blob: 940f0904b370656012a5a4c78cc8c2948229395e [file] [log] [blame]
// 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/int64-lowering.h"
#include "src/compiler/common-operator.h"
#include "src/compiler/diamond.h"
#include "src/compiler/graph.h"
#include "src/compiler/linkage.h"
#include "src/compiler/machine-operator.h"
#include "src/compiler/node-matchers.h"
#include "src/compiler/node-properties.h"
#include "src/compiler/node.h"
#include "src/compiler/wasm-compiler.h"
#include "src/zone/zone.h"
namespace v8 {
namespace internal {
namespace compiler {
Int64Lowering::Int64Lowering(Graph* graph, MachineOperatorBuilder* machine,
CommonOperatorBuilder* common, Zone* zone,
Signature<MachineRepresentation>* signature)
: zone_(zone),
graph_(graph),
machine_(machine),
common_(common),
state_(graph, 3),
stack_(zone),
replacements_(nullptr),
signature_(signature),
placeholder_(graph->NewNode(common->Parameter(-2, "placeholder"),
graph->start())) {
DCHECK_NOT_NULL(graph);
DCHECK_NOT_NULL(graph->end());
replacements_ = zone->NewArray<Replacement>(graph->NodeCount());
memset(replacements_, 0, sizeof(Replacement) * graph->NodeCount());
}
void Int64Lowering::LowerGraph() {
if (!machine()->Is32()) {
return;
}
stack_.push_back({graph()->end(), 0});
state_.Set(graph()->end(), State::kOnStack);
while (!stack_.empty()) {
NodeState& top = stack_.back();
if (top.input_index == top.node->InputCount()) {
// All inputs of top have already been lowered, now lower top.
stack_.pop_back();
state_.Set(top.node, State::kVisited);
LowerNode(top.node);
} else {
// Push the next input onto the stack.
Node* input = top.node->InputAt(top.input_index++);
if (state_.Get(input) == State::kUnvisited) {
if (input->opcode() == IrOpcode::kPhi) {
// To break cycles with phi nodes we push phis on a separate stack so
// that they are processed after all other nodes.
PreparePhiReplacement(input);
stack_.push_front({input, 0});
} else if (input->opcode() == IrOpcode::kEffectPhi ||
input->opcode() == IrOpcode::kLoop) {
stack_.push_front({input, 0});
} else {
stack_.push_back({input, 0});
}
state_.Set(input, State::kOnStack);
}
}
}
}
namespace {
int GetReturnIndexAfterLowering(
CallDescriptor* descriptor, int old_index) {
int result = old_index;
for (int i = 0; i < old_index; i++) {
if (descriptor->GetReturnType(i).representation() ==
MachineRepresentation::kWord64) {
result++;
}
}
return result;
}
int GetReturnCountAfterLowering(CallDescriptor* descriptor) {
return GetReturnIndexAfterLowering(
descriptor, static_cast<int>(descriptor->ReturnCount()));
}
int GetParameterIndexAfterLowering(
Signature<MachineRepresentation>* signature, int old_index) {
int result = old_index;
for (int i = 0; i < old_index; i++) {
if (signature->GetParam(i) == MachineRepresentation::kWord64) {
result++;
}
}
return result;
}
int GetReturnCountAfterLowering(Signature<MachineRepresentation>* signature) {
int result = static_cast<int>(signature->return_count());
for (int i = 0; i < static_cast<int>(signature->return_count()); i++) {
if (signature->GetReturn(i) == MachineRepresentation::kWord64) {
result++;
}
}
return result;
}
} // namespace
// static
int Int64Lowering::GetParameterCountAfterLowering(
Signature<MachineRepresentation>* signature) {
// GetParameterIndexAfterLowering(parameter_count) returns the parameter count
// after lowering.
