }
    269       }
    270 
    271       actual_iter.next();
    272       formal_iter.next();
    273    }
    274 
    275    /* If the function call is a constant expression, don't generate any
    276     * instructions; just generate an ir_constant.
    277     *
    278     * Function calls were first allowed to be constant expressions in GLSL 1.20.
    279     */
    280    if (state->language_version >= 120) {
    281       ir_constant *value = sig->constant_expression_value(actual_parameters, NULL);
    282       if (value != NULL) {
    283 	 return value;
    284       }
    285    }
    286 
    287    ir_dereference_variable *deref = NULL;
    288    if (!sig->return_type->is_void()) {
    289       /* Create a new temporary to hold the return value. */
    290       ir_variable *var;
    291 
    292       var = new(ctx) ir_variable(sig->return_type,
    293 				 ralloc_asprintf(ctx, "%s_retval",
    294 						 sig->function_name()),
    295 				 ir_var_temporary);
    296       instructions->push_tail(var);
    297 
    298       deref = new(ctx) ir_dereference_variable(var);
    299    }
    300    ir_call *call = new(ctx) ir_call(sig, deref, actual_parameters);
    301    instructions->push_tail(call);
    302 
    303    /* Also emit any necessary out-parameter conversions. */
    304    instructions->append_list(&post_call_conversions);
    305 
    306    return deref ? deref->clone(ctx, NULL) : NULL;
    307 }
    308 
    309 /**
    310  * Given a function name and parameter list, find the matching signature.
    311  */
    312 static ir_function_signature *
    313 match_function_by_name(const char *name,
    314 		       exec_list *actual_parameters,
    315 		       struct _mesa_glsl_parse_state *state)
    316 {
    317    void *ctx = state;
    318    ir_function *f = state->symbols->get_function(name);
    319    ir_function_signature *local_sig = NULL;
    320    ir_function_signature *sig = NULL;
    321 
    322    /* Is the function hidden by a record type constructor? */
    323    if (state->symbols->get_type(name))
    324       goto done; /* no match */
    325 
    326    /* Is the function hidden by a variable (impossible in 1.10)? */
    327    if (state->language_version != 110 && state->symbols->get_variable(name))
    328       goto done; /* no match */
    329 
    330    if (f != NULL) {
    331       /* Look for a match in the local shader.  If exact, we're done. */
    332       bool is_exact = false;
    333       sig = local_sig = f->matching_signature(actual_parameters, &is_exact);
    334       if (is_exact)
    335 	 goto done;
    336 
    337       if (!state->es_shader && f->has_user_signature()) {
    338 	 /* In desktop GL, the presence of a user-defined signature hides any
    339 	  * built-in signatures, so we must ignore them.  In contrast, in ES2
    340 	  * user-defined signatures add new overloads, so we must proceed.
    341 	  */
    342 	 goto done;
    343       }
    344    }
    345 
    346    /* Local shader has no exact candidates; check the built-ins. */
    347    _mesa_glsl_initialize_functions(state);
    348    for (unsigned i = 0; i < state->num_builtins_to_link; i++) {
    349       ir_function *builtin =
    350 	 state->builtins_to_link[i]->symbols->get_function(name);
    351       if (builtin == NULL)
    352 	 continue;
    353 
    354       bool is_exact = false;
    355       ir_function_signature *builtin_sig =
    356 	 builtin->matching_signature(actual_parameters, &is_exact);
    357 
    358       if (builtin_sig == NULL)
    359 	 continue;
    360 
    361       /* If the built-in signature is exact, we can stop. */
    362       if (is_exact) {
    363 	 sig = builtin_sig;
    364 	 goto done;
    365       }
    366 
    367       if (sig == NULL) {
    368 	 /* We found an inexact match, which is better than nothing.  However,
    369 	  * we should keep searching for an exact match.
    370 	  */
    371 	 sig = builtin_sig;
    372       }
    373    }
    374 
    375 done:
    376    if (sig != NULL) {
    377       /* If the match is from a linked built-in shader, import the prototype. */
    378       if (sig != local_sig) {
    379 	 if (f == NULL) {
    380 	    f = new(ctx) ir_function(name);
    381 	    state->symbols->add_global_function(f);
    382 	    emit_function(state, f);
    383 	 }
    384 	 f->add_signature(sig->clone_prototype(f, NULL));
    385       }
    386    }
    387    return sig;
    388 }
    389 
    390 /**
    391  * Raise a "no matching function" error, listing all possible overloads the
    392  * compiler considered so developers can figure out what went wrong.
    393  */
    394 static void
    395 no_matching_function_error(const char *name,
    396 			   YYLTYPE *loc,
    397 			   exec_list *actual_parameters,
    398 			   _mesa_glsl_parse_state *state)
    399 {
    400    char *str = prototype_string(NULL, name, actual_parameters);
    401    _mesa_glsl_error(loc, state, "no matching function for call to `%s'", str);
    402    ralloc_free(str);
    403 
    404    const char *prefix = "candidates are: ";
    405 
    406    for (int i = -1; i < (int) state->num_builtins_to_link; i++) {
    407       glsl_symbol_table *syms = i >= 0 ? state->builtins_to_link[i]->symbols
    408 				       : state->symbols;
    409       ir_function *f = syms->get_function(name);
    410       if (f == NULL)
    411 	 continue;
    412 
    413       foreach_list (node, &f->signatures) {
    414 	 ir_function_signature *sig = (ir_function_signature *) node;
    415 
    416 	 str = prototype_string(sig->return_type, f->name, &sig->parameters);
    417 	 _mesa_glsl_error(loc, state, "%s%s", prefix, str);
    418 	 ralloc_free(str);
    419 
    420 	 prefix = "                ";
    421       }
    422    }
    423 }
    424 
    425 /**
    426  * Perform automatic type conversion of constructor parameters
    427  *
    428  * This implements the rules in the "Conversion and Scalar Constructors"
    429  * section (GLSL 1.10 section 5.4.1), not the "Implicit Conversions" rules.
