| // 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/machine-operator-reducer.h" |
| |
| #include "src/base/bits.h" |
| #include "src/base/division-by-constant.h" |
| #include "src/codegen.h" |
| #include "src/compiler/generic-node-inl.h" |
| #include "src/compiler/graph.h" |
| #include "src/compiler/js-graph.h" |
| #include "src/compiler/node-matchers.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace compiler { |
| |
| MachineOperatorReducer::MachineOperatorReducer(JSGraph* jsgraph) |
| : jsgraph_(jsgraph) {} |
| |
| |
| MachineOperatorReducer::~MachineOperatorReducer() {} |
| |
| |
| Node* MachineOperatorReducer::Float32Constant(volatile float value) { |
| return graph()->NewNode(common()->Float32Constant(value)); |
| } |
| |
| |
| Node* MachineOperatorReducer::Float64Constant(volatile double value) { |
| return jsgraph()->Float64Constant(value); |
| } |
| |
| |
| Node* MachineOperatorReducer::Int32Constant(int32_t value) { |
| return jsgraph()->Int32Constant(value); |
| } |
| |
| |
| Node* MachineOperatorReducer::Int64Constant(int64_t value) { |
| return graph()->NewNode(common()->Int64Constant(value)); |
| } |
| |
| |
| Node* MachineOperatorReducer::Word32And(Node* lhs, uint32_t rhs) { |
| return graph()->NewNode(machine()->Word32And(), lhs, Uint32Constant(rhs)); |
| } |
| |
| |
| Node* MachineOperatorReducer::Word32Sar(Node* lhs, uint32_t rhs) { |
| return graph()->NewNode(machine()->Word32Sar(), lhs, Uint32Constant(rhs)); |
| } |
| |
| |
| Node* MachineOperatorReducer::Word32Shr(Node* lhs, uint32_t rhs) { |
| return graph()->NewNode(machine()->Word32Shr(), lhs, Uint32Constant(rhs)); |
| } |
| |
| |
| Node* MachineOperatorReducer::Word32Equal(Node* lhs, Node* rhs) { |
| return graph()->NewNode(machine()->Word32Equal(), lhs, rhs); |
| } |
| |
| |
| Node* MachineOperatorReducer::Int32Add(Node* lhs, Node* rhs) { |
| return graph()->NewNode(machine()->Int32Add(), lhs, rhs); |
| } |
| |
| |
| Node* MachineOperatorReducer::Int32Sub(Node* lhs, Node* rhs) { |
| return graph()->NewNode(machine()->Int32Sub(), lhs, rhs); |
| } |
| |
| |
| Node* MachineOperatorReducer::Int32Mul(Node* lhs, Node* rhs) { |
| return graph()->NewNode(machine()->Int32Mul(), lhs, rhs); |
| } |
| |
| |
| Node* MachineOperatorReducer::TruncatingDiv(Node* dividend, int32_t divisor) { |
| DCHECK_NE(std::numeric_limits<int32_t>::min(), divisor); |
| base::MagicNumbersForDivision<uint32_t> const mag = |
| base::SignedDivisionByConstant(bit_cast<uint32_t>(divisor)); |
| Node* quotient = graph()->NewNode(machine()->Int32MulHigh(), dividend, |
| Uint32Constant(mag.multiplier)); |
| if (divisor > 0 && bit_cast<int32_t>(mag.multiplier) < 0) { |
| quotient = Int32Add(quotient, dividend); |
| } else if (divisor < 0 && bit_cast<int32_t>(mag.multiplier) > 0) { |
| quotient = Int32Sub(quotient, dividend); |
| } |
| if (mag.shift) { |
| quotient = Word32Sar(quotient, mag.shift); |
| } |
| return Int32Add(quotient, Word32Shr(dividend, 31)); |
| } |
| |
| |
| // Perform constant folding and strength reduction on machine operators. |
| Reduction MachineOperatorReducer::Reduce(Node* node) { |
| switch (node->opcode()) { |
| case IrOpcode::kProjection: |
