| // Copyright (c) 2022 The Khronos Group Inc. |
| // Copyright (c) 2022 LunarG Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "source/opt/eliminate_dead_io_components_pass.h" |
| |
| #include <vector> |
| |
| #include "source/opt/instruction.h" |
| #include "source/opt/ir_context.h" |
| #include "source/util/bit_vector.h" |
| |
| namespace spvtools { |
| namespace opt { |
| namespace { |
| constexpr uint32_t kAccessChainBaseInIdx = 0; |
| constexpr uint32_t kAccessChainIndex0InIdx = 1; |
| constexpr uint32_t kAccessChainIndex1InIdx = 2; |
| constexpr uint32_t kConstantValueInIdx = 0; |
| } // namespace |
| |
| Pass::Status EliminateDeadIOComponentsPass::Process() { |
| // Only process input and output variables |
| if (elim_sclass_ != spv::StorageClass::Input && |
| elim_sclass_ != spv::StorageClass::Output) { |
| if (consumer()) { |
| std::string message = |
| "EliminateDeadIOComponentsPass only valid for input and output " |
| "variables."; |
| consumer()(SPV_MSG_ERROR, 0, {0, 0, 0}, message.c_str()); |
| } |
| return Status::Failure; |
| } |
| // If safe mode, only process Input variables in vertex shader |
| const auto stage = context()->GetStage(); |
| if (safe_mode_ && !(stage == spv::ExecutionModel::Vertex && |
| elim_sclass_ == spv::StorageClass::Input)) |
| return Status::SuccessWithoutChange; |
| // Current functionality assumes shader capability. |
| if (!context()->get_feature_mgr()->HasCapability(spv::Capability::Shader)) |
| return Status::SuccessWithoutChange; |
| // Current functionality assumes vert, frag, tesc, tese or geom shader. |
| // TODO(issue #4988): Add GLCompute. |
| if (stage != spv::ExecutionModel::Vertex && |
| stage != spv::ExecutionModel::Fragment && |
| stage != spv::ExecutionModel::TessellationControl && |
| stage != spv::ExecutionModel::TessellationEvaluation && |
| stage != spv::ExecutionModel::Geometry) |
| return Status::SuccessWithoutChange; |
| analysis::DefUseManager* def_use_mgr = context()->get_def_use_mgr(); |
| analysis::TypeManager* type_mgr = context()->get_type_mgr(); |
| bool modified = false; |
| std::vector<Instruction*> vars_to_move; |
| for (auto& var : context()->types_values()) { |
| if (var.opcode() != spv::Op::OpVariable) { |
| continue; |
| } |
| analysis::Type* var_type = type_mgr->GetType(var.type_id()); |
| analysis::Pointer* ptr_type = var_type->AsPointer(); |
| if (ptr_type == nullptr) { |
| continue; |
| } |
| const auto sclass = ptr_type->storage_class(); |
| if (sclass != elim_sclass_) { |
| continue; |
| } |
| // For tesc, or input variables in tese or geom shaders, |
| // there is a outer per-vertex-array that must be ignored |
| // for the purposes of this analysis/optimization. Do the |
| // analysis on the inner type in these cases. |
| bool skip_first_index = false; |
| auto core_type = ptr_type->pointee_type(); |
| if (stage == spv::ExecutionModel::TessellationControl || |
| (sclass == spv::StorageClass::Input && |
| (stage == spv::ExecutionModel::TessellationEvaluation || |
| stage == spv::ExecutionModel::Geometry))) { |
| auto arr_type = core_type->AsArray(); |
| if (!arr_type) continue; |
| core_type = arr_type->element_type(); |
| skip_first_index = true; |
| } |
| const analysis::Array* arr_type = core_type->AsArray(); |
| if (arr_type != nullptr) { |
| // Only process array if input of vertex shader, or output of |
| // fragment shader. Otherwise, if one shader has a runtime index and the |
