/* * 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 lower_ubo_reference.cpp * * IR lower pass to replace dereferences of variables in a uniform * buffer object with usage of ir_binop_ubo_load expressions, each of * which can read data up to the size of a vec4. * * This relieves drivers of the responsibility to deal with tricky UBO * layout issues like std140 structures and row_major matrices on * their own. */ #include "ir.h" #include "ir_builder.h" #include "ir_rvalue_visitor.h" #include "main/macros.h" #include "glsl_parser_extras.h" using namespace ir_builder; /** * Determine if a thing being dereferenced is row-major * * There is some trickery here. * * If the thing being dereferenced is a member of uniform block \b without an * instance name, then the name of the \c ir_variable is the field name of an * interface type. If this field is row-major, then the thing referenced is * row-major. * * If the thing being dereferenced is a member of uniform block \b with an * instance name, then the last dereference in the tree will be an * \c ir_dereference_record. If that record field is row-major, then the * thing referenced is row-major. */ static bool is_dereferenced_thing_row_major(const ir_rvalue *deref) { bool matrix = false; const ir_rvalue *ir = deref; while (true) { matrix = matrix || ir->type->without_array()->is_matrix(); switch (ir->ir_type) { case ir_type_dereference_array: { const ir_dereference_array *const array_deref = (const ir_dereference_array *) ir; ir = array_deref->array; break; } case ir_type_dereference_record: { const ir_dereference_record *const record_deref = (const ir_dereference_record *) ir; ir = record_deref->record; const int idx = ir->type->field_index(record_deref->field); assert(idx >= 0); const enum glsl_matrix_layout matrix_layout = glsl_matrix_layout(ir->type->fields.structure[idx].matrix_layout); switch (matrix_layout) { case GLSL_MATRIX_LAYOUT_INHERITED: break; case GLSL_MATRIX_LAYOUT_COLUMN_MAJOR: return false; case GLSL_MATRIX_LAYOUT_ROW_MAJOR: return matrix || deref->type->without_array()->is_record(); } break; } case ir_type_dereference_variable: { const ir_dereference_variable *const var_deref = (const ir_dereference_variable *) ir; const enum glsl_matrix_layout matrix_layout = glsl_matrix_layout(var_deref->var->data.matrix_layout); switch (matrix_layout) { case GLSL_MATRIX_LAYOUT_INHERITED: assert(!matrix); return false; case GLSL_MATRIX_LAYOUT_COLUMN_MAJOR: return false; case GLSL_MATRIX_LAYOUT_ROW_MAJOR: return matrix || deref->type->without_array()->is_record(); } unreachable("invalid matrix layout"); break; } default: return false; } } /* The tree must have ended with a dereference that wasn't an * ir_dereference_variable. That is invalid, and it should be impossible. */ unreachable("invalid dereference tree"); return false; } namespace { class lower_ubo_reference_visitor : public ir_rvalue_enter_visitor { public: lower_ubo_reference_visitor(struct gl_shader *shader) : shader(shader) { } void handle_rvalue(ir_rvalue **rvalue); ir_visitor_status visit_enter(ir_assignment *ir); void setup_for_load_or_store(ir_variable *var, ir_rvalue *deref, ir_rvalue **offset, unsigned *const_offset, bool *row_major, int *matrix_columns, unsigned packing); ir_expression *ubo_load(const struct glsl_type *type, ir_rvalue *offset); ir_call *ssbo_load(const struct glsl_type *type, ir_rvalue *offset); bool check_for_buffer_array_copy(ir_assignment *ir); bool check_for_buffer_struct_copy(ir_assignment *ir); void check_for_ssbo_store(ir_assignment *ir); void write_to_memory(ir_dereference *deref, ir_variable *var, ir_variable *write_var, unsigned write_mask); ir_call *ssbo_store(ir_rvalue *deref, ir_rvalue *offset, unsigned write_mask); void emit_access(bool is_write, ir_dereference *deref, ir_variable *base_offset, unsigned int deref_offset, bool row_major, int matrix_columns, unsigned packing, unsigned write_mask); ir_visitor_status visit_enter(class ir_expression *); ir_expression *calculate_ssbo_unsized_array_length(ir_expression *expr); void check_ssbo_unsized_array_length_expression(class ir_expression *); void check_ssbo_unsized_array_length_assignment(ir_assignment *ir); ir_expression *process_ssbo_unsized_array_length(ir_rvalue **, ir_dereference *, ir_variable *); ir_expression *emit_ssbo_get_buffer_size(); unsigned calculate_unsized_array_stride(ir_dereference *deref, unsigned packing); ir_call *lower_ssbo_atomic_intrinsic(ir_call *ir); ir_call *check_for_ssbo_atomic_intrinsic(ir_call *ir); ir_visitor_status visit_enter(ir_call *ir); void *mem_ctx; struct gl_shader *shader; struct gl_uniform_buffer_variable *ubo_var; ir_rvalue *uniform_block; bool progress; bool is_shader_storage; }; /** * Determine the name of the interface block field * * This is the name of the specific member as it would appear in the * \c gl_uniform_buffer_variable::Name field in the shader's * \c UniformBlocks array. */ static const char * interface_field_name(void *mem_ctx, char *base_name, ir_rvalue *d, ir_rvalue **nonconst_block_index) { *nonconst_block_index = NULL; char *name_copy = NULL; size_t base_length = 0; /* Loop back through the IR until we find the uniform block */ ir_rvalue *ir = d; while (ir != NULL) { switch (ir->ir_type) { case ir_type_dereference_variable: { /* Exit loop */ ir = NULL; break; } case ir_type_dereference_record: { ir_dereference_record *r = (ir_dereference_record *) ir; ir = r->record->as_dereference(); /* If we got here it means any previous array subscripts belong to * block members and not the block itself so skip over them in the * next pass. */ d = ir; break; } case ir_type_dereference_array: { ir_dereference_array *a = (ir_dereference_array *) ir; ir = a->array->as_dereference(); break; } case ir_type_swizzle: { ir_swizzle *s = (ir_swizzle *) ir; ir = s->val->as_dereference(); /* Skip swizzle in the next pass */ d = ir; break; } default: assert(!"Should not get here."); break; } } while (d != NULL) { switch (d->ir_type) { case ir_type_dereference_variable: { ir_dereference_variable *v = (ir_dereference_variable *) d; if (name_copy != NULL && v->var->is_interface_instance() && v->var->type->is_array()) { return name_copy; } else { *nonconst_block_index = NULL; return base_name; } break; } case ir_type_dereference_array: { ir_dereference_array *a = (ir_dereference_array *) d; size_t new_length; if (name_copy == NULL) { name_copy = ralloc_strdup(mem_ctx, base_name); base_length = strlen(name_copy); } /* For arrays of arrays we start at the innermost array and work our * way out so we need to insert the subscript at the base of the * name string rather than just attaching it to the end. */ new_length = base_length; ir_constant *const_index = a->array_index->as_constant(); char *end = ralloc_strdup(NULL, &name_copy[new_length]); if (!const_index) { ir_rvalue *array_index = a->array_index; if (array_index->type != glsl_type::uint_type) array_index = i2u(array_index); if (a->array->type->is_array() && a->array->type->fields.array->is_array()) { ir_constant *base_size = new(mem_ctx) ir_constant(a->array->type->fields.array->arrays_of_arrays_size()); array_index = mul(array_index, base_size); } if (*nonconst_block_index) { *nonconst_block_index = add(*nonconst_block_index, array_index); } else { *nonconst_block_index = array_index; } ralloc_asprintf_rewrite_tail(&name_copy, &new_length, "[0]%s", end); } else { ralloc_asprintf_rewrite_tail(&name_copy, &new_length, "[%d]%s", const_index->get_uint_component(0), end); } ralloc_free(end); d = a->array->as_dereference(); break; } default: assert(!"Should not get here."); break; } } assert(!"Should not get here."); return NULL; } void lower_ubo_reference_visitor::setup_for_load_or_store(ir_variable *var, ir_rvalue *deref, ir_rvalue **offset, unsigned *const_offset, bool *row_major, int *matrix_columns, unsigned packing) { /* Determine the name of the interface block */ ir_rvalue *nonconst_block_index; const char *const field_name = interface_field_name(mem_ctx, (char *) var->get_interface_type()->name, deref, &nonconst_block_index); /* Locate the block by interface name */ this->is_shader_storage = var->is_in_shader_storage_block(); unsigned num_blocks; struct gl_uniform_block **blocks; if (this->is_shader_storage) { num_blocks = shader->NumShaderStorageBlocks; blocks = shader->ShaderStorageBlocks; } else { num_blocks = shader->NumUniformBlocks; blocks = shader->UniformBlocks; } this->uniform_block = NULL; for (unsigned i = 0; i < num_blocks; i++) { if (strcmp(field_name, blocks[i]->Name) == 0) { ir_constant *index = new(mem_ctx) ir_constant(i); if (nonconst_block_index) { this->uniform_block = add(nonconst_block_index, index); } else { this->uniform_block = index; } this->ubo_var = var->is_interface_instance() ? &blocks[i]->Uniforms[0] : &blocks[i]->Uniforms[var->data.location]; break; } } assert(this->uniform_block); *offset = new(mem_ctx) ir_constant(0u); *const_offset = 0; *row_major = is_dereferenced_thing_row_major(deref); *matrix_columns = 1; /* Calculate the offset to the start of the region of the UBO * dereferenced by *rvalue. This may be a variable offset if an * array dereference has a variable index. */ while (deref) { switch (deref->ir_type) { case ir_type_dereference_variable: { *const_offset += ubo_var->Offset; deref = NULL; break; } case ir_type_dereference_array: { ir_dereference_array *deref_array = (ir_dereference_array *) deref; unsigned array_stride; if (deref_array->array->type->is_vector()) { /* We get this when storing or loading a component out of a vector * with a non-constant index. This happens for v[i] = f where v is * a vector (or m[i][j] = f where m is a matrix). If we don't * lower that here, it gets turned into v = vector_insert(v, i, * f), which loads the entire vector, modifies one component and * then write the entire thing back. That breaks if another * thread or SIMD channel is modifying the same vector. */ array_stride = 