| /* |
| * Copyright © 2012 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. |
| */ |
| |
| /** |
| * \file link_varyings.cpp |
| * |
| * Linker functions related specifically to linking varyings between shader |
| * stages. |
| */ |
| |
| |
| #include "main/mtypes.h" |
| #include "glsl_symbol_table.h" |
| #include "ir_optimization.h" |
| #include "linker.h" |
| #include "link_varyings.h" |
| #include "main/macros.h" |
| #include "program/hash_table.h" |
| #include "program.h" |
| |
| |
| /** |
| * Validate that outputs from one stage match inputs of another |
| */ |
| bool |
| cross_validate_outputs_to_inputs(struct gl_shader_program *prog, |
| gl_shader *producer, gl_shader *consumer) |
| { |
| glsl_symbol_table parameters; |
| /* FINISHME: Figure these out dynamically. */ |
| const char *const producer_stage = "vertex"; |
| const char *const consumer_stage = "fragment"; |
| |
| /* Find all shader outputs in the "producer" stage. |
| */ |
| foreach_list(node, producer->ir) { |
| ir_variable *const var = ((ir_instruction *) node)->as_variable(); |
| |
| if ((var == NULL) || (var->mode != ir_var_shader_out)) |
| continue; |
| |
| parameters.add_variable(var); |
| } |
| |
| |
| /* Find all shader inputs in the "consumer" stage. Any variables that have |
| * matching outputs already in the symbol table must have the same type and |
| * qualifiers. |
| */ |
| foreach_list(node, consumer->ir) { |
| ir_variable *const input = ((ir_instruction *) node)->as_variable(); |
| |
| if ((input == NULL) || (input->mode != ir_var_shader_in)) |
| continue; |
| |
| ir_variable *const output = parameters.get_variable(input->name); |
| if (output != NULL) { |
| /* Check that the types match between stages. |
| */ |
| if (input->type != output->type) { |
| /* There is a bit of a special case for gl_TexCoord. This |
| * built-in is unsized by default. Applications that variable |
| * access it must redeclare it with a size. There is some |
| * language in the GLSL spec that implies the fragment shader |
| * and vertex shader do not have to agree on this size. Other |
| * driver behave this way, and one or two applications seem to |
| * rely on it. |
| * |
| * Neither declaration needs to be modified here because the array |
| * sizes are fixed later when update_array_sizes is called. |
| * |
| * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec: |
| * |
| * "Unlike user-defined varying variables, the built-in |
| * varying variables don't have a strict one-to-one |
| * correspondence between the vertex language and the |
| * fragment language." |
| */ |
| if (!output->type->is_array() |
| || (strncmp("gl_", output->name, 3) != 0)) { |
| linker_error(prog, |
| "%s shader output `%s' declared as type `%s', " |
| "but %s shader input declared as type `%s'\n", |
| producer_stage, output->name, |
| output->type->name, |
| consumer_stage, input->type->name); |
| return false; |
| } |
| } |
| |
| /* Check that all of the qualifiers match between stages. |
| */ |
| if (input->centroid != output->centroid) { |
| linker_error(prog, |
| "%s shader output `%s' %s centroid qualifier, " |
| "but %s shader input %s centroid qualifier\n", |
| producer_stage, |
| output->name, |
| (output->centroid) ? "has" : "lacks", |
| consumer_stage, |
| (input->centroid) ? "has" : "lacks"); |
| return false; |
| } |
| |
| if (input->invariant != output->invariant) { |
| linker_error(prog, |
| "%s shader output `%s' %s invariant qualifier, " |
| "but %s shader input %s invariant qualifier\n", |
| producer_stage, |
| output->name, |
| (output->invariant) ? "has" : "lacks", |
| consumer_stage, |
| (input->invariant) ? "has" : "lacks"); |
| return false; |
| } |
| |
| if (input->interpolation != output->interpolation) { |
| linker_error(prog, |
| "%s shader output `%s' specifies %s " |
| "interpolation qualifier, " |
| "but %s shader input specifies %s " |
| "interpolation qualifier\n", |
| producer_stage, |
| output->name, |
| output->interpolation_string(), |
| consumer_stage, |
| input->interpolation_string()); |
| return false; |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| |
| /** |
| * Initialize this object based on a string that was passed to |
| * glTransformFeedbackVaryings. |
| * |
| * If the input is mal-formed, this call still succeeds, but it sets |
| * this->var_name to a mal-formed input, so tfeedback_decl::find_output_var() |
| * will fail to find any matching variable. |