| return ReduceProjection(OpParameter<size_t>(node), node->InputAt(0)); |
| case IrOpcode::kWord32And: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.right().node()); // x & 0 => 0 |
| if (m.right().Is(-1)) return Replace(m.left().node()); // x & -1 => x |
| if (m.IsFoldable()) { // K & K => K |
| return ReplaceInt32(m.left().Value() & m.right().Value()); |
| } |
| if (m.LeftEqualsRight()) return Replace(m.left().node()); // x & x => x |
| if (m.left().IsWord32And() && m.right().HasValue()) { |
| Int32BinopMatcher mleft(m.left().node()); |
| if (mleft.right().HasValue()) { // (x & K) & K => x & K |
| node->ReplaceInput(0, mleft.left().node()); |
| node->ReplaceInput( |
| 1, Int32Constant(m.right().Value() & mleft.right().Value())); |
| return Changed(node); |
| } |
| } |
| break; |
| } |
| case IrOpcode::kWord32Or: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.left().node()); // x | 0 => x |
| if (m.right().Is(-1)) return Replace(m.right().node()); // x | -1 => -1 |
| if (m.IsFoldable()) { // K | K => K |
| return ReplaceInt32(m.left().Value() | m.right().Value()); |
| } |
| if (m.LeftEqualsRight()) return Replace(m.left().node()); // x | x => x |
| if (m.left().IsWord32Shl() && m.right().IsWord32Shr()) { |
| Int32BinopMatcher mleft(m.left().node()); |
| Int32BinopMatcher mright(m.right().node()); |
| if (mleft.left().node() == mright.left().node()) { |
| // (x << y) | (x >> (32 - y)) => x ror y |
| if (mright.right().IsInt32Sub()) { |
| Int32BinopMatcher mrightright(mright.right().node()); |
| if (mrightright.left().Is(32) && |
| mrightright.right().node() == mleft.right().node()) { |
| node->set_op(machine()->Word32Ror()); |
| node->ReplaceInput(0, mleft.left().node()); |
| node->ReplaceInput(1, mleft.right().node()); |
| return Changed(node); |
| } |
| } |
| // (x << K) | (x >> (32 - K)) => x ror K |
| if (mleft.right().IsInRange(0, 31) && |
| mright.right().Is(32 - mleft.right().Value())) { |
| node->set_op(machine()->Word32Ror()); |
| node->ReplaceInput(0, mleft.left().node()); |
| node->ReplaceInput(1, mleft.right().node()); |
| return Changed(node); |
| } |
| } |
| } |
| if (m.left().IsWord32Shr() && m.right().IsWord32Shl()) { |
| // (x >> (32 - y)) | (x << y) => x ror y |
| Int32BinopMatcher mleft(m.left().node()); |
| Int32BinopMatcher mright(m.right().node()); |
| if (mleft.left().node() == mright.left().node()) { |
| if (mleft.right().IsInt32Sub()) { |
| Int32BinopMatcher mleftright(mleft.right().node()); |
| if (mleftright.left().Is(32) && |
| mleftright.right().node() == mright.right().node()) { |
| node->set_op(machine()->Word32Ror()); |
| node->ReplaceInput(0, mright.left().node()); |
| node->ReplaceInput(1, mright.right().node()); |
| return Changed(node); |
| } |
| } |
| // (x >> (32 - K)) | (x << K) => x ror K |
| if (mright.right().IsInRange(0, 31) && |
| mleft.right().Is(32 - mright.right().Value())) { |
| node->set_op(machine()->Word32Ror()); |
| node->ReplaceInput(0, mright.left().node()); |
| node->ReplaceInput(1, mright.right().node()); |
| return Changed(node); |
| } |
| } |
| } |
| break; |
| } |