4; if (deref_array->array->type->is_double()) array_stride *= 2; } else if (deref_array->array->type->is_matrix() && *row_major) { /* When loading a vector out of a row major matrix, the * step between the columns (vectors) is the size of a * float, while the step between the rows (elements of a * vector) is handled below in emit_ubo_loads. */ array_stride = 4; if (deref_array->array->type->is_double()) array_stride *= 2; *matrix_columns = deref_array->array->type->matrix_columns; } else if (deref_array->type->without_array()->is_interface()) { /* We're processing an array dereference of an interface instance * array. The thing being dereferenced *must* be a variable * dereference because interfaces cannot be embedded in other * types. In terms of calculating the offsets for the lowering * pass, we don't care about the array index. All elements of an * interface instance array will have the same offsets relative to * the base of the block that backs them. */ deref = deref_array->array->as_dereference(); break; } else { /* Whether or not the field is row-major (because it might be a * bvec2 or something) does not affect the array itself. We need * to know whether an array element in its entirety is row-major. */ const bool array_row_major = is_dereferenced_thing_row_major(deref_array); /* The array type will give the correct interface packing * information */ if (packing == GLSL_INTERFACE_PACKING_STD430) { array_stride = deref_array->type->std430_array_stride(array_row_major); } else { array_stride = deref_array->type->std140_size(array_row_major); array_stride = glsl_align(array_stride, 16); } } ir_rvalue *array_index = deref_array->array_index; if (array_index->type->base_type == GLSL_TYPE_INT) array_index = i2u(array_index); ir_constant *const_index = array_index->constant_expression_value(NULL); if (const_index) { *const_offset += array_stride * const_index->value.u[0]; } else { *offset = add(*offset, mul(array_index, new(mem_ctx) ir_constant(array_stride))); } deref = deref_array->array->as_dereference(); break; } case ir_type_dereference_record: { ir_dereference_record *deref_record = (ir_dereference_record *) deref; const glsl_type *struct_type = deref_record->record->type; unsigned intra_struct_offset = 0; for (unsigned int i = 0; i < struct_type->length; i++) { const glsl_type *type = struct_type->fields.structure[i].type; ir_dereference_record *field_deref = new(mem_ctx) ir_dereference_record(deref_record->record, struct_type->fields.structure[i].name); const bool field_row_major = is_dereferenced_thing_row_major(field_deref); ralloc_free(field_deref); unsigned field_align = 0; if (packing == GLSL_INTERFACE_PACKING_STD430) field_align = type->std430_base_alignment(field_row_major); else field_align = type->std140_base_alignment(field_row_major); intra_struct_offset = glsl_align(intra_struct_offset, field_align); if (strcmp(struct_type->fields.structure[i].name, deref_record->field) == 0) break; if (packing == GLSL_INTERFACE_PACKING_STD430) intra_struct_offset += type->std430_size(field_row_major); else intra_struct_offset += type->std140_size(field_row_major); /* If the field just examined was itself a structure, apply rule * #9: * * "The structure may have padding at the end; the base offset * of the member following the sub-structure is rounded up to * the next multiple of the base alignment of the structure." */ if (type->without_array()->is_record()) { intra_struct_offset = glsl_align(intra_struct_offset, field_align); } } *const_offset += intra_struct_offset; deref = deref_record->record->as_dereference(); break; } case ir_type_swizzle: { ir_swizzle *deref_swizzle = (ir_swizzle *) deref; assert(deref_swizzle->mask.num_components == 1); *const_offset += deref_swizzle->mask.x * sizeof(int); deref = deref_swizzle->val->as_dereference(); break; } default: assert(!"not reached"); deref = NULL; break; } } } void lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue) { if (!*rvalue) return; ir_dereference *deref = (*rvalue)->as_dereference(); if (!deref) return; ir_variable *var = deref->variable_referenced(); if (!var || !var->is_in_buffer_block()) return; mem_ctx = ralloc_parent(shader->ir); ir_rvalue *offset = NULL; unsigned const_offset; bool row_major; int matrix_columns; unsigned packing = var->get_interface_type()->interface_packing; /* Compute the offset to the start if the dereference as well as other * information we need to configure the write */ setup_for_load_or_store(var, deref, &offset, &const_offset, &row_major, &matrix_columns, packing); assert(offset); /* Now that we've calculated the offset to the start of the * dereference, walk over the type and emit loads into a temporary. */ const glsl_type *type = (*rvalue)->type; ir_variable *load_var = new(mem_ctx) ir_variable(type, "ubo_load_temp", ir_var_temporary); base_ir->insert_before(load_var); ir_variable *load_offset = new(mem_ctx) ir_variable(glsl_type::uint_type, "ubo_load_temp_offset", ir_var_temporary); base_ir->insert_before(load_offset); base_ir->insert_before(assign(load_offset, offset)); deref = new(mem_ctx) ir_dereference_variable(load_var); emit_access(false, deref, load_offset, const_offset, row_major, matrix_columns, packing, 0); *rvalue = deref; progress = true; } ir_expression * lower_ubo_reference_visitor::ubo_load(const glsl_type *type, ir_rvalue *offset) { ir_rvalue *block_ref = this->uniform_block->clone(mem_ctx, NULL); return new(mem_ctx) ir_expression(ir_binop_ubo_load, type, block_ref, offset); } static bool shader_storage_buffer_object(const _mesa_glsl_parse_state *state) { return state->ARB_shader_storage_buffer_object_enable; } ir_call * lower_ubo_reference_visitor::ssbo_store(ir_rvalue *deref, ir_rvalue *offset, unsigned write_mask) { exec_list sig_params; ir_variable *block_ref = new(mem_ctx) ir_variable(glsl_type::uint_type, "block_ref" , ir_var_function_in); sig_params.push_tail(block_ref); ir_variable *offset_ref = new(mem_ctx) ir_variable(glsl_type::uint_type, "offset" , ir_var_function_in); sig_params.push_tail(offset_ref); ir_variable *val_ref = new(mem_ctx) ir_variable(deref->type, "value" , ir_var_function_in); sig_params.push_tail(val_ref); ir_variable *writemask_ref = new(mem_ctx) ir_variable(glsl_type::uint_type, "write_mask" , ir_var_function_in); sig_params.push_tail(writemask_ref); ir_function_signature *sig = new(mem_ctx) ir_function_signature(glsl_type::void_type, shader_storage_buffer_object); assert(sig); sig->replace_parameters(&sig_params); sig->is_intrinsic = true; ir_function *f = new(mem_ctx) ir_function("__intrinsic_store_ssbo"); f->add_signature(sig); exec_list call_params; call_params.push_tail(this->uniform_block->clone(mem_ctx, NULL)); call_params.push_tail(offset->clone(mem_ctx, NULL)); call_params.push_tail(deref->clone(mem_ctx, NULL)); call_params.push_tail(new(mem_ctx) ir_constant(write_mask)); return new(mem_ctx) ir_call(sig, NULL, &call_params); } ir_call * lower_ubo_reference_visitor::ssbo_load(const struct glsl_type *type, ir_rvalue *offset) { exec_list sig_params; ir_variable *block_ref = new(mem_ctx) ir_variable(glsl_type::uint_type, "block_ref" , ir_var_function_in); sig_params.push_tail(block_ref); ir_variable *offset_ref = new(mem_ctx) ir_variable(glsl_type::uint_type, "offset_ref" , ir_var_function_in); sig_params.push_tail(offset_ref); ir_function_signature *sig = new(mem_ctx) ir_function_signature(type, shader_storage_buffer_object); assert(sig); sig->replace_parameters(&sig_params); sig->is_intrinsic = true; ir_function *f = new(mem_ctx) ir_function("__intrinsic_load_ssbo"); f->add_signature(sig); ir_variable *result = new(mem_ctx) ir_variable(type, "ssbo_load_result", ir_var_temporary); base_ir->insert_before(result); ir_dereference_variable *deref_result = new(mem_ctx) ir_dereference_variable(result); exec_list call_params; call_params.push_tail(this->uniform_block->clone(mem_ctx, NULL)); call_params.push_tail(offset->clone(mem_ctx, NULL)); return new(mem_ctx) ir_call(sig, deref_result, &call_params); } static inline int writemask_for_size(unsigned n) { return ((1 << n) - 1); } /** * Takes a deref and recursively calls itself to break the deref down to the * point that the reads or writes generated are contiguous scalars or vectors. */ void lower_ubo_reference_visitor::emit_access(bool is_write, ir_dereference *deref, ir_variable *base_offset, unsigned int deref_offset, bool row_major, int matrix_columns, unsigned packing, unsigned write_mask) { if (deref->type->is_record()) { unsigned int field_offset = 0; for (unsigned i = 0; i < deref->type->length; i++) { const struct glsl_struct_field *field = &deref->type->fields.structure[i]; ir_dereference *field_deref = new(mem_ctx) ir_dereference_record(deref->clone(mem_ctx, NULL), field->name); field_offset = glsl_align(field_offset, field->type->std140_base_alignment(row_major)); emit_access(is_write, field_deref, base_offset, deref_offset + field_offset, row_major, 1, packing, writemask_for_size(field_deref->type->vector_elements)); field_offset += field->type->std140_size(row_major); } return; } if (deref->type->is_array()) { unsigned array_stride = packing == GLSL_INTERFACE_PACKING_STD430 ? deref->type->fields.array->std430_array_stride(row_major) : glsl_align(deref->type->fields.array->std140_size(row_major), 16); for (unsigned i = 0; i < deref->type->length; i++) { ir_constant *element = new(mem_ctx) ir_constant(i); ir_dereference *element_deref = new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL), element); emit_access(is_write, element_deref, base_offset, deref_offset + i * array_stride, row_major, 1, packing, writemask_for_size(element_deref->type->vector_elements)); } return; } if (deref->type->is_matrix()) { for (unsigned i = 0; i < deref->type->matrix_columns; i++) { ir_constant *col = new(mem_ctx) ir_constant(i); ir_dereference *col_deref = new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL), col); if (row_major) { /* For a row-major matrix, the next column starts at the next * element. */ int size_mul = deref->type->is_double() ? 