| */ |
| void |
| tfeedback_decl::init(struct gl_context *ctx, struct gl_shader_program *prog, |
| const void *mem_ctx, const char *input) |
| { |
| /* We don't have to be pedantic about what is a valid GLSL variable name, |
| * because any variable with an invalid name can't exist in the IR anyway. |
| */ |
| |
| this->location = -1; |
| this->orig_name = input; |
| this->is_clip_distance_mesa = false; |
| this->skip_components = 0; |
| this->next_buffer_separator = false; |
| this->matched_candidate = NULL; |
| |
| if (ctx->Extensions.ARB_transform_feedback3) { |
| /* Parse gl_NextBuffer. */ |
| if (strcmp(input, "gl_NextBuffer") == 0) { |
| this->next_buffer_separator = true; |
| return; |
| } |
| |
| /* Parse gl_SkipComponents. */ |
| if (strcmp(input, "gl_SkipComponents1") == 0) |
| this->skip_components = 1; |
| else if (strcmp(input, "gl_SkipComponents2") == 0) |
| this->skip_components = 2; |
| else if (strcmp(input, "gl_SkipComponents3") == 0) |
| this->skip_components = 3; |
| else if (strcmp(input, "gl_SkipComponents4") == 0) |
| this->skip_components = 4; |
| |
| if (this->skip_components) |
| return; |
| } |
| |
| /* Parse a declaration. */ |
| const char *base_name_end; |
| long subscript = parse_program_resource_name(input, &base_name_end); |
| this->var_name = ralloc_strndup(mem_ctx, input, base_name_end - input); |
| if (subscript >= 0) { |
| this->array_subscript = subscript; |
| this->is_subscripted = true; |
| } else { |
| this->is_subscripted = false; |
| } |
| |
| /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this |
| * class must behave specially to account for the fact that gl_ClipDistance |
| * is converted from a float[8] to a vec4[2]. |
| */ |
| if (ctx->ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerClipDistance && |
| strcmp(this->var_name, "gl_ClipDistance") == 0) { |
| this->is_clip_distance_mesa = true; |
| } |
| } |
| |
| |
| /** |
| * Determine whether two tfeedback_decl objects refer to the same variable and |
| * array index (if applicable). |
| */ |
| bool |
| tfeedback_decl::is_same(const tfeedback_decl &x, const tfeedback_decl &y) |
| { |
| assert(x.is_varying() && y.is_varying()); |
| |
| if (strcmp(x.var_name, y.var_name) != 0) |
| return false; |
| if (x.is_subscripted != y.is_subscripted) |
| return false; |
| if (x.is_subscripted && x.array_subscript != y.array_subscript) |
| return false; |
| return true; |
| } |
| |
| |
| /** |
| * Assign a location for this tfeedback_decl object based on the transform |
| * feedback candidate found by find_candidate. |
| * |
| * If an error occurs, the error is reported through linker_error() and false |
| * is returned. |
| */ |
| bool |
| tfeedback_decl::assign_location(struct gl_context *ctx, |
| struct gl_shader_program *prog) |
| { |
| assert(this->is_varying()); |
| |
| unsigned fine_location |
| = this->matched_candidate->toplevel_var->location * 4 |
| + this->matched_candidate->toplevel_var->location_frac |
| + this->matched_candidate->offset; |
| |
| if (this->matched_candidate->type->is_array()) { |
| /* Array variable */ |
| const unsigned matrix_cols = |
| this->matched_candidate->type->fields.array->matrix_columns; |
| const unsigned vector_elements = |
| this->matched_candidate->type->fields.array->vector_elements; |
| unsigned actual_array_size = this->is_clip_distance_mesa ? |
| prog->Vert.ClipDistanceArraySize : |
| this->matched_candidate->type->array_size(); |
| |
| if (this->is_subscripted) { |
| /* Check array bounds. */ |
| if (this->array_subscript >= actual_array_size) { |
| linker_error(prog, "Transform feedback varying %s has index " |
| "%i, but the array size is %u.", |
| this->orig_name, this->array_subscript, |
| actual_array_size); |
| return false; |
| } |
| unsigned array_elem_size = this->is_clip_distance_mesa ? |
| 1 : vector_elements * matrix_cols; |
| fine_location += array_elem_size * this->array_subscript; |
| this->size = 1; |
| } else { |
| this->size = actual_array_size; |
| } |
| this->vector_elements = vector_elements; |
| this->matrix_columns = matrix_cols; |
| if (this->is_clip_distance_mesa) |
| this->type = GL_FLOAT; |
| else |
| this->type = this->matched_candidate->type->fields.array->gl_type; |
| } else { |
| /* Regular variable (scalar, vector, or matrix) */ |
| if (this->is_subscripted) { |
| linker_error(prog, "Transform feedback varying %s requested, " |
| "but %s is not an array.", |
| this->orig_name, this->var_name); |
