[Mesa-dev] [PATCH 2/5] glsl: Separate varying linking code to its own file.
Paul Berry
stereotype441 at gmail.com
Wed Dec 19 08:42:15 PST 2012
linker.cpp is getting pretty big, and we're about to add even more
varying packing code, so split out the linker code that concerns
varyings to its own file.
---
src/glsl/Makefile.sources | 1 +
src/glsl/link_varyings.cpp | 1043 ++++++++++++++++++++++++++++++++++++++++
src/glsl/link_varyings.h | 186 ++++++++
src/glsl/linker.cpp | 1125 +-------------------------------------------
src/glsl/linker.h | 9 +
5 files changed, 1240 insertions(+), 1124 deletions(-)
create mode 100644 src/glsl/link_varyings.cpp
create mode 100644 src/glsl/link_varyings.h
diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
index d984c5c..2227c5e 100644
--- a/src/glsl/Makefile.sources
+++ b/src/glsl/Makefile.sources
@@ -46,6 +46,7 @@ LIBGLSL_FILES = \
$(GLSL_SRCDIR)/link_functions.cpp \
$(GLSL_SRCDIR)/link_uniforms.cpp \
$(GLSL_SRCDIR)/link_uniform_initializers.cpp \
+ $(GLSL_SRCDIR)/link_varyings.cpp \
$(GLSL_SRCDIR)/loop_analysis.cpp \
$(GLSL_SRCDIR)/loop_controls.cpp \
$(GLSL_SRCDIR)/loop_unroll.cpp \
diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
new file mode 100644
index 0000000..b9c3f5d
--- /dev/null
+++ b/src/glsl/link_varyings.cpp
@@ -0,0 +1,1043 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file link_varyings.cpp
+ *
+ * Linker functions related specifically to linking varyings between shader
+ * stages.
+ */
+
+
+#include "main/mtypes.h"
+#include "glsl_symbol_table.h"
+#include "ir_optimization.h"
+#include "linker.h"
+#include "link_varyings.h"
+#include "main/macros.h"
+
+
+/**
+ * Validate that outputs from one stage match inputs of another
+ */
+bool
+cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
+ gl_shader *producer, gl_shader *consumer)
+{
+ glsl_symbol_table parameters;
+ /* FINISHME: Figure these out dynamically. */
+ const char *const producer_stage = "vertex";
+ const char *const consumer_stage = "fragment";
+
+ /* Find all shader outputs in the "producer" stage.
+ */
+ foreach_list(node, producer->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ /* FINISHME: For geometry shaders, this should also look for inout
+ * FINISHME: variables.
+ */
+ if ((var == NULL) || (var->mode != ir_var_out))
+ continue;
+
+ parameters.add_variable(var);
+ }
+
+
+ /* Find all shader inputs in the "consumer" stage. Any variables that have
+ * matching outputs already in the symbol table must have the same type and
+ * qualifiers.
+ */
+ foreach_list(node, consumer->ir) {
+ ir_variable *const input = ((ir_instruction *) node)->as_variable();
+
+ /* FINISHME: For geometry shaders, this should also look for inout
+ * FINISHME: variables.
+ */
+ if ((input == NULL) || (input->mode != ir_var_in))
+ continue;
+
+ ir_variable *const output = parameters.get_variable(input->name);
+ if (output != NULL) {
+ /* Check that the types match between stages.
+ */
+ if (input->type != output->type) {
+ /* There is a bit of a special case for gl_TexCoord. This
+ * built-in is unsized by default. Applications that variable
+ * access it must redeclare it with a size. There is some
+ * language in the GLSL spec that implies the fragment shader
+ * and vertex shader do not have to agree on this size. Other
+ * driver behave this way, and one or two applications seem to
+ * rely on it.
+ *
+ * Neither declaration needs to be modified here because the array
+ * sizes are fixed later when update_array_sizes is called.
+ *
+ * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec:
+ *
+ * "Unlike user-defined varying variables, the built-in
+ * varying variables don't have a strict one-to-one
+ * correspondence between the vertex language and the
+ * fragment language."
+ */
+ if (!output->type->is_array()
+ || (strncmp("gl_", output->name, 3) != 0)) {
+ linker_error(prog,
+ "%s shader output `%s' declared as type `%s', "
+ "but %s shader input declared as type `%s'\n",
+ producer_stage, output->name,
+ output->type->name,
+ consumer_stage, input->type->name);
+ return false;
+ }
+ }
+
+ /* Check that all of the qualifiers match between stages.
+ */
+ if (input->centroid != output->centroid) {
+ linker_error(prog,
+ "%s shader output `%s' %s centroid qualifier, "
+ "but %s shader input %s centroid qualifier\n",
+ producer_stage,
+ output->name,
+ (output->centroid) ? "has" : "lacks",
+ consumer_stage,
+ (input->centroid) ? "has" : "lacks");
+ return false;
+ }
+
+ if (input->invariant != output->invariant) {
+ linker_error(prog,
+ "%s shader output `%s' %s invariant qualifier, "
+ "but %s shader input %s invariant qualifier\n",
+ producer_stage,
+ output->name,
+ (output->invariant) ? "has" : "lacks",
+ consumer_stage,
+ (input->invariant) ? "has" : "lacks");
+ return false;
+ }
+
+ if (input->interpolation != output->interpolation) {
+ linker_error(prog,
+ "%s shader output `%s' specifies %s "
+ "interpolation qualifier, "
+ "but %s shader input specifies %s "
+ "interpolation qualifier\n",
+ producer_stage,
+ output->name,
+ output->interpolation_string(),
+ consumer_stage,
+ input->interpolation_string());
+ return false;
+ }
+ }
+ }
+
+ return true;
+}
+
+
+/**
+ * Initialize this object based on a string that was passed to
+ * glTransformFeedbackVaryings. If there is a parse error, the error is
+ * reported using linker_error(), and false is returned.
+ */
+bool
+tfeedback_decl::init(struct gl_context *ctx, struct gl_shader_program *prog,
+ const void *mem_ctx, const char *input)
+{
+ /* We don't have to be pedantic about what is a valid GLSL variable name,
+ * because any variable with an invalid name can't exist in the IR anyway.
+ */
+
+ this->location = -1;
+ this->orig_name = input;
+ this->is_clip_distance_mesa = false;
+ this->skip_components = 0;
+ this->next_buffer_separator = false;
+
+ if (ctx->Extensions.ARB_transform_feedback3) {
+ /* Parse gl_NextBuffer. */
+ if (strcmp(input, "gl_NextBuffer") == 0) {
+ this->next_buffer_separator = true;
+ return true;
+ }
+
+ /* 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 true;
+ }
+
+ /* Parse a declaration. */
+ const char *bracket = strrchr(input, '[');
+
+ if (bracket) {
+ this->var_name = ralloc_strndup(mem_ctx, input, bracket - input);
+ if (sscanf(bracket, "[%u]", &this->array_subscript) != 1) {
+ linker_error(prog, "Cannot parse transform feedback varying %s", input);
+ return false;
+ }
+ this->is_subscripted = true;
+ } else {
+ this->var_name = ralloc_strdup(mem_ctx, input);
+ this->is_subscripted = false;
+ }
+
+ /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this
+ * class must behave specially to account for the fact that gl_ClipDistance
+ * is converted from a float[8] to a vec4[2].
+ */
+ if (ctx->ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerClipDistance &&
+ strcmp(this->var_name, "gl_ClipDistance") == 0) {
+ this->is_clip_distance_mesa = true;
+ }
+
+ return true;
+}
+
+
+/**
+ * Determine whether two tfeedback_decl objects refer to the same variable and
+ * array index (if applicable).
+ */
+bool
+tfeedback_decl::is_same(const tfeedback_decl &x, const tfeedback_decl &y)
+{
+ assert(x.is_varying() && y.is_varying());
+
+ if (strcmp(x.var_name, y.var_name) != 0)
+ return false;
+ if (x.is_subscripted != y.is_subscripted)
+ return false;
+ if (x.is_subscripted && x.array_subscript != y.array_subscript)
+ return false;
+ return true;
+}
+
+
+/**
+ * Assign a location for this tfeedback_decl object based on the location
+ * assignment in output_var.
+ *
+ * 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,
+ ir_variable *output_var)
+{
+ assert(this->is_varying());
+
+ if (output_var->type->is_array()) {
+ /* Array variable */
+ const unsigned matrix_cols =
+ output_var->type->fields.array->matrix_columns;
+ const unsigned vector_elements =
+ output_var->type->fields.array->vector_elements;
+ unsigned actual_array_size = this->is_clip_distance_mesa ?