8 : 4; emit_access(is_write, col_deref, base_offset, deref_offset + i * size_mul, row_major, deref->type->matrix_columns, packing, writemask_for_size(col_deref->type->vector_elements)); } else { int size_mul; /* std430 doesn't round up vec2 size to a vec4 size */ if (packing == GLSL_INTERFACE_PACKING_STD430 && deref->type->vector_elements == 2 && !deref->type->is_double()) { size_mul = 8; } else { /* std140 always rounds the stride of arrays (and matrices) to a * vec4, so matrices are always 16 between columns/rows. With * doubles, they will be 32 apart when there are more than 2 rows. * * For both std140 and std430, if the member is a * three-'component vector with components consuming N basic * machine units, the base alignment is 4N. For vec4, base * alignment is 4N. */ size_mul = (deref->type->is_double() && deref->type->vector_elements > 2) ? 32 : 16; } emit_access(is_write, col_deref, base_offset, deref_offset + i * size_mul, row_major, deref->type->matrix_columns, packing, writemask_for_size(col_deref->type->vector_elements)); } } return; } assert(deref->type->is_scalar() || deref->type->is_vector()); if (!row_major) { ir_rvalue *offset = add(base_offset, new(mem_ctx) ir_constant(deref_offset)); if (is_write) base_ir->insert_after(ssbo_store(deref, offset, write_mask)); else { if (!this->is_shader_storage) { base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), ubo_load(deref->type, offset))); } else { ir_call *load_ssbo = ssbo_load(deref->type, offset); base_ir->insert_before(load_ssbo); ir_rvalue *value = load_ssbo->return_deref->as_rvalue()->clone(mem_ctx, NULL); base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), value)); } } } else { unsigned N = deref->type->is_double() ? 8 : 4; /* We're dereffing a column out of a row-major matrix, so we * gather the vector from each stored row. */ assert(deref->type->base_type == GLSL_TYPE_FLOAT || deref->type->base_type == GLSL_TYPE_DOUBLE); /* Matrices, row_major or not, are stored as if they were * arrays of vectors of the appropriate size in std140. * Arrays have their strides rounded up to a vec4, so the * matrix stride is always 16. However a double matrix may either be 16 * or 32 depending on the number of columns. */ assert(matrix_columns <= 4); unsigned matrix_stride = 0; /* Matrix stride for std430 mat2xY matrices are not rounded up to * vec4 size. From OpenGL 4.3 spec, section 7.6.2.2 "Standard Uniform * Block Layout": * * "2. If the member is a two- or four-component vector with components * consuming N basic machine units, the base alignment is 2N or 4N, * respectively." [...] * "4. If the member is an array of scalars or vectors, the base alignment * and array stride are set to match the base alignment of a single array * element, according to rules (1), (2), and (3), and rounded up to the * base alignment of a vec4." [...] * "7. If the member is a row-major matrix with C columns and R rows, the * matrix is stored identically to an array of R row vectors with C * components each, according to rule (4)." [...] * "When using the std430 storage layout, shader storage blocks will be * laid out in buffer storage identically to uniform and shader storage * blocks using the std140 layout, except that the base alignment and * stride of arrays of scalars and vectors in rule 4 and of structures in * rule 9 are not rounded up a multiple of the base alignment of a vec4." */ if (packing == GLSL_INTERFACE_PACKING_STD430 && matrix_columns == 2) matrix_stride = 2 * N; else matrix_stride = glsl_align(matrix_columns * N, 16); const glsl_type *deref_type = deref->type->base_type == GLSL_TYPE_FLOAT ? glsl_type::float_type : glsl_type::double_type; for (unsigned i = 0; i < deref->type->vector_elements; i++) { ir_rvalue *chan_offset = add(base_offset, new(mem_ctx) ir_constant(deref_offset + i * matrix_stride)); if (is_write) { /* If the component is not in the writemask, then don't * store any value. */ if (!((1 << i) & write_mask)) continue; base_ir->insert_after(ssbo_store(swizzle(deref, i, 1), chan_offset, 1)); } else { if (!this->is_shader_storage) { base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), ubo_load(deref_type, chan_offset), (1U << i))); } else { ir_call *load_ssbo = ssbo_load(deref_type, chan_offset); base_ir->insert_before(load_ssbo); ir_rvalue *value = load_ssbo->return_deref->as_rvalue()->clone(mem_ctx, NULL); base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), value, (1U << i))); } } } } } void lower_ubo_reference_visitor::write_to_memory(ir_dereference *deref, ir_variable *var, ir_variable *write_var, unsigned write_mask) { ir_rvalue *offset = NULL; unsigned const_offset; bool row_major; int matrix_columns; unsigned packing = var->get_interface_type()->interface_packing; /* Compute the offset to the start if the dereference as well as other * information we need to configure the