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Diffstat (limited to 'src/compiler/glsl/link_varyings.cpp')
| -rw-r--r-- | src/compiler/glsl/link_varyings.cpp | 3328 |
1 files changed, 0 insertions, 3328 deletions
diff --git a/src/compiler/glsl/link_varyings.cpp b/src/compiler/glsl/link_varyings.cpp deleted file mode 100644 index abae4377e83..00000000000 --- a/src/compiler/glsl/link_varyings.cpp +++ /dev/null @@ -1,3328 +0,0 @@ -/* - * 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/errors.h" -#include "main/mtypes.h" -#include "glsl_symbol_table.h" -#include "glsl_parser_extras.h" -#include "ir_optimization.h" -#include "linker.h" -#include "link_varyings.h" -#include "main/macros.h" -#include "util/hash_table.h" -#include "util/u_math.h" -#include "program.h" - - -/** - * Get the varying type stripped of the outermost array if we're processing - * a stage whose varyings are arrays indexed by a vertex number (such as - * geometry shader inputs). - */ -static const glsl_type * -get_varying_type(const ir_variable *var, gl_shader_stage stage) -{ - const glsl_type *type = var->type; - - if (!var->data.patch && - ((var->data.mode == ir_var_shader_out && - stage == MESA_SHADER_TESS_CTRL) || - (var->data.mode == ir_var_shader_in && - (stage == MESA_SHADER_TESS_CTRL || stage == MESA_SHADER_TESS_EVAL || - stage == MESA_SHADER_GEOMETRY)))) { - assert(type->is_array()); - type = type->fields.array; - } - - return type; -} - -static bool -varying_has_user_specified_location(const ir_variable *var) -{ - return var->data.explicit_location && - var->data.location >= VARYING_SLOT_VAR0; -} - -static void -create_xfb_varying_names(void *mem_ctx, const glsl_type *t, char **name, - size_t name_length, unsigned *count, - const char *ifc_member_name, - const glsl_type *ifc_member_t, char ***varying_names) -{ - if (t->is_interface()) { - size_t new_length = name_length; - - assert(ifc_member_name && ifc_member_t); - ralloc_asprintf_rewrite_tail(name, &new_length, ".%s", ifc_member_name); - - create_xfb_varying_names(mem_ctx, ifc_member_t, name, new_length, count, - NULL, NULL, varying_names); - } else if (t->is_struct()) { - for (unsigned i = 0; i < t->length; i++) { - const char *field = t->fields.structure[i].name; - size_t new_length = name_length; - - ralloc_asprintf_rewrite_tail(name, &new_length, ".%s", field); - - create_xfb_varying_names(mem_ctx, t->fields.structure[i].type, name, - new_length, count, NULL, NULL, - varying_names); - } - } else if (t->without_array()->is_struct() || - t->without_array()->is_interface() || - (t->is_array() && t->fields.array->is_array())) { - for (unsigned i = 0; i < t->length; i++) { - size_t new_length = name_length; - - /* Append the subscript to the current variable name */ - ralloc_asprintf_rewrite_tail(name, &new_length, "[%u]", i); - - create_xfb_varying_names(mem_ctx, t->fields.array, name, new_length, - count, ifc_member_name, ifc_member_t, - varying_names); - } - } else { - (*varying_names)[(*count)++] = ralloc_strdup(mem_ctx, *name); - } -} - -static bool -process_xfb_layout_qualifiers(void *mem_ctx, const gl_linked_shader *sh, - struct gl_shader_program *prog, - unsigned *num_tfeedback_decls, - char ***varying_names) -{ - bool has_xfb_qualifiers = false; - - /* We still need to enable transform feedback mode even if xfb_stride is - * only applied to a global out. Also we don't bother to propagate - * xfb_stride to interface block members so this will catch that case also. - */ - for (unsigned j = 0; j < MAX_FEEDBACK_BUFFERS; j++) { - if (prog->TransformFeedback.BufferStride[j]) { - has_xfb_qualifiers = true; - break; - } - } - - foreach_in_list(ir_instruction, node, sh->ir) { - ir_variable *var = node->as_variable(); - if (!var || var->data.mode != ir_var_shader_out) - continue; - - /* From the ARB_enhanced_layouts spec: - * - * "Any shader making any static use (after preprocessing) of any of - * these *xfb_* qualifiers will cause the shader to be in a - * transform feedback capturing mode and hence responsible for - * describing the transform feedback setup. This mode will capture - * any output selected by *xfb_offset*, directly or indirectly, to - * a transform feedback buffer." - */ - if (var->data.explicit_xfb_buffer || var->data.explicit_xfb_stride) { - has_xfb_qualifiers = true; - } - - if (var->data.explicit_xfb_offset) { - *num_tfeedback_decls += var->type->varying_count(); - has_xfb_qualifiers = true; - } - } - - if (*num_tfeedback_decls == 0) - return has_xfb_qualifiers; - - unsigned i = 0; - *varying_names = ralloc_array(mem_ctx, char *, *num_tfeedback_decls); - foreach_in_list(ir_instruction, node, sh->ir) { - ir_variable *var = node->as_variable(); - if (!var || var->data.mode != ir_var_shader_out) - continue; - - if (var->data.explicit_xfb_offset) { - char *name; - const glsl_type *type, *member_type; - - if (var->data.from_named_ifc_block) { - type = var->get_interface_type(); - - /* Find the member type before it was altered by lowering */ - const glsl_type *type_wa = type->without_array(); - member_type = - type_wa->fields.structure[type_wa->field_index(var->name)].type; - name = ralloc_strdup(NULL, type_wa->name); - } else { - type = var->type; - member_type = NULL; - name = ralloc_strdup(NULL, var->name); - } - create_xfb_varying_names(mem_ctx, type, &name, strlen(name), &i, - var->name, member_type, varying_names); - ralloc_free(name); - } - } - - assert(i == *num_tfeedback_decls); - return has_xfb_qualifiers; -} - -/** - * Validate the types and qualifiers of an output from one stage against the - * matching input to another stage. - */ -static void -cross_validate_types_and_qualifiers(struct gl_context *ctx, - struct gl_shader_program *prog, - const ir_variable *input, - const ir_variable *output, - gl_shader_stage consumer_stage, - gl_shader_stage producer_stage) -{ - /* Check that the types match between stages. - */ - const glsl_type *type_to_match = input->type; - - /* VS -> GS, VS -> TCS, VS -> TES, TES -> GS */ - const bool extra_array_level = (producer_stage == MESA_SHADER_VERTEX && - consumer_stage != MESA_SHADER_FRAGMENT) || - consumer_stage == MESA_SHADER_GEOMETRY; - if (extra_array_level) { - assert(type_to_match->is_array()); - type_to_match = type_to_match->fields.array; - } - - if (type_to_match != output->type) { - if (output->type->is_struct()) { - /* Structures across shader stages can have different name - * and considered to match in type if and only if structure - * members match in name, type, qualification, and declaration - * order. The precision doesn’t need to match. - */ - if (!output->type->record_compare(type_to_match, - false, /* match_name */ - true, /* match_locations */ - false /* match_precision */)) { - linker_error(prog, - "%s shader output `%s' declared as struct `%s', " - "doesn't match in type with %s shader input " - "declared as struct `%s'\n", - _mesa_shader_stage_to_string(producer_stage), - output->name, - output->type->name, - _mesa_shader_stage_to_string(consumer_stage), - input->type->name); - } - } else if (!output->type->is_array() || !is_gl_identifier(output->name)) { - /* 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." - */ - linker_error(prog, - "%s shader output `%s' declared as type `%s', " - "but %s shader input declared as type `%s'\n", - _mesa_shader_stage_to_string(producer_stage), - output->name, - output->type->name, - _mesa_shader_stage_to_string(consumer_stage), - input->type->name); - return; - } - } - - /* Check that all of the qualifiers match between stages. - */ - - /* According to the OpenGL and OpenGLES GLSL specs, the centroid qualifier - * should match until OpenGL 4.3 and OpenGLES 3.1. The OpenGLES 3.0 - * conformance test suite does not verify that the qualifiers must match. - * The deqp test suite expects the opposite (OpenGLES 3.1) behavior for - * OpenGLES 3.0 drivers, so we relax the checking in all cases. - */ - if (false /* always skip the centroid check */ && - prog->data->Version < (prog->IsES ? 310 : 430) && - input->data.centroid != output->data.centroid) { - linker_error(prog, - "%s shader output `%s' %s centroid qualifier, " - "but %s shader input %s centroid qualifier\n", - _mesa_shader_stage_to_string(producer_stage), - output->name, - (output->data.centroid) ? "has" : "lacks", - _mesa_shader_stage_to_string(consumer_stage), - (input->data.centroid) ? "has" : "lacks"); - return; - } - - if (input->data.sample != output->data.sample) { - linker_error(prog, - "%s shader output `%s' %s sample qualifier, " - "but %s shader input %s sample qualifier\n", - _mesa_shader_stage_to_string(producer_stage), - output->name, - (output->data.sample) ? "has" : "lacks", - _mesa_shader_stage_to_string(consumer_stage), - (input->data.sample) ? "has" : "lacks"); - return; - } - - if (input->data.patch != output->data.patch) { - linker_error(prog, - "%s shader output `%s' %s patch qualifier, " - "but %s shader input %s patch qualifier\n", - _mesa_shader_stage_to_string(producer_stage), - output->name, - (output->data.patch) ? "has" : "lacks", - _mesa_shader_stage_to_string(consumer_stage), - (input->data.patch) ? "has" : "lacks"); - return; - } - - /* The GLSL 4.30 and GLSL ES 3.00 specifications say: - * - * "As only outputs need be declared with invariant, an output from - * one shader stage will still match an input of a subsequent stage - * without the input being declared as invariant." - * - * while GLSL 4.20 says: - * - * "For variables leaving one shader and coming into another shader, - * the invariant keyword has to be used in both shaders, or a link - * error will result." - * - * and GLSL ES 1.00 section 4.6.4 "Invariance and Linking" says: - * - * "The invariance of varyings that are declared in both the vertex - * and fragment shaders must match." - */ - if (input->data.explicit_invariant != output->data.explicit_invariant && - prog->data->Version < (prog->IsES ? 