+ prog->Vert.ClipDistanceArraySize : output_var->type->array_size();
+
+ if (this->is_subscripted) {
+ /* Check array bounds. */
+ if (this->array_subscript >= actual_array_size) {
+ linker_error(prog, "Transform feedback varying %s has index "
+ "%i, but the array size is %u.",
+ this->orig_name, this->array_subscript,
+ actual_array_size);
+ return false;
+ }
+ if (this->is_clip_distance_mesa) {
+ this->location =
+ output_var->location + this->array_subscript / 4;
+ this->location_frac = this->array_subscript % 4;
+ } else {
+ unsigned fine_location
+ = output_var->location * 4 + output_var->location_frac;
+ unsigned array_elem_size = vector_elements * matrix_cols;
+ fine_location += array_elem_size * this->array_subscript;
+ this->location = fine_location / 4;
+ this->location_frac = fine_location % 4;
+ }
+ this->size = 1;
+ } else {
+ this->location = output_var->location;
+ this->location_frac = output_var->location_frac;
+ this->size = actual_array_size;
+ }
+ this->vector_elements = vector_elements;
+ this->matrix_columns = matrix_cols;
+ if (this->is_clip_distance_mesa)
+ this->type = GL_FLOAT;
+ else
+ this->type = output_var->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->location = output_var->location;
+ this->location_frac = output_var->location_frac;
+ this->size = 1;
+ this->vector_elements = output_var->type->vector_elements;
+ this->matrix_columns = output_var->type->matrix_columns;
+ this->type = output_var->type->gl_type;
+ }
+
+ /* From GL_EXT_transform_feedback:
+ * A program will fail to link if:
+ *
+ * * the total number of components to capture in any varying
+ * variable in <varyings> is greater than the constant
+ * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the
+ * buffer mode is SEPARATE_ATTRIBS_EXT;
+ */
+ if (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS &&
+ this->num_components() >
+ ctx->Const.MaxTransformFeedbackSeparateComponents) {
+ linker_error(prog, "Transform feedback varying %s exceeds "
+ "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.",
+ this->orig_name);
+ return false;
+ }
+
+ return true;
+}
+
+
+unsigned
+tfeedback_decl::get_num_outputs() const
+{
+ if (!this->is_varying()) {
+ return 0;
+ }
+
+ return (this->num_components() + this->location_frac + 3)/4;
+}
+
+
+/**
+ * Update gl_transform_feedback_info to reflect this tfeedback_decl.
+ *
+ * If an error occurs, the error is reported through linker_error() and false
+ * is returned.
+ */
+bool
+tfeedback_decl::store(struct gl_context *ctx, struct gl_shader_program *prog,
+ struct gl_transform_feedback_info *info,
+ unsigned buffer, const unsigned max_outputs) const
+{
+ assert(!this->next_buffer_separator);
+
+ /* Handle gl_SkipComponents. */
+ if (this->skip_components) {
+ info->BufferStride[buffer] += this->skip_components;
+ return true;
+ }
+
+ /* From GL_EXT_transform_feedback:
+ * A program will fail to link if:
+ *
+ * * the total number of components to capture is greater than
+ * the constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT
+ * and the buffer mode is INTERLEAVED_ATTRIBS_EXT.
+ */
+ if (prog->TransformFeedback.BufferMode == GL_INTERLEAVED_ATTRIBS &&
+ info->BufferStride[buffer] + this->num_components() >
+ ctx->Const.MaxTransformFeedbackInterleavedComponents) {
+ linker_error(prog, "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS "
+ "limit has been exceeded.");
+ return false;
+ }
+
+ unsigned location = this->location;
+ unsigned location_frac = this->location_frac;
+ unsigned num_components = this->num_components();
+ while (num_components > 0) {
+ unsigned output_size = MIN2(num_components, 4 - location_frac);
+ assert(info->NumOutputs < max_outputs);
+ info->Outputs[info->NumOutputs].ComponentOffset = location_frac;
+ info->Outputs[info->NumOutputs].OutputRegister = location;
+ info->Outputs[info->NumOutputs].NumComponents = output_size;
+ info->Outputs[info->NumOutputs].OutputBuffer = buffer;
+ info->Outputs[info->NumOutputs].DstOffset = info->BufferStride[buffer];
+ ++info->NumOutputs;
+ info->BufferStride[buffer] += output_size;
+ num_components -= output_size;
+ location++;
+ location_frac = 0;
+ }
+
+ info->Varyings[info->NumVarying].Name = ralloc_strdup(prog, this->orig_name);
+ info->Varyings[info->NumVarying].Type = this->type;
+ info->Varyings[info->NumVarying].Size = this->size;
+ info->NumVarying++;
+
+ return true;
+}
+
+
+ir_variable *
+tfeedback_decl::find_output_var(gl_shader_program *prog,
+ gl_shader *producer) const
+{
+ const char *name = this->is_clip_distance_mesa
+ ? "gl_ClipDistanceMESA" : this->var_name;
+ ir_variable *var = producer->symbols->get_variable(name);
+ if (var && var->mode == ir_var_out)
+ return var;
+
+ /* 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 NULL;
+}
+
+
+/**
+ * Parse all the transform feedback declarations that were passed to
+ * glTransformFeedbackVaryings() and store them in tfeedback_decl objects.
+ *
+ * If an error occurs, the error is reported through linker_error() and false
+ * is returned.
+ */
+bool
+parse_tfeedback_decls(struct gl_context *ctx, struct gl_shader_program *prog,
+ const void *mem_ctx, unsigned num_names,
+ char **varying_names, tfeedback_decl *decls)
+{
+ for (unsigned i = 0; i < num_names; ++i) {
+ if (!decls[i].init(ctx, prog, mem_ctx, varying_names[i]))
+ return false;
+
+ if (!decls[i].is_varying())
+ continue;
+
+ /* From GL_EXT_transform_feedback:
+ * A program will fail to link if:
+ *
+ * * any two entries in the <varyings> array specify the same varying
+ * variable;
+ *
+ * We interpret this to mean "any two entries in the <varyings> array
+ * specify the same varying variable and array index", since transform
+ * feedback of arrays would be useless otherwise.
+ */
+ for (unsigned j = 0; j < i; ++j) {
+ if (!decls[j].is_varying())
+ continue;
+
+ if (tfeedback_decl::is_same(decls[i], decls[j])) {
+ linker_error(prog, "Transform feedback varying %s specified "
+ "more than once.", varying_names[i]);
+ return false;
+ }
+ }
+ }
+ return true;
+}
+
+
+/**
+ * Store transform feedback location assignments into
+ * prog->LinkedTransformFeedback based on the data stored in tfeedback_decls.
+ *
+ * If an error occurs, the error is reported through linker_error() and false
+ * is returned.
+ */
+bool
+store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog,
+ unsigned num_tfeedback_decls,
+ tfeedback_decl *tfeedback_decls)
+{
+ bool separate_attribs_mode =
+ prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS;
+
+ ralloc_free(prog->LinkedTransformFeedback.Varyings);
+ ralloc_free(prog->LinkedTransformFeedback.Outputs);
+
+ memset(&prog->LinkedTransformFeedback, 0,
+ sizeof(prog->LinkedTransformFeedback));
+
+ prog->LinkedTransformFeedback.Varyings =
+ rzalloc_array(prog,
+ struct gl_transform_feedback_varying_info,
+ num_tfeedback_decls);
+
+ unsigned num_outputs = 0;
+ for (unsigned i = 0; i < num_tfeedback_decls; ++i)
+ num_outputs += tfeedback_decls[i].get_num_outputs();
+
+ prog->LinkedTransformFeedback.Outputs =
+ rzalloc_array(prog,
+ struct gl_transform_feedback_output,
+ num_outputs);
+
+ unsigned num_buffers = 0;
+
+ if (separate_attribs_mode) {
+ /* GL_SEPARATE_ATTRIBS */
+ for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
+ if (!tfeedback_decls[i].store(ctx, prog, &prog->LinkedTransformFeedback,
+ num_buffers, num_outputs))
+ return false;
+
+ num_buffers++;
+ }
+ }
+ else {
+ /* GL_INVERLEAVED_ATTRIBS */
+ for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
+ if (tfeedback_decls[i].is_next_buffer_separator()) {
+ num_buffers++;
+ continue;
+ }
+
+ if (!tfeedback_decls[i].store(ctx, prog,
+ &prog->LinkedTransformFeedback,
+ num_buffers, num_outputs))
+ return false;
+ }
+ num_buffers++;
+ }
+
+ assert(prog->LinkedTransformFeedback.NumOutputs == num_outputs);
+
+ prog->LinkedTransformFeedback.NumBuffers = num_buffers;
+ return true;
+}
+
+
+/**
+ * Data structure recording the relationship between outputs of one shader
+ * stage (the "producer") and inputs of another (the "consumer").
+ */
+class varying_matches
+{
+public:
+ varying_matches(bool disable_varying_packing);
+ ~varying_matches();
+ void record(ir_variable *producer_var, ir_variable *consumer_var);
+ unsigned assign_locations();
+ void store_locations(unsigned producer_base, unsigned consumer_base) const;
+
+private:
+ /**
+ * If true, this driver disables varying packing, so all varyings need to
+ * be aligned on slot boundaries, and take up a number of slots equal to
+ * their number of matrix columns times their array size.
