/* * 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 "lower_buffer_access.h" #include "ir_builder.h" #include "main/macros.h" #include "glsl_parser_extras.h" using namespace ir_builder; namespace { class lower_ubo_reference_visitor : public lower_buffer_access::lower_buffer_access { public: lower_ubo_reference_visitor(struct gl_linked_shader *shader, bool clamp_block_indices) : shader(shader), clamp_block_indices(clamp_block_indices), struct_field(NULL), variable(NULL) { } void handle_rvalue(ir_rvalue **rvalue); ir_visitor_status visit_enter(ir_assignment *ir); void setup_for_load_or_store(void *mem_ctx, ir_variable *var, ir_rvalue *deref, ir_rvalue **offset, unsigned *const_offset, bool *row_major, int *matrix_columns, enum glsl_interface_packing packing); uint32_t ssbo_access_params(); ir_expression *ubo_load(void *mem_ctx, const struct glsl_type *type, ir_rvalue *offset); ir_call *ssbo_load(void *mem_ctx, 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(void *mem_ctx, ir_dereference *deref, ir_variable *var, ir_variable *write_var, unsigned write_mask); ir_call *ssbo_store(void *mem_ctx, ir_rvalue *deref, ir_rvalue *offset, unsigned write_mask); enum { ubo_load_access, ssbo_load_access, ssbo_store_access, ssbo_unsized_array_length_access, ssbo_atomic_access, } buffer_access_type; void insert_buffer_access(void *mem_ctx, ir_dereference *deref, const glsl_type *type, ir_rvalue *offset, unsigned mask, int channel); 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(void *mem_ctx); unsigned calculate_unsized_array_stride(ir_dereference *deref, enum glsl_interface_packing 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); struct gl_linked_shader *shader; bool clamp_block_indices; struct gl_uniform_buffer_variable *ubo_var; const struct glsl_struct_field *struct_field; ir_variable *variable; ir_rvalue *uniform_block; bool progress; }; /** * 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; } static ir_rvalue * clamp_to_array_bounds(void *mem_ctx, ir_rvalue *index, const glsl_type *type) { assert(type->is_array()); const unsigned array_size = type->arrays_of_arrays_size(); ir_constant *max_index = new(mem_ctx) ir_constant(array_size - 1); max_index->type = index->type; ir_constant *zero = new(mem_ctx) ir_constant(0); zero->type = index->type; if (index->type->base_type == GLSL_TYPE_INT) index = max2(index, zero); index = min2(index, max_index); return index; } void lower_ubo_reference_visitor::setup_for_load_or_store(void *mem_ctx, ir_variable *var, ir_rvalue *deref, ir_rvalue **offset, unsigned *const_offset, bool *row_major, int *matrix_columns, enum glsl_interface_packing 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); if (nonconst_block_index && clamp_block_indices) { nonconst_block_index = clamp_to_array_bounds(mem_ctx, nonconst_block_index, var->type); } /* Locate the block by interface name */ unsigned num_blocks; struct gl_uniform_block **blocks; if (this->buffer_access_type != ubo_load_access) { 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); *const_offset = ubo_var->Offset; this->struct_field = NULL; setup_buffer_access(mem_ctx, deref, offset, const_offset, row_major, matrix_columns, &this->struct_field, packing); } 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; void *mem_ctx = ralloc_parent(shader->ir); ir_rvalue *offset = NULL; unsigned const_offset; bool row_major; int matrix_columns; enum glsl_interface_packing packing = var->get_interface_type_packing(); this->buffer_access_type = var->is_in_shader_storage_block() ? ssbo_load_access : ubo_load_access; this->variable = var; /* 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(mem_ctx, 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(mem_ctx, false, deref, load_offset, const_offset, row_major, matrix_columns, packing, 0); *rvalue = deref; progress = true; } ir_expression * lower_ubo_reference_visitor::ubo_load(void *mem_ctx, 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->has_shader_storage_buffer_objects(); } uint32_t lower_ubo_reference_visitor::ssbo_access_params() { assert(variable); if (variable->is_interface_instance()) { assert(struct_field); return ((struct_field->image_coherent ? ACCESS_COHERENT : 0) | (struct_field->image_restrict ? ACCESS_RESTRICT : 0) | (struct_field->image_volatile ? ACCESS_VOLATILE : 0)); } else { return ((variable->data.image_coherent ? ACCESS_COHERENT : 0) | (variable->data.image_restrict ? ACCESS_RESTRICT : 0) | (variable->data.image_volatile ? ACCESS_VOLATILE : 0)); } } ir_call * lower_ubo_reference_visitor::ssbo_store(void *mem_ctx, 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_variable *access_ref = new(mem_ctx) ir_variable(glsl_type::uint_type, "access" , ir_var_function_in); sig_params.push_tail(access_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; sig->intrinsic_id = ir_intrinsic_ssbo_store; 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)); call_params.push_tail(new(mem_ctx) ir_constant(ssbo_access_params())); return new(mem_ctx) ir_call(sig, NULL, &call_params); } ir_call * lower_ubo_reference_visitor::ssbo_load(void *mem_ctx, 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_variable *access_ref = new(mem_ctx) ir_variable(glsl_type::uint_type, "access" , ir_var_function_in); sig_params.push_tail(access_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; sig->intrinsic_id = ir_intrinsic_ssbo_load; 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)); call_params.push_tail(new(mem_ctx) ir_constant(ssbo_access_params())); return new(mem_ctx) ir_call(sig, deref_result, &call_params); } void lower_ubo_reference_visitor::insert_buffer_access(void *mem_ctx, ir_dereference *deref, const glsl_type *type, ir_rvalue *offset, unsigned mask, int channel) { switch (this->buffer_access_type) { case ubo_load_access: base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), ubo_load(mem_ctx, type, offset), mask)); break; case ssbo_load_access: { ir_call *load_ssbo = ssbo_load(mem_ctx, type, offset); base_ir->insert_before(load_ssbo); ir_rvalue *value = load_ssbo->return_deref->as_rvalue()->clone(mem_ctx, NULL); ir_assignment *assignment = assign(deref->clone(mem_ctx, NULL), value, mask); base_ir->insert_before(assignment); break; } case ssbo_store_access: if (channel >= 0) { base_ir->insert_after(ssbo_store(mem_ctx, swizzle(deref, channel, 1), offset, 1)); } else { base_ir->insert_after(ssbo_store(mem_ctx, deref, offset, mask)); } break; default: unreachable("invalid buffer_access_type in insert_buffer_access"); } } void lower_ubo_reference_visitor::write_to_memory(void *mem_ctx, 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; enum glsl_interface_packing packing = var->get_interface_type_packing(); this->buffer_access_type = ssbo_store_access; this->variable = var; /* 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(mem_ctx, 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(mem_ctx, 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(void *mem_ctx) { 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, enum glsl_interface_packing 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) { void *mem_ctx = ralloc_parent(*rvalue); ir_rvalue *base_offset = NULL; unsigned const_offset; bool row_major; int matrix_columns; enum glsl_interface_packing packing = var->get_interface_type_packing(); int unsized_array_stride = calculate_unsized_array_stride(deref, packing); this->buffer_access_type = ssbo_unsized_array_length_access; this->variable = var; /* 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(mem_ctx, 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(mem_ctx); 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_shader_storage_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. */ void *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(mem_ctx, 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); void *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)); void *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 */ void *mem_ctx = ralloc_parent(shader->ir); ir_rvalue *offset = NULL; unsigned const_offset; bool row_major; int matrix_columns; enum glsl_interface_packing packing = var->get_interface_type_packing(); this->buffer_access_type = ssbo_atomic_access; this->variable = var; setup_for_load_or_store(mem_ctx, 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; assert(ir->callee->intrinsic_id >= ir_intrinsic_generic_load); assert(ir->callee->intrinsic_id <= ir_intrinsic_generic_atomic_comp_swap); sig->intrinsic_id = MAP_INTRINSIC_TO_TYPE(ir->callee->intrinsic_id, ssbo); char func_name[64]; sprintf(func_name, "%s_ssbo", 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) { exec_list& params = ir->actual_parameters; if (params.length() < 2 || params.length() > 3) return ir; ir_rvalue *rvalue = ((ir_instruction *) params.get_head())->as_rvalue(); if (!rvalue) return ir; ir_variable *var = rvalue->variable_referenced(); if (!var || !var->is_in_shader_storage_block()) return ir; const enum ir_intrinsic_id id = ir->callee->intrinsic_id; if (id == ir_intrinsic_generic_atomic_add || id == ir_intrinsic_generic_atomic_min || id == ir_intrinsic_generic_atomic_max || id == ir_intrinsic_generic_atomic_and || id == ir_intrinsic_generic_atomic_or || id == ir_intrinsic_generic_atomic_xor || id == ir_intrinsic_generic_atomic_exchange || id == ir_intrinsic_generic_atomic_comp_swap) { 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_linked_shader *shader, bool clamp_block_indices) { lower_ubo_reference_visitor v(shader, clamp_block_indices); /* 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); }