diff options
Diffstat (limited to 'mesalib/src/glsl/lower_packed_varyings.cpp')
| -rw-r--r-- | mesalib/src/glsl/lower_packed_varyings.cpp | 291 |
1 files changed, 255 insertions, 36 deletions
diff --git a/mesalib/src/glsl/lower_packed_varyings.cpp b/mesalib/src/glsl/lower_packed_varyings.cpp index cdf2289b4..31a50bba5 100644 --- a/mesalib/src/glsl/lower_packed_varyings.cpp +++ b/mesalib/src/glsl/lower_packed_varyings.cpp @@ -74,6 +74,74 @@ * 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" @@ -93,7 +161,8 @@ public: 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); @@ -101,13 +170,16 @@ private: 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); /** @@ -145,15 +217,23 @@ private: 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; }; 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), @@ -161,7 +241,8 @@ lower_packed_varyings_visitor::lower_packed_varyings_visitor( 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) { } @@ -195,7 +276,7 @@ lower_packed_varyings_visitor::run(exec_list *instructions) /* 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); } } @@ -277,6 +358,15 @@ lower_packed_varyings_visitor::bitwise_assign_unpack(ir_rvalue *lhs, * 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. */ @@ -284,8 +374,15 @@ unsigned 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) { + /* 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_record()) { for (unsigned i = 0; i < rvalue->type->length; i++) { if (i != 0) @@ -296,7 +393,8 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue, 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); + unpacked_var, deref_name, false, + vertex_index); } return fine_location; } else if (rvalue->type->is_array()) { @@ -304,13 +402,15 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue, * 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. @@ -340,9 +440,10 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue, 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. @@ -353,19 +454,19 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue, 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; } @@ -376,13 +477,24 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue, * 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) @@ -392,8 +504,20 @@ lower_packed_varyings_visitor::lower_arraylike(ir_rvalue *rvalue, 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, subscripted_name, + false, i); + } else { + fine_location = + this->lower_rvalue(dereference_array, fine_location, + unpacked_var, subscripted_name, + false, vertex_index); + } } return fine_location; } @@ -406,11 +530,14 @@ lower_packed_varyings_visitor::lower_arraylike(ir_rvalue *rvalue, * 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); @@ -421,18 +548,44 @@ lower_packed_varyings_visitor::get_packed_varying(unsigned location, 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); + } + } + + 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 this->packed_varyings[slot]; + return deref; } bool @@ -440,6 +593,10 @@ lower_packed_varyings_visitor::needs_lowering(ir_variable *var) { /* 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) @@ -447,19 +604,81 @@ lower_packed_varyings_visitor::needs_lowering(ir_variable *var) 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; + 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); + } } |