return GetParameterIndexAfterLowering(
signature, static_cast<int>(signature->parameter_count()));
}
// static
bool Int64Lowering::IsI64AsTwoParameters(MachineOperatorBuilder* machine,
MachineRepresentation type) {
return machine->Is32() && type == MachineRepresentation::kWord64;
}
void Int64Lowering::GetIndexNodes(Node* index, Node*& index_low,
Node*& index_high) {
if (HasReplacementLow(index)) {
index = GetReplacementLow(index);
}
#if defined(V8_TARGET_LITTLE_ENDIAN)
index_low = index;
index_high = graph()->NewNode(machine()->Int32Add(), index,
graph()->NewNode(common()->Int32Constant(4)));
#elif defined(V8_TARGET_BIG_ENDIAN)
index_low = graph()->NewNode(machine()->Int32Add(), index,
graph()->NewNode(common()->Int32Constant(4)));
index_high = index;
#endif
}
void Int64Lowering::LowerNode(Node* node) {
switch (node->opcode()) {
case IrOpcode::kInt64Constant: {
int64_t value = OpParameter<int64_t>(node);
Node* low_node = graph()->NewNode(
common()->Int32Constant(static_cast<int32_t>(value & 0xFFFFFFFF)));
Node* high_node = graph()->NewNode(
common()->Int32Constant(static_cast<int32_t>(value >> 32)));
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kLoad:
case IrOpcode::kUnalignedLoad: {
MachineRepresentation rep;
if (node->opcode() == IrOpcode::kLoad) {
rep = LoadRepresentationOf(node->op()).representation();
} else {
DCHECK_EQ(IrOpcode::kUnalignedLoad, node->opcode());
rep = UnalignedLoadRepresentationOf(node->op()).representation();
}
if (rep == MachineRepresentation::kWord64) {
Node* base = node->InputAt(0);
Node* index = node->InputAt(1);
Node* index_low;
Node* index_high;
GetIndexNodes(index, index_low, index_high);
const Operator* load_op;
if (node->opcode() == IrOpcode::kLoad) {
load_op = machine()->Load(MachineType::Int32());
} else {
DCHECK_EQ(IrOpcode::kUnalignedLoad, node->opcode());
load_op = machine()->UnalignedLoad(MachineType::Int32());
}
Node* high_node;
if (node->InputCount() > 2) {
Node* effect_high = node->InputAt(2);
Node* control_high = node->InputAt(3);
high_node = graph()->NewNode(load_op, base, index_high, effect_high,
control_high);
// change the effect change from old_node --> old_effect to
// old_node --> high_node --> old_effect.
node->ReplaceInput(2, high_node);
} else {
high_node = graph()->NewNode(load_op, base, index_high);
}
node->ReplaceInput(1, index_low);
NodeProperties::ChangeOp(node, load_op);
ReplaceNode(node, node, high_node);
} else {
DefaultLowering(node);
}
break;
}
case IrOpcode::kStore:
case IrOpcode::kUnalignedStore: {
MachineRepresentation rep;
if (node->opcode() == IrOpcode::kStore) {
rep = StoreRepresentationOf(node->op()).representation();
} else {
DCHECK_EQ(IrOpcode::kUnalignedStore, node->opcode());
rep = UnalignedStoreRepresentationOf(node->op());
}
if (rep == MachineRepresentation::kWord64) {
// We change the original store node to store the low word, and create
// a new store node to store the high word. The effect and control edges
// are copied from the original store to the new store node, the effect
// edge of the original store is redirected to the new store.
Node* base = node->InputAt(0);
Node* index = node->InputAt(1);
Node* index_low;
Node* index_high;
GetIndexNodes(index, index_low, index_high);
Node* value = node->InputAt(2);
DCHECK(HasReplacementLow(value));
DCHECK(HasReplacementHigh(value));
const Operator* store_op;
if (node->opcode() == IrOpcode::kStore) {
WriteBarrierKind write_barrier_kind =
StoreRepresentationOf(node->op()).write_barrier_kind();
store_op = machine()->Store(StoreRepresentation(
MachineRepresentation::kWord32, write_barrier_kind));
} else {
DCHECK_EQ(IrOpcode::kUnalignedStore, node->opcode());
store_op = machine()->UnalignedStore(MachineRepresentation::kWord32);
}
Node* high_node;
if (node->InputCount() > 3) {
Node* effect_high = node->InputAt(3);
Node* control_high = node->InputAt(4);
high_node = graph()->NewNode(store_op, base, index_high,
GetReplacementHigh(value), effect_high,
control_high);
node->ReplaceInput(3, high_node);
} else {
high_node = graph()->NewNode(store_op, base, index_high,
GetReplacementHigh(value));
}
node->ReplaceInput(1, index_low);
node->ReplaceInput(2, GetReplacementLow(value));
NodeProperties::ChangeOp(node, store_op);
ReplaceNode(node, node, high_node);
} else {
DefaultLowering(node, true);
}
break;
}
case IrOpcode::kStart: {
int parameter_count = GetParameterCountAfterLowering(signature());
// Only exchange the node if the parameter count actually changed.
