diff options
| -rw-r--r-- | compiler/optimizing/load_store_elimination.cc | 57 |
1 files changed, 37 insertions, 20 deletions
diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc index fae1eb963b..8eeb6af65c 100644 --- a/compiler/optimizing/load_store_elimination.cc +++ b/compiler/optimizing/load_store_elimination.cc @@ -16,6 +16,11 @@ #include "load_store_elimination.h" +#include <algorithm> +#include <optional> +#include <sstream> +#include <variant> + #include "base/arena_allocator.h" #include "base/arena_bit_vector.h" #include "base/array_ref.h" @@ -759,11 +764,9 @@ class LSEVisitor final : private HGraphDelegateVisitor { DataType::Type type, bool can_use_default_or_phi); bool MaterializeLoopPhis(const ScopedArenaVector<size_t>& phi_placeholder_indexes, - DataType::Type type, - Phase phase); + DataType::Type type); bool MaterializeLoopPhis(const ArenaBitVector& phi_placeholders_to_materialize, - DataType::Type type, - Phase phase); + DataType::Type type); std::optional<PhiPlaceholder> TryToMaterializeLoopPhis(PhiPlaceholder phi_placeholder, HInstruction* load); void ProcessLoopPhiWithUnknownInput(PhiPlaceholder loop_phi_with_unknown_input); @@ -1058,11 +1061,23 @@ class LSEVisitor final : private HGraphDelegateVisitor { ScopedArenaVector<HInstruction*> singleton_new_instances_; + Phase current_phase_; + friend std::ostream& operator<<(std::ostream& os, const Value& v); + friend std::ostream& operator<<(std::ostream& os, const Phase& phase); DISALLOW_COPY_AND_ASSIGN(LSEVisitor); }; +std::ostream& operator<<(std::ostream& oss, const LSEVisitor::Phase& phase) { + switch (phase) { + case LSEVisitor::Phase::kLoadElimination: + return oss << "kLoadElimination"; + case LSEVisitor::Phase::kStoreElimination: + return oss << "kStoreElimination"; + } +} + constexpr bool operator==(const LSEVisitor::PhiPlaceholder& p1, const LSEVisitor::PhiPlaceholder& p2) { return p1.Equals(p2); @@ -1132,7 +1147,6 @@ std::ostream& operator<<(std::ostream& os, const LSEVisitor::Value& v) { return v.Dump(os); } - LSEVisitor::LSEVisitor(HGraph* graph, const HeapLocationCollector& heap_location_collector, OptimizingCompilerStats* stats) @@ -1167,7 +1181,8 @@ LSEVisitor::LSEVisitor(HGraph* graph, /*start_bits=*/ num_phi_placeholders_, /*expandable=*/ false, kArenaAllocLSE), - singleton_new_instances_(allocator_.Adapter(kArenaAllocLSE)) { + singleton_new_instances_(allocator_.Adapter(kArenaAllocLSE)), + current_phase_(Phase::kLoadElimination) { // Clear bit vectors. phi_placeholders_to_search_for_kept_stores_.ClearAllBits(); kept_stores_.ClearAllBits(); @@ -1386,7 +1401,8 @@ void LSEVisitor::MaterializeNonLoopPhis(PhiPlaceholder phi_placeholder, DataType // And the only way for such merged value to reach a different heap location is through // a load at which point we materialize the Phi. Therefore all non-loop Phi placeholders // seen here are tied to one heap location. - DCHECK(!current_block->IsLoopHeader()); + DCHECK(!current_block->IsLoopHeader()) + << current_phi_placeholder << " phase: " << current_phase_; DCHECK_EQ(current_phi_placeholder.GetHeapLocation(), idx); phi_inputs.clear(); @@ -1400,6 +1416,8 @@ void LSEVisitor::MaterializeNonLoopPhis(PhiPlaceholder phi_placeholder, DataType } else if (pred_value.IsDefault()) { phi_inputs.push_back(GetDefaultValue(type)); } else { + DCHECK(pred_value.IsInstruction()) << pred_value << " block " << current_block->GetBlockId() + << " pred: " << predecessor->GetBlockId(); phi_inputs.push_back(pred_value.GetInstruction()); } } @@ -1743,8 +1761,7 @@ std::optional<LSEVisitor::PhiPlaceholder> LSEVisitor::FindLoopPhisToMaterialize( } bool