// Copyright 2014 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "src/compiler/simplified-operator-reducer.h" #include "src/compiler/common-operator.h" #include "src/compiler/js-graph.h" #include "src/compiler/js-heap-broker.h" #include "src/compiler/machine-operator.h" #include "src/compiler/node-matchers.h" #include "src/compiler/opcodes.h" #include "src/compiler/operator-properties.h" #include "src/compiler/simplified-operator.h" #include "src/compiler/type-cache.h" #include "src/numbers/conversions-inl.h" namespace v8 { namespace internal { namespace compiler { namespace { Decision DecideObjectIsSmi(Node* const input) { NumberMatcher m(input); if (m.HasResolvedValue()) { return IsSmiDouble(m.ResolvedValue()) ? Decision::kTrue : Decision::kFalse; } if (m.IsAllocate()) return Decision::kFalse; if (m.IsChangeBitToTagged()) return Decision::kFalse; if (m.IsChangeInt31ToTaggedSigned()) return Decision::kTrue; if (m.IsHeapConstant()) return Decision::kFalse; return Decision::kUnknown; } } // namespace SimplifiedOperatorReducer::SimplifiedOperatorReducer( Editor* editor, JSGraph* jsgraph, JSHeapBroker* broker, BranchSemantics branch_semantics) : AdvancedReducer(editor), jsgraph_(jsgraph), broker_(broker), branch_semantics_(branch_semantics) {} SimplifiedOperatorReducer::~SimplifiedOperatorReducer() = default; Reduction SimplifiedOperatorReducer::Reduce(Node* node) { switch (node->opcode()) { case IrOpcode::kBooleanNot: { HeapObjectMatcher m(node->InputAt(0)); if (m.Is(factory()->true_value())) return ReplaceBoolean(false); if (m.Is(factory()->false_value())) return ReplaceBoolean(true); if (m.IsBooleanNot()) return Replace(m.InputAt(0)); break; } case IrOpcode::kChangeBitToTagged: { Int32Matcher m(node->InputAt(0)); if (m.Is(0)) return Replace(jsgraph()->FalseConstant()); if (m.Is(1)) return Replace(jsgraph()->TrueConstant()); if (m.IsChangeTaggedToBit()) return Replace(m.InputAt(0)); break; } case IrOpcode::kChangeTaggedToBit: { HeapObjectMatcher m(node->InputAt(0)); if (m.HasResolvedValue()) { base::Optional<bool> maybe_result = m.Ref(broker()).TryGetBooleanValue(); if (maybe_result.has_value()) return ReplaceInt32(*maybe_result); } if (m.IsChangeBitToTagged()) return Replace(m.InputAt(0)); break; } case IrOpcode::kChangeFloat64ToTagged: { Float64Matcher m(node->InputAt(0)); if (m.HasResolvedValue()) return ReplaceNumber(m.ResolvedValue()); if (m.IsChangeTaggedToFloat64()) return Replace(m.node()->InputAt(0)); break; } case IrOpcode::kChangeInt31ToTaggedSigned: case IrOpcode::kChangeInt32ToTagged: { Int32Matcher m(node->InputAt(0)); if (m.HasResolvedValue()) return ReplaceNumber(m.ResolvedValue()); if (m.IsChangeTaggedSignedToInt32()) { return Replace(m.InputAt(0)); } break; } case IrOpcode::kChangeTaggedToFloat64: case IrOpcode::kTruncateTaggedToFloat64: { NumberMatcher m(node->InputAt(0)); if (m.HasResolvedValue()) return ReplaceFloat64(m.ResolvedValue()); if (m.IsChangeFloat64ToTagged() || m.IsChangeFloat64ToTaggedPointer()) { return Replace(m.node()->InputAt(0)); } if (m.IsChangeInt31ToTaggedSigned() || m.IsChangeInt32ToTagged()) { return Change(node, machine()->ChangeInt32ToFloat64(), m.InputAt(0)); } if (m.IsChangeUint32ToTagged()) { return Change(node, machine()->ChangeUint32ToFloat64(), m.InputAt(0)); } break; } case IrOpcode::kChangeTaggedSignedToInt32: case IrOpcode::kChangeTaggedToInt32: { NumberMatcher m(node->InputAt(0)); if (m.HasResolvedValue()) return ReplaceInt32(DoubleToInt32(m.ResolvedValue())); if (m.IsChangeFloat64ToTagged() || m.IsChangeFloat64ToTaggedPointer()) { return Change(node, machine()->ChangeFloat64ToInt32(), m.InputAt(0)); } if (m.IsChangeInt31ToTaggedSigned() || m.IsChangeInt32ToTagged()) { return Replace(m.InputAt(0)); } break; } case IrOpcode::kChangeTaggedToUint32: { NumberMatcher m(node->InputAt(0)); if (m.HasResolvedValue()) return ReplaceUint32(DoubleToUint32(m.ResolvedValue())); if (m.IsChangeFloat64ToTagged() || m.IsChangeFloat64ToTaggedPointer()) { return Change(node, machine()->ChangeFloat64ToUint32(), m.InputAt(0)); } if (m.IsChangeUint32ToTagged()) return Replace(m.InputAt(0)); break; } case IrOpcode::kChangeUint32ToTagged: { Uint32Matcher m(node->InputAt(0)); if (m.HasResolvedValue()) return ReplaceNumber(FastUI2D(m.ResolvedValue())); break; } case IrOpcode::kTruncateTaggedToWord32: { NumberMatcher m(node->InputAt(0)); if (m.HasResolvedValue()) return ReplaceInt32(DoubleToInt32(m.ResolvedValue())); if (m.IsChangeInt31ToTaggedSigned() || m.IsChangeInt32ToTagged() || m.IsChangeUint32ToTagged()) { return Replace(m.InputAt(0)); } if (m.IsChangeFloat64ToTagged() || m.IsChangeFloat64ToTaggedPointer()) { return