    430  */
    431 static ir_rvalue *
    432 convert_component(ir_rvalue *src, const glsl_type *desired_type)
    433 {
    434    void *ctx = ralloc_parent(src);
    435    const unsigned a = desired_type->base_type;
    436    const unsigned b = src->type->base_type;
    437    ir_expression *result = NULL;
    438 
    439    if (src->type->is_error())
    440       return src;
    441 
    442    assert(a <= GLSL_TYPE_BOOL);
    443    assert(b <= GLSL_TYPE_BOOL);
    444 
    445    if (a == b)
    446       return src;
    447 
    448    switch (a) {
    449    case GLSL_TYPE_UINT:
    450       switch (b) {
    451       case GLSL_TYPE_INT:
    452 	 result = new(ctx) ir_expression(ir_unop_i2u, src);
    453 	 break;
    454       case GLSL_TYPE_FLOAT:
    455 	 result = new(ctx) ir_expression(ir_unop_f2u, src);
    456 	 break;
    457       case GLSL_TYPE_BOOL:
    458 	 result = new(ctx) ir_expression(ir_unop_i2u,
    459 		  new(ctx) ir_expression(ir_unop_b2i, src));
    460 	 break;
    461       }
    462       break;
    463    case GLSL_TYPE_INT:
    464       switch (b) {
    465       case GLSL_TYPE_UINT:
    466 	 result = new(ctx) ir_expression(ir_unop_u2i, src);
    467 	 break;
    468       case GLSL_TYPE_FLOAT:
    469 	 result = new(ctx) ir_expression(ir_unop_f2i, src);
    470 	 break;
    471       case GLSL_TYPE_BOOL:
    472 	 result = new(ctx) ir_expression(ir_unop_b2i, src);
    473 	 break;
    474       }
    475       break;
    476    case GLSL_TYPE_FLOAT:
    477       switch (b) {
    478       case GLSL_TYPE_UINT:
    479 	 result = new(ctx) ir_expression(ir_unop_u2f, desired_type, src, NULL);
    480 	 break;
    481       case GLSL_TYPE_INT:
    482 	 result = new(ctx) ir_expression(ir_unop_i2f, desired_type, src, NULL);
    483 	 break;
    484       case GLSL_TYPE_BOOL:
    485 	 result = new(ctx) ir_expression(ir_unop_b2f, desired_type, src, NULL);
    486 	 break;
    487       }
    488       break;
    489    case GLSL_TYPE_BOOL:
    490       switch (b) {
    491       case GLSL_TYPE_UINT:
    492 	 result = new(ctx) ir_expression(ir_unop_i2b,
    493 		  new(ctx) ir_expression(ir_unop_u2i, src));
    494 	 break;
    495       case GLSL_TYPE_INT:
    496 	 result = new(ctx) ir_expression(ir_unop_i2b, desired_type, src, NULL);
    497 	 break;
    498       case GLSL_TYPE_FLOAT:
    499 	 result = new(ctx) ir_expression(ir_unop_f2b, desired_type, src, NULL);
    500 	 break;
    501       }
    502       break;
    503    }
    504 
    505    assert(result != NULL);
    506    assert(result->type == desired_type);
    507 
    508    /* Try constant folding; it may fold in the conversion we just added. */
    509    ir_constant *const constant = result->constant_expression_value();
    510    return (constant != NULL) ? (ir_rvalue *) constant : (ir_rvalue *) result;
    511 }
    512 
    513 /**
    514  * Dereference a specific component from a scalar, vector, or matrix
    515  */
    516 static ir_rvalue *
    517 dereference_component(ir_rvalue *src, unsigned component)
    518 {
    519    void *ctx = ralloc_parent(src);
    520    assert(component < src->type->components());
    521 
    522    /* If the source is a constant, just create a new constant instead of a
    523     * dereference of the existing constant.
    524     */
    525    ir_constant *constant = src->as_constant();
    526    if (constant)
    527       return new(ctx) ir_constant(constant, component);
    528 
    529    if (src->type->is_scalar()) {
    530       return src;
    531    } else if (src->type->is_vector()) {
    532       return new(ctx) ir_swizzle(src, component, 0, 0, 0, 1);
    533    } else {
    534       assert(src->type->is_matrix());
    535 
    536       /* Dereference a row of the matrix, then call this function again to get
    537        * a specific element from that row.
    538        */
    539       const int c = component / src->type->column_type()->vector_elements;
    540       const int r = component % src->type->column_type()->vector_elements;
    541       ir_constant *const col_index = new(ctx) ir_constant(c);
    542       ir_dereference *const col = new(ctx) ir_dereference_array(src, col_index);
    543 
    544       col->type = src->type->column_type();
    545 
    546       return dereference_component(col, r);
    547    }
    548 
    549    assert(!"Should not get here.");
    550    return NULL;
    551 }
    552 
    553 
    554 static ir_rvalue *
    555 process_array_constructor(exec_list *instructions,
    556 			  const glsl_type *constructor_type,
    557 			  YYLTYPE *loc, exec_list *parameters,
    558 			  struct _mesa_glsl_parse_state *state)
    559 {
    560    void *ctx = state;
    561    /* Array constructors come in two forms: sized and unsized.  Sized array
    562     * constructors look like 'vec4[2](a, b)', where 'a' and 'b' are vec4
    563     * variables.  In this case the number of parameters must exactly match the
    564     * specified size of the array.
    565     *
    566     * Unsized array constructors look like 'vec4[](a, b)', where 'a' and 'b'
    567     * are vec4 variables.  In this case the size of the array being constructed
    568     * is determined by the number of parameters.
    569     *
    570     * From page 52 (page 58 of the PDF) of the GLSL 1.50 spec:
    571     *
    572     *    "There must be exactly the same number of arguments as the size of
    573     *    the array being constructed. If no size is present in the
    574     *    constructor, then the array is explicitly sized to the number of
    575     *    arguments provided. The arguments are assigned in order, starting at
    576     *    element 0, to the elements of the constructed array. Each argument
    577     *    must be the same type as the element type of the array, or be a type
    578     *    that can be converted to the element type of the array according to
    579     *    Section 4.1.10 "Implicit Conversions.""