| case IrOpcode::kWord32Xor: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.left().node()); // x ^ 0 => x |
| if (m.IsFoldable()) { // K ^ K => K |
| return ReplaceInt32(m.left().Value() ^ m.right().Value()); |
| } |
| if (m.LeftEqualsRight()) return ReplaceInt32(0); // x ^ x => 0 |
| if (m.left().IsWord32Xor() && m.right().Is(-1)) { |
| Int32BinopMatcher mleft(m.left().node()); |
| if (mleft.right().Is(-1)) { // (x ^ -1) ^ -1 => x |
| return Replace(mleft.left().node()); |
| } |
| } |
| break; |
| } |
| case IrOpcode::kWord32Shl: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.left().node()); // x << 0 => x |
| if (m.IsFoldable()) { // K << K => K |
| return ReplaceInt32(m.left().Value() << m.right().Value()); |
| } |
| if (m.right().IsInRange(1, 31)) { |
| // (x >>> K) << K => x & ~(2^K - 1) |
| // (x >> K) << K => x & ~(2^K - 1) |
| if (m.left().IsWord32Sar() || m.left().IsWord32Shr()) { |
| Int32BinopMatcher mleft(m.left().node()); |
| if (mleft.right().Is(m.right().Value())) { |
| node->set_op(machine()->Word32And()); |
| node->ReplaceInput(0, mleft.left().node()); |
| node->ReplaceInput( |
| 1, Uint32Constant(~((1U << m.right().Value()) - 1U))); |
| return Changed(node); |
| } |
| } |
| } |
| break; |
| } |
| case IrOpcode::kWord32Shr: { |
| Uint32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.left().node()); // x >>> 0 => x |
| if (m.IsFoldable()) { // K >>> K => K |
| return ReplaceInt32(m.left().Value() >> m.right().Value()); |
| } |
| break; |
| } |
| case IrOpcode::kWord32Sar: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.left().node()); // x >> 0 => x |
| if (m.IsFoldable()) { // K >> K => K |
| return ReplaceInt32(m.left().Value() >> m.right().Value()); |
| } |
| break; |
| } |
| case IrOpcode::kWord32Ror: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.left().node()); // x ror 0 => x |
| if (m.IsFoldable()) { // K ror K => K |
| return ReplaceInt32( |
| base::bits::RotateRight32(m.left().Value(), m.right().Value())); |
| } |
| break; |
| } |
| case IrOpcode::kWord32Equal: { |
| Int32BinopMatcher m(node); |
| if (m.IsFoldable()) { // K == K => K |
| return ReplaceBool(m.left().Value() == m.right().Value()); |
| } |
| if (m.left().IsInt32Sub() && m.right().Is(0)) { // x - y == 0 => x == y |
| Int32BinopMatcher msub(m.left().node()); |
| node->ReplaceInput(0, msub.left().node()); |
| node->ReplaceInput(1, msub.right().node()); |
| return Changed(node); |
| } |
| // TODO(turbofan): fold HeapConstant, ExternalReference, pointer compares |
| if (m.LeftEqualsRight()) return ReplaceBool(true); // x == x => true |
| break; |
| } |
| case IrOpcode::kWord64Equal: { |
| Int64BinopMatcher m(node); |
| if (m.IsFoldable()) { // K == K => K |
| return ReplaceBool(m.left().Value() == m.right().Value()); |
| } |
| if (m.left().IsInt64Sub() && m.right().Is(0)) { // x - y == 0 => x == y |
| Int64BinopMatcher msub(m.left().node()); |
| node->ReplaceInput(0, msub.left().node()); |
| node->ReplaceInput(1, msub.right().node()); |
| return Changed(node); |
| } |
| // TODO(turbofan): fold HeapConstant, ExternalReference, pointer compares |
| if (m.LeftEqualsRight()) return ReplaceBool(true); // x == x => true |
| break; |
| } |