+ */
+ const bool disable_varying_packing;
+
+ /**
+ * Enum representing the order in which varyings are packed within a
+ * packing class.
+ *
+ * Currently we pack vec4's first, then vec2's, then scalar values, then
+ * vec3's. This order ensures that the only vectors that are at risk of
+ * having to be "double parked" (split between two adjacent varying slots)
+ * are the vec3's.
+ */
+ enum packing_order_enum {
+ PACKING_ORDER_VEC4,
+ PACKING_ORDER_VEC2,
+ PACKING_ORDER_SCALAR,
+ PACKING_ORDER_VEC3,
+ };
+
+ static unsigned compute_packing_class(ir_variable *var);
+ static packing_order_enum compute_packing_order(ir_variable *var);
+ static int match_comparator(const void *x_generic, const void *y_generic);
+
+ /**
+ * Structure recording the relationship between a single producer output
+ * and a single consumer input.
+ */
+ struct match {
+ /**
+ * Packing class for this varying, computed by compute_packing_class().
+ */
+ unsigned packing_class;
+
+ /**
+ * Packing order for this varying, computed by compute_packing_order().
+ */
+ packing_order_enum packing_order;
+ unsigned num_components;
+
+ /**
+ * The output variable in the producer stage.
+ */
+ ir_variable *producer_var;
+
+ /**
+ * The input variable in the consumer stage.
+ */
+ ir_variable *consumer_var;
+
+ /**
+ * The location which has been assigned for this varying. This is
+ * expressed in multiples of a float, with the first generic varying
+ * (i.e. the one referred to by VERT_RESULT_VAR0 or FRAG_ATTRIB_VAR0)
+ * represented by the value 0.
+ */
+ unsigned generic_location;
+ } *matches;
+
+ /**
+ * The number of elements in the \c matches array that are currently in
+ * use.
+ */
+ unsigned num_matches;
+
+ /**
+ * The number of elements that were set aside for the \c matches array when
+ * it was allocated.
+ */
+ unsigned matches_capacity;
+};
+
+
+varying_matches::varying_matches(bool disable_varying_packing)
+ : disable_varying_packing(disable_varying_packing)
+{
+ /* Note: this initial capacity is rather arbitrarily chosen to be large
+ * enough for many cases without wasting an unreasonable amount of space.
+ * varying_matches::record() will resize the array if there are more than
+ * this number of varyings.
+ */
+ this->matches_capacity = 8;
+ this->matches = (match *)
+ malloc(sizeof(*this->matches) * this->matches_capacity);
+ this->num_matches = 0;
+}
+
+
+varying_matches::~varying_matches()
+{
+ free(this->matches);
+}
+
+
+/**
+ * Record the given producer/consumer variable pair in the list of variables
+ * that should later be assigned locations.
+ *
+ * It is permissible for \c consumer_var to be NULL (this happens if a
+ * variable is output by the producer and consumed by transform feedback, but
+ * not consumed by the consumer).
+ *
+ * If \c producer_var has already been paired up with a consumer_var, or
+ * producer_var is part of fixed pipeline functionality (and hence already has
+ * a location assigned), this function has no effect.
+ */
+void
+varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
+{
+ if (!producer_var->is_unmatched_generic_inout) {
+ /* Either a location already exists for this variable (since it is part
+ * of fixed functionality), or it has already been recorded as part of a
+ * previous match.
+ */
+ return;
+ }
+
+ if (this->num_matches == this->matches_capacity) {
+ this->matches_capacity *= 2;
+ this->matches = (match *)
+ realloc(this->matches,
+ sizeof(*this->matches) * this->matches_capacity);
+ }
+ this->matches[this->num_matches].packing_class
+ = this->compute_packing_class(producer_var);
+ this->matches[this->num_matches].packing_order
+ = this->compute_packing_order(producer_var);
+ if (this->disable_varying_packing) {
+ unsigned slots = producer_var->type->is_array()
+ ? (producer_var->type->length
+ * producer_var->type->fields.array->matrix_columns)
+ : producer_var->type->matrix_columns;
+ this->matches[this->num_matches].num_components = 4 * slots;
+ } else {
+ this->matches[this->num_matches].num_components
+ = producer_var->type->component_slots();
+ }
+ this->matches[this->num_matches].producer_var = producer_var;
+ this->matches[this->num_matches].consumer_var = consumer_var;
+ this->num_matches++;
+ producer_var->is_unmatched_generic_inout = 0;
+ if (consumer_var)
+ consumer_var->is_unmatched_generic_inout = 0;
+}
+
+
+/**
+ * Choose locations for all of the variable matches that were previously
+ * passed to varying_matches::record().
+ */
+unsigned
+varying_matches::assign_locations()
+{
+ /* Sort varying matches into an order that makes them easy to pack. */
+ qsort(this->matches, this->num_matches, sizeof(*this->matches),
+ &varying_matches::match_comparator);
+
+ unsigned generic_location = 0;
+
+ for (unsigned i = 0; i < this->num_matches; i++) {
+ /* Advance to the next slot if this varying has a different packing
+ * class than the previous one, and we're not already on a slot
+ * boundary.
+ */
+ if (i > 0 &&
+ this->matches[i - 1].packing_class
+ != this->matches[i].packing_class) {
+ generic_location = ALIGN(generic_location, 4);
+ }
+
+ this->matches[i].generic_location = generic_location;
+
+ generic_location += this->matches[i].num_components;
+ }
+
+ return (generic_location + 3) / 4;
+}
+
+
+/**
+ * Update the producer and consumer shaders to reflect the locations
+ * assignments that were made by varying_matches::assign_locations().
+ */
+void
+varying_matches::store_locations(unsigned producer_base,
+ unsigned consumer_base) const
+{
+ for (unsigned i = 0; i < this->num_matches; i++) {
+ ir_variable *producer_var = this->matches[i].producer_var;
+ ir_variable *consumer_var = this->matches[i].consumer_var;
+ unsigned generic_location = this->matches[i].generic_location;
+ unsigned slot = generic_location / 4;
+ unsigned offset = generic_location % 4;
+
+ producer_var->location = producer_base + slot;
+ producer_var->location_frac = offset;
+ if (consumer_var) {
+ assert(consumer_var->location == -1);
+ consumer_var->location = consumer_base + slot;
+ consumer_var->location_frac = offset;
+ }
+ }
+}
+
+
+/**
+ * Compute the "packing class" of the given varying. This is an unsigned
+ * integer with the property that two variables in the same packing class can
+ * be safely backed into the same vec4.
+ */
+unsigned
+varying_matches::compute_packing_class(ir_variable *var)
+{
+ /* In this initial implementation we conservatively assume that variables
+ * can only be packed if their base type (float/int/uint/bool) matches and
+ * their interpolation and centroid qualifiers match.
+ *
+ * TODO: relax these restrictions when the driver back-end permits.
+ */
+ unsigned packing_class = var->centroid ? 1 : 0;
+ packing_class *= 4;
+ packing_class += var->interpolation;
+ packing_class *= GLSL_TYPE_ERROR;
+ packing_class += var->type->get_scalar_type()->base_type;
+ return packing_class;
+}
+
+
+/**
+ * Compute the "packing order" of the given varying. This is a sort key we
+ * use to determine when to attempt to pack the given varying relative to
+ * other varyings in the same packing class.
+ */
+varying_matches::packing_order_enum
+varying_matches::compute_packing_order(ir_variable *var)
+{
+ const glsl_type *element_type = var->type;
+
+ /* FINISHME: Support for "varying" records in GLSL 1.50. */
+ while (element_type->base_type == GLSL_TYPE_ARRAY) {
+ element_type = element_type->fields.array;
+ }
+
+ switch (element_type->vector_elements) {
+ case 1: return PACKING_ORDER_SCALAR;
+ case 2: return PACKING_ORDER_VEC2;
+ case 3: return PACKING_ORDER_VEC3;
+ case 4: return PACKING_ORDER_VEC4;
+ default:
+ assert(!"Unexpected value of vector_elements");
+ return PACKING_ORDER_VEC4;
+ }
+}
+
+
+/**
+ * Comparison function passed to qsort() to sort varyings by packing_class and
+ * then by packing_order.
+ */
+int
+varying_matches::match_comparator(const void *x_generic, const void *y_generic)
+{
+ const match *x = (const match *) x_generic;
+ const match *y = (const match *) y_generic;
+
+ if (x->packing_class != y->packing_class)
+ return x->packing_class - y->packing_class;
+ return x->packing_order - y->packing_order;
+}
+
+
+/**
+ * Is the given variable a varying variable to be counted against the
+ * limit in ctx->Const.MaxVarying?
+ * This includes variables such as texcoords, colors and generic
+ * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord.