| return false; |
| } |
| this->size = 1; |
| this->vector_elements = this->matched_candidate->type->vector_elements; |
| this->matrix_columns = this->matched_candidate->type->matrix_columns; |
| this->type = this->matched_candidate->type->gl_type; |
| } |
| this->location = fine_location / 4; |
| this->location_frac = fine_location % 4; |
| |
| /* From GL_EXT_transform_feedback: |
| * A program will fail to link if: |
| * |
| * * the total number of components to capture in any varying |
| * variable in <varyings> is greater than the constant |
| * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the |
| * buffer mode is SEPARATE_ATTRIBS_EXT; |
| */ |
| if (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS && |
| this->num_components() > |
| ctx->Const.MaxTransformFeedbackSeparateComponents) { |
| linker_error(prog, "Transform feedback varying %s exceeds " |
| "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.", |
| this->orig_name); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| |
| unsigned |
| tfeedback_decl::get_num_outputs() const |
| { |
| if (!this->is_varying()) { |
| return 0; |
| } |
| |
| return (this->num_components() + this->location_frac + 3)/4; |
| } |
| |
| |
| /** |
| * Update gl_transform_feedback_info to reflect this tfeedback_decl. |
| * |
| * If an error occurs, the error is reported through linker_error() and false |
| * is returned. |
| */ |
| bool |
| tfeedback_decl::store(struct gl_context *ctx, struct gl_shader_program *prog, |
| struct gl_transform_feedback_info *info, |
| unsigned buffer, const unsigned max_outputs) const |
| { |
| assert(!this->next_buffer_separator); |
| |
| /* Handle gl_SkipComponents. */ |
| if (this->skip_components) { |
| info->BufferStride[buffer] += this->skip_components; |
| return true; |
| } |
| |
| /* From GL_EXT_transform_feedback: |
| * A program will fail to link if: |
| * |
| * * the total number of components to capture is greater than |
| * the constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT |
| * and the buffer mode is INTERLEAVED_ATTRIBS_EXT. |
| */ |
| if (prog->TransformFeedback.BufferMode == GL_INTERLEAVED_ATTRIBS && |
| info->BufferStride[buffer] + this->num_components() > |
| ctx->Const.MaxTransformFeedbackInterleavedComponents) { |
| linker_error(prog, "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS " |
| "limit has been exceeded."); |
| return false; |
| } |
| |
| unsigned location = this->location; |
| unsigned location_frac = this->location_frac; |
| unsigned num_components = this->num_components(); |
| while (num_components > 0) { |
| unsigned output_size = MIN2(num_components, 4 - location_frac); |
| assert(info->NumOutputs < max_outputs); |
| info->Outputs[info->NumOutputs].ComponentOffset = location_frac; |
| info->Outputs[info->NumOutputs].OutputRegister = location; |
| info->Outputs[info->NumOutputs].NumComponents = output_size; |
| info->Outputs[info->NumOutputs].OutputBuffer = buffer; |
| info->Outputs[info->NumOutputs].DstOffset = info->BufferStride[buffer]; |
| ++info->NumOutputs; |
| info->BufferStride[buffer] += output_size; |
| num_components -= output_size; |
| location++; |
| location_frac = 0; |
| } |
| |
| info->Varyings[info->NumVarying].Name = ralloc_strdup(prog, this->orig_name); |
| info->Varyings[info->NumVarying].Type = this->type; |
| info->Varyings[info->NumVarying].Size = this->size; |
| info->NumVarying++; |
| |
| return true; |
| } |
| |
| |
| const tfeedback_candidate * |
| tfeedback_decl::find_candidate(gl_shader_program *prog, |
| hash_table *tfeedback_candidates) |
| { |
| const char *name = this->is_clip_distance_mesa |
| ? "gl_ClipDistanceMESA" : this->var_name; |
| this->matched_candidate = (const tfeedback_candidate *) |
| hash_table_find(tfeedback_candidates, name); |
| if (!this->matched_candidate) { |
| /* From GL_EXT_transform_feedback: |
| * A program will fail to link if: |
| * |
| * * any variable name specified in the <varyings> array is not |
| * declared as an output in the geometry shader (if present) or |
| * the vertex shader (if no geometry shader is present); |
| */ |
| linker_error(prog, "Transform feedback varying %s undeclared.", |
| this->orig_name); |
| } |
| return this->matched_candidate; |
| } |
| |
| |
| /** |
| * Parse all the transform feedback declarations that were passed to |
| * glTransformFeedbackVaryings() and store them in tfeedback_decl objects. |
| * |