    580     */
    581    exec_list actual_parameters;
    582    const unsigned parameter_count =
    583       process_parameters(instructions, &actual_parameters, parameters, state);
    584 
    585    if ((parameter_count == 0)
    586        || ((constructor_type->length != 0)
    587 	   && (constructor_type->length != parameter_count))) {
    588       const unsigned min_param = (constructor_type->length == 0)
    589 	 ? 1 : constructor_type->length;
    590 
    591       _mesa_glsl_error(loc, state, "array constructor must have %s %u "
    592 		       "parameter%s",
    593 		       (constructor_type->length != 0) ? "at least" : "exactly",
    594 		       min_param, (min_param <= 1) ? "" : "s");
    595       return ir_rvalue::error_value(ctx);
    596    }
    597 
    598    if (constructor_type->length == 0) {
    599       constructor_type =
    600 	 glsl_type::get_array_instance(constructor_type->element_type(),
    601 				       parameter_count);
    602       assert(constructor_type != NULL);
    603       assert(constructor_type->length == parameter_count);
    604    }
    605 
    606    bool all_parameters_are_constant = true;
    607 
    608    /* Type cast each parameter and, if possible, fold constants. */
    609    foreach_list_safe(n, &actual_parameters) {
    610       ir_rvalue *ir = (ir_rvalue *) n;
    611       ir_rvalue *result = ir;
    612 
    613       /* Apply implicit conversions (not the scalar constructor rules!). See
    614        * the spec quote above. */
    615       if (constructor_type->element_type()->is_float()) {
    616 	 const glsl_type *desired_type =
    617 	    glsl_type::get_instance(GLSL_TYPE_FLOAT,
    618 				    ir->type->vector_elements,
    619 				    ir->type->matrix_columns);
    620 	 if (result->type->can_implicitly_convert_to(desired_type)) {
    621 	    /* Even though convert_component() implements the constructor
    622 	     * conversion rules (not the implicit conversion rules), its safe
    623 	     * to use it here because we already checked that the implicit
    624 	     * conversion is legal.
    625 	     */
    626 	    result = convert_component(ir, desired_type);
    627 	 }
    628       }
    629 
    630       if (result->type != constructor_type->element_type()) {
    631 	 _mesa_glsl_error(loc, state, "type error in array constructor: "
    632 			  "expected: %s, found %s",
    633 			  constructor_type->element_type()->name,
    634 			  result->type->name);
    635       }
    636 
    637       /* Attempt to convert the parameter to a constant valued expression.
    638        * After doing so, track whether or not all the parameters to the
    639        * constructor are trivially constant valued expressions.
    640        */
    641       ir_rvalue *const constant = result->constant_expression_value();
    642 
    643       if (constant != NULL)
    644          result = constant;
    645       else
    646          all_parameters_are_constant = false;
    647 
    648       ir->replace_with(result);
    649    }
    650 
    651    if (all_parameters_are_constant)
    652       return new(ctx) ir_constant(constructor_type, &actual_parameters);
    653 
    654    ir_variable *var = new(ctx) ir_variable(constructor_type, "array_ctor",
    655 					   ir_var_temporary);
    656    instructions->push_tail(var);
    657 
    658    int i = 0;
    659    foreach_list(node, &actual_parameters) {
    660       ir_rvalue *rhs = (ir_rvalue *) node;
    661       ir_rvalue *lhs = new(ctx) ir_dereference_array(var,
    662 						     new(ctx) ir_constant(i));
    663 
    664       ir_instruction *assignment = new(ctx) ir_assignment(lhs, rhs, NULL);
    665       instructions->push_tail(assignment);
    666 
    667       i++;
    668    }
    669 
    670    return new(ctx) ir_dereference_variable(var);
    671 }
    672 
    673 
    674 /**
    675  * Try to convert a record constructor to a constant expression
    676  */
    677 static ir_constant *
    678 constant_record_constructor(const glsl_type *constructor_type,
    679 			    exec_list *parameters, void *mem_ctx)
    680 {
    681    foreach_list(node, parameters) {
    682       ir_constant *constant = ((ir_instruction *) node)->as_constant();
    683       if (constant == NULL)
    684 	 return NULL;
    685       node->replace_with(constant);
    686    }
    687 
    688    return new(mem_ctx) ir_constant(constructor_type, parameters);
    689 }
    690 
    691 
    692 /**
    693  * Determine if a list consists of a single scalar r-value
    694  */
    695 bool
    696 single_scalar_parameter(exec_list *parameters)
    697 {
    698    const ir_rvalue *const p = (ir_rvalue *) parameters->head;
    699    assert(((ir_rvalue *)p)->as_rvalue() != NULL);
    700 
    701    return (p->type->is_scalar() && p->next->is_tail_sentinel());
    702 }
    703 
    704 
    705 /**
    706  * Generate inline code for a vector constructor
    707  *
    708  * The generated constructor code will consist of a temporary variable
    709  * declaration of the same type as the constructor.  A sequence of assignments
    710  * from constructor parameters to the temporary will follow.
    711  *
    712  * \return
    713  * An \c ir_dereference_variable of the temprorary generated in the constructor
    714  * body.
    715  */
    716 ir_rvalue *
    717 emit_inline_vector_constructor(const glsl_type *type,
    718 			       exec_list *instructions,
    719 			       exec_list *parameters,
    720 			       void *ctx)
    721 {
    722    assert(!parameters->is_empty());
    723 
    724    ir_variable *var = new(ctx) ir_variable(type, "vec_ctor", ir_var_temporary);
    725    instructions->push_tail(var);
    726 
    727    /* There are two kinds of vector constructors.
    728     *
    729     *  - Construct a vector from a single scalar by replicating that scalar to
    730     *    all components of the vector.
    731     *
    732     *  - Construct a vector from an arbirary combination of vectors and
    733     *    scalars.  The components of the constructor parameters are assigned
    734     *    to the vector in order until the vector is full.
    735     */
    736    const unsigned lhs_components = type->components();
    737    if (single_scalar_parameter(parameters)) {
    738       ir_rvalue *first_param = (ir_rvalue *)parameters->head;
    739       ir_rvalue *rhs = new(ctx) ir_swizzle(first_param, 0, 0, 0, 0,
    740 					   lhs_components);
    741       ir_dereference_variable *lhs = new(ctx) ir_dereference_variable(var);
    742       const unsigned mask = (1U << lhs_components) - 1;
    743 
    744       assert(rhs->type == lhs->type);
    745 
    746       ir_instruction *inst = new(ctx) ir_assignment(lhs, rhs, NULL, mask);
    747       instructions->push_tail(inst);
    748    } else {
    749       unsigned base_component = 0;
    750       unsigned base_lhs_component = 0;
    751       ir_constant_data data;
    752       unsigned constant_mask = 0, constant_components = 0;
    753 
    754       memset(&data, 0, sizeof(data));
    755 
    756       foreach_list(node, parameters) {
    757 	 ir_rvalue *param = (ir_rvalue *) node;
    758 	 unsigned rhs_components = param->type->components();
    759 
    760 	 /* Do not try to assign more components to the vector than it has!
