* This lowering pass also packs flat floats, ints, and uints together, by
* using ivec4 as the base type of flat "varyings", and using appropriate
* casts to convert floats and uints into ints.
+ *
+ * This lowering pass also handles varyings whose type is a struct or an array
+ * of struct. Structs are packed in order and with no gaps, so there may be a
+ * performance penalty due to structure elements being double-parked.
+ *
+ * Lowering of geometry shader inputs is slightly more complex, since geometry
+ * inputs are always arrays, so we need to lower arrays to arrays. For
+ * example, the following input:
+ *
+ * in struct Foo {
+ * float f;
+ * vec3 v;
+ * vec2 a[2];
+ * } arr[3]; // location=4, location_frac=0
+ *
+ * Would get lowered like this if it occurred in a fragment shader:
+ *
+ * struct Foo {
+ * float f;
+ * vec3 v;
+ * vec2 a[2];
+ * } arr[3];
+ * in vec4 packed4; // location=4, location_frac=0
+ * in vec4 packed5; // location=5, location_frac=0
+ * in vec4 packed6; // location=6, location_frac=0
+ * in vec4 packed7; // location=7, location_frac=0
+ * in vec4 packed8; // location=8, location_frac=0
+ * in vec4 packed9; // location=9, location_frac=0
+ *
+ * main()
+ * {
+ * arr[0].f = packed4.x;
+ * arr[0].v = packed4.yzw;
+ * arr[0].a[0] = packed5.xy;
+ * arr[0].a[1] = packed5.zw;
+ * arr[1].f = packed6.x;
+ * arr[1].v = packed6.yzw;
+ * arr[1].a[0] = packed7.xy;
+ * arr[1].a[1] = packed7.zw;
+ * arr[2].f = packed8.x;
+ * arr[2].v = packed8.yzw;
+ * arr[2].a[0] = packed9.xy;
+ * arr[2].a[1] = packed9.zw;
+ * ...
+ * }
+ *
+ * But it would get lowered like this if it occurred in a geometry shader:
+ *
+ * struct Foo {
+ * float f;
+ * vec3 v;
+ * vec2 a[2];
+ * } arr[3];
+ * in vec4 packed4[3]; // location=4, location_frac=0
+ * in vec4 packed5[3]; // location=5, location_frac=0
+ *
+ * main()
+ * {
+ * arr[0].f = packed4[0].x;
+ * arr[0].v = packed4[0].yzw;
+ * arr[0].a[0] = packed5[0].xy;
+ * arr[0].a[1] = packed5[0].zw;
+ * arr[1].f = packed4[1].x;
+ * arr[1].v = packed4[1].yzw;
+ * arr[1].a[0] = packed5[1].xy;
+ * arr[1].a[1] = packed5[1].zw;
+ * arr[2].f = packed4[2].x;
+ * arr[2].v = packed4[2].yzw;
+ * arr[2].a[0] = packed5[2].xy;
+ * arr[2].a[1] = packed5[2].zw;
+ * ...
+ * }
*/
#include "glsl_symbol_table.h"
#include "ir.h"
#include "ir_optimization.h"
+namespace {
+
/**
* Visitor that performs varying packing. For each varying declared in the
* shader, this visitor determines whether it needs to be packed. If so, it
lower_packed_varyings_visitor(void *mem_ctx, unsigned location_base,
unsigned locations_used,
ir_variable_mode mode,
- exec_list *main_instructions);
+ unsigned gs_input_vertices,
+ exec_list *out_instructions);
void run(exec_list *instructions);
ir_assignment *bitwise_assign_pack(ir_rvalue *lhs, ir_rvalue *rhs);
ir_assignment *bitwise_assign_unpack(ir_rvalue *lhs, ir_rvalue *rhs);
unsigned lower_rvalue(ir_rvalue *rvalue, unsigned fine_location,
- ir_variable *unpacked_var, const char *name);
+ ir_variable *unpacked_var, const char *name,
+ bool gs_input_toplevel, unsigned vertex_index);
unsigned lower_arraylike(ir_rvalue *rvalue, unsigned array_size,
unsigned fine_location,
- ir_variable *unpacked_var, const char *name);
- ir_variable *get_packed_varying(unsigned location,
- ir_variable *unpacked_var,
- const char *name);
+ ir_variable *unpacked_var, const char *name,
+ bool gs_input_toplevel, unsigned vertex_index);
+ ir_dereference *get_packed_varying_deref(unsigned location,
+ ir_variable *unpacked_var,
+ const char *name,
+ unsigned vertex_index);
bool needs_lowering(ir_variable *var);
/**
/**
* Location representing the first generic varying slot for this shader
- * stage (e.g. VERT_RESULT_VAR0 if we are packing vertex shader outputs).
