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Diffstat (limited to 'src/glsl/lower_shared_reference.cpp')
| -rw-r--r-- | src/glsl/lower_shared_reference.cpp | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/src/glsl/lower_shared_reference.cpp b/src/glsl/lower_shared_reference.cpp new file mode 100644 index 00000000000..533cd9202f4 --- /dev/null +++ b/src/glsl/lower_shared_reference.cpp @@ -0,0 +1,496 @@ +/* + * Copyright (c) 2015 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_shared_reference.cpp + * + * IR lower pass to replace dereferences of compute shader shared variables + * with intrinsic function calls. + * + * This relieves drivers of the responsibility of allocating space for the + * shared variables in the shared memory region. + */ + +#include "lower_buffer_access.h" +#include "ir_builder.h" +#include "main/macros.h" +#include "util/list.h" +#include "glsl_parser_extras.h" + +using namespace ir_builder; + +namespace { + +struct var_offset { + struct list_head node; + const ir_variable *var; + unsigned offset; +}; + +class lower_shared_reference_visitor : + public lower_buffer_access::lower_buffer_access { +public: + + lower_shared_reference_visitor(struct gl_shader *shader) + : list_ctx(ralloc_context(NULL)), shader(shader), shared_size(0u) + { + list_inithead(&var_offsets); + } + + ~lower_shared_reference_visitor() + { + ralloc_free(list_ctx); + } + + enum { + shared_load_access, + shared_store_access, + shared_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); + + void handle_rvalue(ir_rvalue **rvalue); + ir_visitor_status visit_enter(ir_assignment *ir); + void handle_assignment(ir_assignment *ir); + + ir_call *lower_shared_atomic_intrinsic(ir_call *ir); + ir_call *check_for_shared_atomic_intrinsic(ir_call *ir); + ir_visitor_status visit_enter(ir_call *ir); + + unsigned get_shared_offset(const ir_variable *); + + ir_call *shared_load(void *mem_ctx, const struct glsl_type *type, + ir_rvalue *offset); + ir_call *shared_store(void *mem_ctx, ir_rvalue *deref, ir_rvalue *offset, + unsigned write_mask); + + void *list_ctx; + struct gl_shader *shader; + struct list_head var_offsets; + unsigned shared_size; + bool progress; +}; + +unsigned +lower_shared_reference_visitor::get_shared_offset(const ir_variable *var) +{ + list_for_each_entry(var_offset, var_entry, &var_offsets, node) { + if (var_entry->var == var) + return var_entry->offset; + } + + struct var_offset *new_entry = rzalloc(list_ctx, struct var_offset); + list_add(&new_entry->node, &var_offsets); + new_entry->var = var; + + unsigned var_align = var->type->std430_base_alignment(false); + new_entry->offset = glsl_align(shared_size, var_align); + + unsigned var_size = var->type->std430_size(false); + shared_size = new_entry->offset + var_size; + + return new_entry->offset; +} + +void +lower_shared_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->data.mode != ir_var_shader_shared) + return; + + buffer_access_type = shared_load_access; + + void *mem_ctx = ralloc_parent(shader->ir); + + ir_rvalue *offset = NULL; + unsigned const_offset = get_shared_offset(var); + bool row_major; + int matrix_columns; + assert(var->get_interface_type() == NULL); + const unsigned packing = GLSL_INTERFACE_PACKING_STD430; + + setup_buffer_access(mem_ctx, var, deref, + &offset, &const_offset, + &row_major, &matrix_columns, packing); + + /* 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, + "shared_load_temp", + ir_var_temporary); + base_ir->insert_before(load_var); + + ir_variable *load_offset = new(mem_ctx) ir_variable(glsl_type::uint_type, + "shared_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; +} + +void +lower_shared_reference_visitor::handle_assignment(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->data.mode != ir_var_shader_shared) + return; + + buffer_access_type = shared_store_access; + + /* We have a write to a shared 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 *store_var = new(mem_ctx) ir_variable(type, + "shared_store_temp", + ir_var_temporary); + base_ir->insert_before(store_var); + ir->lhs = new(mem_ctx) ir_dereference_variable(store_var); + + ir_rvalue *offset = NULL; + unsigned const_offset = get_shared_offset(var); + bool row_major; + int matrix_columns; + assert(var->get_interface_type() == NULL); + const unsigned packing = GLSL_INTERFACE_PACKING_STD430; + + setup_buffer_access(mem_ctx, var, deref, + &offset, &const_offset, + &row_major, &matrix_columns, packing); + + deref = new(mem_ctx) ir_dereference_variable(store_var); + + ir_variable *store_offset = new(mem_ctx) ir_variable(glsl_type::uint_type, + "shared_store_temp_offset", + ir_var_temporary); + base_ir->insert_before(store_offset); + base_ir->insert_before(assign(store_offset, offset)); + + /* Now we have to write the value assigned to the temporary back to memory */ + emit_access(mem_ctx, true, deref, store_offset, const_offset, row_major, + matrix_columns, packing, ir->write_mask); + + progress = true; +} + +ir_visitor_status +lower_shared_reference_visitor::visit_enter(ir_assignment *ir) +{ + handle_assignment(ir); + return rvalue_visit(ir); +} + +void +lower_shared_reference_visitor::insert_buffer_access(void *mem_ctx, + ir_dereference *deref, + const glsl_type *type, + ir_rvalue *offset, + unsigned mask, + int channel) +{ + if (buffer_access_type == shared_store_access) { + ir_call *store = shared_store(mem_ctx, deref, offset, mask); + base_ir->insert_after(store); + } else { + ir_call *load = shared_load(mem_ctx, type, offset); + base_ir->insert_before(load); + ir_rvalue *value = load->return_deref->as_rvalue()->clone(mem_ctx, NULL); + base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), + value)); + } +} + +static bool +compute_shader_enabled(const _mesa_glsl_parse_state *state) +{ + return state->stage == MESA_SHADER_COMPUTE; +} + +ir_call * +lower_shared_reference_visitor::shared_store(void *mem_ctx, + ir_rvalue *deref, + ir_rvalue *offset, + unsigned write_mask) +{ + exec_list sig_params; + + 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, compute_shader_enabled); + assert(sig); + sig->replace_parameters(&sig_params); + sig->is_intrinsic = true; + + ir_function *f = new(mem_ctx) ir_function("__intrinsic_store_shared"); + f->add_signature(sig); + + exec_list call_params; + 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_shared_reference_visitor::shared_load(void *mem_ctx, + const struct glsl_type *type, + ir_rvalue *offset) +{ + exec_list sig_params; + + 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, compute_shader_enabled); + assert(sig); + sig->replace_parameters(&sig_params); + sig->is_intrinsic = true; + + ir_function *f = new(mem_ctx) ir_function("__intrinsic_load_shared"); + f->add_signature(sig); + + ir_variable *result = new(mem_ctx) + ir_variable(type, "shared_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(offset->clone(mem_ctx, NULL)); + + return new(mem_ctx) ir_call(sig, deref_result, &call_params); +} + +/* Lowers the intrinsic call to a new internal intrinsic that swaps the access + * to the shared variable in the first parameter by an offset. This involves + * creating the new internal intrinsic (i.e. the new function signature). + */ +ir_call * +lower_shared_reference_visitor::lower_shared_atomic_intrinsic(ir_call *ir) +{ + /* Shared atomics usually have 2 parameters, the shared 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 shared 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 + */ + void *mem_ctx = ralloc_parent(shader->ir); + + ir_rvalue *offset = NULL; + unsigned const_offset = get_shared_offset(var); + bool row_major; + int matrix_columns; + assert(var->get_interface_type() == NULL); + const unsigned packing = GLSL_INTERFACE_PACKING_STD430; + buffer_access_type = shared_atomic_access; + + setup_buffer_access(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)); + + /* Create the new internal function signature that will take an offset + * instead of a shared variable + */ + exec_list sig_params; + ir_variable *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, + compute_shader_enabled); + assert(sig); + sig->replace_parameters(&sig_params); + sig->is_intrinsic = true; + + char func_name[64]; + sprintf(func_name, "%s_shared", 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(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_shared_reference_visitor::check_for_shared_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->data.mode != ir_var_shader_shared) + return ir; + + const char *callee = ir->callee_name(); + if (!strcmp("__intrinsic_atomic_add", callee) || + !strcmp("__intrinsic_atomic_min", callee) || + !strcmp("__intrinsic_atomic_max", callee) || + !strcmp("__intrinsic_atomic_and", callee) || + !strcmp("__intrinsic_atomic_or", callee) || + !strcmp("__intrinsic_atomic_xor", callee) || + !strcmp("__intrinsic_atomic_exchange", callee) || + !strcmp("__intrinsic_atomic_comp_swap", callee)) { + return lower_shared_atomic_intrinsic(ir); + } + + return ir; +} + +ir_visitor_status +lower_shared_reference_visitor::visit_enter(ir_call *ir) +{ + ir_call *new_ir = check_for_shared_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_shared_reference(struct gl_shader *shader, unsigned *shared_size) +{ + if (shader->Stage != MESA_SHADER_COMPUTE) + return; + + lower_shared_reference_visitor v(shader); + + /* Loop over the instructions lowering references, because we take a deref + * of an shared variable array using a shared variable dereference as the + * index will produce a collection of instructions all of which have cloned + * shared variable dereferences for that array index. + */ + do { + v.progress = false; + visit_list_elements(&v, shader->ir); + } while (v.progress); + + *shared_size = v.shared_size; +} |