+ */
+static bool
+is_varying_var(GLenum shaderType, const ir_variable *var)
+{
+ /* Only fragment shaders will take a varying variable as an input */
+ if (shaderType == GL_FRAGMENT_SHADER &&
+ var->mode == ir_var_in) {
+ switch (var->location) {
+ case FRAG_ATTRIB_WPOS:
+ case FRAG_ATTRIB_FACE:
+ case FRAG_ATTRIB_PNTC:
+ return false;
+ default:
+ return true;
+ }
+ }
+ return false;
+}
+
+
+/**
+ * Assign locations for all variables that are produced in one pipeline stage
+ * (the "producer") and consumed in the next stage (the "consumer").
+ *
+ * Variables produced by the producer may also be consumed by transform
+ * feedback.
+ *
+ * \param num_tfeedback_decls is the number of declarations indicating
+ * variables that may be consumed by transform feedback.
+ *
+ * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects
+ * representing the result of parsing the strings passed to
+ * glTransformFeedbackVaryings(). assign_location() will be called for
+ * each of these objects that matches one of the outputs of the
+ * producer.
+ *
+ * When num_tfeedback_decls is nonzero, it is permissible for the consumer to
+ * be NULL. In this case, varying locations are assigned solely based on the
+ * requirements of transform feedback.
+ */
+bool
+assign_varying_locations(struct gl_context *ctx,
+ void *mem_ctx,
+ struct gl_shader_program *prog,
+ gl_shader *producer, gl_shader *consumer,
+ unsigned num_tfeedback_decls,
+ tfeedback_decl *tfeedback_decls)
+{
+ /* FINISHME: Set dynamically when geometry shader support is added. */
+ const unsigned producer_base = VERT_RESULT_VAR0;
+ const unsigned consumer_base = FRAG_ATTRIB_VAR0;
+ varying_matches matches(ctx->Const.DisableVaryingPacking);
+
+ /* Operate in a total of three passes.
+ *
+ * 1. Assign locations for any matching inputs and outputs.
+ *
+ * 2. Mark output variables in the producer that do not have locations as
+ * not being outputs. This lets the optimizer eliminate them.
+ *
+ * 3. Mark input variables in the consumer that do not have locations as
+ * not being inputs. This lets the optimizer eliminate them.
+ */
+
+ foreach_list(node, producer->ir) {
+ ir_variable *const output_var = ((ir_instruction *) node)->as_variable();
+
+ if ((output_var == NULL) || (output_var->mode != ir_var_out))
+ continue;
+
+ ir_variable *input_var =
+ consumer ? consumer->symbols->get_variable(output_var->name) : NULL;
+
+ if (input_var && input_var->mode != ir_var_in)
+ input_var = NULL;
+
+ if (input_var) {
+ matches.record(output_var, input_var);
+ }
+ }
+
+ for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
+ if (!tfeedback_decls[i].is_varying())
+ continue;
+
+ ir_variable *output_var
+ = tfeedback_decls[i].find_output_var(prog, producer);
+
+ if (output_var == NULL)
+ return false;
+
+ if (output_var->is_unmatched_generic_inout) {
+ matches.record(output_var, NULL);
+ }
+ }
+
+ const unsigned slots_used = matches.assign_locations();
+ matches.store_locations(producer_base, consumer_base);
+
+ for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
+ if (!tfeedback_decls[i].is_varying())
+ continue;
+
+ ir_variable *output_var
+ = tfeedback_decls[i].find_output_var(prog, producer);
+
+ if (!tfeedback_decls[i].assign_location(ctx, prog, output_var))
+ return false;
+ }
+
+ if (ctx->Const.DisableVaryingPacking) {
+ /* Transform feedback code assumes varyings are packed, so if the driver
+ * has disabled varying packing, make sure it does not support transform
+ * feedback.
+ */
+ assert(!ctx->Extensions.EXT_transform_feedback);
+ } else {
+ lower_packed_varyings(mem_ctx, producer_base, slots_used, ir_var_out,
+ producer);
+ if (consumer) {
+ lower_packed_varyings(mem_ctx, consumer_base, slots_used, ir_var_in,
+ consumer);
+ }
+ }
+
+ unsigned varying_vectors = 0;
+
+ if (consumer) {
+ foreach_list(node, consumer->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != ir_var_in))
+ continue;
+
+ if (var->is_unmatched_generic_inout) {
+ if (prog->Version <= 120) {
+ /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
+ *
+ * Only those varying variables used (i.e. read) in
+ * the fragment shader executable must be written to
+ * by the vertex shader executable; declaring
+ * superfluous varying variables in a vertex shader is
+ * permissible.
+ *
+ * We interpret this text as meaning that the VS must
+ * write the variable for the FS to read it. See
+ * "glsl1-varying read but not written" in piglit.
+ */
+
+ linker_error(prog, "fragment shader varying %s not written "
+ "by vertex shader\n.", var->name);
+ }
+
+ /* An 'in' variable is only really a shader input if its
+ * value is written by the previous stage.
+ */
+ var->mode = ir_var_auto;
+ } else if (is_varying_var(consumer->Type, var)) {
+ /* The packing rules are used for vertex shader inputs are also
+ * used for fragment shader inputs.
+ */
+ varying_vectors += count_attribute_slots(var->type);
+ }
+ }
+ }
+
+ if (ctx->API == API_OPENGLES2 || prog->IsES) {
+ if (varying_vectors > ctx->Const.MaxVarying) {
+ if (ctx->Const.GLSLSkipStrictMaxVaryingLimitCheck) {
+ linker_warning(prog, "shader uses too many varying vectors "
+ "(%u > %u), but the driver will try to optimize "
+ "them out; this is non-portable out-of-spec "
+ "behavior\n",
+ varying_vectors, ctx->Const.MaxVarying);
+ } else {
+ linker_error(prog, "shader uses too many varying vectors "
+ "(%u > %u)\n",
+ varying_vectors, ctx->Const.MaxVarying);
+ return false;
+ }
+ }
+ } else {
+ const unsigned float_components = varying_vectors * 4;
+ if (float_components > ctx->Const.MaxVarying * 4) {
+ if (ctx->Const.GLSLSkipStrictMaxVaryingLimitCheck) {
+ linker_warning(prog, "shader uses too many varying components "
+ "(%u > %u), but the driver will try to optimize "
+ "them out; this is non-portable out-of-spec "
+ "behavior\n",
+ float_components, ctx->Const.MaxVarying * 4);
+ } else {
+ linker_error(prog, "shader uses too many varying components "
+ "(%u > %u)\n",
+ float_components, ctx->Const.MaxVarying * 4);
+ return false;
+ }
+ }
+ }
+
+ return true;
+}
diff --git a/src/glsl/link_varyings.h b/src/glsl/link_varyings.h
new file mode 100644
index 0000000..057e4b2
--- /dev/null
+++ b/src/glsl/link_varyings.h
@@ -0,0 +1,186 @@
+/*
+ * 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.
+ */
+
+#pragma once
+#ifndef GLSL_LINK_VARYINGS_H
+#define GLSL_LINK_VARYINGS_H
+
+/**
+ * \file link_varyings.h
+ *
+ * Linker functions related specifically to linking varyings between shader
+ * stages.
+ */
+
+
+#include "main/glheader.h"
+
+
+struct gl_shader_program;
+struct gl_shader;
+class ir_variable;
+
+
+/**
+ * Data structure tracking information about a transform feedback declaration
+ * during linking.
+ */
+class tfeedback_decl
+{
+public:
+ bool init(struct gl_context *ctx, struct gl_shader_program *prog,
+ const void *mem_ctx, const char *input);
+ static bool is_same(const tfeedback_decl &x, const tfeedback_decl &y);
+ bool assign_location(struct gl_context *ctx, struct gl_shader_program *prog,
+ ir_variable *output_var);
+ unsigned get_num_outputs() const;
+ bool store(struct gl_context *ctx, struct gl_shader_program *prog,
+ struct gl_transform_feedback_info *info, unsigned buffer,
+ const unsigned max_outputs) const;
+ ir_variable *find_output_var(gl_shader_program *prog,
+ gl_shader *producer) const;
+
+ bool is_next_buffer_separator() const
+ {
+ return this->next_buffer_separator;
+ }
+
+ bool is_varying() const
+ {
+ return !this->next_buffer_separator && !this->skip_components;
+ }
+
+ /**
+ * The total number of varying components taken up by this variable. Only
+ * valid if assign_location() has been called.
+ */
+ unsigned num_components() const
+ {
+ if (this->is_clip_distance_mesa)
+ return this->size;
+ else
+ return this->vector_elements * this->matrix_columns * this->size;
+ }
+
+private:
+ /**
+ * The name that was supplied to glTransformFeedbackVaryings. Used for
+ * error reporting and glGetTransformFeedbackVarying().
+ */
+ const char *orig_name;
+
+ /**
+ * The name of the variable, parsed from orig_name.
+ */
+ const char *var_name;
+
+ /**
+ * True if the declaration in orig_name represents an array.
+ */
+ bool is_subscripted;
+
+ /**
+ * If is_subscripted is true, the subscript that was specified in orig_name.