| // other does not, interface incompatibility can occur. |
| if (!((sclass == spv::StorageClass::Input && |
| stage == spv::ExecutionModel::Vertex) || |
| (sclass == spv::StorageClass::Output && |
| stage == spv::ExecutionModel::Fragment))) |
| continue; |
| unsigned arr_len_id = arr_type->LengthId(); |
| Instruction* arr_len_inst = def_use_mgr->GetDef(arr_len_id); |
| if (arr_len_inst->opcode() != spv::Op::OpConstant) { |
| continue; |
| } |
| // SPIR-V requires array size is >= 1, so this works for signed or |
| // unsigned size. |
| unsigned original_max = |
| arr_len_inst->GetSingleWordInOperand(kConstantValueInIdx) - 1; |
| unsigned max_idx = FindMaxIndex(var, original_max); |
| if (max_idx != original_max) { |
| ChangeArrayLength(var, max_idx + 1); |
| vars_to_move.push_back(&var); |
| modified = true; |
| } |
| continue; |
| } |
| const analysis::Struct* struct_type = core_type->AsStruct(); |
| if (struct_type == nullptr) continue; |
| const auto elt_types = struct_type->element_types(); |
| unsigned original_max = static_cast<unsigned>(elt_types.size()) - 1; |
| unsigned max_idx = FindMaxIndex(var, original_max, skip_first_index); |
| if (max_idx != original_max) { |
| ChangeIOVarStructLength(var, max_idx + 1); |
| vars_to_move.push_back(&var); |
| modified = true; |
| } |
| } |
| |
| // Move changed vars after their new type instruction to preserve backward |
| // referencing. |
| for (auto var : vars_to_move) { |
| auto type_id = var->type_id(); |
| auto type_inst = def_use_mgr->GetDef(type_id); |
| var->RemoveFromList(); |
| var->InsertAfter(type_inst); |
| } |
| |
| return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange; |
| } |
| |
| unsigned EliminateDeadIOComponentsPass::FindMaxIndex( |
| const Instruction& var, const unsigned original_max, |
| const bool skip_first_index) { |
| unsigned max = 0; |
| bool seen_non_const_ac = false; |
| assert(var.opcode() == spv::Op::OpVariable && "must be variable"); |
| context()->get_def_use_mgr()->WhileEachUser( |
| var.result_id(), [&max, &seen_non_const_ac, var, skip_first_index, |
| this](Instruction* use) { |
| auto use_opcode = use->opcode(); |
| if (use_opcode == spv::Op::OpLoad || use_opcode == spv::Op::OpStore || |
| use_opcode == spv::Op::OpCopyMemory || |
| use_opcode == spv::Op::OpCopyMemorySized || |
| use_opcode == spv::Op::OpCopyObject) { |
| seen_non_const_ac = true; |
| return false; |
| } |
| if (use->opcode() != spv::Op::OpAccessChain && |
| use->opcode() != spv::Op::OpInBoundsAccessChain) { |
| return true; |
| } |
| // OpAccessChain with no indices currently not optimized |
| if (use->NumInOperands() == 1 || |
| (skip_first_index && use->NumInOperands() == 2)) { |
| seen_non_const_ac = true; |
| return false; |
| } |
| const unsigned base_id = |
| use->GetSingleWordInOperand(kAccessChainBaseInIdx); |
| USE_ASSERT(base_id == var.result_id() && "unexpected base"); |
| const unsigned in_idx = skip_first_index ? kAccessChainIndex1InIdx |
| : kAccessChainIndex0InIdx; |
| const unsigned idx_id = use->GetSingleWordInOperand(in_idx); |
| Instruction* idx_inst = context()->get_def_use_mgr()->GetDef(idx_id); |
| if (idx_inst->opcode() != spv::Op::OpConstant) { |
| seen_non_const_ac = true; |
| return false; |
| } |
| unsigned value = idx_inst->GetSingleWordInOperand(kConstantValueInIdx); |
| if (value > max) max = value; |
| return true; |
| }); |
| return seen_non_const_ac ? original_max : max; |