300 : 430)) { - linker_error(prog, - "%s shader output `%s' %s invariant qualifier, " - "but %s shader input %s invariant qualifier\n", - _mesa_shader_stage_to_string(producer_stage), - output->name, - (output->data.explicit_invariant) ? "has" : "lacks", - _mesa_shader_stage_to_string(consumer_stage), - (input->data.explicit_invariant) ? "has" : "lacks"); - return; - } - - /* GLSL >= 4.40 removes text requiring interpolation qualifiers - * to match cross stage, they must only match within the same stage. - * - * From page 84 (page 90 of the PDF) of the GLSL 4.40 spec: - * - * "It is a link-time error if, within the same stage, the interpolation - * qualifiers of variables of the same name do not match. - * - * Section 4.3.9 (Interpolation) of the GLSL ES 3.00 spec says: - * - * "When no interpolation qualifier is present, smooth interpolation - * is used." - * - * So we match variables where one is smooth and the other has no explicit - * qualifier. - */ - unsigned input_interpolation = input->data.interpolation; - unsigned output_interpolation = output->data.interpolation; - if (prog->IsES) { - if (input_interpolation == INTERP_MODE_NONE) - input_interpolation = INTERP_MODE_SMOOTH; - if (output_interpolation == INTERP_MODE_NONE) - output_interpolation = INTERP_MODE_SMOOTH; - } - if (input_interpolation != output_interpolation && - prog->data->Version < 440) { - if (!ctx->Const.AllowGLSLCrossStageInterpolationMismatch) { - linker_error(prog, - "%s shader output `%s' specifies %s " - "interpolation qualifier, " - "but %s shader input specifies %s " - "interpolation qualifier\n", - _mesa_shader_stage_to_string(producer_stage), - output->name, - interpolation_string(output->data.interpolation), - _mesa_shader_stage_to_string(consumer_stage), - interpolation_string(input->data.interpolation)); - return; - } else { - linker_warning(prog, - "%s shader output `%s' specifies %s " - "interpolation qualifier, " - "but %s shader input specifies %s " - "interpolation qualifier\n", - _mesa_shader_stage_to_string(producer_stage), - output->name, - interpolation_string(output->data.interpolation), - _mesa_shader_stage_to_string(consumer_stage), - interpolation_string(input->data.interpolation)); - } - } -} - -/** - * Validate front and back color outputs against single color input - */ -static void -cross_validate_front_and_back_color(struct gl_context *ctx, - struct gl_shader_program *prog, - const ir_variable *input, - const ir_variable *front_color, - const ir_variable *back_color, - gl_shader_stage consumer_stage, - gl_shader_stage producer_stage) -{ - if (front_color != NULL && front_color->data.assigned) - cross_validate_types_and_qualifiers(ctx, prog, input, front_color, - consumer_stage, producer_stage); - - if (back_color != NULL && back_color->data.assigned) - cross_validate_types_and_qualifiers(ctx, prog, input, back_color, - consumer_stage, producer_stage); -} - -static unsigned -compute_variable_location_slot(ir_variable *var, gl_shader_stage stage) -{ - unsigned location_start = VARYING_SLOT_VAR0; - - switch (stage) { - case MESA_SHADER_VERTEX: - if (var->data.mode == ir_var_shader_in) - location_start = VERT_ATTRIB_GENERIC0; - break; - case MESA_SHADER_TESS_CTRL: - case MESA_SHADER_TESS_EVAL: - if (var->data.patch) - location_start = VARYING_SLOT_PATCH0; - break; - case MESA_SHADER_FRAGMENT: - if (var->data.mode == ir_var_shader_out) - location_start = FRAG_RESULT_DATA0; - break; - default: - break; - } - - return var->data.location - location_start; -} - -struct explicit_location_info { - ir_variable *var; - bool base_type_is_integer; - unsigned base_type_bit_size; - unsigned interpolation; - bool centroid; - bool sample; - bool patch; -}; - -static bool -check_location_aliasing(struct explicit_location_info explicit_locations[][4], - ir_variable *var, - unsigned location, - unsigned component, - unsigned location_limit, - const glsl_type *type, - unsigned interpolation, - bool centroid, - bool sample, - bool patch, - gl_shader_program *prog, - gl_shader_stage stage) -{ - unsigned last_comp; - unsigned base_type_bit_size; - const glsl_type *type_without_array = type->without_array(); - const bool base_type_is_integer = - glsl_base_type_is_integer(type_without_array->base_type); - const bool is_struct = type_without_array->is_struct(); - if (is_struct) { - /* structs don't have a defined underlying base type so just treat all - * component slots as used and set the bit size to 0. If there is - * location aliasing, we'll fail anyway later. - */ - last_comp = 4; - base_type_bit_size = 0; - } else { - unsigned dmul = type_without_array->is_64bit() ? 2 : 1; - last_comp = component + type_without_array->vector_elements * dmul; - base_type_bit_size = - glsl_base_type_get_bit_size(type_without_array->base_type); - } - - while (location < location_limit) { - unsigned comp = 0; - while (comp < 4) { - struct explicit_location_info *info = - &explicit_locations[location][comp]; - - if (info->var) { - if (info->var->type->without_array()->is_struct() || is_struct) { - /* Structs cannot share location since they are incompatible - * with any other underlying numerical type. - */ - linker_error(prog, - "%s shader has multiple %sputs sharing the " - "same location that don't have the same " - "underlying numerical type. Struct variable '%s', " - "location %u\n", - _mesa_shader_stage_to_string(stage), - var->data.mode == ir_var_shader_in ? "in" : "out", - is_struct ? var->name : info->var->name, - location); - return false; - } else if (comp >= component && comp < last_comp) { - /* Component aliasing is not allowed */ - linker_error(prog, - "%s shader has multiple %sputs explicitly " - "assigned to location %d and component %d\n", - _mesa_shader_stage_to_string(stage), - var->data.mode == ir_var_shader_in ? "in" : "out", - location, comp); - return false; - } else { - /* From the OpenGL 4.60.5 spec, section 4.4.1 Input Layout - * Qualifiers, Page 67, (Location aliasing): - * - * " Further, when location aliasing, the aliases sharing the - * location must have the same underlying numerical type - * and bit width (floating-point or integer, 32-bit versus - * 64-bit, etc.) and the same auxiliary storage and - * interpolation qualification." - */ - - /* If the underlying numerical type isn't integer, implicitly - * it will be float or else we would have failed by now. - */ - if (info->base_type_is_integer != base_type_is_integer) { - linker_error(prog, - "%s shader has multiple %sputs sharing the " - "same location that don't have the same " - "underlying numerical type. Location %u " - "component %u.\n", - _mesa_shader_stage_to_string(stage), - var->data.mode == ir_var_shader_in ? - "in" : "out", location, comp); - return false; - } - - if (info->base_type_bit_size != base_type_bit_size) { - linker_error(prog, - "%s shader has multiple %sputs sharing the " - "same location that don't have the same " - "underlying numerical bit size. Location %u " - "component %u.\n", - _mesa_shader_stage_to_string(stage), - var->data.mode == ir_var_shader_in ? - "in" : "out", location, comp); - return false; - } - - if (info->interpolation != interpolation) { - linker_error(prog, - "%s shader has multiple %sputs sharing the " - "same location that don't have the same " - "interpolation qualification. Location %u " - "component %u.\n", - _mesa_shader_stage_to_string(stage), - var->data.mode == ir_var_shader_in ? - "in" : "out", location, comp); - return false; - } - - if (info->centroid != centroid || - info->sample != sample || - info->patch != patch) { - linker_error(prog, - "%s shader has multiple %sputs sharing the " - "same location that don't have the same " - "auxiliary storage qualification. Location %u " - "component %u.\n", - _mesa_shader_stage_to_string(stage), - var->data.mode == ir_var_shader_in ? - "in" : "out", location, comp); - return false; - } - } - } else if (comp >= component && comp < last_comp) { - info->var = var; - info->base_type_is_integer = base_type_is_integer; - info->base_type_bit_size = base_type_bit_size; - info->interpolation = interpolation; - info->centroid = centroid; - info->sample = sample; - info->patch = patch; - } - - comp++; - - /* We need to do some special handling for doubles as dvec3 and - * dvec4 consume two consecutive locations. We don't need to - * worry about components beginning at anything other than 0 as - * the spec does not allow this for dvec3 and dvec4. - */ - if (comp == 4 && last_comp > 4) { - last_comp = last_comp - 4; - /* Bump location index and reset the component index */ - location++; - comp = 0; - component = 0; - } - } - - location++; - } - - return true; -} - -static bool -validate_explicit_variable_location(struct gl_context *ctx, - struct explicit_location_info explicit_locations[][4], - ir_variable *var, - gl_shader_program *prog, - gl_linked_shader *sh) -{ - const glsl_type *type = get_varying_type(var, sh->Stage); - unsigned num_elements = type->count_attribute_slots(false); - unsigned idx = compute_variable_location_slot(var, sh->Stage); - unsigned slot_limit = idx + num_elements; - - /* Vertex shader inputs and fragment shader outputs are validated in - * assign_attribute_or_color_locations() so we should not attempt to - * validate them again here. - */ - unsigned slot_max; - if (var->data.mode == ir_var_shader_out) { - assert(sh->Stage != MESA_SHADER_FRAGMENT); - slot_max = - ctx->Const.Program[sh->Stage].MaxOutputComponents / 4; - } else { - assert(var->data.mode == ir_var_shader_in); - assert(sh->Stage != MESA_SHADER_VERTEX); - slot_max = - ctx->Const.Program[sh->Stage].MaxInputComponents / 4; - } - - if (slot_limit > slot_max) { - linker_error(prog, - "Invalid location %u in %s shader\n", - idx, _mesa_shader_stage_to_string(sh->Stage)); - return false; - } - - const glsl_type *type_without_array = type->without_array(); - if (type_without_array->is_interface()) { - for (unsigned i = 0; i < type_without_array->length; i++) { - glsl_struct_field *field = &type_without_array->fields.structure[i]; - unsigned field_location = field->location - - (field->patch ? VARYING_SLOT_PATCH0 : VARYING_SLOT_VAR0); - unsigned field_slots = field->type->count_attribute_slots(false); - if (!check_location_aliasing(explicit_locations, var, - field_location, - 0, - field_location + field_slots, - field->type, - field->interpolation, - field->centroid, - field->sample, - field->patch, - prog, sh->Stage)) { - return false; - } - } - } else if (!check_location_aliasing(explicit_locations, var, - idx, var->data.location_frac, - slot_limit, type, - var->data.interpolation, - var->data.centroid, - var->data.sample, - var->data.patch, - prog, sh->Stage)) { - return false; - } - - return true; -} - -/** - * Validate explicit locations for the inputs to the first stage and the - * outputs of the last stage in a program, if those are not the VS and FS - * shaders. - */ -void -validate_first_and_last_interface_explicit_locations(struct gl_context *ctx, - struct gl_shader_program *prog, - gl_shader_stage first_stage, - gl_shader_stage last_stage) -{ - /* VS inputs and FS outputs are validated in - * assign_attribute_or_color_locations() - */ - bool validate_first_stage = first_stage != MESA_SHADER_VERTEX; - bool validate_last_stage = last_stage != MESA_SHADER_FRAGMENT; - if (!validate_first_stage && !validate_last_stage) - return; - - struct explicit_location_info explicit_locations[MAX_VARYING][4]; - - gl_shader_stage stages[2] = { first_stage, last_stage }; - bool validate_stage[2] = { validate_first_stage, validate_last_stage }; - ir_variable_mode var_direction[2] = { ir_var_shader_in, ir_var_shader_out }; - - for (unsigned i = 0; i < 2; i++) { - if (!validate_stage[i]) - continue; - - gl_shader_stage stage = stages[i]; - - gl_linked_shader *sh = prog->_LinkedShaders[stage]; - assert(sh); - - memset(explicit_locations, 0, sizeof(explicit_locations)); - - foreach_in_list(ir_instruction, node, sh->ir) { - ir_variable *const var = node->as_variable(); - - if (var == NULL || - !var->data.explicit_location || - var->data.location < VARYING_SLOT_VAR0 || - var->data.mode != var_direction[i]) - continue; - - if (!validate_explicit_variable_location( - ctx, explicit_locations, var, prog, sh)) { - return; - } - } - } -} - -/** - * Check if we should force input / output matching between shader - * interfaces. - * - * Section 4.3.4 (Inputs) of the GLSL 4.10 specifications say: - * - * "Only the input variables that are actually read need to be - * written by the previous stage; it is allowed to have - * superfluous declarations of input variables." - * - * However it's not defined anywhere as to how we should handle - * inputs that are not written in the previous stage and it's not - * clear what "actually read" means. - * - * The GLSL 4.20 spec however is much clearer: - * - * "Only the input variables that are statically read need to - * be written by the previous stage; it is allowed to have - * superfluous declarations of input variables." - * - * It also has a table that states it is an error to statically - * read an input that is not defined in the previous stage. While - * it is not an error to not statically write to the output (it - * just needs to be defined to not be an error). - * - * The text in the GLSL 4.20 spec was an attempt to clarify the - * previous spec iterations. However given the difference in spec - * and that some applications seem to depend on not erroring when - * the input is not actually read in control flow we only apply - * this rule to GLSL 4.20 and higher. GLSL 4.10 shaders have been - * seen in the wild that depend on the less strict interpretation. - */ -static bool -static_input_output_matching(struct gl_shader_program *prog) -{ - return prog->data->Version >= (prog->IsES ? 