+ */
+ unsigned array_subscript;
+
+ /**
+ * True if the variable is gl_ClipDistance and the driver lowers
+ * gl_ClipDistance to gl_ClipDistanceMESA.
+ */
+ bool is_clip_distance_mesa;
+
+ /**
+ * The vertex shader output location that the linker assigned for this
+ * variable. -1 if a location hasn't been assigned yet.
+ */
+ int location;
+
+ /**
+ * If non-zero, then this variable may be packed along with other variables
+ * into a single varying slot, so this offset should be applied when
+ * accessing components. For example, an offset of 1 means that the x
+ * component of this variable is actually stored in component y of the
+ * location specified by \c location.
+ *
+ * Only valid if location != -1.
+ */
+ unsigned location_frac;
+
+ /**
+ * If location != -1, the number of vector elements in this variable, or 1
+ * if this variable is a scalar.
+ */
+ unsigned vector_elements;
+
+ /**
+ * If location != -1, the number of matrix columns in this variable, or 1
+ * if this variable is not a matrix.
+ */
+ unsigned matrix_columns;
+
+ /** Type of the varying returned by glGetTransformFeedbackVarying() */
+ GLenum type;
+
+ /**
+ * If location != -1, the size that should be returned by
+ * glGetTransformFeedbackVarying().
+ */
+ unsigned size;
+
+ /**
+ * How many components to skip. If non-zero, this is
+ * gl_SkipComponents{1,2,3,4} from ARB_transform_feedback3.
+ */
+ unsigned skip_components;
+
+ /**
+ * Whether this is gl_NextBuffer from ARB_transform_feedback3.
+ */
+ bool next_buffer_separator;
+};
+
+
+bool
+cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
+ gl_shader *producer, gl_shader *consumer);
+
+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);
+
+bool
+store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog,
+ unsigned num_tfeedback_decls,
+ tfeedback_decl *tfeedback_decls);
+
+bool
+assign_varying_locations(struct gl_context *ctx,
+ void *mem_ctx,
+ struct gl_shader_program *prog,
+ gl_shader *producer, gl_shader *consumer,
+ unsigned num_tfeedback_decls,
+ tfeedback_decl *tfeedback_decls);
+
+#endif /* GLSL_LINK_VARYINGS_H */
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index c5c462b..70f3d5b 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -70,6 +70,7 @@
#include "program.h"
#include "program/hash_table.h"
#include "linker.h"
+#include "link_varyings.h"
#include "ir_optimization.h"
extern "C" {
@@ -649,126 +650,6 @@ interstage_cross_validate_uniform_blocks(struct gl_shader_program *prog)
return true;
}
-/**
- * Validate that outputs from one stage match inputs of another
- */
-bool
-cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
- gl_shader *producer, gl_shader *consumer)
-{
- glsl_symbol_table parameters;
- /* FINISHME: Figure these out dynamically. */
- const char *const producer_stage = "vertex";
- const char *const consumer_stage = "fragment";
-
- /* Find all shader outputs in the "producer" stage.
- */
- foreach_list(node, producer->ir) {
- ir_variable *const var = ((ir_instruction *) node)->as_variable();
-
- /* FINISHME: For geometry shaders, this should also look for inout
- * FINISHME: variables.
- */
- if ((var == NULL) || (var->mode != ir_var_out))
- continue;
-
- parameters.add_variable(var);
- }
-
-
- /* Find all shader inputs in the "consumer" stage. Any variables that have
- * matching outputs already in the symbol table must have the same type and
- * qualifiers.
- */
- foreach_list(node, consumer->ir) {
- ir_variable *const input = ((ir_instruction *) node)->as_variable();
-
- /* FINISHME: For geometry shaders, this should also look for inout
- * FINISHME: variables.
- */
- if ((input == NULL) || (input->mode != ir_var_in))
- continue;
-
- ir_variable *const output = parameters.get_variable(input->name);
- if (output != NULL) {
- /* Check that the types match between stages.
- */
- if (input->type != output->type) {
- /* There is a bit of a special case for gl_TexCoord. This
- * built-in is unsized by default. Applications that variable
- * access it must redeclare it with a size. There is some
- * language in the GLSL spec that implies the fragment shader
- * and vertex shader do not have to agree on this size. Other
- * driver behave this way, and one or two applications seem to
- * rely on it.
- *
- * Neither declaration needs to be modified here because the array
- * sizes are fixed later when update_array_sizes is called.
- *
- * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec:
- *
- * "Unlike user-defined varying variables, the built-in
- * varying variables don't have a strict one-to-one
- * correspondence between the vertex language and the
- * fragment language."
- */
- if (!output->type->is_array()
- || (strncmp("gl_", output->name, 3) != 0)) {
- linker_error(prog,
- "%s shader output `%s' declared as type `%s', "
- "but %s shader input declared as type `%s'\n",
- producer_stage, output->name,
- output->type->name,
- consumer_stage, input->type->name);
- return false;
- }
- }
-
- /* Check that all of the qualifiers match between stages.
- */
- if (input->centroid != output->centroid) {
- linker_error(prog,
- "%s shader output `%s' %s centroid qualifier, "
- "but %s shader input %s centroid qualifier\n",
- producer_stage,
- output->name,
- (output->centroid) ? "has" : "lacks",
- consumer_stage,
- (input->centroid) ? "has" : "lacks");
- return false;
- }
-
- if (input->invariant != output->invariant) {
- linker_error(prog,
- "%s shader output `%s' %s invariant qualifier, "
- "but %s shader input %s invariant qualifier\n",
- producer_stage,
- output->name,
- (output->invariant) ? "has" : "lacks",
- consumer_stage,
- (input->invariant) ? "has" : "lacks");
- return false;
- }
-
- if (input->interpolation != output->interpolation) {
- linker_error(prog,
- "%s shader output `%s' specifies %s "
- "interpolation qualifier, "
- "but %s shader input specifies %s "
- "interpolation qualifier\n",
- producer_stage,
- output->name,
- output->interpolation_string(),
- consumer_stage,
- input->interpolation_string());
- return false;
- }
- }
- }
-
- return true;
-}
-
/**
* Populates a shaders symbol table with all global declarations
@@ -1526,1010 +1407,6 @@ demote_shader_inputs_and_outputs(gl_shader *sh, enum ir_variable_mode mode)
/**
- * Data structure tracking information about a transform feedback declaration
- * during linking.
- */
-class tfeedback_decl
-{
-public:
- bool init(struct gl_context *ctx, struct gl_shader_program *prog,
- const void *mem_ctx, const char *input);
- static bool is_same(const tfeedback_decl &x, const tfeedback_decl &y);
- bool assign_location(struct gl_context *ctx, struct gl_shader_program *prog,
- ir_variable *output_var);
- unsigned get_num_outputs() const;
- bool store(struct gl_context *ctx, struct gl_shader_program *prog,
- struct gl_transform_feedback_info *info, unsigned buffer,
- const unsigned max_outputs) const;
- ir_variable *find_output_var(gl_shader_program *prog,
- gl_shader *producer) const;
-
- bool is_next_buffer_separator() const
- {
- return this->next_buffer_separator;
- }
-
- bool is_varying() const
- {
- return !this->next_buffer_separator && !this->skip_components;
- }
-
- /**
- * The total number of varying components taken up by this variable. Only
- * valid if assign_location() has been called.
- */
- unsigned num_components() const
- {
- if (this->is_clip_distance_mesa)
- return this->size;
- else
- return this->vector_elements * this->matrix_columns * this->size;
- }
-
-private:
- /**
- * The name that was supplied to glTransformFeedbackVaryings. Used for
- * error reporting and glGetTransformFeedbackVarying().
- */
- const char *orig_name;
-
- /**
- * The name of the variable, parsed from orig_name.
- */
- const char *var_name;
-
- /**
- * True if the declaration in orig_name represents an array.
- */
- bool is_subscripted;
-
- /**
- * If is_subscripted is true, the subscript that was specified in orig_name.
- */
- unsigned array_subscript;
-
- /**
- * True if the variable is gl_ClipDistance and the driver lowers
- * gl_ClipDistance to gl_ClipDistanceMESA.
- */
- bool is_clip_distance_mesa;
-
- /**
- * The vertex shader output location that the linker assigned for this
- * variable. -1 if a location hasn't been assigned yet.
- */
- int location;
-
- /**
- * If non-zero, then this variable may be packed along with other variables
- * into a single varying slot, so this offset should be applied when
- * accessing components. For example, an offset of 1 means that the x
- * component of this variable is actually stored in component y of the
- * location specified by \c location.
- *
- * Only valid if location != -1.
- */
- unsigned location_frac;
-
- /**
- * If location != -1, the number of vector elements in this variable, or 1
- * if this variable is a scalar.
- */
- unsigned vector_elements;
-
- /**
- * If location != -1, the number of matrix columns in this variable, or 1
- * if this variable is not a matrix.