    761 	  */
    762 	 if ((rhs_components + base_lhs_component) > lhs_components) {
    763 	    rhs_components = lhs_components - base_lhs_component;
    764 	 }
    765 
    766 	 const ir_constant *const c = param->as_constant();
    767 	 if (c != NULL) {
    768 	    for (unsigned i = 0; i < rhs_components; i++) {
    769 	       switch (c->type->base_type) {
    770 	       case GLSL_TYPE_UINT:
    771 		  data.u[i + base_component] = c->get_uint_component(i);
    772 		  break;
    773 	       case GLSL_TYPE_INT:
    774 		  data.i[i + base_component] = c->get_int_component(i);
    775 		  break;
    776 	       case GLSL_TYPE_FLOAT:
    777 		  data.f[i + base_component] = c->get_float_component(i);
    778 		  break;
    779 	       case GLSL_TYPE_BOOL:
    780 		  data.b[i + base_component] = c->get_bool_component(i);
    781 		  break;
    782 	       default:
    783 		  assert(!"Should not get here.");
    784 		  break;
    785 	       }
    786 	    }
    787 
    788 	    /* Mask of fields to be written in the assignment.
    789 	     */
    790 	    constant_mask |= ((1U << rhs_components) - 1) << base_lhs_component;
    791 	    constant_components += rhs_components;
    792 
    793 	    base_component += rhs_components;
    794 	 }
    795 	 /* Advance the component index by the number of components
    796 	  * that were just assigned.
    797 	  */
    798 	 base_lhs_component += rhs_components;
    799       }
    800 
    801       if (constant_mask != 0) {
    802 	 ir_dereference *lhs = new(ctx) ir_dereference_variable(var);
    803 	 const glsl_type *rhs_type = glsl_type::get_instance(var->type->base_type,
    804 							     constant_components,
    805 							     1);
    806 	 ir_rvalue *rhs = new(ctx) ir_constant(rhs_type, &data);
    807 
    808 	 ir_instruction *inst =
    809 	    new(ctx) ir_assignment(lhs, rhs, NULL, constant_mask);
    810 	 instructions->push_tail(inst);
    811       }
    812 
    813       base_component = 0;
    814       foreach_list(node, parameters) {
    815 	 ir_rvalue *param = (ir_rvalue *) node;
    816 	 unsigned rhs_components = param->type->components();
    817 
    818 	 /* Do not try to assign more components to the vector than it has!
    819 	  */
    820 	 if ((rhs_components + base_component) > lhs_components) {
    821 	    rhs_components = lhs_components - base_component;
    822 	 }
    823 
    824 	 const ir_constant *const c = param->as_constant();
    825 	 if (c == NULL) {
    826 	    /* Mask of fields to be written in the assignment.
    827 	     */
    828 	    const unsigned write_mask = ((1U << rhs_components) - 1)
    829 	       << base_component;
    830 
    831 	    ir_dereference *lhs = new(ctx) ir_dereference_variable(var);
    832 
    833 	    /* Generate a swizzle so that LHS and RHS sizes match.
    834 	     */
    835 	    ir_rvalue *rhs =
    836 	       new(ctx) ir_swizzle(param, 0, 1, 2, 3, rhs_components);
    837 
    838 	    ir_instruction *inst =
    839 	       new(ctx) ir_assignment(lhs, rhs, NULL, write_mask);
    840 	    instructions->push_tail(inst);
    841 	 }
    842 
    843 	 /* Advance the component index by the number of components that were
    844 	  * just assigned.
    845 	  */
    846 	 base_component += rhs_components;
    847       }
    848    }
    849    return new(ctx) ir_dereference_variable(var);
    850 }
    851 
    852 
    853 /**
    854  * Generate assignment of a portion of a vector to a portion of a matrix column
    855  *
    856  * \param src_base  First component of the source to be used in assignment
    857  * \param column    Column of destination to be assiged
    858  * \param row_base  First component of the destination column to be assigned
    859  * \param count     Number of components to be assigned
    860  *
    861  * \note
    862  * \c src_base + \c count must be less than or equal to the number of components
    863  * in the source vector.
    864  */
    865 ir_instruction *
    866 assign_to_matrix_column(ir_variable *var, unsigned column, unsigned row_base,
    867 			ir_rvalue *src, unsigned src_base, unsigned count,
    868 			void *mem_ctx)
    869 {
    870    ir_constant *col_idx = new(mem_ctx) ir_constant(column);
    871    ir_dereference *column_ref = new(mem_ctx) ir_dereference_array(var, col_idx);
    872 
    873    assert(column_ref->type->components() >= (row_base + count));
    874    assert(src->type->components() >= (src_base + count));
    875 
    876    /* Generate a swizzle that extracts the number of components from the source
    877     * that are to be assigned to the column of the matrix.
    878     */
    879    if (count < src->type->vector_elements) {
    880       src = new(mem_ctx) ir_swizzle(src,
    881 				    src_base + 0, src_base + 1,
    882 				    src_base + 2, src_base + 3,
    883 				    count);
    884    }
    885 
    886    /* Mask of fields to be written in the assignment.
    887     */
    888    const unsigned write_mask = ((1U << count) - 1) << row_base;
    889 
    890    return new(mem_ctx) ir_assignment(column_ref, src, NULL, write_mask);
    891 }
    892 
    893 
    894 /**
    895  * Generate inline code for a matrix constructor
    896  *
    897  * The generated constructor code will consist of a temporary variable
    898  * declaration of the same type as the constructor.  A sequence of assignments
    899  * from constructor parameters to the temporary will follow.
    900  *
    901  * \return
    902  * An \c ir_dereference_variable of the temprorary generated in the constructor
    903  * body.
    904  */
    905 ir_rvalue *
    906 emit_inline_matrix_constructor(const glsl_type *type,
    907 			       exec_list *instructions,
    908 			       exec_list *parameters,
    909 			       void *ctx)
    910 {
    911    assert(!parameters->is_empty());
    912 
    913    ir_variable *var = new(ctx) ir_variable(type, "mat_ctor", ir_var_temporary);
    914    instructions->push_tail(var);
    915 
    916    /* There are three kinds of matrix constructors.
    917     *
    918     *  - Construct a matrix from a single scalar by replicating that scalar to
    919     *    along the diagonal of the matrix and setting all other components to
    920     *    zero.
    921     *
    922     *  - Construct a matrix from an arbirary combination of vectors and
    923     *    scalars.  The components of the constructor parameters are assigned
    924     *    to the matrix in colum-major order until the matrix is full.
    925     *
    926     *  - Construct a matrix from a single matrix.  The source matrix is copied
    927     *    to the upper left portion of the constructed matrix, and the remaining
    928     *    elements take values from the identity matrix.
    929     */
    930    ir_rvalue *const first_param = (ir_rvalue *) parameters->head;
    931    if (single_scalar_parameter(parameters)) {
    932       /* Assign the scalar to the X component of a vec4, and fill the remaining
    933        * components with zero.