| } |
| |
| void EliminateDeadIOComponentsPass::ChangeArrayLength(Instruction& arr_var, |
| unsigned length) { |
| analysis::TypeManager* type_mgr = context()->get_type_mgr(); |
| analysis::ConstantManager* const_mgr = context()->get_constant_mgr(); |
| analysis::DefUseManager* def_use_mgr = context()->get_def_use_mgr(); |
| analysis::Pointer* ptr_type = |
| type_mgr->GetType(arr_var.type_id())->AsPointer(); |
| const analysis::Array* arr_ty = ptr_type->pointee_type()->AsArray(); |
| assert(arr_ty && "expecting array type"); |
| uint32_t length_id = const_mgr->GetUIntConstId(length); |
| analysis::Array new_arr_ty(arr_ty->element_type(), |
| arr_ty->GetConstantLengthInfo(length_id, length)); |
| analysis::Type* reg_new_arr_ty = type_mgr->GetRegisteredType(&new_arr_ty); |
| analysis::Pointer new_ptr_ty(reg_new_arr_ty, ptr_type->storage_class()); |
| analysis::Type* reg_new_ptr_ty = type_mgr->GetRegisteredType(&new_ptr_ty); |
| uint32_t new_ptr_ty_id = type_mgr->GetTypeInstruction(reg_new_ptr_ty); |
| arr_var.SetResultType(new_ptr_ty_id); |
| def_use_mgr->AnalyzeInstUse(&arr_var); |
| } |
| |
| void EliminateDeadIOComponentsPass::ChangeIOVarStructLength(Instruction& io_var, |
| unsigned length) { |
| analysis::TypeManager* type_mgr = context()->get_type_mgr(); |
| analysis::Pointer* ptr_type = |
| type_mgr->GetType(io_var.type_id())->AsPointer(); |
| auto core_type = ptr_type->pointee_type(); |
| // Check for per-vertex-array of struct from tesc, tese and geom and grab |
| // embedded struct type. |
| const auto arr_type = core_type->AsArray(); |
| if (arr_type) core_type = arr_type->element_type(); |
| const analysis::Struct* struct_ty = core_type->AsStruct(); |
| assert(struct_ty && "expecting struct type"); |
| const auto orig_elt_types = struct_ty->element_types(); |
| std::vector<const analysis::Type*> new_elt_types; |
| for (unsigned u = 0; u < length; ++u) |
| new_elt_types.push_back(orig_elt_types[u]); |
| analysis::Struct new_struct_ty(new_elt_types); |
| uint32_t old_struct_ty_id = type_mgr->GetTypeInstruction(struct_ty); |
| std::vector<Instruction*> decorations = |
| context()->get_decoration_mgr()->GetDecorationsFor(old_struct_ty_id, |
| true); |
| for (auto dec : decorations) { |
| if (dec->opcode() == spv::Op::OpMemberDecorate) { |
| uint32_t midx = dec->GetSingleWordInOperand(1); |
| if (midx >= length) continue; |
| } |
| type_mgr->AttachDecoration(*dec, &new_struct_ty); |
| } |
| // Clone name instructions for new struct type |
| analysis::Type* reg_new_str_ty = type_mgr->GetRegisteredType(&new_struct_ty); |
| uint32_t new_struct_ty_id = type_mgr->GetTypeInstruction(reg_new_str_ty); |
| context()->CloneNames(old_struct_ty_id, new_struct_ty_id, length); |
| // Attach new type to var |
| analysis::Type* reg_new_var_ty = reg_new_str_ty; |
| if (arr_type) { |
| analysis::Array new_arr_ty(reg_new_var_ty, arr_type->length_info()); |
| reg_new_var_ty = type_mgr->GetRegisteredType(&new_arr_ty); |
| } |
| analysis::Pointer new_ptr_ty(reg_new_var_ty, elim_sclass_); |
| analysis::Type* reg_new_ptr_ty = type_mgr->GetRegisteredType(&new_ptr_ty); |
| uint32_t new_ptr_ty_id = type_mgr->GetTypeInstruction(reg_new_ptr_ty); |
| io_var.SetResultType(new_ptr_ty_id); |
| analysis::DefUseManager* def_use_mgr = context()->get_def_use_mgr(); |
| def_use_mgr->AnalyzeInstUse(&io_var); |
| } |
| |
| } // namespace opt |
| } // namespace spvtools |