| case IrOpcode::kInt32Add: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.left().node()); // x + 0 => x |
| if (m.IsFoldable()) { // K + K => K |
| return ReplaceInt32(static_cast<uint32_t>(m.left().Value()) + |
| static_cast<uint32_t>(m.right().Value())); |
| } |
| break; |
| } |
| case IrOpcode::kInt32Sub: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.left().node()); // x - 0 => x |
| if (m.IsFoldable()) { // K - K => K |
| return ReplaceInt32(static_cast<uint32_t>(m.left().Value()) - |
| static_cast<uint32_t>(m.right().Value())); |
| } |
| if (m.LeftEqualsRight()) return ReplaceInt32(0); // x - x => 0 |
| break; |
| } |
| case IrOpcode::kInt32Mul: { |
| Int32BinopMatcher m(node); |
| if (m.right().Is(0)) return Replace(m.right().node()); // x * 0 => 0 |
| if (m.right().Is(1)) return Replace(m.left().node()); // x * 1 => x |
| if (m.IsFoldable()) { // K * K => K |
| return ReplaceInt32(m.left().Value() * m.right().Value()); |
| } |
| if (m.right().Is(-1)) { // x * -1 => 0 - x |
| node->set_op(machine()->Int32Sub()); |
| node->ReplaceInput(0, Int32Constant(0)); |
| node->ReplaceInput(1, m.left().node()); |
| return Changed(node); |
| } |
| if (m.right().IsPowerOf2()) { // x * 2^n => x << n |
| node->set_op(machine()->Word32Shl()); |
| node->ReplaceInput(1, Int32Constant(WhichPowerOf2(m.right().Value()))); |
| return Changed(node); |
| } |
| break; |
| } |
| case IrOpcode::kInt32Div: |
| return ReduceInt32Div(node); |
| case IrOpcode::kUint32Div: |
| return ReduceUint32Div(node); |
| case IrOpcode::kInt32Mod: |
| return ReduceInt32Mod(node); |
| case IrOpcode::kUint32Mod: |
| return ReduceUint32Mod(node); |
| case IrOpcode::kInt32LessThan: { |
| Int32BinopMatcher m(node); |
| if (m.IsFoldable()) { // K < K => K |
| return ReplaceBool(m.left().Value() < m.right().Value()); |
| } |
| if (m.left().IsInt32Sub() && m.right().Is(0)) { // x - y < 0 => x < y |
| Int32BinopMatcher msub(m.left().node()); |
| node->ReplaceInput(0, msub.left().node()); |
| node->ReplaceInput(1, msub.right().node()); |
| return Changed(node); |
| } |
| if (m.left().Is(0) && m.right().IsInt32Sub()) { // 0 < x - y => y < x |
| Int32BinopMatcher msub(m.right().node()); |
| node->ReplaceInput(0, msub.right().node()); |
| node->ReplaceInput(1, msub.left().node()); |
| return Changed(node); |
| } |
| if (m.LeftEqualsRight()) return ReplaceBool(false); // x < x => false |
| break; |
| } |
| case IrOpcode::kInt32LessThanOrEqual: { |
| Int32BinopMatcher m(node); |
| if (m.IsFoldable()) { // K <= K => K |
| return ReplaceBool(m.left().Value() <= m.right().Value()); |
| } |
| if (m.left().IsInt32Sub() && m.right().Is(0)) { // x - y <= 0 => x <= y |
| Int32BinopMatcher msub(m.left().node()); |
| node->ReplaceInput(0, msub.left().node()); |
| node->ReplaceInput(1, msub.right().node()); |
| return Changed(node); |
| } |
| if (m.left().Is(0) && m.right().IsInt32Sub()) { // 0 <= x - y => y <= x |
| Int32BinopMatcher msub(m.right().node()); |
| node->ReplaceInput(0, msub.right().node()); |
| node->ReplaceInput(1, msub.left().node()); |
| return Changed(node); |
| } |
| if (m.LeftEqualsRight()) return ReplaceBool(true); // x <= x => true |