    934        */
    935       ir_variable *rhs_var =
    936 	 new(ctx) ir_variable(glsl_type::vec4_type, "mat_ctor_vec",
    937 			      ir_var_temporary);
    938       instructions->push_tail(rhs_var);
    939 
    940       ir_constant_data zero;
    941       zero.f[0] = 0.0;
    942       zero.f[1] = 0.0;
    943       zero.f[2] = 0.0;
    944       zero.f[3] = 0.0;
    945 
    946       ir_instruction *inst =
    947 	 new(ctx) ir_assignment(new(ctx) ir_dereference_variable(rhs_var),
    948 				new(ctx) ir_constant(rhs_var->type, &zero),
    949 				NULL);
    950       instructions->push_tail(inst);
    951 
    952       ir_dereference *const rhs_ref = new(ctx) ir_dereference_variable(rhs_var);
    953 
    954       inst = new(ctx) ir_assignment(rhs_ref, first_param, NULL, 0x01);
    955       instructions->push_tail(inst);
    956 
    957       /* Assign the temporary vector to each column of the destination matrix
    958        * with a swizzle that puts the X component on the diagonal of the
    959        * matrix.  In some cases this may mean that the X component does not
    960        * get assigned into the column at all (i.e., when the matrix has more
    961        * columns than rows).
    962        */
    963       static const unsigned rhs_swiz[4][4] = {
    964 	 { 0, 1, 1, 1 },
    965 	 { 1, 0, 1, 1 },
    966 	 { 1, 1, 0, 1 },
    967 	 { 1, 1, 1, 0 }
    968       };
    969 
    970       const unsigned cols_to_init = MIN2(type->matrix_columns,
    971 					 type->vector_elements);
    972       for (unsigned i = 0; i < cols_to_init; i++) {
    973 	 ir_constant *const col_idx = new(ctx) ir_constant(i);
    974 	 ir_rvalue *const col_ref = new(ctx) ir_dereference_array(var, col_idx);
    975 
    976 	 ir_rvalue *const rhs_ref = new(ctx) ir_dereference_variable(rhs_var);
    977 	 ir_rvalue *const rhs = new(ctx) ir_swizzle(rhs_ref, rhs_swiz[i],
    978 						    type->vector_elements);
    979 
    980 	 inst = new(ctx) ir_assignment(col_ref, rhs, NULL);
    981 	 instructions->push_tail(inst);
    982       }
    983 
    984       for (unsigned i = cols_to_init; i < type->matrix_columns; i++) {
    985 	 ir_constant *const col_idx = new(ctx) ir_constant(i);
    986 	 ir_rvalue *const col_ref = new(ctx) ir_dereference_array(var, col_idx);
    987 
    988 	 ir_rvalue *const rhs_ref = new(ctx) ir_dereference_variable(rhs_var);
    989 	 ir_rvalue *const rhs = new(ctx) ir_swizzle(rhs_ref, 1, 1, 1, 1,
    990 						    type->vector_elements);
    991 
    992 	 inst = new(ctx) ir_assignment(col_ref, rhs, NULL);
    993 	 instructions->push_tail(inst);
    994       }
    995    } else if (first_param->type->is_matrix()) {
    996       /* From page 50 (56 of the PDF) of the GLSL 1.50 spec:
    997        *
    998        *     "If a matrix is constructed from a matrix, then each component
    999        *     (column i, row j) in the result that has a corresponding
   1000        *     component (column i, row j) in the argument will be initialized
   1001        *     from there. All other components will be initialized to the
   1002        *     identity matrix. If a matrix argument is given to a matrix
   1003        *     constructor, it is an error to have any other arguments."
   1004        */
   1005       assert(first_param->next->is_tail_sentinel());
   1006       ir_rvalue *const src_matrix = first_param;
   1007 
   1008       /* If the source matrix is smaller, pre-initialize the relavent parts of
   1009        * the destination matrix to the identity matrix.
   1010        */
   1011       if ((src_matrix->type->matrix_columns < var->type->matrix_columns)
   1012 	  || (src_matrix->type->vector_elements < var->type->vector_elements)) {
   1013 
   1014 	 /* If the source matrix has fewer rows, every column of the destination
   1015 	  * must be initialized.  Otherwise only the columns in the destination
   1016 	  * that do not exist in the source must be initialized.
   1017 	  */
   1018 	 unsigned col =
   1019 	    (src_matrix->type->vector_elements < var->type->vector_elements)
   1020 	    ? 0 : src_matrix->type->matrix_columns;
   1021 
   1022 	 const glsl_type *const col_type = var->type->column_type();
   1023 	 for (/* empty */; col < var->type->matrix_columns; col++) {
   1024 	    ir_constant_data ident;
   1025 
   1026 	    ident.f[0] = 0.0;
   1027 	    ident.f[1] = 0.0;
   1028 	    ident.f[2] = 0.0;
   1029 	    ident.f[3] = 0.0;
   1030 
   1031 	    ident.f[col] = 1.0;
   1032 
   1033 	    ir_rvalue *const rhs = new(ctx) ir_constant(col_type, &ident);
   1034 
   1035 	    ir_rvalue *const lhs =
   1036 	       new(ctx) ir_dereference_array(var, new(ctx) ir_constant(col));
   1037 
   1038 	    ir_instruction *inst = new(ctx) ir_assignment(lhs, rhs, NULL);
   1039 	    instructions->push_tail(inst);
   1040 	 }
   1041       }
   1042 
   1043       /* Assign columns from the source matrix to the destination matrix.
   1044        *
   1045        * Since the parameter will be used in the RHS of multiple assignments,
   1046        * generate a temporary and copy the paramter there.
   1047        */
   1048       ir_variable *const rhs_var =
   1049 	 new(ctx) ir_variable(first_param->type, "mat_ctor_mat",
   1050 			      ir_var_temporary);
   1051       instructions->push_tail(rhs_var);
   1052 
   1053       ir_dereference *const rhs_var_ref =
   1054 	 new(ctx) ir_dereference_variable(rhs_var);
   1055       ir_instruction *const inst =
   1056 	 new(ctx) ir_assignment(rhs_var_ref, first_param, NULL);
   1057       instructions->push_tail(inst);
   1058 
   1059       const unsigned last_row = MIN2(src_matrix->type->vector_elements,
   1060 				     var->type->vector_elements);
   1061       const unsigned last_col = MIN2(src_matrix->type->matrix_columns,
   1062 				     var->type->matrix_columns);
   1063 
   1064       unsigned swiz[4] = { 0, 0, 0, 0 };
   1065       for (unsigned i = 1; i < last_row; i++)
   1066 	 swiz[i] = i;
   1067 
   1068       const unsigned write_mask = (1U << last_row) - 1;
   1069 
   1070       for (unsigned i = 0; i < last_col; i++) {
   1071 	 ir_dereference *const lhs =
   1072 	    new(ctx) ir_dereference_array(var, new(ctx) ir_constant(i));
   1073 	 ir_rvalue *const rhs_col =
   1074 	    new(ctx) ir_dereference_array(rhs_var, new(ctx) ir_constant(i));
   1075 
   1076 	 /* If one matrix has columns that are smaller than the columns of the
   1077 	  * other matrix, wrap the column access of the larger with a swizzle
   1078 	  * so that the LHS and RHS of the assignment have the same size (and
   1079 	  * therefore have the same type).