0 : 420); -} - -/** - * Validate that outputs from one stage match inputs of another - */ -void -cross_validate_outputs_to_inputs(struct gl_context *ctx, - struct gl_shader_program *prog, - gl_linked_shader *producer, - gl_linked_shader *consumer) -{ - glsl_symbol_table parameters; - struct explicit_location_info output_explicit_locations[MAX_VARYING][4] = {}; - struct explicit_location_info input_explicit_locations[MAX_VARYING][4] = {}; - - /* Find all shader outputs in the "producer" stage. - */ - foreach_in_list(ir_instruction, node, producer->ir) { - ir_variable *const var = node->as_variable(); - - if (var == NULL || var->data.mode != ir_var_shader_out) - continue; - - if (!var->data.explicit_location - || var->data.location < VARYING_SLOT_VAR0) - parameters.add_variable(var); - else { - /* User-defined varyings with explicit locations are handled - * differently because they do not need to have matching names. - */ - if (!validate_explicit_variable_location(ctx, - output_explicit_locations, - var, prog, producer)) { - return; - } - } - } - - - /* 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. - * - * Exception: if the consumer is the geometry shader, then the inputs - * should be arrays and the type of the array element should match the type - * of the corresponding producer output. - */ - foreach_in_list(ir_instruction, node, consumer->ir) { - ir_variable *const input = node->as_variable(); - - if (input == NULL || input->data.mode != ir_var_shader_in) - continue; - - if (strcmp(input->name, "gl_Color") == 0 && input->data.used) { - const ir_variable *const front_color = - parameters.get_variable("gl_FrontColor"); - - const ir_variable *const back_color = - parameters.get_variable("gl_BackColor"); - - cross_validate_front_and_back_color(ctx, prog, input, - front_color, back_color, - consumer->Stage, producer->Stage); - } else if (strcmp(input->name, "gl_SecondaryColor") == 0 && input->data.used) { - const ir_variable *const front_color = - parameters.get_variable("gl_FrontSecondaryColor"); - - const ir_variable *const back_color = - parameters.get_variable("gl_BackSecondaryColor"); - - cross_validate_front_and_back_color(ctx, prog, input, - front_color, back_color, - consumer->Stage, producer->Stage); - } else { - /* The rules for connecting inputs and outputs change in the presence - * of explicit locations. In this case, we no longer care about the - * names of the variables. Instead, we care only about the - * explicitly assigned location. - */ - ir_variable *output = NULL; - if (input->data.explicit_location - && input->data.location >= VARYING_SLOT_VAR0) { - - const glsl_type *type = get_varying_type(input, consumer->Stage); - unsigned num_elements = type->count_attribute_slots(false); - unsigned idx = - compute_variable_location_slot(input, consumer->Stage); - unsigned slot_limit = idx + num_elements; - - if (!validate_explicit_variable_location(ctx, - input_explicit_locations, - input, prog, consumer)) { - return; - } - - while (idx < slot_limit) { - if (idx >= MAX_VARYING) { - linker_error(prog, - "Invalid location %u in %s shader\n", idx, - _mesa_shader_stage_to_string(consumer->Stage)); - return; - } - - output = output_explicit_locations[idx][input->data.location_frac].var; - - if (output == NULL) { - /* A linker failure should only happen when there is no - * output declaration and there is Static Use of the - * declared input. - */ - if (input->data.used && static_input_output_matching(prog)) { - linker_error(prog, - "%s shader input `%s' with explicit location " - "has no matching output\n", - _mesa_shader_stage_to_string(consumer->Stage), - input->name); - break; - } - } else if (input->data.location != output->data.location) { - linker_error(prog, - "%s shader input `%s' with explicit location " - "has no matching output\n", - _mesa_shader_stage_to_string(consumer->Stage), - input->name); - break; - } - idx++; - } - } else { - output = parameters.get_variable(input->name); - } - - if (output != NULL) { - /* Interface blocks have their own validation elsewhere so don't - * try validating them here. - */ - if (!(input->get_interface_type() && - output->get_interface_type())) - cross_validate_types_and_qualifiers(ctx, prog, input, output, - consumer->Stage, - producer->Stage); - } else { - /* Check for input vars with unmatched output vars in prev stage - * taking into account that interface blocks could have a matching - * output but with different name, so we ignore them. - */ - assert(!input->data.assigned); - if (input->data.used && !input->get_interface_type() && - !input->data.explicit_location && - static_input_output_matching(prog)) - linker_error(prog, - "%s shader input `%s' " - "has no matching output in the previous stage\n", - _mesa_shader_stage_to_string(consumer->Stage), - input->name); - } - } - } -} - -/** - * Demote shader inputs and outputs that are not used in other stages, and - * remove them via dead code elimination. - */ -static void -remove_unused_shader_inputs_and_outputs(bool is_separate_shader_object, - gl_linked_shader *sh, - enum ir_variable_mode mode) -{ - if (is_separate_shader_object) - return; - - foreach_in_list(ir_instruction, node, sh->ir) { - ir_variable *const var = node->as_variable(); - - if (var == NULL || var->data.mode != int(mode)) - continue; - - /* A shader 'in' or 'out' variable is only really an input or output if - * its value is used by other shader stages. This will cause the - * variable to have a location assigned. - */ - if (var->data.is_unmatched_generic_inout && !var->data.is_xfb_only) { - assert(var->data.mode != ir_var_temporary); - - /* Assign zeros to demoted inputs to allow more optimizations. */ - if (var->data.mode == ir_var_shader_in && !var->constant_value) - var->constant_value = ir_constant::zero(var, var->type); - - var->data.mode = ir_var_auto; - } - } - - /* Eliminate code that is now dead due to unused inputs/outputs being - * demoted. - */ - while (do_dead_code(sh->ir, false)) - ; - -} - -/** - * 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, 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->lowered_builtin_array_variable = none; - this->skip_components = 0; - this->next_buffer_separator = false; - this->matched_candidate = NULL; - this->stream_id = 0; - this->buffer = 0; - this->offset = 0; - - 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, strlen(input), - &base_name_end); - this->var_name = ralloc_strndup(mem_ctx, input, base_name_end - input); - if (this->var_name == NULL) { - _mesa_error_no_memory(__func__); - return; - } - - 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->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerCombinedClipCullDistance && - strcmp(this->var_name, "gl_ClipDistance") == 0) { - this->lowered_builtin_array_variable = clip_distance; - } - if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerCombinedClipCullDistance && - strcmp(this->var_name, "gl_CullDistance") == 0) { - this->lowered_builtin_array_variable = cull_distance; - } - - if (ctx->Const.LowerTessLevel && - (strcmp(this->var_name, "gl_TessLevelOuter") == 0)) - this->lowered_builtin_array_variable = tess_level_outer; - if (ctx->Const.LowerTessLevel && - (strcmp(this->var_name, "gl_TessLevelInner") == 0)) - this->lowered_builtin_array_variable = tess_level_inner; -} - - -/** - * 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 and stream ID 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->data.location * 4 - + this->matched_candidate->toplevel_var->data.location_frac - + this->matched_candidate->struct_offset_floats; - const unsigned dmul = - this->matched_candidate->type->without_array()->is_64bit() ? 2 : 1; - - 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; - switch (this->lowered_builtin_array_variable) { - case clip_distance: - actual_array_size = prog->last_vert_prog ? - prog->last_vert_prog->info.clip_distance_array_size : 0; - break; - case cull_distance: - actual_array_size = prog->last_vert_prog ? - prog->last_vert_prog->info.cull_distance_array_size : 0; - break; - case tess_level_outer: - actual_array_size = 4; - break; - case tess_level_inner: - actual_array_size = 2; - break; - case none: - default: - actual_array_size = this->matched_candidate->type->array_size(); - break; - } - - 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->lowered_builtin_array_variable ? - 1 : vector_elements * matrix_cols * dmul; - 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->lowered_builtin_array_variable) - 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; - } - - /* Only transform feedback varyings can be assigned to non-zero streams, - * so assign the stream id here. - */ - this->stream_id = this->matched_candidate->toplevel_var->data.stream; - - unsigned array_offset = this->array_subscript * 4 * dmul; - unsigned struct_offset = this->matched_candidate->xfb_offset_floats * 4; - this->buffer = this->matched_candidate->toplevel_var->data.xfb_buffer; - this->offset = this->matched_candidate->toplevel_var->data.offset + - array_offset + struct_offset; - - return true; -} - - -unsigned -tfeedback_decl::get_num_outputs() const -{ - if (!this->is_varying()) { - return 0; - } - - if (varying_has_user_specified_location(this->matched_candidate->toplevel_var)) { - unsigned dmul = this->is_64bit() ? 