write */ setup_for_load_or_store(var, deref, &offset, &const_offset, &row_major, &matrix_columns, packing); assert(offset); /* Now emit writes from the temporary to memory */ ir_variable *write_offset = new(mem_ctx) ir_variable(glsl_type::uint_type, "ssbo_store_temp_offset", ir_var_temporary); base_ir->insert_before(write_offset); base_ir->insert_before(assign(write_offset, offset)); deref = new(mem_ctx) ir_dereference_variable(write_var); emit_access(true, deref, write_offset, const_offset, row_major, matrix_columns, packing, write_mask); } ir_visitor_status lower_ubo_reference_visitor::visit_enter(ir_expression *ir) { check_ssbo_unsized_array_length_expression(ir); return rvalue_visit(ir); } ir_expression * lower_ubo_reference_visitor::calculate_ssbo_unsized_array_length(ir_expression *expr) { if (expr->operation != ir_expression_operation(ir_unop_ssbo_unsized_array_length)) return NULL; ir_rvalue *rvalue = expr->operands[0]->as_rvalue(); if (!rvalue || !rvalue->type->is_array() || !rvalue->type->is_unsized_array()) return NULL; ir_dereference *deref = expr->operands[0]->as_dereference(); if (!deref) return NULL; ir_variable *var = expr->operands[0]->variable_referenced(); if (!var || !var->is_in_shader_storage_block()) return NULL; return process_ssbo_unsized_array_length(&rvalue, deref, var); } void lower_ubo_reference_visitor::check_ssbo_unsized_array_length_expression(ir_expression *ir) { if (ir->operation == ir_expression_operation(ir_unop_ssbo_unsized_array_length)) { /* Don't replace this unop if it is found alone. It is going to be * removed by the optimization passes or replaced if it is part of * an ir_assignment or another ir_expression. */ return; } for (unsigned i = 0; i < ir->get_num_operands(); i++) { if (ir->operands[i]->ir_type != ir_type_expression) continue; ir_expression *expr = (ir_expression *) ir->operands[i]; ir_expression *temp = calculate_ssbo_unsized_array_length(expr); if (!temp) continue; delete expr; ir->operands[i] = temp; } } void lower_ubo_reference_visitor::check_ssbo_unsized_array_length_assignment(ir_assignment *ir) { if (!ir->rhs || ir->rhs->ir_type != ir_type_expression) return; ir_expression *expr = (ir_expression *) ir->rhs; ir_expression *temp = calculate_ssbo_unsized_array_length(expr); if (!temp) return; delete expr; ir->rhs = temp; return; } ir_expression * lower_ubo_reference_visitor::emit_ssbo_get_buffer_size() { ir_rvalue *block_ref = this->uniform_block->clone(mem_ctx, NULL); return new(mem_ctx) ir_expression(ir_unop_get_buffer_size, glsl_type::int_type, block_ref); } unsigned lower_ubo_reference_visitor::calculate_unsized_array_stride(ir_dereference *deref, unsigned packing) { unsigned array_stride = 0; switch (deref->ir_type) { case ir_type_dereference_variable: { ir_dereference_variable *deref_var = (ir_dereference_variable *)deref; const struct glsl_type *unsized_array_type = NULL; /* An unsized array can be sized by other lowering passes, so pick * the first field of the array which has the data type of the unsized * array. */ unsized_array_type = deref_var->var->type->fields.array; /* Whether or not the field is row-major (because it might be a * bvec2 or something) does not affect the array itself. We need * to know whether an array element in its entirety is row-major. */ const bool array_row_major = is_dereferenced_thing_row_major(deref_var); if (packing == GLSL_INTERFACE_PACKING_STD430) { array_stride = unsized_array_type->std430_array_stride(array_row_major); } else { array_stride = unsized_array_type->std140_size(array_row_major); array_stride = glsl_align(array_stride, 16); } break; } case ir_type_dereference_record: { ir_dereference_record *deref_record = (ir_dereference_record *) deref; ir_dereference *interface_deref = deref_record->record->as_dereference(); assert(interface_deref != NULL); const struct glsl_type *interface_type = interface_deref->type; unsigned record_length = interface_type->length; /* Unsized array is always the last element of the interface */ const struct glsl_type *unsized_array_type = interface_type->fields.structure[record_length - 1].type->fields.array; const bool array_row_major = is_dereferenced_thing_row_major(deref_record); if (packing == GLSL_INTERFACE_PACKING_STD430) { array_stride = unsized_array_type->std430_array_stride(array_row_major); } else { array_stride = unsized_array_type->std140_size(array_row_major); array_stride = glsl_align(array_stride, 16); } break; } default: unreachable("Unsupported dereference type"); } return array_stride; } ir_expression * lower_ubo_reference_visitor::process_ssbo_unsized_array_length(ir_rvalue **rvalue, ir_dereference *deref, ir_variable *var) { mem_ctx = ralloc_parent(*rvalue); ir_rvalue *base_offset = NULL; unsigned const_offset; bool row_major; int matrix_columns; unsigned packing = var->get_interface_type()->interface_packing; int unsized_array_stride = calculate_unsized_array_stride(deref, packing); /* Compute the offset to the start