Change(node, machine()->TruncateFloat64ToWord32(), m.InputAt(0)); } break; } case IrOpcode::kCheckedFloat64ToInt32: { Float64Matcher m(node->InputAt(0)); if (m.HasResolvedValue() && IsInt32Double(m.ResolvedValue())) { Node* value = jsgraph()->Int32Constant(static_cast<int32_t>(m.ResolvedValue())); ReplaceWithValue(node, value); return Replace(value); } break; } case IrOpcode::kCheckedTaggedToArrayIndex: case IrOpcode::kCheckedTaggedToInt32: case IrOpcode::kCheckedTaggedSignedToInt32: { NodeMatcher m(node->InputAt(0)); if (m.IsConvertTaggedHoleToUndefined()) { node->ReplaceInput(0, m.InputAt(0)); return Changed(node); } break; } case IrOpcode::kCheckIf: { HeapObjectMatcher m(node->InputAt(0)); if (m.Is(factory()->true_value())) { Node* const effect = NodeProperties::GetEffectInput(node); return Replace(effect); } break; } case IrOpcode::kCheckNumber: { NodeMatcher m(node->InputAt(0)); if (m.IsConvertTaggedHoleToUndefined()) { node->ReplaceInput(0, m.InputAt(0)); return Changed(node); } break; } case IrOpcode::kCheckHeapObject: { Node* const input = node->InputAt(0); if (DecideObjectIsSmi(input) == Decision::kFalse) { ReplaceWithValue(node, input); return Replace(input); } NodeMatcher m(input); if (m.IsCheckHeapObject()) { ReplaceWithValue(node, input); return Replace(input); } break; } case IrOpcode::kCheckSmi: { Node* const input = node->InputAt(0); if (DecideObjectIsSmi(input) == Decision::kTrue) { ReplaceWithValue(node, input); return Replace(input); } NodeMatcher m(input); if (m.IsCheckSmi()) { ReplaceWithValue(node, input); return Replace(input); } else if (m.IsConvertTaggedHoleToUndefined()) { node->ReplaceInput(0, m.InputAt(0)); return Changed(node); } break; } case IrOpcode::kObjectIsSmi: { Node* const input = node->InputAt(0); switch (DecideObjectIsSmi(input)) { case Decision::kTrue: return ReplaceBoolean(true); case Decision::kFalse: return ReplaceBoolean(false); case Decision::kUnknown: break; } break; } case IrOpcode::kNumberAbs: { NumberMatcher m(node->InputAt(0)); if (m.HasResolvedValue()) return ReplaceNumber(std::fabs(m.ResolvedValue())); break; } case IrOpcode::kReferenceEqual: { HeapObjectBinopMatcher m(node); if (m.left().node() == m.right().node()) return ReplaceBoolean(true); break; } case IrOpcode::kCheckedInt32Add: { // (x + a) + b => x + (a + b) where a and b are constants and have the // same sign. Int32BinopMatcher m(node); if (m.right().HasResolvedValue()) { Node* checked_int32_add = m.left().node(); if (checked_int32_add->opcode() == IrOpcode::kCheckedInt32Add) { Int32BinopMatcher n(checked_int32_add); if (n.right().HasResolvedValue() && (n.right().ResolvedValue() >= 0) == (m.right().ResolvedValue() >= 0)) { int32_t val; bool overflow = base::bits::SignedAddOverflow32( n.right().ResolvedValue(), m.right().ResolvedValue(), &val); if (!overflow) { bool has_no_other_uses = true; for (Edge edge : checked_int32_add->use_edges()) { if (!edge.from()->IsDead() && edge.from() != node) { has_no_other_uses = false; break; } } if (has_no_other_uses) { node->ReplaceInput(0, n.left().node()); node->ReplaceInput(1, jsgraph()->Int32Constant(val)); RelaxEffectsAndControls(checked_int32_add); return Changed(node); } } } } } break; } default: break; } return NoChange(); } Reduction SimplifiedOperatorReducer::Change(Node* node, const Operator* op, Node* a) { DCHECK_EQ(node->InputCount(), OperatorProperties::GetTotalInputCount(op)); DCHECK_LE(1, node->InputCount()); node->ReplaceInput(0, a); NodeProperties::ChangeOp(node, op); return Changed(node); } Reduction SimplifiedOperatorReducer::ReplaceBoolean(bool value) { if (branch_semantics_ == BranchSemantics::kJS) { return Replace(jsgraph()->BooleanConstant(value)); } else { return ReplaceInt32(value); } } Reduction SimplifiedOperatorReducer::ReplaceFloat64(double value) { return Replace(jsgraph()->Float64Constant(value)); } Reduction SimplifiedOperatorReducer::ReplaceInt32(int32_t value) { return Replace(jsgraph()->Int32Constant(value)); } Reduction SimplifiedOperatorReducer::ReplaceNumber(double value) { return Replace(jsgraph()->Constant(value)); } Reduction SimplifiedOperatorReducer::ReplaceNumber(int32_t value) { return Replace(jsgraph()->Constant(value)); } Factory* SimplifiedOperatorReducer::factory() const { return jsgraph()->isolate()->factory(); } Graph* SimplifiedOperatorReducer::graph() const { return jsgraph()->graph(); } MachineOperatorBuilder* SimplifiedOperatorReducer::machine() const { return jsgraph()->machine(); } SimplifiedOperatorBuilder* SimplifiedOperatorReducer::simplified() const { return jsgraph()->simplified(); } } // namespace compiler } // namespace internal } // namespace v8