LSEVisitor::MaterializeLoopPhis(const ScopedArenaVector<size_t>& phi_placeholder_indexes, - DataType::Type type, - Phase phase) { + DataType::Type type) { // Materialize all predecessors that do not need a loop Phi and determine if all inputs // other than loop Phis are the same. const ArenaVector<HBasicBlock*>& blocks = GetGraph()->GetBlocks(); @@ -1757,7 +1774,7 @@ bool LSEVisitor::MaterializeLoopPhis(const ScopedArenaVector<size_t>& phi_placeh for (HBasicBlock* predecessor : block->GetPredecessors()) { Value value = ReplacementOrValue(heap_values_for_[predecessor->GetBlockId()][idx].value); if (value.NeedsNonLoopPhi()) { - DCHECK(phase == Phase::kLoadElimination); + DCHECK(current_phase_ == Phase::kLoadElimination); MaterializeNonLoopPhis(value.GetPhiPlaceholder(), type); value = Replacement(value); } @@ -1815,7 +1832,7 @@ bool LSEVisitor::MaterializeLoopPhis(const ScopedArenaVector<size_t>& phi_placeh } } - if (phase == Phase::kStoreElimination) { + if (current_phase_ == Phase::kStoreElimination) { // We're not creating Phis during the final store elimination phase. return false; } @@ -1872,8 +1889,7 @@ bool LSEVisitor::MaterializeLoopPhis(const ScopedArenaVector<size_t>& phi_placeh } bool LSEVisitor::MaterializeLoopPhis(const ArenaBitVector& phi_placeholders_to_materialize, - DataType::Type type, - Phase phase) { + DataType::Type type) { // Use local allocator to reduce peak memory usage. ScopedArenaAllocator allocator(allocator_.GetArenaStack()); @@ -1954,8 +1970,8 @@ bool LSEVisitor::MaterializeLoopPhis(const ArenaBitVector& phi_placeholders_to_m for (uint32_t matrix_index : current_dependencies->Indexes()) { current_subset.push_back(phi_placeholder_indexes[matrix_index]); } - if (!MaterializeLoopPhis(current_subset, type, phase)) { - DCHECK(phase == Phase::kStoreElimination); + if (!MaterializeLoopPhis(current_subset, type)) { + DCHECK_EQ(current_phase_, Phase::kStoreElimination); // This is the final store elimination phase and we shall not be able to eliminate any // stores that depend on the current subset, so mark these Phi placeholders unreplaceable. for (uint32_t matrix_index = 0; matrix_index != num_phi_placeholders; ++matrix_index) { @@ -2007,8 +2023,8 @@ std::optional<LSEVisitor::PhiPlaceholder> LSEVisitor::TryToMaterializeLoopPhis( return loop_phi_with_unknown_input; // Return failure. } - bool success = - MaterializeLoopPhis(phi_placeholders_to_materialize, type, Phase::kLoadElimination); + DCHECK_EQ(current_phase_, Phase::kLoadElimination); + bool success = MaterializeLoopPhis(phi_placeholders_to_materialize, type); DCHECK(success); // Report success. @@ -2361,8 +2377,8 @@ void LSEVisitor::FindOldValueForPhiPlaceholder(PhiPlaceholder phi_placeholder, return; } - bool success = - MaterializeLoopPhis(phi_placeholders_to_materialize, type, Phase::kStoreElimination); + DCHECK_EQ(current_phase_, Phase::kStoreElimination); + bool success = MaterializeLoopPhis(phi_placeholders_to_materialize, type); DCHECK(phi_placeholder_replacements_[PhiPlaceholderIndex(phi_placeholder)].IsValid()); DCHECK_EQ(phi_placeholder_replacements_[PhiPlaceholderIndex(phi_placeholder)].IsUnknown(), !success); @@ -2428,10 +2444,11 @@ void LSEVisitor::Run() { } // 2. Process loads that require loop Phis, trying to find/create replacements. + current_phase_ = Phase::kLoadElimination; ProcessLoadsRequiringLoopPhis(); // 3. Determine which stores to keep and which to eliminate. - + current_phase_ = Phase::kStoreElimination; // Finish marking stores for keeping. SearchPhiPlaceholdersForKeptStores(); |