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Diffstat (limited to 'src/compiler/glsl/ir_function.cpp')
| -rw-r--r-- | src/compiler/glsl/ir_function.cpp | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/src/compiler/glsl/ir_function.cpp b/src/compiler/glsl/ir_function.cpp new file mode 100644 index 00000000000..0b4cb4bd30d --- /dev/null +++ b/src/compiler/glsl/ir_function.cpp @@ -0,0 +1,404 @@ +/* + * Copyright © 2010 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#include "compiler/glsl_types.h" +#include "ir.h" +#include "glsl_parser_extras.h" +#include "main/errors.h" + +typedef enum { + PARAMETER_LIST_NO_MATCH, + PARAMETER_LIST_EXACT_MATCH, + PARAMETER_LIST_INEXACT_MATCH /*< Match requires implicit conversion. */ +} parameter_list_match_t; + +/** + * \brief Check if two parameter lists match. + * + * \param list_a Parameters of the function definition. + * \param list_b Actual parameters passed to the function. + * \see matching_signature() + */ +static parameter_list_match_t +parameter_lists_match(_mesa_glsl_parse_state *state, + const exec_list *list_a, const exec_list *list_b) +{ + const exec_node *node_a = list_a->head; + const exec_node *node_b = list_b->head; + + /* This is set to true if there is an inexact match requiring an implicit + * conversion. */ + bool inexact_match = false; + + for (/* empty */ + ; !node_a->is_tail_sentinel() + ; node_a = node_a->next, node_b = node_b->next) { + /* If all of the parameters from the other parameter list have been + * exhausted, the lists have different length and, by definition, + * do not match. + */ + if (node_b->is_tail_sentinel()) + return PARAMETER_LIST_NO_MATCH; + + + const ir_variable *const param = (ir_variable *) node_a; + const ir_rvalue *const actual = (ir_rvalue *) node_b; + + if (param->type == actual->type) + continue; + + /* Try to find an implicit conversion from actual to param. */ + inexact_match = true; + switch ((enum ir_variable_mode)(param->data.mode)) { + case ir_var_auto: + case ir_var_uniform: + case ir_var_shader_storage: + case ir_var_temporary: + /* These are all error conditions. It is invalid for a parameter to + * a function to be declared as auto (not in, out, or inout) or + * as uniform. + */ + assert(0); + return PARAMETER_LIST_NO_MATCH; + + case ir_var_const_in: + case ir_var_function_in: + if (!actual->type->can_implicitly_convert_to(param->type, state)) + return PARAMETER_LIST_NO_MATCH; + break; + + case ir_var_function_out: + if (!param->type->can_implicitly_convert_to(actual->type, state)) + return PARAMETER_LIST_NO_MATCH; + break; + + case ir_var_function_inout: + /* Since there are no bi-directional automatic conversions (e.g., + * there is int -> float but no float -> int), inout parameters must + * be exact matches. + */ + return PARAMETER_LIST_NO_MATCH; + + default: + assert(false); + return PARAMETER_LIST_NO_MATCH; + } + } + + /* If all of the parameters from the other parameter list have been + * exhausted, the lists have different length and, by definition, do not + * match. + */ + if (!node_b->is_tail_sentinel()) + return PARAMETER_LIST_NO_MATCH; + + if (inexact_match) + return PARAMETER_LIST_INEXACT_MATCH; + else + return PARAMETER_LIST_EXACT_MATCH; +} + + +/* Classes of parameter match, sorted (mostly) best matches first. + * See is_better_parameter_match() below for the exceptions. + * */ +typedef enum { + PARAMETER_EXACT_MATCH, + PARAMETER_FLOAT_TO_DOUBLE, + PARAMETER_INT_TO_FLOAT, + PARAMETER_INT_TO_DOUBLE, + PARAMETER_OTHER_CONVERSION, +} parameter_match_t; + + +static parameter_match_t +get_parameter_match_type(const ir_variable *param, + const ir_rvalue *actual) +{ + const glsl_type *from_type; + const glsl_type *to_type; + + if (param->data.mode == ir_var_function_out) { + from_type = param->type; + to_type = actual->type; + } else { + from_type = actual->type; + to_type = param->type; + } + + if (from_type == to_type) + return PARAMETER_EXACT_MATCH; + + if (to_type->base_type == GLSL_TYPE_DOUBLE) { + if (from_type->base_type == GLSL_TYPE_FLOAT) + return PARAMETER_FLOAT_TO_DOUBLE; + return PARAMETER_INT_TO_DOUBLE; + } + + if (to_type->base_type == GLSL_TYPE_FLOAT) + return PARAMETER_INT_TO_FLOAT; + + /* int -> uint and any other oddball conversions */ + return PARAMETER_OTHER_CONVERSION; +} + + +static bool +is_better_parameter_match(parameter_match_t a_match, + parameter_match_t b_match) +{ + /* From section 6.1 of the GLSL 4.00 spec (and the ARB_gpu_shader5 spec): + * + * 1. An exact match is better than a match involving any implicit + * conversion. + * + * 2. A match involving an implicit conversion from float to double + * is better than match involving any other implicit conversion. + * + * [XXX: Not in GLSL 4.0: Only in ARB_gpu_shader5: + * 3. A match involving an implicit conversion from either int or uint + * to float is better than a match involving an implicit conversion + * from either int or uint to double.] + * + * If none of the rules above apply to a particular pair of conversions, + * neither conversion is considered better than the other. + * + * -- + * + * Notably, the int->uint conversion is *not* considered to be better + * or worse than int/uint->float or int/uint->double. + */ + + if (a_match >= PARAMETER_INT_TO_FLOAT && b_match == PARAMETER_OTHER_CONVERSION) + return false; + + return a_match < b_match; +} + + +static bool +is_best_inexact_overload(const exec_list *actual_parameters, + ir_function_signature **matches, + int num_matches, + ir_function_signature *sig) +{ + /* From section 6.1 of the GLSL 4.00 spec (and the ARB_gpu_shader5 spec): + * + * "A function definition A is considered a better + * match than function definition B if: + * + * * for at least one function argument, the conversion for that argument + * in A is better than the corresponding conversion in B; and + * + * * there is no function argument for which the conversion in B is better + * than the corresponding conversion in A. + * + * If a single function definition is considered a better match than every + * other matching function definition, it will be used. Otherwise, a + * semantic error occurs and the shader will fail to compile." + */ + for (ir_function_signature **other = matches; + other < matches + num_matches; other++) { + if (*other == sig) + continue; + + const exec_node *node_a = sig->parameters.head; + const exec_node *node_b = (*other)->parameters.head; + const exec_node *node_p = actual_parameters->head; + + bool better_for_some_parameter = false; + + for (/* empty */ + ; !node_a->is_tail_sentinel() + ; node_a = node_a->next, + node_b = node_b->next, + node_p = node_p->next) { + parameter_match_t a_match = get_parameter_match_type( + (const ir_variable *)node_a, + (const ir_rvalue *)node_p); + parameter_match_t b_match = get_parameter_match_type( + (const ir_variable *)node_b, + (const ir_rvalue *)node_p); + + if (is_better_parameter_match(a_match, b_match)) + better_for_some_parameter = true; + + if (is_better_parameter_match(b_match, a_match)) + return false; /* B is better for this parameter */ + } + + if (!better_for_some_parameter) + return false; /* A must be better than B for some parameter */ + + } + + return true; +} + + +static ir_function_signature * +choose_best_inexact_overload(_mesa_glsl_parse_state *state, + const exec_list *actual_parameters, + ir_function_signature **matches, + int num_matches) +{ + if (num_matches == 0) + return NULL; + + if (num_matches == 1) + return *matches; + + /* Without GLSL 4.0 / ARB_gpu_shader5, there is no overload resolution + * among multiple inexact matches. Note that state may be NULL here if + * called from the linker; in that case we assume everything supported in + * any GLSL version is available. */ + if (!state || state->is_version(400, 0) || state->ARB_gpu_shader5_enable) { + for (ir_function_signature **sig = matches; sig < matches + num_matches; sig++) { + if (is_best_inexact_overload(actual_parameters, matches, num_matches, *sig)) + return *sig; + } + } + + return NULL; /* no best candidate */ +} + + +ir_function_signature * +ir_function::matching_signature(_mesa_glsl_parse_state *state, + const exec_list *actual_parameters, + bool allow_builtins) +{ + bool is_exact; + return matching_signature(state, actual_parameters, allow_builtins, + &is_exact); +} + +ir_function_signature * +ir_function::matching_signature(_mesa_glsl_parse_state *state, + const exec_list *actual_parameters, + bool allow_builtins, + bool *is_exact) +{ + ir_function_signature **inexact_matches = NULL; + ir_function_signature **inexact_matches_temp; + ir_function_signature *match = NULL; + int num_inexact_matches = 0; + + /* From page 42 (page 49 of the PDF) of the GLSL 1.20 spec: + * + * "If an exact match is found, the other signatures are ignored, and + * the exact match is used. Otherwise, if no exact match is found, then + * the implicit conversions in Section 4.1.10 "Implicit Conversions" will + * be applied to the calling arguments if this can make their types match + * a signature. In this case, it is a semantic error if there are + * multiple ways to apply these conversions to the actual arguments of a + * call such that the call can be made to match multiple signatures." + */ + foreach_in_list(ir_function_signature, sig, &this->signatures) { + /* Skip over any built-ins that aren't available in this shader. */ + if (sig->is_builtin() && (!allow_builtins || + !sig->is_builtin_available(state))) + continue; + + switch (parameter_lists_match(state, & sig->parameters, actual_parameters)) { + case PARAMETER_LIST_EXACT_MATCH: + *is_exact = true; + free(inexact_matches); + return sig; + case PARAMETER_LIST_INEXACT_MATCH: + inexact_matches_temp = (ir_function_signature **) + realloc(inexact_matches, + sizeof(*inexact_matches) * + (num_inexact_matches + 1)); + if (inexact_matches_temp == NULL) { + _mesa_error_no_memory(__func__); + free(inexact_matches); + return NULL; + } + inexact_matches = inexact_matches_temp; + inexact_matches[num_inexact_matches++] = sig; + continue; + case PARAMETER_LIST_NO_MATCH: + continue; + default: + assert(false); + return NULL; + } + } + + /* There is no exact match (we would have returned it by now). If there + * are multiple inexact matches, the call is ambiguous, which is an error. + * + * FINISHME: Report a decent error. Returning NULL will likely result in + * FINISHME: a "no matching signature" error; it should report that the + * FINISHME: call is ambiguous. But reporting errors from here is hard. + */ + *is_exact = false; + + match = choose_best_inexact_overload(state, actual_parameters, + inexact_matches, num_inexact_matches); + + free(inexact_matches); + return match; +} + + +static bool +parameter_lists_match_exact(const exec_list *list_a, const exec_list *list_b) +{ + const exec_node *node_a = list_a->head; + const exec_node *node_b = list_b->head; + + for (/* empty */ + ; !node_a->is_tail_sentinel() && !node_b->is_tail_sentinel() + ; node_a = node_a->next, node_b = node_b->next) { + ir_variable *a = (ir_variable *) node_a; + ir_variable *b = (ir_variable *) node_b; + + /* If the types of the parameters do not match, the parameters lists + * are different. + */ + if (a->type != b->type) + return false; + } + + /* Unless both lists are exhausted, they differ in length and, by + * definition, do not match. + */ + return (node_a->is_tail_sentinel() == node_b->is_tail_sentinel()); +} + +ir_function_signature * +ir_function::exact_matching_signature(_mesa_glsl_parse_state *state, + const exec_list *actual_parameters) +{ + foreach_in_list(ir_function_signature, sig, &this->signatures) { + /* Skip over any built-ins that aren't available in this shader. */ + if (sig->is_builtin() && !sig->is_builtin_available(state)) + continue; + + if (parameter_lists_match_exact(&sig->parameters, actual_parameters)) + return sig; + } + return NULL; +} |