| break; |
| } |
| case IrOpcode::kUint32LessThan: { |
| Uint32BinopMatcher m(node); |
| if (m.left().Is(kMaxUInt32)) return ReplaceBool(false); // M < x => false |
| if (m.right().Is(0)) return ReplaceBool(false); // x < 0 => false |
| if (m.IsFoldable()) { // K < K => K |
| return ReplaceBool(m.left().Value() < m.right().Value()); |
| } |
| if (m.LeftEqualsRight()) return ReplaceBool(false); // x < x => false |
| if (m.left().IsWord32Sar() && m.right().HasValue()) { |
| Int32BinopMatcher mleft(m.left().node()); |
| if (mleft.right().HasValue()) { |
| // (x >> K) < C => x < (C << K) | (2^K - 1) |
| // when C < (M >> K) |
| const uint32_t c = m.right().Value(); |
| const uint32_t k = mleft.right().Value() & 0x1f; |
| if (c < static_cast<uint32_t>(kMaxInt >> k)) { |
| node->ReplaceInput(0, mleft.left().node()); |
| node->ReplaceInput(1, Uint32Constant((c << k) | ((1 << k) - 1))); |
| return Changed(node); |
| } |
| } |
| } |
| break; |
| } |
| case IrOpcode::kUint32LessThanOrEqual: { |
| Uint32BinopMatcher m(node); |
| if (m.left().Is(0)) return ReplaceBool(true); // 0 <= x => true |
| if (m.right().Is(kMaxUInt32)) return ReplaceBool(true); // x <= M => true |
| if (m.IsFoldable()) { // K <= K => K |
| return ReplaceBool(m.left().Value() <= m.right().Value()); |
| } |
| if (m.LeftEqualsRight()) return ReplaceBool(true); // x <= x => true |
| break; |
| } |
| case IrOpcode::kFloat64Add: { |
| Float64BinopMatcher m(node); |
| if (m.right().IsNaN()) { // x + NaN => NaN |
| return Replace(m.right().node()); |
| } |
| if (m.IsFoldable()) { // K + K => K |
| return ReplaceFloat64(m.left().Value() + m.right().Value()); |
| } |
| break; |
| } |
| case IrOpcode::kFloat64Sub: { |
| Float64BinopMatcher m(node); |
| if (m.right().Is(0) && (Double(m.right().Value()).Sign() > 0)) { |
| return Replace(m.left().node()); // x - 0 => x |
| } |
| if (m.right().IsNaN()) { // x - NaN => NaN |
| return Replace(m.right().node()); |
| } |
| if (m.left().IsNaN()) { // NaN - x => NaN |
| return Replace(m.left().node()); |
| } |
| if (m.IsFoldable()) { // K - K => K |
| return ReplaceFloat64(m.left().Value() - m.right().Value()); |
| } |
| break; |
| } |
| case IrOpcode::kFloat64Mul: { |
| Float64BinopMatcher m(node); |
| if (m.right().Is(1)) return Replace(m.left().node()); // x * 1.0 => x |
| if (m.right().IsNaN()) { // x * NaN => NaN |
| return Replace(m.right().node()); |
| } |
| if (m.IsFoldable()) { // K * K => K |
| return ReplaceFloat64(m.left().Value() * m.right().Value()); |
| } |
| break; |
| } |
| case IrOpcode::kFloat64Div: { |
| Float64BinopMatcher m(node); |
| if (m.right().Is(1)) return Replace(m.left().node()); // x / 1.0 => x |
| if (m.right().IsNaN()) { // x / NaN => NaN |
| return Replace(m.right().node()); |
| } |
| if (m.left().IsNaN()) { // NaN / x => NaN |
| return Replace(m.left().node()); |
| } |
| if (m.IsFoldable()) { // K / K => K |
| return ReplaceFloat64(m.left().Value() / m.right().Value()); |
| } |
| break; |
| } |
| case IrOpcode::kFloat64Mod: { |
| Float64BinopMatcher m(node); |
| if (m.right().Is(0)) { // x % 0 => NaN |
| return ReplaceFloat64(base::OS::nan_value()); |
| } |