| * If an error occurs, the error is reported through linker_error() and false |
| * is returned. |
| */ |
| bool |
| parse_tfeedback_decls(struct gl_context *ctx, struct gl_shader_program *prog, |
| const void *mem_ctx, unsigned num_names, |
| char **varying_names, tfeedback_decl *decls) |
| { |
| for (unsigned i = 0; i < num_names; ++i) { |
| decls[i].init(ctx, prog, mem_ctx, varying_names[i]); |
| |
| if (!decls[i].is_varying()) |
| continue; |
| |
| /* From GL_EXT_transform_feedback: |
| * A program will fail to link if: |
| * |
| * * any two entries in the <varyings> array specify the same varying |
| * variable; |
| * |
| * We interpret this to mean "any two entries in the <varyings> array |
| * specify the same varying variable and array index", since transform |
| * feedback of arrays would be useless otherwise. |
| */ |
| for (unsigned j = 0; j < i; ++j) { |
| if (!decls[j].is_varying()) |
| continue; |
| |
| if (tfeedback_decl::is_same(decls[i], decls[j])) { |
| linker_error(prog, "Transform feedback varying %s specified " |
| "more than once.", varying_names[i]); |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| |
| /** |
| * Store transform feedback location assignments into |
| * prog->LinkedTransformFeedback based on the data stored in tfeedback_decls. |
| * |
| * If an error occurs, the error is reported through linker_error() and false |
| * is returned. |
| */ |
| bool |
| store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog, |
| unsigned num_tfeedback_decls, |
| tfeedback_decl *tfeedback_decls) |
| { |
| bool separate_attribs_mode = |
| prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS; |
| |
| ralloc_free(prog->LinkedTransformFeedback.Varyings); |
| ralloc_free(prog->LinkedTransformFeedback.Outputs); |
| |
| memset(&prog->LinkedTransformFeedback, 0, |
| sizeof(prog->LinkedTransformFeedback)); |
| |
| prog->LinkedTransformFeedback.Varyings = |
| rzalloc_array(prog, |
| struct gl_transform_feedback_varying_info, |
| num_tfeedback_decls); |
| |
| unsigned num_outputs = 0; |
| for (unsigned i = 0; i < num_tfeedback_decls; ++i) |
| num_outputs += tfeedback_decls[i].get_num_outputs(); |
| |
| prog->LinkedTransformFeedback.Outputs = |
| rzalloc_array(prog, |
| struct gl_transform_feedback_output, |
| num_outputs); |
| |
| unsigned num_buffers = 0; |
| |
| if (separate_attribs_mode) { |
| /* GL_SEPARATE_ATTRIBS */ |
| for (unsigned i = 0; i < num_tfeedback_decls; ++i) { |
| if (!tfeedback_decls[i].store(ctx, prog, &prog->LinkedTransformFeedback, |
| num_buffers, num_outputs)) |
| return false; |
| |
| num_buffers++; |
| } |
| } |
| else { |
| /* GL_INVERLEAVED_ATTRIBS */ |
| for (unsigned i = 0; i < num_tfeedback_decls; ++i) { |
| if (tfeedback_decls[i].is_next_buffer_separator()) { |
| num_buffers++; |
| continue; |
| } |
| |
| if (!tfeedback_decls[i].store(ctx, prog, |
| &prog->LinkedTransformFeedback, |
| num_buffers, num_outputs)) |
| return false; |
| } |
| num_buffers++; |
| } |
| |
| assert(prog->LinkedTransformFeedback.NumOutputs == num_outputs); |
| |
| prog->LinkedTransformFeedback.NumBuffers = num_buffers; |
| return true; |
| } |
| |
| |
| /** |
| * Data structure recording the relationship between outputs of one shader |
| * stage (the "producer") and inputs of another (the "consumer"). |
| */ |
| class varying_matches |
| { |
| public: |
| varying_matches(bool disable_varying_packing); |
| ~varying_matches(); |
| void record(ir_variable *producer_var, ir_variable *consumer_var); |
| unsigned assign_locations(); |
| void store_locations(unsigned producer_base, unsigned consumer_base) const; |
| |
| private: |
| /** |
| * If true, this driver disables varying packing, so all varyings need to |
| * be aligned on slot boundaries, and take up a number of slots equal to |
| * their number of matrix columns times their array size. |
| */ |
| const bool disable_varying_packing; |
| |
| /** |
| * Enum representing the order in which varyings are packed within a |
| * packing class. |
| * |
| * Currently we pack vec4's first, then vec2's, then scalar values, then |
| * vec3's. This order ensures that the only vectors that are at risk of |
| * having to be "double parked" (split between two adjacent varying slots) |
| * are the vec3's. |
| */ |
| enum packing_order_enum { |
| PACKING_ORDER_VEC4, |
| PACKING_ORDER_VEC2, |
| PACKING_ORDER_SCALAR, |
| PACKING_ORDER_VEC3, |
| }; |
| |
| static unsigned compute_packing_class(ir_variable *var); |