- */
- unsigned matrix_columns;
-
- /** Type of the varying returned by glGetTransformFeedbackVarying() */
- GLenum type;
-
- /**
- * If location != -1, the size that should be returned by
- * glGetTransformFeedbackVarying().
- */
- unsigned size;
-
- /**
- * How many components to skip. If non-zero, this is
- * gl_SkipComponents{1,2,3,4} from ARB_transform_feedback3.
- */
- unsigned skip_components;
-
- /**
- * Whether this is gl_NextBuffer from ARB_transform_feedback3.
- */
- bool next_buffer_separator;
-};
-
-
-/**
- * Initialize this object based on a string that was passed to
- * glTransformFeedbackVaryings. If there is a parse error, the error is
- * reported using linker_error(), and false is returned.
- */
-bool
-tfeedback_decl::init(struct gl_context *ctx, struct gl_shader_program *prog,
- const void *mem_ctx, const char *input)
-{
- /* We don't have to be pedantic about what is a valid GLSL variable name,
- * because any variable with an invalid name can't exist in the IR anyway.
- */
-
- this->location = -1;
- this->orig_name = input;
- this->is_clip_distance_mesa = false;
- this->skip_components = 0;
- this->next_buffer_separator = false;
-
- if (ctx->Extensions.ARB_transform_feedback3) {
- /* Parse gl_NextBuffer. */
- if (strcmp(input, "gl_NextBuffer") == 0) {
- this->next_buffer_separator = true;
- return true;
- }
-
- /* 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 true;
- }
-
- /* Parse a declaration. */
- const char *bracket = strrchr(input, '[');
-
- if (bracket) {
- this->var_name = ralloc_strndup(mem_ctx, input, bracket - input);
- if (sscanf(bracket, "[%u]", &this->array_subscript) != 1) {
- linker_error(prog, "Cannot parse transform feedback varying %s", input);
- return false;
- }
- this->is_subscripted = true;
- } else {
- this->var_name = ralloc_strdup(mem_ctx, input);
- this->is_subscripted = false;
- }
-
- /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this
- * class must behave specially to account for the fact that gl_ClipDistance
- * is converted from a float[8] to a vec4[2].
- */
- if (ctx->ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerClipDistance &&
- strcmp(this->var_name, "gl_ClipDistance") == 0) {
- this->is_clip_distance_mesa = true;
- }
-
- return true;
-}
-
-
-/**
- * Determine whether two tfeedback_decl objects refer to the same variable and
- * array index (if applicable).
- */
-bool
-tfeedback_decl::is_same(const tfeedback_decl &x, const tfeedback_decl &y)
-{
- assert(x.is_varying() && y.is_varying());
-
- if (strcmp(x.var_name, y.var_name) != 0)
- return false;
- if (x.is_subscripted != y.is_subscripted)
- return false;
- if (x.is_subscripted && x.array_subscript != y.array_subscript)
- return false;
- return true;
-}
-
-
-/**
- * Assign a location for this tfeedback_decl object based on the location
- * assignment in output_var.
- *
- * 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,
- ir_variable *output_var)
-{
- assert(this->is_varying());
-
- if (output_var->type->is_array()) {
- /* Array variable */
- const unsigned matrix_cols =
- output_var->type->fields.array->matrix_columns;
- const unsigned vector_elements =
- output_var->type->fields.array->vector_elements;
- unsigned actual_array_size = this->is_clip_distance_mesa ?
- prog->Vert.ClipDistanceArraySize : output_var->type->array_size();
-
- if (this->is_subscripted) {
- /* Check array bounds. */
- if (this->array_subscript >= actual_array_size) {
- linker_error(prog, "Transform feedback varying %s has index "
- "%i, but the array size is %u.",
- this->orig_name, this->array_subscript,
- actual_array_size);
- return false;
- }
- if (this->is_clip_distance_mesa) {
- this->location =
- output_var->location + this->array_subscript / 4;
- this->location_frac = this->array_subscript % 4;
- } else {
- unsigned fine_location
- = output_var->location * 4 + output_var->location_frac;
- unsigned array_elem_size = vector_elements * matrix_cols;
- fine_location += array_elem_size * this->array_subscript;
- this->location = fine_location / 4;
- this->location_frac = fine_location % 4;
- }
- this->size = 1;
- } else {
- this->location = output_var->location;
- this->location_frac = output_var->location_frac;
- this->size = actual_array_size;
- }
- this->vector_elements = vector_elements;
- this->matrix_columns = matrix_cols;
- if (this->is_clip_distance_mesa)
- this->type = GL_FLOAT;
- else
- this->type = output_var->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->location = output_var->location;
- this->location_frac = output_var->location_frac;
- this->size = 1;
- this->vector_elements = output_var->type->vector_elements;
- this->matrix_columns = output_var->type->matrix_columns;
- this->type = output_var->type->gl_type;
- }
-
- /* From GL_EXT_transform_feedback:
- * A program will fail to link if:
- *
- * * the total number of components to capture in any varying
- * variable in <varyings> is greater than the constant
- * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the
- * buffer mode is SEPARATE_ATTRIBS_EXT;
- */
- if (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS &&
- this->num_components() >
- ctx->Const.MaxTransformFeedbackSeparateComponents) {
- linker_error(prog, "Transform feedback varying %s exceeds "
- "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.",
- this->orig_name);
- return false;
- }
-
- return true;
-}
-
-
-unsigned
-tfeedback_decl::get_num_outputs() const
-{
- if (!this->is_varying()) {
- return 0;
- }
-
- return (this->num_components() + this->location_frac + 3)/4;
-}
-
-
-/**
- * Update gl_transform_feedback_info to reflect this tfeedback_decl.
- *
- * If an error occurs, the error is reported through linker_error() and false
- * is returned.
- */
-bool
-tfeedback_decl::store(struct gl_context *ctx, struct gl_shader_program *prog,
- struct gl_transform_feedback_info *info,
- unsigned buffer, const unsigned max_outputs) const
-{
- assert(!this->next_buffer_separator);
-
- /* Handle gl_SkipComponents. */
- if (this->skip_components) {
- info->BufferStride[buffer] += this->skip_components;
- return true;
- }
-
- /* From GL_EXT_transform_feedback:
- * A program will fail to link if:
- *
- * * the total number of components to capture is greater than
- * the constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT
- * and the buffer mode is INTERLEAVED_ATTRIBS_EXT.
- */
- if (prog->TransformFeedback.BufferMode == GL_INTERLEAVED_ATTRIBS &&
- info->BufferStride[buffer] + this->num_components() >
- ctx->Const.MaxTransformFeedbackInterleavedComponents) {
- linker_error(prog, "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS "
- "limit has been exceeded.");
- return false;
- }
-
- unsigned location = this->location;
- unsigned location_frac = this->location_frac;
- unsigned num_components = this->num_components();
- while (num_components > 0) {
- unsigned output_size = MIN2(num_components, 4 - location_frac);
- assert(info->NumOutputs < max_outputs);
- info->Outputs[info->NumOutputs].ComponentOffset = location_frac;
- info->Outputs[info->NumOutputs].OutputRegister = location;
- info->Outputs[info->NumOutputs].NumComponents = output_size;
- info->Outputs[info->NumOutputs].OutputBuffer = buffer;
- info->Outputs[info->NumOutputs].DstOffset = info->BufferStride[buffer];
- ++info->NumOutputs;
- info->BufferStride[buffer] += output_size;
- num_components -= output_size;
- location++;
- location_frac = 0;
- }
-
- info->Varyings[info->NumVarying].Name = ralloc_strdup(prog, this->orig_name);
- info->Varyings[info->NumVarying].Type = this->type;
- info->Varyings[info->NumVarying].Size = this->size;
- info->NumVarying++;
-
- return true;
-}
-
-
-ir_variable *
-tfeedback_decl::find_output_var(gl_shader_program *prog,
- gl_shader *producer) const
-{
- const char *name = this->is_clip_distance_mesa
- ? "gl_ClipDistanceMESA" : this->var_name;
- ir_variable *var = producer->symbols->get_variable(name);
- if (var && var->mode == ir_var_out)
- return var;
-
- /* 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 NULL;
-}
-
-
-/**
- * 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) {
- if (!decls[i].init(ctx, prog, mem_ctx, varying_names[i]))
- return false;
-
- if (!decls[i].is_varying())
- continue;
-
- /* From GL_EXT_transform_feedback:
- * A program will fail to link if:
- *
- * * any two entries in the <varyings> array specify the same varying
- * variable;
- *
- * We interpret this to mean "any two entries in the <varyings> array
- * specify the same varying variable and array index", since transform
- * feedback of arrays would be useless otherwise.
- */
- for (unsigned j = 0; j < i; ++j) {
- if (!decls[j].is_varying())
- continue;
-
- if (tfeedback_decl::is_same(decls[i], decls[j])) {
- linker_error(prog, "Transform feedback varying %s specified "
- "more than once.", varying_names[i]);
- return false;
- }
- }
- }
- return true;
-}
-
-
-/**
- * Data structure recording the relationship between outputs of one shader
- * stage (the "producer") and inputs of another (the "consumer").