2 : 1; - unsigned rows_per_element = DIV_ROUND_UP(this->vector_elements * dmul, 4); - return this->size * this->matrix_columns * rows_per_element; - } else { - 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, unsigned buffer_index, - const unsigned max_outputs, - BITSET_WORD *used_components[MAX_FEEDBACK_BUFFERS], - bool *explicit_stride, unsigned *max_member_alignment, - bool has_xfb_qualifiers, const void* mem_ctx) const -{ - unsigned xfb_offset = 0; - unsigned size = this->size; - /* Handle gl_SkipComponents. */ - if (this->skip_components) { - info->Buffers[buffer].Stride += this->skip_components; - size = this->skip_components; - goto store_varying; - } - - if (this->next_buffer_separator) { - size = 0; - goto store_varying; - } - - if (has_xfb_qualifiers) { - xfb_offset = this->offset / 4; - } else { - xfb_offset = info->Buffers[buffer].Stride; - } - info->Varyings[info->NumVarying].Offset = xfb_offset * 4; - - { - unsigned location = this->location; - unsigned location_frac = this->location_frac; - unsigned num_components = this->num_components(); - - /* 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." - * - * From GL_ARB_enhanced_layouts: - * - * " The resulting stride (implicit or explicit) must be less than or - * equal to the implementation-dependent constant - * gl_MaxTransformFeedbackInterleavedComponents." - */ - if ((prog->TransformFeedback.BufferMode == GL_INTERLEAVED_ATTRIBS || - has_xfb_qualifiers) && - xfb_offset + num_components > - ctx->Const.MaxTransformFeedbackInterleavedComponents) { - linker_error(prog, - "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS " - "limit has been exceeded."); - return false; - } - - /* From the OpenGL 4.60.5 spec, section 4.4.2. Output Layout Qualifiers, - * Page 76, (Transform Feedback Layout Qualifiers): - * - * " No aliasing in output buffers is allowed: It is a compile-time or - * link-time error to specify variables with overlapping transform - * feedback offsets." - */ - const unsigned max_components = - ctx->Const.MaxTransformFeedbackInterleavedComponents; - const unsigned first_component = xfb_offset; - const unsigned last_component = xfb_offset + num_components - 1; - const unsigned start_word = BITSET_BITWORD(first_component); - const unsigned end_word = BITSET_BITWORD(last_component); - BITSET_WORD *used; - assert(last_component < max_components); - - if (!used_components[buffer]) { - used_components[buffer] = - rzalloc_array(mem_ctx, BITSET_WORD, BITSET_WORDS(max_components)); - } - used = used_components[buffer]; - - for (unsigned word = start_word; word <= end_word; word++) { - unsigned start_range = 0; - unsigned end_range = BITSET_WORDBITS - 1; - - if (word == start_word) - start_range = first_component % BITSET_WORDBITS; - - if (word == end_word) - end_range = last_component % BITSET_WORDBITS; - - if (used[word] & BITSET_RANGE(start_range, end_range)) { - linker_error(prog, - "variable '%s', xfb_offset (%d) is causing aliasing.", - this->orig_name, xfb_offset * 4); - return false; - } - used[word] |= BITSET_RANGE(start_range, end_range); - } - - const unsigned type_num_components = - this->vector_elements * (this->is_64bit() ? 2 : 1); - unsigned current_type_components_left = type_num_components; - - while (num_components > 0) { - unsigned output_size = 0; - - /* From GL_ARB_enhanced_layouts: - * - * "When an attribute variable declared using an array type is bound to - * generic attribute index <i>, the active array elements are assigned to - * consecutive generic attributes beginning with generic attribute <i>. The - * number of attributes and components assigned to each element are - * determined according to the data type of array elements and "component" - * layout qualifier (if any) specified in the declaration of the array." - * - * "When an attribute variable declared using a matrix type is bound to a - * generic attribute index <i>, its values are taken from consecutive generic - * attributes beginning with generic attribute <i>. Such matrices are - * treated as an array of column vectors with values taken from the generic - * attributes. - * This means there may be gaps in the varyings we are taking values from." - * - * Examples: - * - * | layout(location=0) dvec3[2] a; | layout(location=4) vec2[4] b; | - * | | | - * | 32b 32b 32b 32b | 32b 32b 32b 32b | - * | 0 X X Y Y | 4 X Y 0 0 | - * | 1 Z Z 0 0 | 5 X Y 0 0 | - * | 2 X X Y Y | 6 X Y 0 0 | - * | 3 Z Z 0 0 | 7 X Y 0 0 | - * - */ - if (varying_has_user_specified_location(this->matched_candidate->toplevel_var)) { - output_size = MIN3(num_components, current_type_components_left, 4); - current_type_components_left -= output_size; - if (current_type_components_left == 0) { - current_type_components_left = type_num_components; - } - } else { - output_size = MIN2(num_components, 4 - location_frac); - } - - assert((info->NumOutputs == 0 && max_outputs == 0) || - info->NumOutputs < max_outputs); - - /* From the ARB_enhanced_layouts spec: - * - * "If such a block member or variable is not written during a shader - * invocation, the buffer contents at the assigned offset will be - * undefined. Even if there are no static writes to a variable or - * member that is assigned a transform feedback offset, the space is - * still allocated in the buffer and still affects the stride." - */ - if (this->is_varying_written()) { - info->Outputs[info->NumOutputs].ComponentOffset = location_frac; - info->Outputs[info->NumOutputs].OutputRegister = location; - info->Outputs[info->NumOutputs].NumComponents = output_size; - info->Outputs[info->NumOutputs].StreamId = stream_id; - info->Outputs[info->NumOutputs].OutputBuffer = buffer; - info->Outputs[info->NumOutputs].DstOffset = xfb_offset; - ++info->NumOutputs; - } - info->Buffers[buffer].Stream = this->stream_id; - xfb_offset += output_size; - - num_components -= output_size; - location++; - location_frac = 0; - } - } - - if (explicit_stride && explicit_stride[buffer]) { - if (this->is_64bit() && info->Buffers[buffer].Stride % 2) { - linker_error(prog, "invalid qualifier xfb_stride=%d must be a " - "multiple of 8 as its applied to a type that is or " - "contains a double.", - info->Buffers[buffer].Stride * 4); - return false; - } - - if (xfb_offset > info->Buffers[buffer].Stride) { - linker_error(prog, "xfb_offset (%d) overflows xfb_stride (%d) for " - "buffer (%d)", xfb_offset * 4, - info->Buffers[buffer].Stride * 4, buffer); - return false; - } - } else { - if (max_member_alignment && has_xfb_qualifiers) { - max_member_alignment[buffer] = MAX2(max_member_alignment[buffer], - this->is_64bit() ? 2 : 1); - info->Buffers[buffer].Stride = ALIGN(xfb_offset, - max_member_alignment[buffer]); - } else { - info->Buffers[buffer].Stride = xfb_offset; - } - } - - store_varying: - info->Varyings[info->NumVarying].Name = ralloc_strdup(prog, - this->orig_name); - info->Varyings[info->NumVarying].Type = this->type; - info->Varyings[info->NumVarying].Size = size; - info->Varyings[info->NumVarying].BufferIndex = buffer_index; - info->NumVarying++; - info->Buffers[buffer].NumVaryings++; - - return true; -} - - -const tfeedback_candidate * -tfeedback_decl::find_candidate(gl_shader_program *prog, - hash_table *tfeedback_candidates) -{ - const char *name = this->var_name; - switch (this->lowered_builtin_array_variable) { - case none: - name = this->var_name; - break; - case clip_distance: - name = "gl_ClipDistanceMESA"; - break; - case cull_distance: - name = "gl_CullDistanceMESA"; - break; - case tess_level_outer: - name = "gl_TessLevelOuterMESA"; - break; - case tess_level_inner: - name = "gl_TessLevelInnerMESA"; - break; - } - hash_entry *entry = _mesa_hash_table_search(tfeedback_candidates, name); - - this->matched_candidate = entry ? - (const tfeedback_candidate *) entry->data : NULL; - - 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; -} - -/** - * Force a candidate over the previously matched one. It happens when a new - * varying needs to be created to match the xfb declaration, for example, - * to fullfil an alignment criteria. - */ -void -tfeedback_decl::set_lowered_candidate(const tfeedback_candidate *candidate) -{ - this->matched_candidate = candidate; - - /* The subscript part is no longer relevant */ - this->is_subscripted = false; - this->array_subscript = 0; -} - - -/** - * 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. - */ -static 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, 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()) { - 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; -} - - -static int -cmp_xfb_offset(const void * x_generic, const void * y_generic) -{ - tfeedback_decl *x = (tfeedback_decl *) x_generic; - tfeedback_decl *y = (tfeedback_decl *) y_generic; - - if (x->get_buffer() != y->get_buffer()) - return x->get_buffer() - y->get_buffer(); - return x->get_offset() - y->get_offset(); -} - -/** - * Store transform feedback location assignments into - * prog->sh.LinkedTransformFeedback based on the data stored in - * tfeedback_decls. - * - * If an error occurs, the error is reported through linker_error() and false - * is returned. - */ -static bool -store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog, - unsigned num_tfeedback_decls, - tfeedback_decl *tfeedback_decls, bool has_xfb_qualifiers, - const void *mem_ctx) -{ - if (!prog->last_vert_prog) - return true; - - /* Make sure MaxTransformFeedbackBuffers is less than 32 so the bitmask for - * tracking the number of buffers doesn't overflow. - */ - assert(ctx->Const.MaxTransformFeedbackBuffers < 32); - - bool separate_attribs_mode = - prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS; - - struct gl_program *xfb_prog = prog->last_vert_prog; - xfb_prog->sh.LinkedTransformFeedback = - rzalloc(xfb_prog, struct gl_transform_feedback_info); - - /* The xfb_offset qualifier does not have to be used in increasing order - * however some drivers expect to receive the list of transform feedback - * declarations in order so sort it now for convenience. - */ - if (has_xfb_qualifiers) { - qsort(tfeedback_decls, num_tfeedback_decls, sizeof(*tfeedback_decls), - cmp_xfb_offset); - } - - xfb_prog->sh.LinkedTransformFeedback->Varyings = - rzalloc_array(xfb_prog, struct gl_transform_feedback_varying_info, - num_tfeedback_decls); - - unsigned num_outputs = 0; - for (unsigned i = 0; i < num_tfeedback_decls; ++i) { - if (tfeedback_decls[i].is_varying_written()) - num_outputs += tfeedback_decls[i].get_num_outputs(); - } - - xfb_prog->sh.LinkedTransformFeedback->Outputs = - rzalloc_array(xfb_prog, struct gl_transform_feedback_output, - num_outputs); - - unsigned num_buffers = 0; - unsigned buffers = 0; - BITSET_WORD *used_components[MAX_FEEDBACK_BUFFERS] = {}; - - if (!has_xfb_qualifiers && separate_attribs_mode) { - /* GL_SEPARATE_ATTRIBS */ - for (unsigned i = 0; i < num_tfeedback_decls; ++i) { - if (!tfeedback_decls[i].store(ctx, prog, - xfb_prog->sh.LinkedTransformFeedback, - num_buffers, num_buffers, num_outputs, - used_components, NULL, NULL, - has_xfb_qualifiers, mem_ctx)) - return false; - - buffers |= 1 << num_buffers; - num_buffers++; - } - } - else { - /* GL_INVERLEAVED_ATTRIBS */ - int buffer_stream_id = -1; - unsigned buffer = - num_tfeedback_decls ? tfeedback_decls[0].get_buffer() : 0; - bool explicit_stride[MAX_FEEDBACK_BUFFERS] = { false }; - unsigned max_member_alignment[MAX_FEEDBACK_BUFFERS] = { 1, 1, 1, 1 }; - /* Apply any xfb_stride global qualifiers */ - if (has_xfb_qualifiers) { - for (unsigned j = 0; j < MAX_FEEDBACK_BUFFERS; j++) { - if (prog->TransformFeedback.BufferStride[j]) { - explicit_stride[j] = true; - xfb_prog->sh.LinkedTransformFeedback->Buffers[j].Stride = - prog->TransformFeedback.BufferStride[j] / 4; - } - } - } - - for (unsigned i = 0; i < num_tfeedback_decls; ++i) { - if (has_xfb_qualifiers && - buffer != tfeedback_decls[i].get_buffer()) { - /* we have moved to the next buffer so reset stream id */ - buffer_stream_id = -1; - num_buffers++; - } - - if (tfeedback_decls[i].is_next_buffer_separator()) { - if (!tfeedback_decls[i].store(ctx, prog, - xfb_prog->sh.LinkedTransformFeedback, - buffer, num_buffers, num_outputs, - used_components, explicit_stride, - max_member_alignment, - has_xfb_qualifiers, - mem_ctx)) - return false; - num_buffers++; - buffer_stream_id = -1; - continue; - } - - if (has_xfb_qualifiers) { - buffer = tfeedback_decls[i].get_buffer(); - } else { - buffer = num_buffers; - } - - if (tfeedback_decls[i].is_varying()) { - if (buffer_stream_id == -1) { - /* First varying writing to this buffer: remember its stream */ - buffer_stream_id = (int) tfeedback_decls[i].get_stream_id(); - - /* Only mark a buffer as active when there is a varying - * attached to it. This behaviour is based on a revised version - * of section 13.2.2 of the GL 4.6 spec. - */ - buffers |= 1 << buffer; - } else if (buffer_stream_id != - (int) tfeedback_decls[i].get_stream_id()) { - /* Varying writes to the same buffer from a different