| static packing_order_enum compute_packing_order(ir_variable *var); |
| static int match_comparator(const void *x_generic, const void *y_generic); |
| |
| /** |
| * Structure recording the relationship between a single producer output |
| * and a single consumer input. |
| */ |
| struct match { |
| /** |
| * Packing class for this varying, computed by compute_packing_class(). |
| */ |
| unsigned packing_class; |
| |
| /** |
| * Packing order for this varying, computed by compute_packing_order(). |
| */ |
| packing_order_enum packing_order; |
| unsigned num_components; |
| |
| /** |
| * The output variable in the producer stage. |
| */ |
| ir_variable *producer_var; |
| |
| /** |
| * The input variable in the consumer stage. |
| */ |
| ir_variable *consumer_var; |
| |
| /** |
| * The location which has been assigned for this varying. This is |
| * expressed in multiples of a float, with the first generic varying |
| * (i.e. the one referred to by VERT_RESULT_VAR0 or FRAG_ATTRIB_VAR0) |
| * represented by the value 0. |
| */ |
| unsigned generic_location; |
| } *matches; |
| |
| /** |
| * The number of elements in the \c matches array that are currently in |
| * use. |
| */ |
| unsigned num_matches; |
| |
| /** |
| * The number of elements that were set aside for the \c matches array when |
| * it was allocated. |
| */ |
| unsigned matches_capacity; |
| }; |
| |
| |
| varying_matches::varying_matches(bool disable_varying_packing) |
| : disable_varying_packing(disable_varying_packing) |
| { |
| /* Note: this initial capacity is rather arbitrarily chosen to be large |
| * enough for many cases without wasting an unreasonable amount of space. |
| * varying_matches::record() will resize the array if there are more than |
| * this number of varyings. |
| */ |
| this->matches_capacity = 8; |
| this->matches = (match *) |
| malloc(sizeof(*this->matches) * this->matches_capacity); |
| this->num_matches = 0; |
| } |
| |
| |
| varying_matches::~varying_matches() |
| { |
| free(this->matches); |
| } |
| |
| |
| /** |
| * Record the given producer/consumer variable pair in the list of variables |
| * that should later be assigned locations. |
| * |
| * It is permissible for \c consumer_var to be NULL (this happens if a |
| * variable is output by the producer and consumed by transform feedback, but |
| * not consumed by the consumer). |
| * |
| * If \c producer_var has already been paired up with a consumer_var, or |
| * producer_var is part of fixed pipeline functionality (and hence already has |
| * a location assigned), this function has no effect. |
| */ |
| void |
| varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var) |
| { |
| if (!producer_var->is_unmatched_generic_inout) { |
| /* Either a location already exists for this variable (since it is part |
| * of fixed functionality), or it has already been recorded as part of a |
| * previous match. |
| */ |
| return; |
| } |
| |
| if (this->num_matches == this->matches_capacity) { |
| this->matches_capacity *= 2; |
| this->matches = (match *) |
| realloc(this->matches, |
| sizeof(*this->matches) * this->matches_capacity); |
| } |
| this->matches[this->num_matches].packing_class |
| = this->compute_packing_class(producer_var); |
| this->matches[this->num_matches].packing_order |
| = this->compute_packing_order(producer_var); |
| if (this->disable_varying_packing) { |
| unsigned slots = producer_var->type->is_array() |
| ? (producer_var->type->length |
| * producer_var->type->fields.array->matrix_columns) |
| : producer_var->type->matrix_columns; |
| this->matches[this->num_matches].num_components = 4 * slots; |
| } else { |
| this->matches[this->num_matches].num_components |
| = producer_var->type->component_slots(); |
| } |
| this->matches[this->num_matches].producer_var = producer_var; |
| this->matches[this->num_matches].consumer_var = consumer_var; |
| this->num_matches++; |
| producer_var->is_unmatched_generic_inout = 0; |
| if (consumer_var) |
| consumer_var->is_unmatched_generic_inout = 0; |
| } |
| |
| |
| /** |
| * Choose locations for all of the variable matches that were previously |
| * passed to varying_matches::record(). |
| */ |
| unsigned |
| varying_matches::assign_locations() |
| { |
| /* Sort varying matches into an order that makes them easy to pack. */ |
| qsort(this->matches, this->num_matches, sizeof(*this->matches), |
| &varying_matches::match_comparator); |
| |