- */
-class varying_matches
-{
-public:
- varying_matches(bool disable_varying_packing);
- ~varying_matches();
- void record(ir_variable *producer_var, ir_variable *consumer_var);
- unsigned assign_locations();
- void store_locations(unsigned producer_base, unsigned consumer_base) const;
-
-private:
- /**
- * If true, this driver disables varying packing, so all varyings need to
- * be aligned on slot boundaries, and take up a number of slots equal to
- * their number of matrix columns times their array size.
- */
- const bool disable_varying_packing;
-
- /**
- * Enum representing the order in which varyings are packed within a
- * packing class.
- *
- * Currently we pack vec4's first, then vec2's, then scalar values, then
- * vec3's. This order ensures that the only vectors that are at risk of
- * having to be "double parked" (split between two adjacent varying slots)
- * are the vec3's.
- */
- enum packing_order_enum {
- PACKING_ORDER_VEC4,
- PACKING_ORDER_VEC2,
- PACKING_ORDER_SCALAR,
- PACKING_ORDER_VEC3,
- };
-
- static unsigned compute_packing_class(ir_variable *var);
- static packing_order_enum compute_packing_order(ir_variable *var);
- static int match_comparator(const void *x_generic, const void *y_generic);
-
- /**
- * Structure recording the relationship between a single producer output
- * and a single consumer input.
- */
- struct match {
- /**
- * Packing class for this varying, computed by compute_packing_class().
- */
- unsigned packing_class;
-
- /**
- * Packing order for this varying, computed by compute_packing_order().
- */
- packing_order_enum packing_order;
- unsigned num_components;
-
- /**
- * The output variable in the producer stage.
- */
- ir_variable *producer_var;
-
- /**
- * The input variable in the consumer stage.
- */
- ir_variable *consumer_var;
-
- /**
- * The location which has been assigned for this varying. This is
- * expressed in multiples of a float, with the first generic varying
- * (i.e. the one referred to by VERT_RESULT_VAR0 or FRAG_ATTRIB_VAR0)
- * represented by the value 0.
- */
- unsigned generic_location;
- } *matches;
-
- /**
- * The number of elements in the \c matches array that are currently in
- * use.
- */
- unsigned num_matches;
-
- /**
- * The number of elements that were set aside for the \c matches array when
- * it was allocated.
- */
- unsigned matches_capacity;
-};
-
-
-varying_matches::varying_matches(bool disable_varying_packing)
- : disable_varying_packing(disable_varying_packing)
-{
- /* Note: this initial capacity is rather arbitrarily chosen to be large
- * enough for many cases without wasting an unreasonable amount of space.
- * varying_matches::record() will resize the array if there are more than
- * this number of varyings.
- */
- this->matches_capacity = 8;
- this->matches = (match *)
- malloc(sizeof(*this->matches) * this->matches_capacity);
- this->num_matches = 0;
-}
-
-
-varying_matches::~varying_matches()
-{
- free(this->matches);
-}
-
-
-/**
- * Record the given producer/consumer variable pair in the list of variables
- * that should later be assigned locations.
- *
- * It is permissible for \c consumer_var to be NULL (this happens if a
- * variable is output by the producer and consumed by transform feedback, but
- * not consumed by the consumer).
- *
- * If \c producer_var has already been paired up with a consumer_var, or
- * producer_var is part of fixed pipeline functionality (and hence already has
- * a location assigned), this function has no effect.
- */
-void
-varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
-{
- if (!producer_var->is_unmatched_generic_inout) {
- /* Either a location already exists for this variable (since it is part
- * of fixed functionality), or it has already been recorded as part of a
- * previous match.
- */
- return;
- }
-
- if (this->num_matches == this->matches_capacity) {
- this->matches_capacity *= 2;
- this->matches = (match *)
- realloc(this->matches,
- sizeof(*this->matches) * this->matches_capacity);
- }
- this->matches[this->num_matches].packing_class
- = this->compute_packing_class(producer_var);
- this->matches[this->num_matches].packing_order
- = this->compute_packing_order(producer_var);
- if (this->disable_varying_packing) {
- unsigned slots = producer_var->type->is_array()
- ? (producer_var->type->length
- * producer_var->type->fields.array->matrix_columns)
- : producer_var->type->matrix_columns;
- this->matches[this->num_matches].num_components = 4 * slots;
- } else {
- this->matches[this->num_matches].num_components
- = producer_var->type->component_slots();
- }
- this->matches[this->num_matches].producer_var = producer_var;
- this->matches[this->num_matches].consumer_var = consumer_var;
- this->num_matches++;
- producer_var->is_unmatched_generic_inout = 0;
- if (consumer_var)
- consumer_var->is_unmatched_generic_inout = 0;
-}
-
-
-/**
- * Choose locations for all of the variable matches that were previously
- * passed to varying_matches::record().
- */
-unsigned
-varying_matches::assign_locations()
-{
- /* Sort varying matches into an order that makes them easy to pack. */
- qsort(this->matches, this->num_matches, sizeof(*this->matches),
- &varying_matches::match_comparator);
-
- unsigned generic_location = 0;
-
- for (unsigned i = 0; i < this->num_matches; i++) {
- /* Advance to the next slot if this varying has a different packing
- * class than the previous one, and we're not already on a slot
- * boundary.
- */
- if (i > 0 &&
- this->matches[i - 1].packing_class
- != this->matches[i].packing_class) {
- generic_location = ALIGN(generic_location, 4);
- }
-
- this->matches[i].generic_location = generic_location;
-
- generic_location += this->matches[i].num_components;
- }
-
- return (generic_location + 3) / 4;
-}
-
-
-/**
- * Update the producer and consumer shaders to reflect the locations
- * assignments that were made by varying_matches::assign_locations().
- */
-void
-varying_matches::store_locations(unsigned producer_base,
- unsigned consumer_base) const
-{
- for (unsigned i = 0; i < this->num_matches; i++) {
- ir_variable *producer_var = this->matches[i].producer_var;
- ir_variable *consumer_var = this->matches[i].consumer_var;
- unsigned generic_location = this->matches[i].generic_location;
- unsigned slot = generic_location / 4;
- unsigned offset = generic_location % 4;
-
- producer_var->location = producer_base + slot;
- producer_var->location_frac = offset;
- if (consumer_var) {
- assert(consumer_var->location == -1);
- consumer_var->location = consumer_base + slot;
- consumer_var->location_frac = offset;
- }
- }
-}
-
-
-/**
- * Compute the "packing class" of the given varying. This is an unsigned
- * integer with the property that two variables in the same packing class can
- * be safely backed into the same vec4.
- */
-unsigned
-varying_matches::compute_packing_class(ir_variable *var)
-{
- /* In this initial implementation we conservatively assume that variables
- * can only be packed if their base type (float/int/uint/bool) matches and
- * their interpolation and centroid qualifiers match.
- *
- * TODO: relax these restrictions when the driver back-end permits.
- */
- unsigned packing_class = var->centroid ? 1 : 0;
- packing_class *= 4;
- packing_class += var->interpolation;
- packing_class *= GLSL_TYPE_ERROR;
- packing_class += var->type->get_scalar_type()->base_type;
- return packing_class;
-}
-
-
-/**
- * Compute the "packing order" of the given varying. This is a sort key we
- * use to determine when to attempt to pack the given varying relative to
- * other varyings in the same packing class.
- */
-varying_matches::packing_order_enum
-varying_matches::compute_packing_order(ir_variable *var)
-{
- const glsl_type *element_type = var->type;
-
- /* FINISHME: Support for "varying" records in GLSL 1.50. */
- while (element_type->base_type == GLSL_TYPE_ARRAY) {
- element_type = element_type->fields.array;
- }
-
- switch (element_type->vector_elements) {
- case 1: return PACKING_ORDER_SCALAR;
- case 2: return PACKING_ORDER_VEC2;
- case 3: return PACKING_ORDER_VEC3;
- case 4: return PACKING_ORDER_VEC4;
- default:
- assert(!"Unexpected value of vector_elements");
- return PACKING_ORDER_VEC4;
- }
-}
-
-
-/**
- * Comparison function passed to qsort() to sort varyings by packing_class and
- * then by packing_order.
- */
-int
-varying_matches::match_comparator(const void *x_generic, const void *y_generic)
-{
- const match *x = (const match *) x_generic;
- const match *y = (const match *) y_generic;
-
- if (x->packing_class != y->packing_class)
- return x->packing_class - y->packing_class;
- return x->packing_order - y->packing_order;
-}
-
-
-/**
- * Is the given variable a varying variable to be counted against the
- * limit in ctx->Const.MaxVarying?
- * This includes variables such as texcoords, colors and generic
- * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord.