stream */ - linker_error(prog, - "Transform feedback can't capture varyings belonging " - "to different vertex streams in a single buffer. " - "Varying %s writes to buffer from stream %u, other " - "varyings in the same buffer write from stream %u.", - tfeedback_decls[i].name(), - tfeedback_decls[i].get_stream_id(), - buffer_stream_id); - return false; - } - } - - if (!tfeedback_decls[i].store(ctx, prog, - xfb_prog->sh.LinkedTransformFeedback, - buffer, num_buffers, num_outputs, - used_components, explicit_stride, - max_member_alignment, - has_xfb_qualifiers, - mem_ctx)) - return false; - } - } - - assert(xfb_prog->sh.LinkedTransformFeedback->NumOutputs == num_outputs); - - xfb_prog->sh.LinkedTransformFeedback->ActiveBuffers = buffers; - return true; -} - -namespace { - -/** - * 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, - bool disable_xfb_packing, - bool xfb_enabled, - bool enhanced_layouts_enabled, - gl_shader_stage producer_stage, - gl_shader_stage consumer_stage); - ~varying_matches(); - void record(ir_variable *producer_var, ir_variable *consumer_var); - unsigned assign_locations(struct gl_shader_program *prog, - uint8_t components[], - uint64_t reserved_slots); - void store_locations() const; - -private: - bool is_varying_packing_safe(const glsl_type *type, - const ir_variable *var) const; - - /** - * 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. - * - * Packing may also be disabled because our current packing method is not - * safe in SSO or versions of OpenGL where interpolation qualifiers are not - * guaranteed to match across stages. - */ - const bool disable_varying_packing; - - /** - * If true, this driver disables packing for varyings used by transform - * feedback. - */ - const bool disable_xfb_packing; - - /** - * If true, this driver has transform feedback enabled. The transform - * feedback code usually requires at least some packing be done even - * when varying packing is disabled, fortunately where transform feedback - * requires packing it's safe to override the disabled setting. See - * is_varying_packing_safe(). - */ - const bool xfb_enabled; - - const bool enhanced_layouts_enabled; - - /** - * 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(const ir_variable *var); - static packing_order_enum compute_packing_order(const ir_variable *var); - static int match_comparator(const void *x_generic, const void *y_generic); - static int xfb_comparator(const void *x_generic, const void *y_generic); - static int not_xfb_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; - - /** - * 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 VARYING_SLOT_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; - - gl_shader_stage producer_stage; - gl_shader_stage consumer_stage; -}; - -} /* anonymous namespace */ - -varying_matches::varying_matches(bool disable_varying_packing, - bool disable_xfb_packing, - bool xfb_enabled, - bool enhanced_layouts_enabled, - gl_shader_stage producer_stage, - gl_shader_stage consumer_stage) - : disable_varying_packing(disable_varying_packing), - disable_xfb_packing(disable_xfb_packing), - xfb_enabled(xfb_enabled), - enhanced_layouts_enabled(enhanced_layouts_enabled), - producer_stage(producer_stage), - consumer_stage(consumer_stage) -{ - /* 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); -} - - -/** - * Packing is always safe on individual arrays, structures, and matrices. It - * is also safe if the varying is only used for transform feedback. - */ -bool -varying_matches::is_varying_packing_safe(const glsl_type *type, - const ir_variable *var) const -{ - if (consumer_stage == MESA_SHADER_TESS_EVAL || - consumer_stage == MESA_SHADER_TESS_CTRL || - producer_stage == MESA_SHADER_TESS_CTRL) - return false; - - return xfb_enabled && (type->is_array() || type->is_struct() || - type->is_matrix() || var->data.is_xfb_only); -} - - -/** - * 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. - * - * Note: as a side effect this function may change the interpolation type of - * \c producer_var, but only when the change couldn't possibly affect - * rendering. - */ -void -varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var) -{ - assert(producer_var != NULL || consumer_var != NULL); - - if ((producer_var && (!producer_var->data.is_unmatched_generic_inout || - producer_var->data.explicit_location)) || - (consumer_var && (!consumer_var->data.is_unmatched_generic_inout || - consumer_var->data.explicit_location))) { - /* 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; - } - - bool needs_flat_qualifier = consumer_var == NULL && - (producer_var->type->contains_integer() || - producer_var->type->contains_double()); - - if (!disable_varying_packing && - (!disable_xfb_packing || producer_var == NULL || !producer_var->data.is_xfb) && - (needs_flat_qualifier || - (consumer_stage != MESA_SHADER_NONE && consumer_stage != MESA_SHADER_FRAGMENT))) { - /* Since this varying is not being consumed by the fragment shader, its - * interpolation type varying cannot possibly affect rendering. - * Also, this variable is non-flat and is (or contains) an integer - * or a double. - * If the consumer stage is unknown, don't modify the interpolation - * type as it could affect rendering later with separate shaders. - * - * lower_packed_varyings requires all integer varyings to flat, - * regardless of where they appear. We can trivially satisfy that - * requirement by changing the interpolation type to flat here. - */ - if (producer_var) { - producer_var->data.centroid = false; - producer_var->data.sample = false; - producer_var->data.interpolation = INTERP_MODE_FLAT; - } - - if (consumer_var) { - consumer_var->data.centroid = false; - consumer_var->data.sample = false; - consumer_var->data.interpolation = INTERP_MODE_FLAT; - } - } - - if (this->num_matches == this->matches_capacity) { - this->matches_capacity *= 2; - this->matches = (match *) - realloc(this->matches, - sizeof(*this->matches) * this->matches_capacity); - } - - /* We must use the consumer to compute the packing class because in GL4.4+ - * there is no guarantee interpolation qualifiers will match across stages. - * - * From Section 4.5 (Interpolation Qualifiers) of the GLSL 4.30 spec: - * - * "The type and presence of interpolation qualifiers of variables with - * the same name declared in all linked shaders for the same cross-stage - * interface must match, otherwise the link command will fail. - * - * When comparing an output from one stage to an input of a subsequent - * stage, the input and output don't match if their interpolation - * qualifiers (or lack thereof) are not the same." - * - * This text was also in at least revison 7 of the 4.40 spec but is no - * longer in revision 9 and not in the 4.50 spec. - */ - const ir_variable *const var = (consumer_var != NULL) - ? consumer_var : producer_var; - - if (producer_var && consumer_var && - consumer_var->data.must_be_shader_input) { - producer_var->data.must_be_shader_input = 1; - } - - this->matches[this->num_matches].packing_class - = this->compute_packing_class(var); - this->matches[this->num_matches].packing_order - = this->compute_packing_order(var); - - this->matches[this->num_matches].producer_var = producer_var; - this->matches[this->num_matches].consumer_var = consumer_var; - this->num_matches++; - if (producer_var) - producer_var->data.is_unmatched_generic_inout = 0; - if (consumer_var) - consumer_var->data.is_unmatched_generic_inout = 0; -} - - -/** - * Choose locations for all of the variable matches that were previously - * passed to varying_matches::record(). - * \param components returns array[slot] of number of components used - * per slot (1, 2, 3 or 4) - * \param reserved_slots bitmask indicating which varying slots are already - * allocated - * \return number of slots (4-element vectors) allocated - */ -unsigned -varying_matches::assign_locations(struct gl_shader_program *prog, - uint8_t components[], - uint64_t reserved_slots) -{ - /* If packing has been disabled then we cannot safely sort the varyings by - * class as it may mean we are using a version of OpenGL where - * interpolation qualifiers are not guaranteed to be matching across - * shaders, sorting in this case could result in mismatching shader - * interfaces. - * When packing is disabled the sort orders varyings used by transform - * feedback first, but also depends on *undefined behaviour* of qsort to - * reverse the order of the varyings. See: xfb_comparator(). - * - * If packing is only disabled for xfb varyings (mutually exclusive with - * disable_varying_packing), we then group varyings depending on if they - * are captured for transform feedback. The same *undefined behaviour* is - * taken advantage of. - */ - if (this->disable_varying_packing) { - /* Only sort varyings that are only used by transform feedback. */ - qsort(this->matches, this->num_matches, sizeof(*this->matches), - &varying_matches::xfb_comparator); - } else if (this->disable_xfb_packing) { - /* Only sort varyings that are NOT used by transform feedback. */ - qsort(this->matches, this->num_matches, sizeof(*this->matches), - &varying_matches::not_xfb_comparator); - } else { - /* 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; - unsigned generic_patch_location = MAX_VARYING*4; - bool previous_var_xfb = false; - bool previous_var_xfb_only = false; - unsigned previous_packing_class = ~0u; - - /* For tranform feedback separate mode, we know the number of attributes - * is <= the number of buffers. So packing isn't critical. In fact, - * packing vec3 attributes can cause trouble because splitting a vec3 - * effectively creates an additional transform feedback output. The - * extra TFB output may exceed device driver limits. - */ - const bool dont_pack_vec3 = - (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS && - prog->TransformFeedback.NumVarying > 0); - - for (unsigned i = 0; i < this->num_matches; i++) { - unsigned *location = &generic_location; - const ir_variable *var; - const glsl_type *type; - bool is_vertex_input = false; - - if (matches[i].consumer_var) { - var = matches[i].consumer_var; - type = get_varying_type(var, consumer_stage); - if (consumer_stage == MESA_SHADER_VERTEX) - is_vertex_input = true; - } else { - var = matches[i].producer_var; - type = get_varying_type(var, producer_stage); - } - - if (var->data.patch) - location = &generic_patch_location; - - /* 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. - * - * Also advance if varying packing is disabled for transform feedback, - * and previous or current varying is used for transform feedback. - * - * Also advance to the next slot if packing is disabled. This makes sure - * we don't assign varyings the same locations which is possible - * because we still pack individual arrays, records and matrices even - * when packing is disabled. Note we don't advance to the next slot if - * we can pack varyings together that are only used for transform - * feedback. - */ - if (var->data.must_be_shader_input || - (this->disable_xfb_packing && - (previous_var_xfb || var->data.is_xfb)) || - (this->disable_varying_packing && - !