diff options
Diffstat (limited to 'compiler/optimizing/scheduler.cc')
| -rw-r--r-- | compiler/optimizing/scheduler.cc | 213 |
1 files changed, 205 insertions, 8 deletions
diff --git a/compiler/optimizing/scheduler.cc b/compiler/optimizing/scheduler.cc index 147fa1c05a..5ad011d8f9 100644 --- a/compiler/optimizing/scheduler.cc +++ b/compiler/optimizing/scheduler.cc @@ -66,28 +66,215 @@ static bool MayHaveReorderingDependency(SideEffects node, SideEffects other) { return false; } +size_t SchedulingGraph::ArrayAccessHeapLocation(HInstruction* array, HInstruction* index) const { + DCHECK(heap_location_collector_ != nullptr); + size_t heap_loc = heap_location_collector_->GetArrayAccessHeapLocation(array, index); + // This array access should be analyzed and added to HeapLocationCollector before. + DCHECK(heap_loc != HeapLocationCollector::kHeapLocationNotFound); + return heap_loc; +} -// Check whether `node` depends on `other`, taking into account `SideEffect` -// information and `CanThrow` information. -static bool HasSideEffectDependency(const HInstruction* node, const HInstruction* other) { - if (MayHaveReorderingDependency(node->GetSideEffects(), other->GetSideEffects())) { +bool SchedulingGraph::ArrayAccessMayAlias(const HInstruction* node, + const HInstruction* other) const { + DCHECK(heap_location_collector_ != nullptr); + size_t node_heap_loc = ArrayAccessHeapLocation(node->InputAt(0), node->InputAt(1)); + size_t other_heap_loc = ArrayAccessHeapLocation(other->InputAt(0), other->InputAt(1)); + + // For example: arr[0] and arr[0] + if (node_heap_loc == other_heap_loc) { return true; } - if (other->CanThrow() && node->GetSideEffects().DoesAnyWrite()) { + // For example: arr[0] and arr[i] + if (heap_location_collector_->MayAlias(node_heap_loc, other_heap_loc)) { return true; } - if (other->GetSideEffects().DoesAnyWrite() && node->CanThrow()) { + return false; +} + +static bool IsArrayAccess(const HInstruction* instruction) { + return instruction->IsArrayGet() || instruction->IsArraySet(); +} + +static bool IsInstanceFieldAccess(const HInstruction* instruction) { + return instruction->IsInstanceFieldGet() || + instruction->IsInstanceFieldSet() || + instruction->IsUnresolvedInstanceFieldGet() || + instruction->IsUnresolvedInstanceFieldSet(); +} + +static bool IsStaticFieldAccess(const HInstruction* instruction) { + return instruction->IsStaticFieldGet() || + instruction->IsStaticFieldSet() || + instruction->IsUnresolvedStaticFieldGet() || + instruction->IsUnresolvedStaticFieldSet(); +} + +static bool IsResolvedFieldAccess(const HInstruction* instruction) { + return instruction->IsInstanceFieldGet() || + instruction->IsInstanceFieldSet() || + instruction->IsStaticFieldGet() || + instruction->IsStaticFieldSet(); +} + +static bool IsUnresolvedFieldAccess(const HInstruction* instruction) { + return instruction->IsUnresolvedInstanceFieldGet() || + instruction->IsUnresolvedInstanceFieldSet() || + instruction->IsUnresolvedStaticFieldGet() || + instruction->IsUnresolvedStaticFieldSet(); +} + +static bool IsFieldAccess(const HInstruction* instruction) { + return IsResolvedFieldAccess(instruction) || IsUnresolvedFieldAccess(instruction); +} + +static const FieldInfo* GetFieldInfo(const HInstruction* instruction) { + if (instruction->IsInstanceFieldGet()) { + return &instruction->AsInstanceFieldGet()->GetFieldInfo(); + } else if (instruction->IsInstanceFieldSet()) { + return &instruction->AsInstanceFieldSet()->GetFieldInfo(); + } else if (instruction->IsStaticFieldGet()) { + return &instruction->AsStaticFieldGet()->GetFieldInfo(); + } else if (instruction->IsStaticFieldSet()) { + return &instruction->AsStaticFieldSet()->GetFieldInfo(); + } else { + LOG(FATAL) << "Unexpected field access type"; + UNREACHABLE(); + } +} + +size_t SchedulingGraph::FieldAccessHeapLocation(HInstruction* obj, const FieldInfo* field) const { + DCHECK(obj != nullptr); + DCHECK(field != nullptr); + DCHECK(heap_location_collector_ != nullptr); + + size_t heap_loc = heap_location_collector_->FindHeapLocationIndex( + heap_location_collector_->FindReferenceInfoOf( + heap_location_collector_->HuntForOriginalReference(obj)), + field->GetFieldOffset().SizeValue(), + nullptr, + field->GetDeclaringClassDefIndex()); + // This field access should be analyzed and added to HeapLocationCollector before. + DCHECK(heap_loc != HeapLocationCollector::kHeapLocationNotFound); + + return heap_loc; +} + +bool SchedulingGraph::FieldAccessMayAlias(const HInstruction* node, + const HInstruction* other) const { + DCHECK(heap_location_collector_ != nullptr); + + // Static and instance