| // Copyright (c) 2017 The Khronos Group Inc. |
| // Copyright (c) 2017 Valve Corporation |
| // Copyright (c) 2017 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 "local_single_block_elim_pass.h" |
| |
| #include "iterator.h" |
| |
| namespace spvtools { |
| namespace opt { |
| |
| namespace { |
| |
| const uint32_t kStoreValIdInIdx = 1; |
| |
| } // anonymous namespace |
| |
| bool LocalSingleBlockLoadStoreElimPass::HasOnlySupportedRefs(uint32_t ptrId) { |
| if (supported_ref_ptrs_.find(ptrId) != supported_ref_ptrs_.end()) |
| return true; |
| analysis::UseList* uses = def_use_mgr_->GetUses(ptrId); |
| assert(uses != nullptr); |
| for (auto u : *uses) { |
| SpvOp op = u.inst->opcode(); |
| if (IsNonPtrAccessChain(op) || op == SpvOpCopyObject) { |
| if (!HasOnlySupportedRefs(u.inst->result_id())) return false; |
| } else if (op != SpvOpStore && op != SpvOpLoad && op != SpvOpName && |
| !IsNonTypeDecorate(op)) |
| return false; |
| } |
| supported_ref_ptrs_.insert(ptrId); |
| return true; |
| } |
| |
| bool LocalSingleBlockLoadStoreElimPass::LocalSingleBlockLoadStoreElim( |
| ir::Function* func) { |
| // Perform local store/load and load/load elimination on each block |
| bool modified = false; |
| for (auto bi = func->begin(); bi != func->end(); ++bi) { |
| var2store_.clear(); |
| var2load_.clear(); |
| pinned_vars_.clear(); |
| for (auto ii = bi->begin(); ii != bi->end(); ++ii) { |
| switch (ii->opcode()) { |
| case SpvOpStore: { |
| // Verify store variable is target type |
| uint32_t varId; |
| ir::Instruction* ptrInst = GetPtr(&*ii, &varId); |
| if (!IsTargetVar(varId)) |
| continue; |
| if (!HasOnlySupportedRefs(varId)) |
| continue; |
| // Register the store |
| if (ptrInst->opcode() == SpvOpVariable) { |
| // if not pinned, look for WAW |
| if (pinned_vars_.find(varId) == pinned_vars_.end()) { |
| auto si = var2store_.find(varId); |
| if (si != var2store_.end()) { |
| def_use_mgr_->KillInst(si->second); |
| } |
| } |
| var2store_[varId] = &*ii; |
| } |
| else { |
| assert(IsNonPtrAccessChain(ptrInst->opcode())); |
| var2store_.erase(varId); |
| } |
| pinned_vars_.erase(varId); |
| var2load_.erase(varId); |
| } break; |
| case SpvOpLoad: { |
| // Verify store variable is target type |
| uint32_t varId; |
| ir::Instruction* ptrInst = GetPtr(&*ii, &varId); |
| if (!IsTargetVar(varId)) |
| continue; |
| if (!HasOnlySupportedRefs(varId)) |
| continue; |
| // Look for previous store or load |
| uint32_t replId = 0; |
| if (ptrInst->opcode() == SpvOpVariable) { |
| auto si = var2store_.find(varId); |
| if (si != var2store_.end()) { |
| replId = si->second->GetSingleWordInOperand(kStoreValIdInIdx); |
| } |
| else { |
| auto li = var2load_.find(varId); |
| if (li != var2load_.end()) { |
| replId = li->second->result_id(); |
| } |
| } |
| } |
| if (replId != 0) { |
| // replace load's result id and delete load |
| ReplaceAndDeleteLoad(&*ii, replId); |
| modified = true; |
| } |
| else { |
| if (ptrInst->opcode() == SpvOpVariable) |
| var2load_[varId] = &*ii; // register load |
| pinned_vars_.insert(varId); |
| } |
| } break; |
| case SpvOpFunctionCall: { |
| // Conservatively assume all locals are redefined for now. |
| // TODO(): Handle more optimally |
| var2store_.clear(); |
| var2load_.clear(); |
| pinned_vars_.clear(); |
| } break; |
| default: |
| break; |
| } |
| } |
| // Go back and delete useless stores in block |
| // TODO(greg-lunarg): Consider moving DCE into separate pass |
| for (auto ii = bi->begin(); ii != bi->end(); ++ii) { |