| if (m.right().IsNaN()) { // x % NaN => NaN |
| return Replace(m.right().node()); |
| } |
| if (m.left().IsNaN()) { // NaN % x => NaN |
| return Replace(m.left().node()); |
| } |
| if (m.IsFoldable()) { // K % K => K |
| return ReplaceFloat64(modulo(m.left().Value(), m.right().Value())); |
| } |
| break; |
| } |
| case IrOpcode::kChangeFloat32ToFloat64: { |
| Float32Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceFloat64(m.Value()); |
| break; |
| } |
| case IrOpcode::kChangeFloat64ToInt32: { |
| Float64Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceInt32(FastD2I(m.Value())); |
| if (m.IsChangeInt32ToFloat64()) return Replace(m.node()->InputAt(0)); |
| break; |
| } |
| case IrOpcode::kChangeFloat64ToUint32: { |
| Float64Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceInt32(FastD2UI(m.Value())); |
| if (m.IsChangeUint32ToFloat64()) return Replace(m.node()->InputAt(0)); |
| break; |
| } |
| case IrOpcode::kChangeInt32ToFloat64: { |
| Int32Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceFloat64(FastI2D(m.Value())); |
| break; |
| } |
| case IrOpcode::kChangeInt32ToInt64: { |
| Int32Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceInt64(m.Value()); |
| break; |
| } |
| case IrOpcode::kChangeUint32ToFloat64: { |
| Uint32Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceFloat64(FastUI2D(m.Value())); |
| break; |
| } |
| case IrOpcode::kChangeUint32ToUint64: { |
| Uint32Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceInt64(static_cast<uint64_t>(m.Value())); |
| break; |
| } |
| case IrOpcode::kTruncateFloat64ToInt32: { |
| Float64Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceInt32(DoubleToInt32(m.Value())); |
| if (m.IsChangeInt32ToFloat64()) return Replace(m.node()->InputAt(0)); |
| break; |
| } |
| case IrOpcode::kTruncateInt64ToInt32: { |
| Int64Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceInt32(static_cast<int32_t>(m.Value())); |
| if (m.IsChangeInt32ToInt64()) return Replace(m.node()->InputAt(0)); |
| break; |
| } |
| case IrOpcode::kTruncateFloat64ToFloat32: { |
| Float64Matcher m(node->InputAt(0)); |
| if (m.HasValue()) return ReplaceFloat32(DoubleToFloat32(m.Value())); |
| if (m.IsChangeFloat32ToFloat64()) return Replace(m.node()->InputAt(0)); |
| break; |
| } |
| case IrOpcode::kStore: { |
| Node* const value = node->InputAt(2); |
| // TODO(turbofan): Extend to 64-bit? |
| if (value->opcode() == IrOpcode::kWord32And) { |
| MachineType const rep = static_cast<MachineType>( |
| StoreRepresentationOf(node->op()).machine_type() & kRepMask); |
| Uint32BinopMatcher m(value); |
| if (m.right().HasValue() && |
| ((rep == kRepWord8 && (m.right().Value() & 0xff) == 0xff) || |
| (rep == kRepWord16 && (m.right().Value() & 0xffff) == 0xffff))) { |
| node->ReplaceInput(2, m.left().node()); |
| return Changed(node); |
| } |
| } |
| break; |
| } |
| default: |
| break; |
| } |
| return NoChange(); |
| } |
| |
| |
| Reduction MachineOperatorReducer::ReduceInt32Div(Node* node) { |
| Int32BinopMatcher m(node); |
| if (m.left().Is(0)) return Replace(m.left().node()); // 0 / x => 0 |
| if (m.right().Is(0)) return Replace(m.right().node()); // x / 0 => 0 |