- */
-static bool
-is_varying_var(GLenum shaderType, const ir_variable *var)
-{
- /* Only fragment shaders will take a varying variable as an input */
- if (shaderType == GL_FRAGMENT_SHADER &&
- var->mode == ir_var_in) {
- switch (var->location) {
- case FRAG_ATTRIB_WPOS:
- case FRAG_ATTRIB_FACE:
- case FRAG_ATTRIB_PNTC:
- return false;
- default:
- return true;
- }
- }
- return false;
-}
-
-
-/**
- * Assign locations for all variables that are produced in one pipeline stage
- * (the "producer") and consumed in the next stage (the "consumer").
- *
- * Variables produced by the producer may also be consumed by transform
- * feedback.
- *
- * \param num_tfeedback_decls is the number of declarations indicating
- * variables that may be consumed by transform feedback.
- *
- * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects
- * representing the result of parsing the strings passed to
- * glTransformFeedbackVaryings(). assign_location() will be called for
- * each of these objects that matches one of the outputs of the
- * producer.
- *
- * When num_tfeedback_decls is nonzero, it is permissible for the consumer to
- * be NULL. In this case, varying locations are assigned solely based on the
- * requirements of transform feedback.
- */
-bool
-assign_varying_locations(struct gl_context *ctx,
- void *mem_ctx,
- struct gl_shader_program *prog,
- gl_shader *producer, gl_shader *consumer,
- unsigned num_tfeedback_decls,
- tfeedback_decl *tfeedback_decls)
-{
- /* FINISHME: Set dynamically when geometry shader support is added. */
- const unsigned producer_base = VERT_RESULT_VAR0;
- const unsigned consumer_base = FRAG_ATTRIB_VAR0;
- varying_matches matches(ctx->Const.DisableVaryingPacking);
-
- /* Operate in a total of three passes.
- *
- * 1. Assign locations for any matching inputs and outputs.
- *
- * 2. Mark output variables in the producer that do not have locations as
- * not being outputs. This lets the optimizer eliminate them.
- *
- * 3. Mark input variables in the consumer that do not have locations as
- * not being inputs. This lets the optimizer eliminate them.
- */
-
- foreach_list(node, producer->ir) {
- ir_variable *const output_var = ((ir_instruction *) node)->as_variable();
-
- if ((output_var == NULL) || (output_var->mode != ir_var_out))
- continue;
-
- ir_variable *input_var =
- consumer ? consumer->symbols->get_variable(output_var->name) : NULL;
-
- if (input_var && input_var->mode != ir_var_in)
- input_var = NULL;
-
- if (input_var) {
- matches.record(output_var, input_var);
- }
- }
-
- for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
- if (!tfeedback_decls[i].is_varying())
- continue;
-
- ir_variable *output_var
- = tfeedback_decls[i].find_output_var(prog, producer);
-
- if (output_var == NULL)
- return false;
-
- if (output_var->is_unmatched_generic_inout) {
- matches.record(output_var, NULL);
- }
- }
-
- const unsigned slots_used = matches.assign_locations();
- matches.store_locations(producer_base, consumer_base);
-
- for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
- if (!tfeedback_decls[i].is_varying())
- continue;
-
- ir_variable *output_var
- = tfeedback_decls[i].find_output_var(prog, producer);
-
- if (!tfeedback_decls[i].assign_location(ctx, prog, output_var))
- return false;
- }
-
- if (ctx->Const.DisableVaryingPacking) {
- /* Transform feedback code assumes varyings are packed, so if the driver
- * has disabled varying packing, make sure it does not support transform
- * feedback.
- */
- assert(!ctx->Extensions.EXT_transform_feedback);
- } else {
- lower_packed_varyings(mem_ctx, producer_base, slots_used, ir_var_out,
- producer);
- if (consumer) {
- lower_packed_varyings(mem_ctx, consumer_base, slots_used, ir_var_in,
- consumer);
- }
- }
-
- unsigned varying_vectors = 0;
-
- if (consumer) {
- foreach_list(node, consumer->ir) {
- ir_variable *const var = ((ir_instruction *) node)->as_variable();
-
- if ((var == NULL) || (var->mode != ir_var_in))
- continue;
-
- if (var->is_unmatched_generic_inout) {
- if (prog->Version <= 120) {
- /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
- *
- * Only those varying variables used (i.e. read) in
- * the fragment shader executable must be written to
- * by the vertex shader executable; declaring
- * superfluous varying variables in a vertex shader is
- * permissible.
- *
- * We interpret this text as meaning that the VS must
- * write the variable for the FS to read it. See
- * "glsl1-varying read but not written" in piglit.
- */
-
- linker_error(prog, "fragment shader varying %s not written "
- "by vertex shader\n.", var->name);
- }
-
- /* An 'in' variable is only really a shader input if its
- * value is written by the previous stage.
- */
- var->mode = ir_var_auto;
- } else if (is_varying_var(consumer->Type, var)) {
- /* The packing rules are used for vertex shader inputs are also
- * used for fragment shader inputs.
- */
- varying_vectors += count_attribute_slots(var->type);
- }
- }
- }
-
- if (ctx->API == API_OPENGLES2 || prog->IsES) {
- if (varying_vectors > ctx->Const.MaxVarying) {
- if (ctx->Const.GLSLSkipStrictMaxVaryingLimitCheck) {
- linker_warning(prog, "shader uses too many varying vectors "
- "(%u > %u), but the driver will try to optimize "
- "them out; this is non-portable out-of-spec "
- "behavior\n",
- varying_vectors, ctx->Const.MaxVarying);
- } else {
- linker_error(prog, "shader uses too many varying vectors "
- "(%u > %u)\n",
- varying_vectors, ctx->Const.MaxVarying);
- return false;
- }
- }
- } else {
- const unsigned float_components = varying_vectors * 4;
- if (float_components > ctx->Const.MaxVarying * 4) {
- if (ctx->Const.GLSLSkipStrictMaxVaryingLimitCheck) {
- linker_warning(prog, "shader uses too many varying components "
- "(%u > %u), but the driver will try to optimize "
- "them out; this is non-portable out-of-spec "
- "behavior\n",
- float_components, ctx->Const.MaxVarying * 4);
- } else {
- linker_error(prog, "shader uses too many varying components "
- "(%u > %u)\n",
- float_components, ctx->Const.MaxVarying * 4);
- return false;
- }
- }
- }
-
- return true;
-}
-
-
-/**
- * Store transform feedback location assignments into
- * prog->LinkedTransformFeedback based on the data stored in tfeedback_decls.
- *
- * If an error occurs, the error is reported through linker_error() and false
- * is returned.
- */
-static bool
-store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog,
- unsigned num_tfeedback_decls,
- tfeedback_decl *tfeedback_decls)
-{
- bool separate_attribs_mode =
- prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS;
-
- ralloc_free(prog->LinkedTransformFeedback.Varyings);
- ralloc_free(prog->LinkedTransformFeedback.Outputs);
-
- memset(&prog->LinkedTransformFeedback, 0,
- sizeof(prog->LinkedTransformFeedback));
-
- prog->LinkedTransformFeedback.Varyings =
- rzalloc_array(prog,
- struct gl_transform_feedback_varying_info,
- num_tfeedback_decls);
-
- unsigned num_outputs = 0;
- for (unsigned i = 0; i < num_tfeedback_decls; ++i)
- num_outputs += tfeedback_decls[i].get_num_outputs();
-
- prog->LinkedTransformFeedback.Outputs =
- rzalloc_array(prog,
- struct gl_transform_feedback_output,
- num_outputs);
-
- unsigned num_buffers = 0;
-
- if (separate_attribs_mode) {
- /* GL_SEPARATE_ATTRIBS */
- for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
- if (!tfeedback_decls[i].store(ctx, prog, &prog->LinkedTransformFeedback,
- num_buffers, num_outputs))
- return false;
-
- num_buffers++;
- }
- }
- else {
- /* GL_INVERLEAVED_ATTRIBS */
- for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
- if (tfeedback_decls[i].is_next_buffer_separator()) {
- num_buffers++;
- continue;
- }
-
- if (!tfeedback_decls[i].store(ctx, prog,
- &prog->LinkedTransformFeedback,
- num_buffers, num_outputs))
- return false;
- }
- num_buffers++;
- }
-
- assert(prog->LinkedTransformFeedback.NumOutputs == num_outputs);
-
- prog->LinkedTransformFeedback.NumBuffers = num_buffers;
- return true;
-}
-
-/**
* Store the gl_FragDepth layout in the gl_shader_program struct.
*/
static void
diff --git a/src/glsl/linker.h b/src/glsl/linker.h
index 7d2e98a..67c7f34 100644
--- a/src/glsl/linker.h
+++ b/src/glsl/linker.h
@@ -91,4 +91,13 @@ private:
void recursion(const glsl_type *t, char **name, size_t name_length);
};
+void
+linker_error(gl_shader_program *prog, const char *fmt, ...);
+
+void
+linker_warning(gl_shader_program *prog, const char *fmt, ...);
+
+unsigned
+count_attribute_slots(const glsl_type *t);
+
#endif /* GLSL_LINKER_H */
--
1.8.0.2
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