+ * stage (e.g. VARYING_SLOT_VAR0 if we are packing vertex shader outputs).
* Varyings whose location is less than this value are assumed to
* correspond to special fixed function hardware, so they are not lowered.
*/
const ir_variable_mode mode;
/**
- * List of instructions corresponding to the main() function. This is
- * where we add instructions to pack or unpack the varyings.
+ * If we are currently lowering geometry shader inputs, the number of input
+ * vertices the geometry shader accepts. Otherwise zero.
*/
- exec_list *main_instructions;
+ const unsigned gs_input_vertices;
+
+ /**
+ * Exec list into which the visitor should insert the packing instructions.
+ * Caller provides this list; it should insert the instructions into the
+ * appropriate place in the shader once the visitor has finished running.
+ */
+ exec_list *out_instructions;
};
+} /* anonymous namespace */
+
lower_packed_varyings_visitor::lower_packed_varyings_visitor(
void *mem_ctx, unsigned location_base, unsigned locations_used,
- ir_variable_mode mode, exec_list *main_instructions)
+ ir_variable_mode mode, unsigned gs_input_vertices,
+ exec_list *out_instructions)
: mem_ctx(mem_ctx),
location_base(location_base),
locations_used(locations_used),
rzalloc_array_size(mem_ctx, sizeof(*packed_varyings),
locations_used)),
mode(mode),
- main_instructions(main_instructions)
+ gs_input_vertices(gs_input_vertices),
+ out_instructions(out_instructions)
{
}
!this->needs_lowering(var))
continue;
+ /* This lowering pass is only capable of packing floats and ints
+ * together when their interpolation mode is "flat". Therefore, to be
+ * safe, caller should ensure that integral varyings always use flat
+ * interpolation, even when this is not required by GLSL.
+ */
+ assert(var->interpolation == INTERP_QUALIFIER_FLAT ||
+ !var->type->contains_integer());
+
/* Change the old varying into an ordinary global. */
var->mode = ir_var_auto;
/* Recursively pack or unpack it. */
this->lower_rvalue(deref, var->location * 4 + var->location_frac, var,
- var->name);
+ var->name, this->gs_input_vertices != 0, 0);
}
}
* in multiples of a float, rather than multiples of a vec4 as is used
* elsewhere in Mesa.
*
+ * \param gs_input_toplevel should be set to true if we are lowering geometry
+ * shader inputs, and we are currently lowering the whole input variable
+ * (i.e. we are lowering the array whose index selects the vertex).
+ *
+ * \param vertex_index: if we are lowering geometry shader inputs, and the
+ * level of the array that we are currently lowering is *not* the top level,
+ * then this indicates which vertex we are currently lowering. Otherwise it
+ * is ignored.
+ *
* \return the location where the next constituent vector (after this one)
* should be packed.
*/
lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue,
unsigned fine_location,
ir_variable *unpacked_var,
- const char *name)
+ const char *name,
+ bool gs_input_toplevel,
+ unsigned vertex_index)
{
- /* FINISHME: Support for "varying" records in GLSL 1.50. */
- assert(!rvalue->type->is_record());
+ /* When gs_input_toplevel is set, we should be looking at a geometry shader
+ * input array.
+ */
+ assert(!gs_input_toplevel || rvalue->type->is_array());
- if (rvalue->type->is_array()) {
+ if (rvalue->type->is_record()) {
+ for (unsigned i = 0; i < rvalue->type->length; i++) {
+ if (i != 0)
+ rvalue = rvalue->clone(this->mem_ctx, NULL);
+ const char *field_name = rvalue->type->fields.structure[i].name;
+ ir_dereference_record *dereference_record = new(this->mem_ctx)
+ ir_dereference_record(rvalue, field_name);
+ char *deref_name
+ = ralloc_asprintf(this->mem_ctx, "%s.%s", name, field_name);
+ fine_location = this->lower_rvalue(dereference_record, fine_location,
+ unpacked_var, deref_name, false,
+ vertex_index);
+ }
+ return fine_location;
+ } else if (rvalue->type->is_array()) {
/* Arrays are packed/unpacked by considering each array element in
* sequence.
*/
return this->lower_arraylike(rvalue, rvalue->type->array_size(),
- fine_location, unpacked_var, name);
+ fine_location, unpacked_var, name,
+ gs_input_toplevel, vertex_index);
} else if (rvalue->type->is_matrix()) {
/* Matrices are packed/unpacked by considering each column vector in
* sequence.