(previous_var_xfb_only && var->data.is_xfb_only)) || - (previous_packing_class != this->matches[i].packing_class) || - (this->matches[i].packing_order == PACKING_ORDER_VEC3 && - dont_pack_vec3)) { - *location = ALIGN(*location, 4); - } - - previous_var_xfb = var->data.is_xfb; - previous_var_xfb_only = var->data.is_xfb_only; - previous_packing_class = this->matches[i].packing_class; - - /* The number of components taken up by this variable. For vertex shader - * inputs, we use the number of slots * 4, as they have different - * counting rules. - */ - unsigned num_components = 0; - if (is_vertex_input) { - num_components = type->count_attribute_slots(is_vertex_input) * 4; - } else { - if ((this->disable_varying_packing && - !is_varying_packing_safe(type, var)) || - (this->disable_xfb_packing && var->data.is_xfb && - !(type->is_array() || type->is_struct() || type->is_matrix())) || - var->data.must_be_shader_input) { - num_components = type->count_attribute_slots(false) * 4; - } else { - num_components = type->component_slots_aligned(*location); - } - } - - /* The last slot for this variable, inclusive. */ - unsigned slot_end = *location + num_components - 1; - - /* FIXME: We could be smarter in the below code and loop back over - * trying to fill any locations that we skipped because we couldn't pack - * the varying between an explicit location. For now just let the user - * hit the linking error if we run out of room and suggest they use - * explicit locations. - */ - while (slot_end < MAX_VARYING * 4u) { - const unsigned slots = (slot_end / 4u) - (*location / 4u) + 1; - const uint64_t slot_mask = ((1ull << slots) - 1) << (*location / 4u); - - assert(slots > 0); - - if ((reserved_slots & slot_mask) == 0) { - break; - } - - *location = ALIGN(*location + 1, 4); - slot_end = *location + num_components - 1; - } - - if (!var->data.patch && slot_end >= MAX_VARYING * 4u) { - linker_error(prog, "insufficient contiguous locations available for " - "%s it is possible an array or struct could not be " - "packed between varyings with explicit locations. Try " - "using an explicit location for arrays and structs.", - var->name); - } - - if (slot_end < MAX_VARYINGS_INCL_PATCH * 4u) { - for (unsigned j = *location / 4u; j < slot_end / 4u; j++) - components[j] = 4; - components[slot_end / 4u] = (slot_end & 3) + 1; - } - - this->matches[i].generic_location = *location; - - *location = slot_end + 1; - } - - 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() const -{ - /* Check is location needs to be packed with lower_packed_varyings() or if - * we can just use ARB_enhanced_layouts packing. - */ - bool pack_loc[MAX_VARYINGS_INCL_PATCH] = {}; - const glsl_type *loc_type[MAX_VARYINGS_INCL_PATCH][4] = { {NULL, NULL} }; - - 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; - - if (producer_var) { - producer_var->data.location = VARYING_SLOT_VAR0 + slot; - producer_var->data.location_frac = offset; - } - - if (consumer_var) { - assert(consumer_var->data.location == -1); - consumer_var->data.location = VARYING_SLOT_VAR0 + slot; - consumer_var->data.location_frac = offset; - } - - /* Find locations suitable for native packing via - * ARB_enhanced_layouts. - */ - if (producer_var && consumer_var) { - if (enhanced_layouts_enabled) { - const glsl_type *type = - get_varying_type(producer_var, producer_stage); - if (type->is_array() || type->is_matrix() || type->is_struct() || - type->is_64bit()) { - unsigned comp_slots = type->component_slots() + offset; - unsigned slots = comp_slots / 4; - if (comp_slots % 4) - slots += 1; - - for (unsigned j = 0; j < slots; j++) { - pack_loc[slot + j] = true; - } - } else if (offset + type->vector_elements > 4) { - pack_loc[slot] = true; - pack_loc[slot + 1] = true; - } else { - loc_type[slot][offset] = type; - } - } - } - } - - /* Attempt to use ARB_enhanced_layouts for more efficient packing if - * suitable. - */ - if (enhanced_layouts_enabled) { - 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; - - if (pack_loc[slot] || !producer_var || !consumer_var) - continue; - - const glsl_type *type = - get_varying_type(producer_var, producer_stage); - bool type_match = true; - for (unsigned j = 0; j < 4; j++) { - if (loc_type[slot][j]) { - if (type->base_type != loc_type[slot][j]->base_type) - type_match = false; - } - } - - if (type_match) { - producer_var->data.explicit_location = 1; - consumer_var->data.explicit_location = 1; - producer_var->data.explicit_component = 1; - consumer_var->data.explicit_component = 1; - } - } - } -} - - -/** - * 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(const 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. - */ - const unsigned interp = var->is_interpolation_flat() - ? unsigned(INTERP_MODE_FLAT) : var->data.interpolation; - - assert(interp < (1 << 3)); - - const unsigned packing_class = (interp << 0) | - (var->data.centroid << 3) | - (var->data.sample << 4) | - (var->data.patch << 5) | - (var->data.must_be_shader_input << 6); - - 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(const ir_variable *var) -{ - const glsl_type *element_type = var->type; - - while (element_type->is_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; -} - - -/** - * Comparison function passed to qsort() to sort varyings used only by - * transform feedback when packing of other varyings is disabled. - */ -int -varying_matches::xfb_comparator(const void *x_generic, const void *y_generic) -{ - const match *x = (const match *) x_generic; - - if (x->producer_var != NULL && x->producer_var->data.is_xfb_only) - return match_comparator(x_generic, y_generic); - - /* FIXME: When the comparator returns 0 it means the elements being - * compared are equivalent. However the qsort documentation says: - * - * "The order of equivalent elements is undefined." - * - * In practice the sort ends up reversing the order of the varyings which - * means locations are also assigned in this reversed order and happens to - * be what we want. This is also whats happening in - * varying_matches::match_comparator(). - */ - return 0; -} - - -/** - * Comparison function passed to qsort() to sort varyings NOT used by - * transform feedback when packing of xfb varyings is disabled. - */ -int -varying_matches::not_xfb_comparator(const void *x_generic, const void *y_generic) -{ - const match *x = (const match *) x_generic; - - if (x->producer_var != NULL && !x->producer_var->data.is_xfb) - return match_comparator(x_generic, y_generic); - - /* FIXME: When the comparator returns 0 it means the elements being - * compared are equivalent. However the qsort documentation says: - * - * "The order of equivalent elements is undefined." - * - * In practice the sort ends up reversing the order of the varyings which - * means locations are also assigned in this reversed order and happens to - * be what we want. This is also whats happening in - * varying_matches::match_comparator(). - */ - return 0; -} - - -/** - * 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 -var_counts_against_varying_limit(gl_shader_stage stage, const ir_variable *var) -{ - /* Only fragment shaders will take a varying variable as an input */ - if (stage == MESA_SHADER_FRAGMENT && - var->data.mode == ir_var_shader_in) { - switch (var->data.location) { - case VARYING_SLOT_POS: - case VARYING_SLOT_FACE: - case VARYING_SLOT_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, - gl_shader_stage stage) - : mem_ctx(mem_ctx), - tfeedback_candidates(tfeedback_candidates), - stage(stage), - toplevel_var(NULL), - varying_floats(0), - xfb_offset_floats(0) - { - } - - void process(ir_variable *var) - { - /* All named varying interface blocks should be flattened by now */ - assert(!var->is_interface_instance()); - assert(var->data.mode == ir_var_shader_out); - - this->toplevel_var = var; - this->varying_floats = 0; - this->xfb_offset_floats = 0; - const glsl_type *t = - var->data.from_named_ifc_block ? var->get_interface_type() : var->type; - if (!var->data.patch && stage == MESA_SHADER_TESS_CTRL) { - assert(t->is_array()); - t = t->fields.array; - } - program_resource_visitor::process(var, t, false); - } - -private: - virtual void visit_field(const glsl_type *type, const char *name, - bool /* row_major */, - const glsl_type * /* record_type */, - const enum glsl_interface_packing, - bool /* last_field */) - { - assert(!type->without_array()->is_struct()); - assert(!type->without_array()->is_interface()); - - tfeedback_candidate *candidate - = rzalloc(this->mem_ctx, tfeedback_candidate); - candidate->toplevel_var = this->toplevel_var; - candidate->type = type; - - if (type->without_array()->is_64bit()) { - /* From ARB_gpu_shader_fp64: - * - * If any variable captured in transform feedback has double-precision - * components, the practical requirements for defined behavior are: - * ... - * (c) each double-precision variable captured must be aligned to a - * multiple of eight bytes relative to the beginning of a vertex. - */ - this->xfb_offset_floats = ALIGN(this->xfb_offset_floats, 2); - /* 64-bit members of structs are also aligned. */ - this->varying_floats = ALIGN(this->varying_floats, 2); - } - - candidate->xfb_offset_floats = this->xfb_offset_floats; - candidate->struct_offset_floats = this->varying_floats; - - _mesa_hash_table_insert(this->tfeedback_candidates, - ralloc_strdup(this->mem_ctx, name), - candidate); - - const unsigned component_slots = type->component_slots(); - - if (varying_has_user_specified_location(this->toplevel_var)) { - this->varying_floats += type->count_attribute_slots(false) * 4; - } else { - this->varying_floats += component_slots; - } - - this->xfb_offset_floats += 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; - - gl_shader_stage stage; - - /** - * 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; - - /** - * Offset within the xfb. Counted in floats. - */ - unsigned xfb_offset_floats; -}; - - -namespace linker { - -void -populate_consumer_input_sets(void *mem_ctx, exec_list *ir, - hash_table *consumer_inputs, - hash_table *consumer_interface_inputs, - ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX]) -{ - memset(consumer_inputs_with_locations, - 0, - sizeof(consumer_inputs_with_locations[0]) * VARYING_SLOT_TESS_MAX); - - foreach_in_list(ir_instruction, node, ir) { - ir_variable *const input_var = node->as_variable(); - - if (input_var != NULL && input_var->data.mode == ir_var_shader_in) { - /* All interface blocks should have been lowered by this point */ - assert(!input_var->type->is_interface()); - - if (input_var->data.explicit_location) { - /* assign_varying_locations only cares about finding the - * ir_variable at the start of a contiguous location block. - * - * - For !producer, consumer_inputs_with_locations isn't used. - * - * - For !consumer, consumer_inputs_with_locations is empty. - * - * For consumer && producer, if you were trying to set some - * ir_variable to the middle of a location block on the other side - * of producer/consumer, cross_validate_outputs_to_inputs() should - * be link-erroring due to either type mismatch or location - * overlaps. If the variables do match up, then they've got a - * matching data.location and you only looked at - * consumer_inputs_with_locations[var->data.location], not any - * following entries for the array/structure. - */ - consumer_inputs_with_locations[input_var->data.location] = - input_var; - } else if (input_var->get_interface_type() != NULL) { - char *const iface_field_name = - ralloc_asprintf(mem_ctx, "%s.