| unsigned generic_location = 0; |
| |
| for (unsigned i = 0; i < this->num_matches; i++) { |
| /* Advance to the next slot if this varying has a different packing |
| * class than the previous one, and we're not already on a slot |
| * boundary. |
| */ |
| if (i > 0 && |
| this->matches[i - 1].packing_class |
| != this->matches[i].packing_class) { |
| generic_location = ALIGN(generic_location, 4); |
| } |
| |
| this->matches[i].generic_location = generic_location; |
| |
| generic_location += this->matches[i].num_components; |
| } |
| |
| return (generic_location + 3) / 4; |
| } |
| |
| |
| /** |
| * Update the producer and consumer shaders to reflect the locations |
| * assignments that were made by varying_matches::assign_locations(). |
| */ |
| void |
| varying_matches::store_locations(unsigned producer_base, |
| unsigned consumer_base) const |
| { |
| for (unsigned i = 0; i < this->num_matches; i++) { |
| ir_variable *producer_var = this->matches[i].producer_var; |
| ir_variable *consumer_var = this->matches[i].consumer_var; |
| unsigned generic_location = this->matches[i].generic_location; |
| unsigned slot = generic_location / 4; |
| unsigned offset = generic_location % 4; |
| |
| producer_var->location = producer_base + slot; |
| producer_var->location_frac = offset; |
| if (consumer_var) { |
| assert(consumer_var->location == -1); |
| consumer_var->location = consumer_base + slot; |
| consumer_var->location_frac = offset; |
| } |
| } |
| } |
| |
| |
| /** |
| * Compute the "packing class" of the given varying. This is an unsigned |
| * integer with the property that two variables in the same packing class can |
| * be safely backed into the same vec4. |
| */ |
| unsigned |
| varying_matches::compute_packing_class(ir_variable *var) |
| { |
| /* Without help from the back-end, there is no way to pack together |
| * variables with different interpolation types, because |
| * lower_packed_varyings must choose exactly one interpolation type for |
| * each packed varying it creates. |
| * |
| * However, we can safely pack together floats, ints, and uints, because: |
| * |
| * - varyings of base type "int" and "uint" must use the "flat" |
| * interpolation type, which can only occur in GLSL 1.30 and above. |
| * |
| * - On platforms that support GLSL 1.30 and above, lower_packed_varyings |
| * can store flat floats as ints without losing any information (using |
| * the ir_unop_bitcast_* opcodes). |
| * |
| * Therefore, the packing class depends only on the interpolation type. |
| */ |
| unsigned packing_class = var->centroid ? 1 : 0; |
| packing_class *= 4; |
| packing_class += var->interpolation; |
| return packing_class; |
| } |
| |
| |
| /** |
| * Compute the "packing order" of the given varying. This is a sort key we |
| * use to determine when to attempt to pack the given varying relative to |
| * other varyings in the same packing class. |
| */ |
| varying_matches::packing_order_enum |
| varying_matches::compute_packing_order(ir_variable *var) |
| { |
| const glsl_type *element_type = var->type; |
| |
| while (element_type->base_type == GLSL_TYPE_ARRAY) { |
| element_type = element_type->fields.array; |
| } |
| |
| switch (element_type->component_slots() % 4) { |
| case 1: return PACKING_ORDER_SCALAR; |
| case 2: return PACKING_ORDER_VEC2; |
| case 3: return PACKING_ORDER_VEC3; |
| case 0: return PACKING_ORDER_VEC4; |
| default: |
| assert(!"Unexpected value of vector_elements"); |
| return PACKING_ORDER_VEC4; |
| } |
| } |
| |
| |
| /** |
| * Comparison function passed to qsort() to sort varyings by packing_class and |
| * then by packing_order. |
| */ |
| int |
| varying_matches::match_comparator(const void *x_generic, const void *y_generic) |
| { |
| const match *x = (const match *) x_generic; |
| const match *y = (const match *) y_generic; |
| |
| if (x->packing_class != y->packing_class) |
| return x->packing_class - y->packing_class; |
| return x->packing_order - y->packing_order; |
| } |
| |
| |
| /** |
| * Is the given variable a varying variable to be counted against the |
| * limit in ctx->Const.MaxVarying? |
| * This includes variables such as texcoords, colors and generic |
| * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord. |
| */ |
| static bool |
| is_varying_var(GLenum shaderType, const ir_variable *var) |
| { |
| /* Only fragment shaders will take a varying variable as an input */ |
| if (shaderType == GL_FRAGMENT_SHADER && |