   1080 	  *
   1081 	  * It would be perfectly valid to unconditionally generate the
   1082 	  * swizzles, this this will typically result in a more compact IR tree.
   1083 	  */
   1084 	 ir_rvalue *rhs;
   1085 	 if (lhs->type->vector_elements != rhs_col->type->vector_elements) {
   1086 	    rhs = new(ctx) ir_swizzle(rhs_col, swiz, last_row);
   1087 	 } else {
   1088 	    rhs = rhs_col;
   1089 	 }
   1090 
   1091 	 ir_instruction *inst =
   1092 	    new(ctx) ir_assignment(lhs, rhs, NULL, write_mask);
   1093 	 instructions->push_tail(inst);
   1094       }
   1095    } else {
   1096       const unsigned cols = type->matrix_columns;
   1097       const unsigned rows = type->vector_elements;
   1098       unsigned col_idx = 0;
   1099       unsigned row_idx = 0;
   1100 
   1101       foreach_list (node, parameters) {
   1102 	 ir_rvalue *const rhs = (ir_rvalue *) node;
   1103 	 const unsigned components_remaining_this_column = rows - row_idx;
   1104 	 unsigned rhs_components = rhs->type->components();
   1105 	 unsigned rhs_base = 0;
   1106 
   1107 	 /* Since the parameter might be used in the RHS of two assignments,
   1108 	  * generate a temporary and copy the paramter there.
   1109 	  */
   1110 	 ir_variable *rhs_var =
   1111 	    new(ctx) ir_variable(rhs->type, "mat_ctor_vec", ir_var_temporary);
   1112 	 instructions->push_tail(rhs_var);
   1113 
   1114 	 ir_dereference *rhs_var_ref =
   1115 	    new(ctx) ir_dereference_variable(rhs_var);
   1116 	 ir_instruction *inst = new(ctx) ir_assignment(rhs_var_ref, rhs, NULL);
   1117 	 instructions->push_tail(inst);
   1118 
   1119 	 /* Assign the current parameter to as many components of the matrix
   1120 	  * as it will fill.
   1121 	  *
   1122 	  * NOTE: A single vector parameter can span two matrix columns.  A
   1123 	  * single vec4, for example, can completely fill a mat2.
   1124 	  */
   1125 	 if (rhs_components >= components_remaining_this_column) {
   1126 	    const unsigned count = MIN2(rhs_components,
   1127 					components_remaining_this_column);
   1128 
   1129 	    rhs_var_ref = new(ctx) ir_dereference_variable(rhs_var);
   1130 
   1131 	    ir_instruction *inst = assign_to_matrix_column(var, col_idx,
   1132 							   row_idx,
   1133 							   rhs_var_ref, 0,
   1134 							   count, ctx);
   1135 	    instructions->push_tail(inst);
   1136 
   1137 	    rhs_base = count;
   1138 
   1139 	    col_idx++;
   1140 	    row_idx = 0;
   1141 	 }
   1142 
   1143 	 /* If there is data left in the parameter and components left to be
   1144 	  * set in the destination, emit another assignment.  It is possible
   1145 	  * that the assignment could be of a vec4 to the last element of the
   1146 	  * matrix.  In this case col_idx==cols, but there is still data
   1147 	  * left in the source parameter.  Obviously, don't emit an assignment
   1148 	  * to data outside the destination matrix.
   1149 	  */
   1150 	 if ((col_idx < cols) && (rhs_base < rhs_components)) {
   1151 	    const unsigned count = rhs_components - rhs_base;
   1152 
   1153 	    rhs_var_ref = new(ctx) ir_dereference_variable(rhs_var);
   1154 
   1155 	    ir_instruction *inst = assign_to_matrix_column(var, col_idx,
   1156 							   row_idx,
   1157 							   rhs_var_ref,
   1158 							   rhs_base,
   1159 							   count, ctx);
   1160 	    instructions->push_tail(inst);
   1161 
   1162 	    row_idx += count;
   1163 	 }
   1164       }
   1165    }
   1166 
   1167    return new(ctx) ir_dereference_variable(var);
   1168 }
   1169 
   1170 
   1171 ir_rvalue *
   1172 emit_inline_record_constructor(const glsl_type *type,
   1173 			       exec_list *instructions,
   1174 			       exec_list *parameters,
   1175 			       void *mem_ctx)
   1176 {
   1177    ir_variable *const var =
   1178       new(mem_ctx) ir_variable(type, "record_ctor", ir_var_temporary);
   1179    ir_dereference_variable *const d = new(mem_ctx) ir_dereference_variable(var);
   1180 
   1181    instructions->push_tail(var);
   1182 
   1183    exec_node *node = parameters->head;
   1184    for (unsigned i = 0; i < type->length; i++) {
   1185       assert(!node->is_tail_sentinel());
   1186 
   1187       ir_dereference *const lhs =
   1188 	 new(mem_ctx) ir_dereference_record(d->clone(mem_ctx, NULL),
   1189 					    type->fields.structure[i].name);
   1190 
   1191       ir_rvalue *const rhs = ((ir_instruction *) node)->as_rvalue();
   1192       assert(rhs != NULL);
   1193 
   1194       ir_instruction *const assign = new(mem_ctx) ir_assignment(lhs, rhs, NULL);
   1195 
   1196       instructions->push_tail(assign);
   1197       node = node->next;
   1198    }
   1199 
   1200    return d;
   1201 }
   1202 
   1203 
   1204 ir_rvalue *
   1205 ast_function_expression::hir(exec_list *instructions,
   1206 			     struct _mesa_glsl_parse_state *state)
   1207 {
   1208    void *ctx = state;
   1209    /* There are three sorts of function calls.
   1210     *
   1211     * 1. constructors - The first subexpression is an ast_type_specifier.