| if (m.right().Is(1)) return Replace(m.left().node()); // x / 1 => x |
| if (m.IsFoldable()) { // K / K => K |
| return ReplaceInt32( |
| base::bits::SignedDiv32(m.left().Value(), m.right().Value())); |
| } |
| if (m.LeftEqualsRight()) { // x / x => x != 0 |
| Node* const zero = Int32Constant(0); |
| return Replace(Word32Equal(Word32Equal(m.left().node(), zero), zero)); |
| } |
| if (m.right().Is(-1)) { // x / -1 => 0 - x |
| node->set_op(machine()->Int32Sub()); |
| node->ReplaceInput(0, Int32Constant(0)); |
| node->ReplaceInput(1, m.left().node()); |
| node->TrimInputCount(2); |
| return Changed(node); |
| } |
| if (m.right().HasValue()) { |
| int32_t const divisor = m.right().Value(); |
| Node* const dividend = m.left().node(); |
| Node* quotient = dividend; |
| if (base::bits::IsPowerOfTwo32(Abs(divisor))) { |
| uint32_t const shift = WhichPowerOf2Abs(divisor); |
| DCHECK_NE(0, shift); |
| if (shift > 1) { |
| quotient = Word32Sar(quotient, 31); |
| } |
| quotient = Int32Add(Word32Shr(quotient, 32u - shift), dividend); |
| quotient = Word32Sar(quotient, shift); |
| } else { |
| quotient = TruncatingDiv(quotient, Abs(divisor)); |
| } |
| if (divisor < 0) { |
| node->set_op(machine()->Int32Sub()); |
| node->ReplaceInput(0, Int32Constant(0)); |
| node->ReplaceInput(1, quotient); |
| node->TrimInputCount(2); |
| return Changed(node); |
| } |
| return Replace(quotient); |
| } |
| return NoChange(); |
| } |
| |
| |
| Reduction MachineOperatorReducer::ReduceUint32Div(Node* node) { |
| Uint32BinopMatcher m(node); |
| if (m.left().Is(0)) return Replace(m.left().node()); // 0 / x => 0 |
| if (m.right().Is(0)) return Replace(m.right().node()); // x / 0 => 0 |
| if (m.right().Is(1)) return Replace(m.left().node()); // x / 1 => x |
| if (m.IsFoldable()) { // K / K => K |
| return ReplaceUint32( |
| base::bits::UnsignedDiv32(m.left().Value(), m.right().Value())); |
| } |
| if (m.LeftEqualsRight()) { // x / x => x != 0 |
| Node* const zero = Int32Constant(0); |
| return Replace(Word32Equal(Word32Equal(m.left().node(), zero), zero)); |
| } |
| if (m.right().IsPowerOf2()) { // x / 2^n => x >> n |
| node->TrimInputCount(2); |
| node->set_op(machine()->Word32Shr()); |
| node->ReplaceInput(1, Uint32Constant(WhichPowerOf2(m.right().Value()))); |
| return Changed(node); |
| } |
| return NoChange(); |
| } |
| |
| |
| Reduction MachineOperatorReducer::ReduceInt32Mod(Node* node) { |
| Int32BinopMatcher m(node); |
| if (m.left().Is(0)) return Replace(m.left().node()); // 0 % x => 0 |
| if (m.right().Is(0)) return Replace(m.right().node()); // x % 0 => 0 |
| if (m.right().Is(1)) return ReplaceInt32(0); // x % 1 => 0 |
| if (m.right().Is(-1)) return ReplaceInt32(0); // x % -1 => 0 |
| if (m.LeftEqualsRight()) return ReplaceInt32(0); // x % x => 0 |
| if (m.IsFoldable()) { // K % K => K |
| return ReplaceInt32( |
| base::bits::SignedMod32(m.left().Value(), m.right().Value())); |
| } |
| if (m.right().HasValue()) { |
| Node* const dividend = m.left().node(); |
| int32_t const divisor = Abs(m.right().Value()); |
| if (base::bits::IsPowerOfTwo32(divisor)) { |
| uint32_t const mask = divisor - 1; |
| Node* const zero = Int32Constant(0); |