if the dereference as well as other * information we need to calculate the length. */ setup_for_load_or_store(var, deref, &base_offset, &const_offset, &row_major, &matrix_columns, packing); /* array.length() = * max((buffer_object_size - offset_of_array) / stride_of_array, 0) */ ir_expression *buffer_size = emit_ssbo_get_buffer_size(); ir_expression *offset_of_array = new(mem_ctx) ir_expression(ir_binop_add, base_offset, new(mem_ctx) ir_constant(const_offset)); ir_expression *offset_of_array_int = new(mem_ctx) ir_expression(ir_unop_u2i, offset_of_array); ir_expression *sub = new(mem_ctx) ir_expression(ir_binop_sub, buffer_size, offset_of_array_int); ir_expression *div = new(mem_ctx) ir_expression(ir_binop_div, sub, new(mem_ctx) ir_constant(unsized_array_stride)); ir_expression *max = new(mem_ctx) ir_expression(ir_binop_max, div, new(mem_ctx) ir_constant(0)); return max; } void lower_ubo_reference_visitor::check_for_ssbo_store(ir_assignment *ir) { if (!ir || !ir->lhs) return; ir_rvalue *rvalue = ir->lhs->as_rvalue(); if (!rvalue) return; ir_dereference *deref = ir->lhs->as_dereference(); if (!deref) return; ir_variable *var = ir->lhs->variable_referenced(); if (!var || !var->is_in_buffer_block()) return; /* We have a write to a buffer variable, so declare a temporary and rewrite * the assignment so that the temporary is the LHS. */ mem_ctx = ralloc_parent(shader->ir); const glsl_type *type = rvalue->type; ir_variable *write_var = new(mem_ctx) ir_variable(type, "ssbo_store_temp", ir_var_temporary); base_ir->insert_before(write_var); ir->lhs = new(mem_ctx) ir_dereference_variable(write_var); /* Now we have to write the value assigned to the temporary back to memory */ write_to_memory(deref, var, write_var, ir->write_mask); progress = true; } static bool is_buffer_backed_variable(ir_variable *var) { return var->is_in_buffer_block() || var->data.mode == ir_var_shader_shared; } bool lower_ubo_reference_visitor::check_for_buffer_array_copy(ir_assignment *ir) { if (!ir || !ir->lhs || !ir->rhs) return false; /* LHS and RHS must be arrays * FIXME: arrays of arrays? */ if (!ir->lhs->type->is_array() || !ir->rhs->type->is_array()) return false; /* RHS must be a buffer-backed variable. This is what can cause the problem * since it would lead to a series of loads that need to live until we * see the writes to the LHS. */ ir_variable *rhs_var = ir->rhs->variable_referenced(); if (!rhs_var || !is_buffer_backed_variable(rhs_var)) return false; /* Split the array copy into individual element copies to reduce * register pressure */ ir_dereference *rhs_deref = ir->rhs->as_dereference(); if (!rhs_deref) return false; ir_dereference *lhs_deref = ir->lhs->as_dereference(); if (!lhs_deref) return false; assert(lhs_deref->type->length == rhs_deref->type->length); mem_ctx = ralloc_parent(shader->ir); for (unsigned i = 0; i < lhs_deref->type->length; i++) { ir_dereference *lhs_i = new(mem_ctx) ir_dereference_array(lhs_deref->clone(mem_ctx, NULL), new(mem_ctx) ir_constant(i)); ir_dereference *rhs_i = new(mem_ctx) ir_dereference_array(rhs_deref->clone(mem_ctx, NULL), new(mem_ctx) ir_constant(i)); ir->insert_after(assign(lhs_i, rhs_i)); } ir->remove(); progress = true; return true; } bool lower_ubo_reference_visitor::check_for_buffer_struct_copy(ir_assignment *ir) { if (!ir || !ir->lhs || !ir->rhs) return false; /* LHS and RHS must be records */ if (!ir->lhs->type->is_record() || !ir->rhs->type->is_record()) return false; /* RHS must be a buffer-backed variable. This is what can cause the problem * since it would lead to a series of loads that need to live until we * see the writes to the LHS. */ ir_variable *rhs_var = ir->rhs->variable_referenced(); if (!rhs_var || !is_buffer_backed_variable(rhs_var)) return false; /* Split the struct copy into individual element copies to reduce * register pressure */ ir_dereference *rhs_deref = ir->rhs->as_dereference(); if (!rhs_deref) return false; ir_dereference *lhs_deref = ir->lhs->as_dereference(); if (!lhs_deref) return false; assert(lhs_deref->type->record_compare(rhs_deref->type)); mem_ctx = ralloc_parent(shader->ir); for (unsigned i = 0; i < lhs_deref->type->length; i++) { const char *field_name = lhs_deref->type->fields.structure[i].name; ir_dereference *lhs_field = new(mem_ctx) ir_dereference_record(lhs_deref->clone(mem_ctx, NULL), field_name); ir_dereference *rhs_field = new(mem_ctx) ir_dereference_record(rhs_deref->clone(mem_ctx, NULL), field_name); ir->insert_after(assign(lhs_field, rhs_field)); } ir->remove(); progress = true; return true; } ir_visitor_status lower_ubo_reference_visitor::visit_enter(ir_assignment *ir) { /* Array and struct copies could involve large amounts of load/store * operations. To improve register pressure we want to special-case * these and split them into individual element copies. * This way we avoid emitting all the loads for the RHS first and * all the writes for the LHS second and register usage is more * efficient. */ if (check_for_buffer_array_copy(ir)) return visit_continue_with_parent; if (check_for_buffer_struct_copy(ir)) return visit_continue_with_parent; check_ssbo_unsized_array_length_assignment(ir); check_for_ssbo_store(ir); return rvalue_visit(ir); } /* Lowers the intrinsic call to a new internal intrinsic that swaps the * access to the buffer variable in the first parameter by an offset * and block index. This involves creating the new internal intrinsic * (i.e. the new function signature). */ ir_call * lower_ubo_reference_visitor::lower_ssbo_atomic_intrinsic(ir_call *ir) { /* SSBO atomics usually have 2 parameters, the buffer variable and an * integer argument. The exception is CompSwap, that has an additional * integer parameter. */ int param_count = ir->actual_parameters.length(); assert(param_count == 2 || param_count == 3); /* First argument must be a scalar integer buffer variable */ exec_node *param = ir->actual_parameters.get_head(); ir_instruction *inst = (ir_instruction *) param; assert(inst->ir_type == ir_type_dereference_variable || inst->ir_type == ir_type_dereference_array || inst->ir_type == ir_type_dereference_record || inst->ir_type == ir_type_swizzle); ir_rvalue *deref = (ir_rvalue *) inst; assert(deref->type->is_scalar() && deref->type->is_integer()); ir_variable *var = deref->variable_referenced(); assert(var); /* Compute the offset to the start if the dereference and the * block index */ mem_ctx = ralloc_parent(shader->ir); ir_rvalue *offset = NULL; unsigned const_offset; bool row_major; int matrix_columns; unsigned packing = var->get_interface_type()->interface_packing; setup_for_load_or_store(var, deref, &offset, &const_offset, &row_major, &matrix_columns, packing); assert(offset); assert(!row_major); assert(matrix_columns == 1); ir_rvalue *deref_offset = add(offset, new(mem_ctx) ir_constant(const_offset)); ir_rvalue *block_index = this->uniform_block->clone(mem_ctx, NULL); /* Create the new internal function signature that will take a block * index and offset instead of a buffer variable */ exec_list sig_params; ir_variable *sig_param = new(mem_ctx) ir_variable(glsl_type::uint_type, "block_ref" , ir_var_function_in); sig_params.push_tail(sig_param); sig_param = new(mem_ctx) ir_variable(glsl_type::uint_type, "offset" , ir_var_function_in); sig_params.push_tail(sig_param); const glsl_type *type = deref->type->base_type == GLSL_TYPE_INT ? glsl_type::int_type : glsl_type::uint_type; sig_param = new(mem_ctx) ir_variable(type, "data1", ir_var_function_in); sig_params.push_tail(sig_param); if (param_count == 3) { sig_param = new(mem_ctx) ir_variable(type, "data2", ir_var_function_in); sig_params.push_tail(sig_param); } ir_function_signature *sig = new(mem_ctx) ir_function_signature(deref->type, shader_storage_buffer_object); assert(sig); sig->replace_parameters(&sig_params); sig->is_intrinsic = true; char func_name[64]; sprintf(func_name, "%s_internal", ir->callee_name()); ir_function *f = new(mem_ctx) ir_function(func_name); f->add_signature(sig); /* Now, create the call to the internal intrinsic */ exec_list call_params; call_params.push_tail(block_index); call_params.push_tail(deref_offset); param = ir->actual_parameters.get_head()->get_next(); ir_rvalue *param_as_rvalue = ((ir_instruction *) param)->as_rvalue(); call_params.push_tail(param_as_rvalue->clone(mem_ctx, NULL)); if (param_count == 3) { param = param->get_next(); param_as_rvalue = ((ir_instruction *) param)->as_rvalue(); call_params.push_tail(param_as_rvalue->clone(mem_ctx, NULL)); } ir_dereference_variable *return_deref = ir->return_deref->clone(mem_ctx, NULL); return new(mem_ctx) ir_call(sig, return_deref, &call_params); } ir_call * lower_ubo_reference_visitor::check_for_ssbo_atomic_intrinsic(ir_call *ir) { const char *callee = ir->callee_name(); if (!strcmp("__intrinsic_ssbo_atomic_add", callee) || !strcmp("__intrinsic_ssbo_atomic_min", callee) || !strcmp("__intrinsic_ssbo_atomic_max", callee) || !strcmp("__intrinsic_ssbo_atomic_and", callee) || !strcmp("__intrinsic_ssbo_atomic_or", callee) || !strcmp("__intrinsic_ssbo_atomic_xor", callee) || !strcmp("__intrinsic_ssbo_atomic_exchange", callee) || !strcmp("__intrinsic_ssbo_atomic_comp_swap", callee)) { return lower_ssbo_atomic_intrinsic(ir); } return ir; } ir_visitor_status lower_ubo_reference_visitor::visit_enter(ir_call *ir) { ir_call *new_ir = check_for_ssbo_atomic_intrinsic(ir); if (new_ir != ir) { progress = true; base_ir->replace_with(new_ir); return visit_continue_with_parent; } return rvalue_visit(ir); } } /* unnamed namespace */ void lower_ubo_reference(struct gl_shader *shader) { lower_ubo_reference_visitor v(shader); /* Loop over the instructions lowering references, because we take * a deref of a UBO array using a UBO dereference as the index will * produce a collection of instructions all of which have cloned * UBO dereferences for that array index. */ do { v.progress = false; visit_list_elements(&v, shader->ir); } while (v.progress); }