field accesses should not alias. + if ((IsInstanceFieldAccess(node) && IsStaticFieldAccess(other)) || + (IsStaticFieldAccess(node) && IsInstanceFieldAccess(other))) { + return false; + } + + // If either of the field accesses is unresolved. + if (IsUnresolvedFieldAccess(node) || IsUnresolvedFieldAccess(other)) { + // Conservatively treat these two accesses may alias. + return true; + } + + // If both fields accesses are resolved. + const FieldInfo* node_field = GetFieldInfo(node); + const FieldInfo* other_field = GetFieldInfo(other); + + size_t node_loc = FieldAccessHeapLocation(node->InputAt(0), node_field); + size_t other_loc = FieldAccessHeapLocation(other->InputAt(0), other_field); + + if (node_loc == other_loc) { return true; } + if (!heap_location_collector_->MayAlias(node_loc, other_loc)) { + return false; + } + + return true; +} + +bool SchedulingGraph::HasMemoryDependency(const HInstruction* node, + const HInstruction* other) const { + if (!MayHaveReorderingDependency(node->GetSideEffects(), other->GetSideEffects())) { + return false; + } + + if (heap_location_collector_ == nullptr || + heap_location_collector_->GetNumberOfHeapLocations() == 0) { + // Without HeapLocation information from load store analysis, + // we cannot do further disambiguation analysis on these two instructions. + // Just simply say that those two instructions have memory dependency. + return true; + } + + if (IsArrayAccess(node) && IsArrayAccess(other)) { + return ArrayAccessMayAlias(node, other); + } + if (IsFieldAccess(node) && IsFieldAccess(other)) { + return FieldAccessMayAlias(node, other); + } + + // TODO(xueliang): LSA to support alias analysis among HVecLoad, HVecStore and ArrayAccess + if (node->IsVecMemoryOperation() && other->IsVecMemoryOperation()) { + return true; + } + if (node->IsVecMemoryOperation() && IsArrayAccess(other)) { + return true; + } + if (IsArrayAccess(node) && other->IsVecMemoryOperation()) { + return true; + } + + // Heap accesses of different kinds should not alias. + if (IsArrayAccess(node) && IsFieldAccess(other)) { + return false; + } + if (IsFieldAccess(node) && IsArrayAccess(other)) { + return false; + } + if (node->IsVecMemoryOperation() && IsFieldAccess(other)) { + return false; + } + if (IsFieldAccess(node) && other->IsVecMemoryOperation()) { + return false; + } + + // We conservatively treat all other cases having dependency, + // for example, Invoke and ArrayGet. + return true; +} + +bool SchedulingGraph::HasExceptionDependency(const HInstruction* node, + const HInstruction* other) const { + if (other->CanThrow() && node->GetSideEffects().DoesAnyWrite()) { + return true; + } + if (other->GetSideEffects().DoesAnyWrite() && node->CanThrow()) { + return true; + } if (other->CanThrow() && node->CanThrow()) { return true; } - // Check side-effect dependency between ArrayGet and BoundsCheck. - if (node->IsArrayGet() && other->IsBoundsCheck() && node->InputAt(1) == other) { + // Above checks should cover all cases where we cannot reorder two + // instructions which may throw exception. + return false; +} + +// Check whether `node` depends on `other`, taking into account `SideEffect` +// information and `CanThrow` information. +bool SchedulingGraph::HasSideEffectDependency(const HInstruction* node, + const HInstruction* other) const { + if (HasMemoryDependency(node, other)) { + return true; + } + + // Even if above memory dependency check has passed, it is still necessary to + // check dependencies between instructions that can throw and instructions + // that write to memory. + if (HasExceptionDependency(node, other)) { return true; } @@ -379,6 +566,14 @@ void HScheduler::Schedule(HBasicBlock* block) { // Build the scheduling graph. scheduling_graph_.Clear(); + + // Only perform LSA/HeapLocation analysis on the basic block that + // is going to get instruction scheduled. + HeapLocationCollector heap_location_collector(block->GetGraph()); + heap_location_collector.VisitBasicBlock(block); + heap_location_collector.BuildAliasingMatrix(); + scheduling_graph_.SetHeapLocationCollector(heap_location_collector); + for (HBackwardInstructionIterator it(block->GetInstructions()); !it.Done(); it.Advance()) { HInstruction* instruction = it.Current(); CHECK_EQ(instruction->GetBlock(), block) @@ -606,7 +801,9 @@ void HInstructionScheduling::Run(bool only_optimize_loop_blocks, // Avoid compilation error when compiling for unsupported instruction set. UNUSED(only_optimize_loop_blocks); UNUSED(schedule_randomly); + UNUSED(codegen_); #endif + switch (instruction_set_) { #ifdef ART_ENABLE_CODEGEN_arm64 case kArm64: { |