| var->mode == ir_var_shader_in) { |
| switch (var->location) { |
| case FRAG_ATTRIB_WPOS: |
| case FRAG_ATTRIB_FACE: |
| case FRAG_ATTRIB_PNTC: |
| return false; |
| default: |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| |
| /** |
| * Visitor class that generates tfeedback_candidate structs describing all |
| * possible targets of transform feedback. |
| * |
| * tfeedback_candidate structs are stored in the hash table |
| * tfeedback_candidates, which is passed to the constructor. This hash table |
| * maps varying names to instances of the tfeedback_candidate struct. |
| */ |
| class tfeedback_candidate_generator : public program_resource_visitor |
| { |
| public: |
| tfeedback_candidate_generator(void *mem_ctx, |
| hash_table *tfeedback_candidates) |
| : mem_ctx(mem_ctx), |
| tfeedback_candidates(tfeedback_candidates) |
| { |
| } |
| |
| void process(ir_variable *var) |
| { |
| this->toplevel_var = var; |
| this->varying_floats = 0; |
| if (var->is_interface_instance()) |
| program_resource_visitor::process(var->interface_type, |
| var->interface_type->name); |
| else |
| program_resource_visitor::process(var); |
| } |
| |
| private: |
| virtual void visit_field(const glsl_type *type, const char *name, |
| bool row_major) |
| { |
| assert(!type->is_record()); |
| assert(!(type->is_array() && type->fields.array->is_record())); |
| assert(!type->is_interface()); |
| assert(!(type->is_array() && type->fields.array->is_interface())); |
| |
| (void) row_major; |
| |
| tfeedback_candidate *candidate |
| = rzalloc(this->mem_ctx, tfeedback_candidate); |
| candidate->toplevel_var = this->toplevel_var; |
| candidate->type = type; |
| candidate->offset = this->varying_floats; |
| hash_table_insert(this->tfeedback_candidates, candidate, |
| ralloc_strdup(this->mem_ctx, name)); |
| this->varying_floats += type->component_slots(); |
| } |
| |
| /** |
| * Memory context used to allocate hash table keys and values. |
| */ |
| void * const mem_ctx; |
| |
| /** |
| * Hash table in which tfeedback_candidate objects should be stored. |
| */ |
| hash_table * const tfeedback_candidates; |
| |
| /** |
| * Pointer to the toplevel variable that is being traversed. |
| */ |
| ir_variable *toplevel_var; |
| |
| /** |
| * Total number of varying floats that have been visited so far. This is |
| * used to determine the offset to each varying within the toplevel |
| * variable. |
| */ |
| unsigned varying_floats; |
| }; |
| |
| |
| /** |
| * Assign locations for all variables that are produced in one pipeline stage |
| * (the "producer") and consumed in the next stage (the "consumer"). |
| * |
| * Variables produced by the producer may also be consumed by transform |
| * feedback. |
| * |
| * \param num_tfeedback_decls is the number of declarations indicating |
| * variables that may be consumed by transform feedback. |
| * |
| * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects |
| * representing the result of parsing the strings passed to |
| * glTransformFeedbackVaryings(). assign_location() will be called for |
| * each of these objects that matches one of the outputs of the |
| * producer. |
| * |
| * When num_tfeedback_decls is nonzero, it is permissible for the consumer to |
| * be NULL. In this case, varying locations are assigned solely based on the |
| * requirements of transform feedback. |
| */ |
| bool |
| assign_varying_locations(struct gl_context *ctx, |
| void *mem_ctx, |
| struct gl_shader_program *prog, |
| gl_shader *producer, gl_shader *consumer, |
| unsigned num_tfeedback_decls, |
| tfeedback_decl *tfeedback_decls) |
| { |
| /* FINISHME: Set dynamically when geometry shader support is added. */ |
| const unsigned producer_base = VERT_RESULT_VAR0; |
| const unsigned consumer_base = FRAG_ATTRIB_VAR0; |
| varying_matches matches(ctx->Const.DisableVaryingPacking); |
| hash_table *tfeedback_candidates |
| = hash_table_ctor(0, hash_table_string_hash, hash_table_string_compare); |
| |
| /* Operate in a total of three passes. |
| * |
| * 1. Assign locations for any matching inputs and outputs. |
| * |
| * 2. Mark output variables in the producer that do not have locations as |
| * not being outputs. This lets the optimizer eliminate them. |
| * |
| * 3. Mark input variables in the consumer that do not have locations as |
| * not being inputs. This lets the optimizer eliminate them. |
| */ |
| |
| foreach_list(node, producer->ir) { |