| if (ii->opcode() != SpvOpStore) |
| continue; |
| if (IsLiveStore(&*ii)) |
| continue; |
| DCEInst(&*ii); |
| } |
| } |
| return modified; |
| } |
| |
| void LocalSingleBlockLoadStoreElimPass::Initialize(ir::Module* module) { |
| |
| module_ = module; |
| |
| // Initialize Target Type Caches |
| seen_target_vars_.clear(); |
| seen_non_target_vars_.clear(); |
| |
| // Clear collections |
| supported_ref_ptrs_.clear(); |
| |
| // TODO(greg-lunarg): Reuse def/use from previous passes |
| def_use_mgr_.reset(new analysis::DefUseManager(consumer(), module_)); |
| |
| // Start new ids with next availablein module |
| next_id_ = module_->id_bound(); |
| |
| // Initialize extensions whitelist |
| InitExtensions(); |
| }; |
| |
| bool LocalSingleBlockLoadStoreElimPass::AllExtensionsSupported() const { |
| // If any extension not in whitelist, return false |
| for (auto& ei : module_->extensions()) { |
| const char* extName = reinterpret_cast<const char*>( |
| &ei.GetInOperand(0).words[0]); |
| if (extensions_whitelist_.find(extName) == extensions_whitelist_.end()) |
| return false; |
| } |
| return true; |
| } |
| |
| Pass::Status LocalSingleBlockLoadStoreElimPass::ProcessImpl() { |
| // Assumes logical addressing only |
| if (module_->HasCapability(SpvCapabilityAddresses)) |
| return Status::SuccessWithoutChange; |
| // Do not process if module contains OpGroupDecorate. Additional |
| // support required in KillNamesAndDecorates(). |
| // TODO(greg-lunarg): Add support for OpGroupDecorate |
| for (auto& ai : module_->annotations()) |
| if (ai.opcode() == SpvOpGroupDecorate) |
| return Status::SuccessWithoutChange; |
| // If any extensions in the module are not explicitly supported, |
| // return unmodified. |
| if (!AllExtensionsSupported()) |
| return Status::SuccessWithoutChange; |
| // Collect all named and decorated ids |
| FindNamedOrDecoratedIds(); |
| // Process all entry point functions |
| ProcessFunction pfn = [this](ir::Function* fp) { |
| return LocalSingleBlockLoadStoreElim(fp); |
| }; |
| bool modified = ProcessEntryPointCallTree(pfn, module_); |
| FinalizeNextId(module_); |
| return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange; |
| } |
| |
| LocalSingleBlockLoadStoreElimPass::LocalSingleBlockLoadStoreElimPass() |
| : next_id_(0) {} |
| |
| Pass::Status LocalSingleBlockLoadStoreElimPass::Process(ir::Module* module) { |
| Initialize(module); |
| return ProcessImpl(); |
| } |
| |
| void LocalSingleBlockLoadStoreElimPass::InitExtensions() { |
| extensions_whitelist_.clear(); |
| extensions_whitelist_.insert({ |
| "SPV_AMD_shader_explicit_vertex_parameter", |
| "SPV_AMD_shader_trinary_minmax", |
| "SPV_AMD_gcn_shader", |
| "SPV_KHR_shader_ballot", |
| "SPV_AMD_shader_ballot", |
| "SPV_AMD_gpu_shader_half_float", |
| "SPV_KHR_shader_draw_parameters", |
| "SPV_KHR_subgroup_vote", |
| "SPV_KHR_16bit_storage", |
| "SPV_KHR_device_group", |
| "SPV_KHR_multiview", |
| "SPV_NVX_multiview_per_view_attributes", |
| "SPV_NV_viewport_array2", |
| "SPV_NV_stereo_view_rendering", |
| "SPV_NV_sample_mask_override_coverage", |
| "SPV_NV_geometry_shader_passthrough", |
| "SPV_AMD_texture_gather_bias_lod", |
| "SPV_KHR_storage_buffer_storage_class", |
| // SPV_KHR_variable_pointers |
| // Currently do not support extended pointer expressions |
| "SPV_AMD_gpu_shader_int16", |
| "SPV_KHR_post_depth_coverage", |
| "SPV_KHR_shader_atomic_counter_ops", |
| }); |
| } |
| |
| } // namespace opt |
| } // namespace spvtools |