%s", - input_var->get_interface_type()->without_array()->name, - input_var->name); - _mesa_hash_table_insert(consumer_interface_inputs, - iface_field_name, input_var); - } else { - _mesa_hash_table_insert(consumer_inputs, - ralloc_strdup(mem_ctx, input_var->name), - input_var); - } - } - } -} - -/** - * Find a variable from the consumer that "matches" the specified variable - * - * This function only finds inputs with names that match. There is no - * validation (here) that the types, etc. are compatible. - */ -ir_variable * -get_matching_input(void *mem_ctx, - const ir_variable *output_var, - hash_table *consumer_inputs, - hash_table *consumer_interface_inputs, - ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX]) -{ - ir_variable *input_var; - - if (output_var->data.explicit_location) { - input_var = consumer_inputs_with_locations[output_var->data.location]; - } else if (output_var->get_interface_type() != NULL) { - char *const iface_field_name = - ralloc_asprintf(mem_ctx, "%s.%s", - output_var->get_interface_type()->without_array()->name, - output_var->name); - hash_entry *entry = _mesa_hash_table_search(consumer_interface_inputs, iface_field_name); - input_var = entry ? (ir_variable *) entry->data : NULL; - } else { - hash_entry *entry = _mesa_hash_table_search(consumer_inputs, output_var->name); - input_var = entry ? (ir_variable *) entry->data : NULL; - } - - return (input_var == NULL || input_var->data.mode != ir_var_shader_in) - ? NULL : input_var; -} - -} - -static int -io_variable_cmp(const void *_a, const void *_b) -{ - const ir_variable *const a = *(const ir_variable **) _a; - const ir_variable *const b = *(const ir_variable **) _b; - - if (a->data.explicit_location && b->data.explicit_location) - return b->data.location - a->data.location; - - if (a->data.explicit_location && !b->data.explicit_location) - return 1; - - if (!a->data.explicit_location && b->data.explicit_location) - return -1; - - return -strcmp(a->name, b->name); -} - -/** - * Sort the shader IO variables into canonical order - */ -static void -canonicalize_shader_io(exec_list *ir, enum ir_variable_mode io_mode) -{ - ir_variable *var_table[MAX_PROGRAM_OUTPUTS * 4]; - unsigned num_variables = 0; - - foreach_in_list(ir_instruction, node, ir) { - ir_variable *const var = node->as_variable(); - - if (var == NULL || var->data.mode != io_mode) - continue; - - /* If we have already encountered more I/O variables that could - * successfully link, bail. - */ - if (num_variables == ARRAY_SIZE(var_table)) - return; - - var_table[num_variables++] = var; - } - - if (num_variables == 0) - return; - - /* Sort the list in reverse order (io_variable_cmp handles this). Later - * we're going to push the variables on to the IR list as a stack, so we - * want the last variable (in canonical order) to be first in the list. - */ - qsort(var_table, num_variables, sizeof(var_table[0]), io_variable_cmp); - - /* Remove the variable from it's current location in the IR, and put it at - * the front. - */ - for (unsigned i = 0; i < num_variables; i++) { - var_table[i]->remove(); - ir->push_head(var_table[i]); - } -} - -/** - * Generate a bitfield map of the explicit locations for shader varyings. - * - * Note: For Tessellation shaders we are sitting right on the limits of the - * 64 bit map. Per-vertex and per-patch both have separate location domains - * with a max of MAX_VARYING. - */ -static uint64_t -reserved_varying_slot(struct gl_linked_shader *stage, - ir_variable_mode io_mode) -{ - assert(io_mode == ir_var_shader_in || io_mode == ir_var_shader_out); - /* Avoid an overflow of the returned value */ - assert(MAX_VARYINGS_INCL_PATCH <= 64); - - uint64_t slots = 0; - int var_slot; - - if (!stage) - return slots; - - foreach_in_list(ir_instruction, node, stage->ir) { - ir_variable *const var = node->as_variable(); - - if (var == NULL || var->data.mode != io_mode || - !var->data.explicit_location || - var->data.location < VARYING_SLOT_VAR0) - continue; - - var_slot = var->data.location - VARYING_SLOT_VAR0; - - unsigned num_elements = get_varying_type(var, stage->Stage) - ->count_attribute_slots(io_mode == ir_var_shader_in && - stage->Stage == MESA_SHADER_VERTEX); - for (unsigned i = 0; i < num_elements; i++) { - if (var_slot >= 0 && var_slot < MAX_VARYINGS_INCL_PATCH) - slots |= UINT64_C(1) << var_slot; - var_slot += 1; - } - } - - return slots; -} - - -/** - * 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. - */ -static bool -assign_varying_locations(struct gl_context *ctx, - void *mem_ctx, - struct gl_shader_program *prog, - gl_linked_shader *producer, - gl_linked_shader *consumer, - unsigned num_tfeedback_decls, - tfeedback_decl *tfeedback_decls, - const uint64_t reserved_slots) -{ - /* Tessellation shaders treat inputs and outputs as shared memory and can - * access inputs and outputs of other invocations. - * Therefore, they can't be lowered to temps easily (and definitely not - * efficiently). - */ - bool unpackable_tess = - (consumer && consumer->Stage == MESA_SHADER_TESS_EVAL) || - (consumer && consumer->Stage == MESA_SHADER_TESS_CTRL) || - (producer && producer->Stage == MESA_SHADER_TESS_CTRL); - - /* Transform feedback code assumes varying arrays are packed, so if the - * driver has disabled varying packing, make sure to at least enable - * packing required by transform feedback. See below for exception. - */ - bool xfb_enabled = - ctx->Extensions.EXT_transform_feedback && !unpackable_tess; - - /* Some drivers actually requires packing to be explicitly disabled - * for varyings used by transform feedback. - */ - bool disable_xfb_packing = - ctx->Const.DisableTransformFeedbackPacking; - - /* Disable packing on outward facing interfaces for SSO because in ES we - * need to retain the unpacked varying information for draw time - * validation. - * - * Packing is still enabled on individual arrays, structs, and matrices as - * these are required by the transform feedback code and it is still safe - * to do so. We also enable packing when a varying is only used for - * transform feedback and its not a SSO. - */ - bool disable_varying_packing = - ctx->Const.DisableVaryingPacking || unpackable_tess; - if (prog->SeparateShader && (producer == NULL || consumer == NULL)) - disable_varying_packing = true; - - varying_matches matches(disable_varying_packing, - disable_xfb_packing, - xfb_enabled, - ctx->Extensions.ARB_enhanced_layouts, - producer ? producer->Stage : MESA_SHADER_NONE, - consumer ? consumer->Stage : MESA_SHADER_NONE); - void *hash_table_ctx = ralloc_context(NULL); - hash_table *tfeedback_candidates = - _mesa_hash_table_create(hash_table_ctx, _mesa_hash_string, - _mesa_key_string_equal); - hash_table *consumer_inputs = - _mesa_hash_table_create(hash_table_ctx, _mesa_hash_string, - _mesa_key_string_equal); - hash_table *consumer_interface_inputs = - _mesa_hash_table_create(hash_table_ctx, _mesa_hash_string, - _mesa_key_string_equal); - ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX] = { - NULL, - }; - - unsigned consumer_vertices = 0; - if (consumer && consumer->Stage == MESA_SHADER_GEOMETRY) - consumer_vertices = prog->Geom.VerticesIn; - - /* Operate in a total of four passes. - * - * 1. Sort inputs / outputs into a canonical order. This is necessary so - * that inputs / outputs of separable shaders will be assigned - * predictable locations regardless of the order in which declarations - * appeared in the shader source. - * - * 2. Assign locations for any matching inputs and outputs. - * - * 3. Mark output variables in the producer that do not have locations as - * not being outputs. This lets the optimizer eliminate them. - * - * 4. Mark input variables in the consumer that do not have locations as - * not being inputs. This lets the optimizer eliminate them. - */ - if (consumer) - canonicalize_shader_io(consumer->ir, ir_var_shader_in); - - if (producer) - canonicalize_shader_io(producer->ir, ir_var_shader_out); - - if (consumer) - linker::populate_consumer_input_sets(mem_ctx, consumer->ir, - consumer_inputs, - consumer_interface_inputs, - consumer_inputs_with_locations); - - if (producer) { - foreach_in_list(ir_instruction, node, producer->ir) { - ir_variable *const output_var = node->as_variable(); - - if (output_var == NULL || output_var->data.mode != ir_var_shader_out) - continue; - - /* Only geometry shaders can use non-zero streams */ - assert(output_var->data.stream == 0 || - (output_var->data.stream < MAX_VERTEX_STREAMS && - producer->Stage == MESA_SHADER_GEOMETRY)); - - if (num_tfeedback_decls > 0) { - tfeedback_candidate_generator g(mem_ctx, tfeedback_candidates, producer->Stage); - /* From OpenGL 4.6 (Core Profile) spec, section 11.1.2.1 - * ("Vertex Shader Variables / Output Variables") - * - * "Each program object can specify a set of output variables from - * one shader to be recorded in transform feedback mode (see - * section 13.3). The variables that can be recorded are those - * emitted by the first active shader, in order, from the - * following list: - * - * * geometry shader - * * tessellation evaluation shader - * * tessellation control shader - * * vertex shader" - * - * But on OpenGL ES 3.2, section 11.1.2.1 ("Vertex Shader - * Variables / Output Variables") tessellation control shader is - * not included in the stages list. - */ - if (!prog->IsES || producer->Stage != MESA_SHADER_TESS_CTRL) { - g.process(output_var); - } - } - - ir_variable *const input_var = - linker::get_matching_input(mem_ctx, output_var, consumer_inputs, - consumer_interface_inputs, - consumer_inputs_with_locations); - - /* If a matching input variable was found, add this output (and the - * input) to the set. If this is a separable program and there is no - * consumer stage, add the output. - * - * Always add TCS outputs. They are shared by all invocations - * within a patch and can be used as shared memory. - */ - if (input_var || (prog->SeparateShader && consumer == NULL) || - producer->Stage == MESA_SHADER_TESS_CTRL) { - matches.record(output_var, input_var); - } - - /* Only stream 0 outputs can be consumed in the next stage */ - if (input_var && output_var->data.stream != 0) { - linker_error(prog, "output %s is assigned to stream=%d but " - "is linked to an input, which requires stream=0", - output_var->name, output_var->data.stream); - ralloc_free(hash_table_ctx); - return false; - } - } - } else { - /* If there's no producer stage, then this must be a separable program. - * For example, we may have a program that has just a fragment shader. - * Later this program will be used with some arbitrary vertex (or - * geometry) shader program. This means that locations must be assigned - * for all the inputs. - */ - foreach_in_list(ir_instruction, node, consumer->ir) { - ir_variable *const input_var = node->as_variable(); - if (input_var && input_var->data.mode == ir_var_shader_in) { - matches.record(NULL, 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) { - ralloc_free(hash_table_ctx); - return false; - } - - /* There are two situations where a new output varying is needed: - * - * - If varying packing is disabled for xfb and the current declaration - * is subscripting an array, whether the subscript is aligned or not. - * to preserve the rest of the array for the consumer. - * - * - If a builtin variable needs to be copied to a new variable - * before its content is modified by another lowering pass (e.g. - * \c gl_Position is transformed by \c nir_lower_viewport_transform). - */ - const bool lowered = - (disable_xfb_packing && tfeedback_decls[i].subscripted()) || - (matched_candidate->toplevel_var->data.explicit_location && - matched_candidate->toplevel_var->data.location < VARYING_SLOT_VAR0 && - (!consumer || consumer->Stage == MESA_SHADER_FRAGMENT) && - (ctx->Const.ShaderCompilerOptions[producer->Stage].LowerBuiltinVariablesXfb & - BITFIELD_BIT(matched_candidate->toplevel_var->data.location))); - - if (lowered) { - ir_variable *new_var; - tfeedback_candidate *new_candidate = NULL; - - new_var = lower_xfb_varying(mem_ctx, producer, tfeedback_decls[i].name()); - if (new_var == NULL) { - ralloc_free(hash_table_ctx); - return false; - } - - /* Create new candidate and replace matched_candidate */ - new_candidate = rzalloc(mem_ctx, tfeedback_candidate); - new_candidate->toplevel_var = new_var; - new_candidate->toplevel_var->data.is_unmatched_generic_inout = 1; - new_candidate->type = new_var->type; - new_candidate->struct_offset_floats = 0; - new_candidate->xfb_offset_floats = 0; - _mesa_hash_table_insert(tfeedback_candidates, - ralloc_strdup(mem_ctx, new_var->name), - new_candidate); - - tfeedback_decls[i].set_lowered_candidate(new_candidate); - matched_candidate = new_candidate; - } - - /* Mark as xfb varying */ - matched_candidate->toplevel_var->data.is_xfb = 1; - - /* Mark xfb varyings as always active */ - matched_candidate->toplevel_var->data.always_active_io = 1; - - /* Mark any corresponding inputs as always active also. We must do this - * because we have a NIR pass that lowers vectors to scalars and another - * that removes unused varyings. - * We don't split varyings marked as always active because there is no - * point in doing so. This means we need to mark both sides of the - * interface as always active otherwise we will have a mismatch and - * start removing things we shouldn't. - */ - ir_variable *const input_var = - linker::get_matching_input(mem_ctx, matched_candidate->toplevel_var, - consumer_inputs, - consumer_interface_inputs, - consumer_inputs_with_locations); - if (input_var) { - input_var->data.is_xfb = 1; - input_var->data.always_active_io = 1; - } - - if (matched_candidate->toplevel_var->data.is_unmatched_generic_inout) { - matched_candidate->toplevel_var->data.is_xfb_only = 1; - matches.record(matched_candidate->toplevel_var, NULL); - } - } - - uint8_t components[MAX_VARYINGS_INCL_PATCH] = {0}; - const unsigned slots_used = matches.assign_locations( - prog, components, reserved_slots); - matches.store_locations(); - - for (unsigned i = 0; i < num_tfeedback_decls; ++i) { - if (tfeedback_decls[i].is_varying()) { - if (!tfeedback_decls[i].assign_location(ctx, prog)) { - ralloc_free(hash_table_ctx); - return false; - } - } - } - ralloc_free(hash_table_ctx); - - if (consumer && producer) { - foreach_in_list(ir_instruction, node, consumer->ir) { - ir_variable *const var = node->as_variable(); - - if (var && var->data.mode == ir_var_shader_in && - var->data.is_unmatched_generic_inout) { - if (!prog->IsES && prog->data->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, "%s shader varying %s not written " - "by %s shader\n.", - _mesa_shader_stage_to_string(consumer->Stage), - var->name, - _mesa_shader_stage_to_string(producer->Stage)); - } else { - linker_warning(prog, "%s shader varying %s not written " - "by %s shader\n.", - _mesa_shader_stage_to_string(consumer->Stage), - var->name, - _mesa_shader_stage_to_string(producer->Stage)); - } - } - } - - /* Now that validation is done its safe to remove unused varyings. As - * we have both a producer and consumer its safe to remove unused - * varyings even if the program is a SSO because the stages are being - * linked together i.e. we have a multi-stage SSO. - */ - remove_unused_shader_inputs_and_outputs(false, producer, - ir_var_shader_out); - remove_unused_shader_inputs_and_outputs(false, consumer, - ir_var_shader_in); - } - - if (producer) { - lower_packed_varyings(mem_ctx, slots_used, components, ir_var_shader_out, - 0, producer, disable_varying_packing, - disable_xfb_packing, xfb_enabled); - } - - if (consumer) { - lower_packed_varyings(mem_ctx, slots_used, components, ir_var_shader_in, - consumer_vertices, consumer, disable_varying_packing, - disable_xfb_packing, xfb_enabled); - } - - return true; -} - -static bool -check_against_output_limit(struct gl_context *ctx, - struct gl_shader_program *prog, - gl_linked_shader *producer, - unsigned num_explicit_locations) -{ - unsigned output_vectors = num_explicit_locations; - - foreach_in_list(ir_instruction, node, producer->ir) { - ir_variable *const var = node->as_variable(); - - if (var && !var->data.explicit_location && - var->data.mode == ir_var_shader_out && - var_counts_against_varying_limit(producer->Stage, var)) { - /* outputs for fragment shader can't be doubles */ - output_vectors += var->type->count_attribute_slots(false); - } - } - - assert(producer->Stage != MESA_SHADER_FRAGMENT); - unsigned max_output_components = - ctx->Const.Program[producer->Stage].MaxOutputComponents; - - const unsigned output_components = output_vectors * 4; - if (output_components > max_output_components) { - if (ctx->API == API_OPENGLES2 || prog->IsES) - linker_error(prog, "%s shader uses too many output vectors " - "(%u > %u)\n", - _mesa_shader_stage_to_string(producer->Stage), - output_vectors, - max_output_components / 4); - else - linker_error(prog, "%s shader uses too many output components " - "(%u > %u)\n", - _mesa_shader_stage_to_string(producer->Stage), - output_components, - max_output_components); - - return false; - } - - return true; -} - -static bool -check_against_input_limit(struct gl_context *ctx, - struct gl_shader_program *prog, - gl_linked_shader *consumer, - unsigned num_explicit_locations) -{ - unsigned input_vectors = num_explicit_locations; - - foreach_in_list(ir_instruction, node, consumer->ir) { - ir_variable *const var = node->as_variable(); - - if (var && !var->data.explicit_location && - var->data.mode == ir_var_shader_in && - var_counts_against_varying_limit(consumer->Stage, var)) { - /* vertex inputs aren't varying counted */ - input_vectors += var->type->count_attribute_slots(false); - } - } - - assert(consumer->Stage != MESA_SHADER_VERTEX); - unsigned max_input_components = - ctx->Const.Program[consumer->Stage].MaxInputComponents; - - const unsigned input_components = input_vectors * 4; - if (input_components > max_input_components) { - if (ctx->API == API_OPENGLES2 || prog->IsES) - linker_error(prog, "%s shader uses too many input vectors " - "(%u > %u)\n", - _mesa_shader_stage_to_string(consumer->Stage), - input_vectors, - max_input_components / 4); - else - linker_error(prog, "%s shader uses too many input components " - "(%u > %u)\n", - _mesa_shader_stage_to_string(consumer->Stage), - input_components, - max_input_components); - - return false; - } - - return true; -} - -bool -link_varyings(struct gl_shader_program *prog, unsigned first, unsigned last, - struct gl_context *ctx, void *mem_ctx) -{ - bool has_xfb_qualifiers = false; - unsigned num_tfeedback_decls = 0; - char **varying_names = NULL; - tfeedback_decl *tfeedback_decls = NULL; - - /* From the ARB_enhanced_layouts spec: - * - * "If the shader used to record output variables for transform feedback - * varyings uses the "xfb_buffer", "xfb_offset", or "xfb_stride" layout - * qualifiers, the values specified by TransformFeedbackVaryings are - * ignored, and the set of variables captured for transform feedback is - * instead derived from the specified layout qualifiers." - */ - for (int i = MESA_SHADER_FRAGMENT - 1; i >= 0; i--) { - /* Find last stage before fragment shader */ - if (prog->_LinkedShaders[i]) { - has_xfb_qualifiers = - process_xfb_layout_qualifiers(mem_ctx, prog->_LinkedShaders[i], - prog, &num_tfeedback_decls, - &varying_names); - break; - } - } - - if (!has_xfb_qualifiers) { - num_tfeedback_decls = prog->TransformFeedback.NumVarying; - varying_names = prog->TransformFeedback.VaryingNames; - } - - if (num_tfeedback_decls != 0) { - /* From GL_EXT_transform_feedback: - * A program will fail to link if: - * - * * the <count> specified by TransformFeedbackVaryingsEXT is - * non-zero, but the program object has no vertex or geometry - * shader; - */ - if (first >= MESA_SHADER_FRAGMENT) { - linker_error(prog, "Transform feedback varyings specified, but " - "no vertex, tessellation, or geometry shader is " - "present.\n"); - return false; - } - - tfeedback_decls = rzalloc_array(mem_ctx, tfeedback_decl, - num_tfeedback_decls); - if (!parse_tfeedback_decls(ctx, prog, mem_ctx, num_tfeedback_decls, - varying_names, tfeedback_decls)) - return false; - } - - /* If there is no fragment shader we need to set transform feedback. - * - * For SSO we also need to assign output locations. We assign them here - * because we need to do it for both single stage programs and multi stage - * programs. - */ - if (last < MESA_SHADER_FRAGMENT && - (num_tfeedback_decls != 0 || prog->SeparateShader)) { - const uint64_t reserved_out_slots = - reserved_varying_slot(prog->_LinkedShaders[last], ir_var_shader_out); - if (!assign_varying_locations(ctx, mem_ctx, prog, - prog->_LinkedShaders[last], NULL, - num_tfeedback_decls, tfeedback_decls, - reserved_out_slots)) - return false; - } - - if (last <= MESA_SHADER_FRAGMENT) { - /* Remove unused varyings from the first/last stage unless SSO */ - remove_unused_shader_inputs_and_outputs(prog->SeparateShader, - prog->_LinkedShaders[first], - ir_var_shader_in); - remove_unused_shader_inputs_and_outputs(prog->SeparateShader, - prog->_LinkedShaders[last], - ir_var_shader_out); - - /* If the program is made up of only a single stage */ - if (first == last) { - gl_linked_shader *const sh = prog->_LinkedShaders[last]; - - do_dead_builtin_varyings(ctx, NULL, sh, 0, NULL); - do_dead_builtin_varyings(ctx, sh, NULL, num_tfeedback_decls, - tfeedback_decls); - - if (prog->SeparateShader) { - const uint64_t reserved_slots = - reserved_varying_slot(sh, ir_var_shader_in); - - /* Assign input locations for SSO, output locations are already - * assigned. - */ - if (!assign_varying_locations(ctx, mem_ctx, prog, - NULL /* producer */, - sh /* consumer */, - 0 /* num_tfeedback_decls */, - NULL /* tfeedback_decls */, - reserved_slots)) - return false; - } - } else { - /* Linking the stages in the opposite order (from fragment to vertex) - * ensures that inter-shader outputs written to in an earlier stage - * are eliminated if they are (transitively) not used in a later - * stage. - */ - int next = last; - for (int i = next - 1; i >= 0; i--) { - if (prog->_LinkedShaders[i] == NULL && i != 0) - continue; - - gl_linked_shader *const sh_i = prog->_LinkedShaders[i]; - gl_linked_shader *const sh_next = prog->_LinkedShaders[next]; - - const uint64_t reserved_out_slots = - reserved_varying_slot(sh_i, ir_var_shader_out); - const uint64_t reserved_in_slots = - reserved_varying_slot(sh_next, ir_var_shader_in); - - do_dead_builtin_varyings(ctx, sh_i, sh_next, - next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0, - tfeedback_decls); - - if (!assign_varying_locations(ctx, mem_ctx, prog, sh_i, sh_next, - next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0, - tfeedback_decls, - reserved_out_slots | reserved_in_slots)) - return false; - - /* This must be done after all dead varyings are eliminated. */ - if (sh_i != NULL) { - unsigned slots_used = util_bitcount64(reserved_out_slots); - if (!check_against_output_limit(ctx, prog, sh_i, slots_used)) { - return false; - } - } - - unsigned slots_used = util_bitcount64(reserved_in_slots); - if (!check_against_input_limit(ctx, prog, sh_next, slots_used)) - return false; - - next = i; - } - } - } - - if (!store_tfeedback_info(ctx, prog, num_tfeedback_decls, tfeedback_decls, - has_xfb_qualifiers, mem_ctx)) - return false; - - return true; -} |