*/
return this->lower_arraylike(rvalue, rvalue->type->matrix_columns,
- fine_location, unpacked_var, name);
+ fine_location, unpacked_var, name,
+ false, vertex_index);
} else if (rvalue->type->vector_elements + fine_location % 4 > 4) {
/* This vector is going to be "double parked" across two varying slots,
* so handle it as two separate assignments.
char *right_name
= ralloc_asprintf(this->mem_ctx, "%s.%s", name, right_swizzle_name);
fine_location = this->lower_rvalue(left_swizzle, fine_location,
- unpacked_var, left_name);
+ unpacked_var, left_name, false,
+ vertex_index);
return this->lower_rvalue(right_swizzle, fine_location, unpacked_var,
- right_name);
+ right_name, false, vertex_index);
} else {
/* No special handling is necessary; pack the rvalue into the
* varying.
unsigned location_frac = fine_location % 4;
for (unsigned i = 0; i < components; ++i)
swizzle_values[i] = i + location_frac;
- ir_dereference_variable *packed_deref = new(this->mem_ctx)
- ir_dereference_variable(this->get_packed_varying(location,
- unpacked_var, name));
+ ir_dereference *packed_deref =
+ this->get_packed_varying_deref(location, unpacked_var, name,
+ vertex_index);
ir_swizzle *swizzle = new(this->mem_ctx)
ir_swizzle(packed_deref, swizzle_values, components);
if (this->mode == ir_var_shader_out) {
ir_assignment *assignment
= this->bitwise_assign_pack(swizzle, rvalue);
- this->main_instructions->push_tail(assignment);
+ this->out_instructions->push_tail(assignment);
} else {
ir_assignment *assignment
= this->bitwise_assign_unpack(rvalue, swizzle);
- this->main_instructions->push_head(assignment);
+ this->out_instructions->push_tail(assignment);
}
return fine_location + components;
}
* constituent elements, accessing each one using an ir_dereference_array.
* This takes care of both arrays and matrices, since ir_dereference_array
* treats a matrix like an array of its column vectors.
+ *
+ * \param gs_input_toplevel should be set to true if we are lowering geometry
+ * shader inputs, and we are currently lowering the whole input variable
+ * (i.e. we are lowering the array whose index selects the vertex).
+ *
+ * \param vertex_index: if we are lowering geometry shader inputs, and the
+ * level of the array that we are currently lowering is *not* the top level,
+ * then this indicates which vertex we are currently lowering. Otherwise it
+ * is ignored.
*/
unsigned
lower_packed_varyings_visitor::lower_arraylike(ir_rvalue *rvalue,
unsigned array_size,
unsigned fine_location,
ir_variable *unpacked_var,
- const char *name)
+ const char *name,
+ bool gs_input_toplevel,
+ unsigned vertex_index)
{
for (unsigned i = 0; i < array_size; i++) {
if (i != 0)
ir_constant *constant = new(this->mem_ctx) ir_constant(i);
ir_dereference_array *dereference_array = new(this->mem_ctx)
ir_dereference_array(rvalue, constant);
- char *subscripted_name
- = ralloc_asprintf(this->mem_ctx, "%s[%d]", name, i);
- fine_location = this->lower_rvalue(dereference_array, fine_location,
- unpacked_var, subscripted_name);
+ if (gs_input_toplevel) {
+ /* Geometry shader inputs are a special case. Instead of storing
+ * each element of the array at a different location, all elements
+ * are at the same location, but with a different vertex index.
+ */
+ (void) this->lower_rvalue(dereference_array, fine_location,
+ unpacked_var, name, false, i);
+ } else {
+ char *subscripted_name
+ = ralloc_asprintf(this->mem_ctx, "%s[%d]", name, i);
+ fine_location =
+ this->lower_rvalue(dereference_array, fine_location,
+ unpacked_var, subscripted_name,
+ false, vertex_index);
+ }
}
return fine_location;
}
* The newly created varying inherits its interpolation parameters from \c
* unpacked_var. Its base type is ivec4 if we are lowering a flat varying,
* vec4 otherwise.
+ *
+ * \param vertex_index: if we are lowering geometry shader inputs, then this
+ * indicates which vertex we are currently lowering. Otherwise it is ignored.
*/
-ir_variable *
-lower_packed_varyings_visitor::get_packed_varying(unsigned location,
- ir_variable *unpacked_var,
- const char *name)
+ir_dereference *
+lower_packed_varyings_visitor::get_packed_varying_deref(
+ unsigned location, ir_variable *unpacked_var, const char *name,
+ unsigned vertex_index)
{
unsigned slot = location - this->location_base;
assert(slot < locations_used);
packed_type = glsl_type::ivec4_type;
else
packed_type = glsl_type::vec4_type;
+ if (this->gs_input_vertices != 0) {
+ packed_type =
+ glsl_type::get_array_instance(packed_type,
+ this->gs_input_vertices);
+ }
ir_variable *packed_var = new(this->mem_ctx)
ir_variable(packed_type, packed_name, this->mode);
+ if (this->gs_input_vertices != 0) {
+ /* Prevent update_array_sizes() from messing with the size of the
+ * array.