   1212     * 2. methods - Only the .length() method of array types.
   1213     * 3. functions - Calls to regular old functions.
   1214     *
   1215     * Method calls are actually detected when the ast_field_selection
   1216     * expression is handled.
   1217     */
   1218    if (is_constructor()) {
   1219       const ast_type_specifier *type = (ast_type_specifier *) subexpressions[0];
   1220       YYLTYPE loc = type->get_location();
   1221       const char *name;
   1222 
   1223       const glsl_type *const constructor_type = type->glsl_type(& name, state);
   1224 
   1225       /* constructor_type can be NULL if a variable with the same name as the
   1226        * structure has come into scope.
   1227        */
   1228       if (constructor_type == NULL) {
   1229 	 _mesa_glsl_error(& loc, state, "unknown type `%s' (structure name "
   1230 			  "may be shadowed by a variable with the same name)",
   1231 			  type->type_name);
   1232 	 return ir_rvalue::error_value(ctx);
   1233       }
   1234 
   1235 
   1236       /* Constructors for samplers are illegal.
   1237        */
   1238       if (constructor_type->is_sampler()) {
   1239 	 _mesa_glsl_error(& loc, state, "cannot construct sampler type `%s'",
   1240 			  constructor_type->name);
   1241 	 return ir_rvalue::error_value(ctx);
   1242       }
   1243 
   1244       if (constructor_type->is_array()) {
   1245 	 if (state->language_version <= 110) {
   1246 	    _mesa_glsl_error(& loc, state,
   1247 			     "array constructors forbidden in GLSL 1.10");
   1248 	    return ir_rvalue::error_value(ctx);
   1249 	 }
   1250 
   1251 	 return process_array_constructor(instructions, constructor_type,
   1252 					  & loc, &this->expressions, state);
   1253       }
   1254 
   1255 
   1256       /* There are two kinds of constructor call.  Constructors for built-in
   1257        * language types, such as mat4 and vec2, are free form.  The only
   1258        * requirement is that the parameters must provide enough values of the
   1259        * correct scalar type.  Constructors for arrays and structures must
   1260        * have the exact number of parameters with matching types in the
   1261        * correct order.  These constructors follow essentially the same type
   1262        * matching rules as functions.
   1263        */
   1264       if (constructor_type->is_record()) {
   1265 	 exec_list actual_parameters;
   1266 
   1267 	 process_parameters(instructions, &actual_parameters,
   1268 			    &this->expressions, state);
   1269 
   1270 	 exec_node *node = actual_parameters.head;
   1271 	 for (unsigned i = 0; i < constructor_type->length; i++) {
   1272 	    ir_rvalue *ir = (ir_rvalue *) node;
   1273 
   1274 	    if (node->is_tail_sentinel()) {
   1275 	       _mesa_glsl_error(&loc, state,
   1276 				"insufficient parameters to constructor "
   1277 				"for `%s'",
   1278 				constructor_type->name);
   1279 	       return ir_rvalue::error_value(ctx);
   1280 	    }
   1281 
   1282 	    if (apply_implicit_conversion(constructor_type->fields.structure[i].type,
   1283 					  ir, state)) {
   1284 	       node->replace_with(ir);
   1285 	    } else {
   1286 	       _mesa_glsl_error(&loc, state,
   1287 				"parameter type mismatch in constructor "
   1288 				"for `%s.%s' (%s vs %s)",
   1289 				constructor_type->name,
   1290 				constructor_type->fields.structure[i].name,
   1291 				ir->type->name,
   1292 				constructor_type->fields.structure[i].type->name);
   1293 	       return ir_rvalue::error_value(ctx);;
   1294 	    }
   1295 
   1296 	    node = node->next;
   1297 	 }
   1298 
   1299 	 if (!node->is_tail_sentinel()) {
   1300 	    _mesa_glsl_error(&loc, state, "too many parameters in constructor "
   1301 			     "for `%s'", constructor_type->name);
   1302 	    return ir_rvalue::error_value(ctx);
   1303 	 }
   1304 
   1305 	 ir_rvalue *const constant =
   1306 	    constant_record_constructor(constructor_type, &actual_parameters,
   1307 					state);
   1308 
   1309 	 return (constant != NULL)
   1310 	    ? constant
   1311 	    : emit_inline_record_constructor(constructor_type, instructions,
   1312 					     &actual_parameters, state);
   1313       }
   1314 
   1315       if (!constructor_type->is_numeric() && !constructor_type->is_boolean())
   1316 	 return ir_rvalue::error_value(ctx);
   1317 
   1318       /* Total number of components of the type being constructed. */
   1319       const unsigned type_components = constructor_type->components();
   1320 
   1321       /* Number of components from parameters that have actually been
   1322        * consumed.  This is used to perform several kinds of error checking.
   1323        */
   1324       unsigned components_used = 0;
   1325 
   1326       unsigned matrix_parameters = 0;
   1327       unsigned nonmatrix_parameters = 0;
   1328       exec_list actual_parameters;
   1329 
   1330       foreach_list (n, &this->expressions) {
   1331 	 ast_node *ast = exec_node_data(ast_node, n, link);
   1332 	 ir_rvalue *result = ast->hir(instructions, state)->as_rvalue();
   1333 
   1334 	 /* From page 50 (page 56 of the PDF) of the GLSL 1.50 spec:
   1335 	  *
   1336 	  *    "It is an error to provide extra arguments beyond this
   1337 	  *    last used argument."
   1338 	  */
   1339 	 if (components_used >= type_components) {
   1340 	    _mesa_glsl_error(& loc, state, "too many parameters to `%s' "
   1341 			     "constructor",
   1342 			     constructor_type->name);
   1343 	    return ir_rvalue::error_value(ctx);
   1344 	 }
   1345 
   1346 	 if (!result->type->is_numeric() && !result->type->is_boolean()) {
   1347 	    _mesa_glsl_error(& loc, state, "cannot construct `%s' from a "
   1348 			     "non-numeric data type",
   1349 			     constructor_type->name);
   1350 	    return ir_rvalue::error_value(ctx);
   1351 	 }
   1352 
   1353 	 /* Count the number of matrix and nonmatrix parameters.  This
   1354 	  * is used below to enforce some of the constructor rules.
   1355 	  */
   1356 	 if (result->type->is_matrix())
   1357 	    matrix_parameters++;
   1358 	 else
   1359 	    nonmatrix_parameters++;
   1360 
   1361 	 actual_parameters.push_tail(result);
   1362 	 components_used += result->type->components();
   1363       }
   1364 
   1365       /* From page 28 (page 34 of the PDF) of the GLSL 1.10 spec:
   1366        *
   1367        *    "It is an error to construct matrices from other matrices. This
   1368        *    is reserved for future use."