| |
| Node* check = |
| graph()->NewNode(machine()->Int32LessThan(), dividend, zero); |
| Node* branch = |
| graph()->NewNode(common()->Branch(), check, graph()->start()); |
| |
| Node* if_true = graph()->NewNode(common()->IfTrue(), branch); |
| Node* neg = Int32Sub(zero, Word32And(Int32Sub(zero, dividend), mask)); |
| |
| Node* if_false = graph()->NewNode(common()->IfFalse(), branch); |
| Node* pos = Word32And(dividend, mask); |
| |
| Node* merge = graph()->NewNode(common()->Merge(2), if_true, if_false); |
| Node* phi = |
| graph()->NewNode(common()->Phi(kMachInt32, 2), neg, pos, merge); |
| return Replace(phi); |
| } else { |
| Node* quotient = TruncatingDiv(dividend, divisor); |
| node->set_op(machine()->Int32Sub()); |
| DCHECK_EQ(dividend, node->InputAt(0)); |
| node->ReplaceInput(1, Int32Mul(quotient, Int32Constant(divisor))); |
| node->TrimInputCount(2); |
| return Changed(node); |
| } |
| } |
| return NoChange(); |
| } |
| |
| |
| Reduction MachineOperatorReducer::ReduceUint32Mod(Node* node) { |
| Uint32BinopMatcher m(node); |
| if (m.left().Is(0)) return Replace(m.left().node()); // 0 % x => 0 |
| if (m.right().Is(0)) return Replace(m.right().node()); // x % 0 => 0 |
| if (m.right().Is(1)) return ReplaceUint32(0); // x % 1 => 0 |
| if (m.LeftEqualsRight()) return ReplaceInt32(0); // x % x => 0 |
| if (m.IsFoldable()) { // K % K => K |
| return ReplaceUint32( |
| base::bits::UnsignedMod32(m.left().Value(), m.right().Value())); |
| } |
| if (m.right().IsPowerOf2()) { // x % 2^n => x & 2^n-1 |
| node->TrimInputCount(2); |
| node->set_op(machine()->Word32And()); |
| node->ReplaceInput(1, Uint32Constant(m.right().Value() - 1)); |
| return Changed(node); |
| } |
| return NoChange(); |
| } |
| |
| |
| Reduction MachineOperatorReducer::ReduceProjection(size_t index, Node* node) { |
| switch (node->opcode()) { |
| case IrOpcode::kInt32AddWithOverflow: { |
| DCHECK(index == 0 || index == 1); |
| Int32BinopMatcher m(node); |
| if (m.IsFoldable()) { |
| int32_t val; |
| bool ovf = base::bits::SignedAddOverflow32(m.left().Value(), |
| m.right().Value(), &val); |
| return ReplaceInt32((index == 0) ? val : ovf); |
| } |
| if (m.right().Is(0)) { |
| return (index == 0) ? Replace(m.left().node()) : ReplaceInt32(0); |
| } |
| break; |
| } |
| case IrOpcode::kInt32SubWithOverflow: { |
| DCHECK(index == 0 || index == 1); |
| Int32BinopMatcher m(node); |
| if (m.IsFoldable()) { |
| int32_t val; |
| bool ovf = base::bits::SignedSubOverflow32(m.left().Value(), |
| m.right().Value(), &val); |
| return ReplaceInt32((index == 0) ? val : ovf); |
| } |
| if (m.right().Is(0)) { |
| return (index == 0) ? Replace(m.left().node()) : ReplaceInt32(0); |
| } |
| break; |
| } |
| default: |
| break; |
| } |
| return NoChange(); |
| } |
| |
| |
| CommonOperatorBuilder* MachineOperatorReducer::common() const { |
| return jsgraph()->common(); |
| } |
| |
| |
| MachineOperatorBuilder* MachineOperatorReducer::machine() const { |
| return jsgraph()->machine(); |
| } |
| |
| |
| Graph* MachineOperatorReducer::graph() const { return jsgraph()->graph(); } |
| |
| } // namespace compiler |
| } // namespace internal |
| } // namespace v8 |