| ir_variable *const output_var = ((ir_instruction *) node)->as_variable(); |
| |
| if ((output_var == NULL) || (output_var->mode != ir_var_shader_out)) |
| continue; |
| |
| tfeedback_candidate_generator g(mem_ctx, tfeedback_candidates); |
| g.process(output_var); |
| |
| ir_variable *input_var = |
| consumer ? consumer->symbols->get_variable(output_var->name) : NULL; |
| |
| if (input_var && input_var->mode != ir_var_shader_in) |
| input_var = NULL; |
| |
| if (input_var) { |
| matches.record(output_var, input_var); |
| } |
| } |
| |
| for (unsigned i = 0; i < num_tfeedback_decls; ++i) { |
| if (!tfeedback_decls[i].is_varying()) |
| continue; |
| |
| const tfeedback_candidate *matched_candidate |
| = tfeedback_decls[i].find_candidate(prog, tfeedback_candidates); |
| |
| if (matched_candidate == NULL) { |
| hash_table_dtor(tfeedback_candidates); |
| return false; |
| } |
| |
| if (matched_candidate->toplevel_var->is_unmatched_generic_inout) |
| matches.record(matched_candidate->toplevel_var, NULL); |
| } |
| |
| const unsigned slots_used = matches.assign_locations(); |
| matches.store_locations(producer_base, consumer_base); |
| |
| for (unsigned i = 0; i < num_tfeedback_decls; ++i) { |
| if (!tfeedback_decls[i].is_varying()) |
| continue; |
| |
| if (!tfeedback_decls[i].assign_location(ctx, prog)) { |
| hash_table_dtor(tfeedback_candidates); |
| return false; |
| } |
| } |
| |
| hash_table_dtor(tfeedback_candidates); |
| |
| if (ctx->Const.DisableVaryingPacking) { |
| /* Transform feedback code assumes varyings are packed, so if the driver |
| * has disabled varying packing, make sure it does not support transform |
| * feedback. |
| */ |
| assert(!ctx->Extensions.EXT_transform_feedback); |
| } else { |
| lower_packed_varyings(mem_ctx, producer_base, slots_used, |
| ir_var_shader_out, producer); |
| if (consumer) { |
| lower_packed_varyings(mem_ctx, consumer_base, slots_used, |
| ir_var_shader_in, consumer); |
| } |
| } |
| |
| unsigned varying_vectors = 0; |
| |
| if (consumer) { |
| foreach_list(node, consumer->ir) { |
| ir_variable *const var = ((ir_instruction *) node)->as_variable(); |
| |
| if ((var == NULL) || (var->mode != ir_var_shader_in)) |
| continue; |
| |
| if (var->is_unmatched_generic_inout) { |
| if (prog->Version <= 120) { |
| /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec: |
| * |
| * Only those varying variables used (i.e. read) in |
| * the fragment shader executable must be written to |
| * by the vertex shader executable; declaring |
| * superfluous varying variables in a vertex shader is |
| * permissible. |
| * |
| * We interpret this text as meaning that the VS must |
| * write the variable for the FS to read it. See |
| * "glsl1-varying read but not written" in piglit. |
| */ |
| |
| linker_error(prog, "fragment shader varying %s not written " |
| "by vertex shader\n.", var->name); |
| } |
| |
| /* An 'in' variable is only really a shader input if its |
| * value is written by the previous stage. |
| */ |
| var->mode = ir_var_auto; |
| } else if (is_varying_var(consumer->Type, var)) { |
| /* The packing rules are used for vertex shader inputs are also |
| * used for fragment shader inputs. |
| */ |
| varying_vectors += count_attribute_slots(var->type); |
| } |
| } |
| } |
| |
| if (ctx->API == API_OPENGLES2 || prog->IsES) { |
| if (varying_vectors > ctx->Const.MaxVarying) { |
| if (ctx->Const.GLSLSkipStrictMaxVaryingLimitCheck) { |
| linker_warning(prog, "shader uses too many varying vectors " |
| "(%u > %u), but the driver will try to optimize " |
| "them out; this is non-portable out-of-spec " |
| "behavior\n", |
| varying_vectors, ctx->Const.MaxVarying); |
| } else { |
| linker_error(prog, "shader uses too many varying vectors " |
| "(%u > %u)\n", |
| varying_vectors, ctx->Const.MaxVarying); |
| return false; |
| } |
| } |
| } else { |
| const unsigned float_components = varying_vectors * 4; |
| if (float_components > ctx->Const.MaxVarying * 4) { |
| if (ctx->Const.GLSLSkipStrictMaxVaryingLimitCheck) { |
| linker_warning(prog, "shader uses too many varying components " |
| "(%u > %u), but the driver will try to optimize " |
| "them out; this is non-portable out-of-spec " |
| "behavior\n", |
| float_components, ctx->Const.MaxVarying * 4); |
| } else { |
| linker_error(prog, "shader uses too many varying components " |
| "(%u > %u)\n", |
| float_components, ctx->Const.MaxVarying * 4); |
| return false; |
| } |
| } |
| } |
| |
| return true; |
| } |