+ */
+ packed_var->max_array_access = this->gs_input_vertices - 1;
+ }
packed_var->centroid = unpacked_var->centroid;
packed_var->interpolation = unpacked_var->interpolation;
packed_var->location = location;
unpacked_var->insert_before(packed_var);
this->packed_varyings[slot] = packed_var;
} else {
- ralloc_asprintf_append((char **) &this->packed_varyings[slot]->name,
- ",%s", name);
+ /* For geometry shader inputs, only update the packed variable name the
+ * first time we visit each component.
+ */
+ if (this->gs_input_vertices == 0 || vertex_index == 0) {
+ ralloc_asprintf_append((char **) &this->packed_varyings[slot]->name,
+ ",%s", name);
+ }
}
- return this->packed_varyings[slot];
+
+ ir_dereference *deref = new(this->mem_ctx)
+ ir_dereference_variable(this->packed_varyings[slot]);
+ if (this->gs_input_vertices != 0) {
+ /* When lowering GS inputs, the packed variable is an array, so we need
+ * to dereference it using vertex_index.
+ */
+ ir_constant *constant = new(this->mem_ctx) ir_constant(vertex_index);
+ deref = new(this->mem_ctx) ir_dereference_array(deref, constant);
+ }
+ return deref;
}
bool
{
/* Things composed of vec4's don't need lowering. Everything else does. */
const glsl_type *type = var->type;
+ if (this->gs_input_vertices != 0) {
+ assert(type->is_array());
+ type = type->element_type();
+ }
if (type->is_array())
type = type->fields.array;
if (type->vector_elements == 4)
return true;
}
+
+/**
+ * Visitor that splices varying packing code before every use of EmitVertex()
+ * in a geometry shader.
+ */
+class lower_packed_varyings_gs_splicer : public ir_hierarchical_visitor
+{
+public:
+ explicit lower_packed_varyings_gs_splicer(void *mem_ctx,
+ const exec_list *instructions);
+
+ virtual ir_visitor_status visit(ir_emit_vertex *ev);
+
+private:
+ /**
+ * Memory context used to allocate new instructions for the shader.
+ */
+ void * const mem_ctx;
+
+ /**
+ * Instructions that should be spliced into place before each EmitVertex()
+ * call.
+ */
+ const exec_list *instructions;
+};
+
+
+lower_packed_varyings_gs_splicer::lower_packed_varyings_gs_splicer(
+ void *mem_ctx, const exec_list *instructions)
+ : mem_ctx(mem_ctx), instructions(instructions)
+{
+}
+
+
+ir_visitor_status
+lower_packed_varyings_gs_splicer::visit(ir_emit_vertex *ev)
+{
+ foreach_list(node, this->instructions) {
+ ir_instruction *ir = (ir_instruction *) node;
+ ev->insert_before(ir->clone(this->mem_ctx, NULL));
+ }
+ return visit_continue;
+}
+
+
void
lower_packed_varyings(void *mem_ctx, unsigned location_base,
unsigned locations_used, ir_variable_mode mode,
- gl_shader *shader)
+ unsigned gs_input_vertices, gl_shader *shader)
{
exec_list *instructions = shader->ir;
ir_function *main_func = shader->symbols->get_function("main");
exec_list void_parameters;
ir_function_signature *main_func_sig
- = main_func->matching_signature(&void_parameters);
- exec_list *main_instructions = &main_func_sig->body;
+ = main_func->matching_signature(NULL, &void_parameters);
+ exec_list new_instructions;
lower_packed_varyings_visitor visitor(mem_ctx, location_base,
locations_used, mode,
- main_instructions);
+ gs_input_vertices, &new_instructions);
visitor.run(instructions);
+ if (mode == ir_var_shader_out) {
+ if (shader->Type == GL_GEOMETRY_SHADER) {
+ /* For geometry shaders, outputs need to be lowered before each call
+ * to EmitVertex()
+ */
+ lower_packed_varyings_gs_splicer splicer(mem_ctx, &new_instructions);
+ splicer.run(instructions);
+ } else {
+ /* For other shader types, outputs need to be lowered at the end of
+ * main()
+ */
+ main_func_sig->body.append_list(&new_instructions);
+ }
+ } else {
+ /* Shader inputs need to be lowered at the beginning of main() */
+ main_func_sig->body.head->insert_before(&new_instructions);
+ }
}
projects / mesa.git / blobdiff