   1369        */
   1370       if (state->language_version == 110 && matrix_parameters > 0
   1371 	  && constructor_type->is_matrix()) {
   1372 	 _mesa_glsl_error(& loc, state, "cannot construct `%s' from a "
   1373 			  "matrix in GLSL 1.10",
   1374 			  constructor_type->name);
   1375 	 return ir_rvalue::error_value(ctx);
   1376       }
   1377 
   1378       /* From page 50 (page 56 of the PDF) of the GLSL 1.50 spec:
   1379        *
   1380        *    "If a matrix argument is given to a matrix constructor, it is
   1381        *    an error to have any other arguments."
   1382        */
   1383       if ((matrix_parameters > 0)
   1384 	  && ((matrix_parameters + nonmatrix_parameters) > 1)
   1385 	  && constructor_type->is_matrix()) {
   1386 	 _mesa_glsl_error(& loc, state, "for matrix `%s' constructor, "
   1387 			  "matrix must be only parameter",
   1388 			  constructor_type->name);
   1389 	 return ir_rvalue::error_value(ctx);
   1390       }
   1391 
   1392       /* From page 28 (page 34 of the PDF) of the GLSL 1.10 spec:
   1393        *
   1394        *    "In these cases, there must be enough components provided in the
   1395        *    arguments to provide an initializer for every component in the
   1396        *    constructed value."
   1397        */
   1398       if (components_used < type_components && components_used != 1
   1399 	  && matrix_parameters == 0) {
   1400 	 _mesa_glsl_error(& loc, state, "too few components to construct "
   1401 			  "`%s'",
   1402 			  constructor_type->name);
   1403 	 return ir_rvalue::error_value(ctx);
   1404       }
   1405 
   1406       /* Later, we cast each parameter to the same base type as the
   1407        * constructor.  Since there are no non-floating point matrices, we
   1408        * need to break them up into a series of column vectors.
   1409        */
   1410       if (constructor_type->base_type != GLSL_TYPE_FLOAT) {
   1411 	 foreach_list_safe(n, &actual_parameters) {
   1412 	    ir_rvalue *matrix = (ir_rvalue *) n;
   1413 
   1414 	    if (!matrix->type->is_matrix())
   1415 	       continue;
   1416 
   1417 	    /* Create a temporary containing the matrix. */
   1418 	    ir_variable *var = new(ctx) ir_variable(matrix->type, "matrix_tmp",
   1419 						    ir_var_temporary);
   1420 	    instructions->push_tail(var);
   1421 	    instructions->push_tail(new(ctx) ir_assignment(new(ctx)
   1422 	       ir_dereference_variable(var), matrix, NULL));
   1423 	    var->constant_value = matrix->constant_expression_value();
   1424 
   1425 	    /* Replace the matrix with dereferences of its columns. */
   1426 	    for (int i = 0; i < matrix->type->matrix_columns; i++) {
   1427 	       matrix->insert_before(new (ctx) ir_dereference_array(var,
   1428 		  new(ctx) ir_constant(i)));
   1429 	    }
   1430 	    matrix->remove();
   1431 	 }
   1432       }
   1433 
   1434       bool all_parameters_are_constant = true;
   1435 
   1436       /* Type cast each parameter and, if possible, fold constants.*/
   1437       foreach_list_safe(n, &actual_parameters) {
   1438 	 ir_rvalue *ir = (ir_rvalue *) n;
   1439 
   1440 	 const glsl_type *desired_type =
   1441 	    glsl_type::get_instance(constructor_type->base_type,
   1442 				    ir->type->vector_elements,
   1443 				    ir->type->matrix_columns);
   1444 	 ir_rvalue *result = convert_component(ir, desired_type);
   1445 
   1446 	 /* Attempt to convert the parameter to a constant valued expression.
   1447 	  * After doing so, track whether or not all the parameters to the
   1448 	  * constructor are trivially constant valued expressions.
   1449 	  */
   1450 	 ir_rvalue *const constant = result->constant_expression_value();
   1451 
   1452 	 if (constant != NULL)
   1453 	    result = constant;
   1454 	 else
   1455 	    all_parameters_are_constant = false;
   1456 
   1457 	 if (result != ir) {
   1458 	    ir->replace_with(result);
   1459 	 }
   1460       }
   1461 
   1462       /* If all of the parameters are trivially constant, create a
   1463        * constant representing the complete collection of parameters.
   1464        */
   1465       if (all_parameters_are_constant) {
   1466 	 return new(ctx) ir_constant(constructor_type, &actual_parameters);
   1467       } else if (constructor_type->is_scalar()) {
   1468 	 return dereference_component((ir_rvalue *) actual_parameters.head,
   1469 				      0);
   1470       } else if (constructor_type->is_vector()) {
   1471 	 return emit_inline_vector_constructor(constructor_type,
   1472 					       instructions,
   1473 					       &actual_parameters,
   1474 					       ctx);
   1475       } else {
   1476 	 assert(constructor_type->is_matrix());
   1477 	 return emit_inline_matrix_constructor(constructor_type,
   1478 					       instructions,
   1479 					       &actual_parameters,
   1480 					       ctx);
   1481       }
   1482    } else {
   1483       const ast_expression *id = subexpressions[0];
   1484       const char *func_name = id->primary_expression.identifier;
   1485       YYLTYPE loc = id->get_location();
   1486       exec_list actual_parameters;
   1487 
   1488       process_parameters(instructions, &actual_parameters, &this->expressions,
   1489 			 state);
   1490 
   1491       ir_function_signature *sig =
   1492 	 match_function_by_name(func_name, &actual_parameters, state);
   1493 
   1494       ir_call *call = NULL;
   1495       ir_rvalue *value = NULL;
   1496       if (sig == NULL) {
   1497 	 no_matching_function_error(func_name, &loc, &actual_parameters, state);
   1498 	 value = ir_rvalue::error_value(ctx);
   1499       } else if (!verify_parameter_modes(state, sig, actual_parameters, this->expressions)) {
   1500 	 /* an error has already been emitted */
   1501 	 value = ir_rvalue::error_value(ctx);
   1502       } else {
   1503 	 value = generate_call(instructions, sig, &loc, &actual_parameters,
   1504 			       &call, state);
   1505       }
   1506 
   1507       return value;
   1508    }
   1509 
   1510    return ir_rvalue::error_value(ctx);
   1511 }
   1512