if (parameter_count != static_cast<int>(signature()->parameter_count())) {
int delta =
parameter_count - static_cast<int>(signature()->parameter_count());
int new_output_count = node->op()->ValueOutputCount() + delta;
NodeProperties::ChangeOp(node, common()->Start(new_output_count));
}
break;
}
case IrOpcode::kParameter: {
DCHECK_EQ(1, node->InputCount());
// Only exchange the node if the parameter count actually changed. We do
// not even have to do the default lowering because the the start node,
// the only input of a parameter node, only changes if the parameter count
// changes.
if (GetParameterCountAfterLowering(signature()) !=
static_cast<int>(signature()->parameter_count())) {
int old_index = ParameterIndexOf(node->op());
// TODO(wasm): Make this part not wasm specific.
// Prevent special lowering of the WasmContext parameter.
if (old_index == kWasmContextParameterIndex) {
DefaultLowering(node);
break;
}
// Adjust old_index to be compliant with the signature.
--old_index;
int new_index = GetParameterIndexAfterLowering(signature(), old_index);
// Adjust new_index to consider the WasmContext parameter.
++new_index;
NodeProperties::ChangeOp(node, common()->Parameter(new_index));
if (signature()->GetParam(old_index) ==
MachineRepresentation::kWord64) {
Node* high_node = graph()->NewNode(common()->Parameter(new_index + 1),
graph()->start());
ReplaceNode(node, node, high_node);
}
}
break;
}
case IrOpcode::kReturn: {
int input_count = node->InputCount();
DefaultLowering(node);
if (input_count != node->InputCount()) {
int new_return_count = GetReturnCountAfterLowering(signature());
if (static_cast<int>(signature()->return_count()) != new_return_count) {
NodeProperties::ChangeOp(node, common()->Return(new_return_count));
}
}
break;
}
case IrOpcode::kTailCall: {
CallDescriptor* descriptor =
const_cast<CallDescriptor*>(CallDescriptorOf(node->op()));
bool returns_require_lowering =
GetReturnCountAfterLowering(descriptor) !=
static_cast<int>(descriptor->ReturnCount());
if (DefaultLowering(node) || returns_require_lowering) {
// Tail calls do not have return values, so adjusting the call
// descriptor is enough.
auto new_descriptor = GetI32WasmCallDescriptor(zone(), descriptor);
NodeProperties::ChangeOp(node, common()->TailCall(new_descriptor));
}
break;
}
case IrOpcode::kCall: {
CallDescriptor* descriptor =
const_cast<CallDescriptor*>(CallDescriptorOf(node->op()));
bool returns_require_lowering =
GetReturnCountAfterLowering(descriptor) !=
static_cast<int>(descriptor->ReturnCount());
if (DefaultLowering(node) || returns_require_lowering) {
// We have to adjust the call descriptor.
NodeProperties::ChangeOp(
node, common()->Call(GetI32WasmCallDescriptor(zone(), descriptor)));
}
if (returns_require_lowering) {
size_t return_arity = descriptor->ReturnCount();
if (return_arity == 1) {
// We access the additional return values through projections.
Node* low_node =
graph()->NewNode(common()->Projection(0), node, graph()->start());
Node* high_node =
graph()->NewNode(common()->Projection(1), node, graph()->start());
ReplaceNode(node, low_node, high_node);
} else {
ZoneVector<Node*> projections(return_arity, zone());
NodeProperties::CollectValueProjections(node, projections.data(),
return_arity);
for (size_t old_index = 0, new_index = 0; old_index < return_arity;
++old_index, ++new_index) {
Node* use_node = projections[old_index];
DCHECK_EQ(ProjectionIndexOf(use_node->op()), old_index);
DCHECK_EQ(GetReturnIndexAfterLowering(descriptor,
static_cast<int>(old_index)),
static_cast<int>(new_index));
if (new_index != old_index) {
NodeProperties::ChangeOp(
use_node, common()->Projection(new_index));
}
if (descriptor->GetReturnType(old_index).representation() ==
MachineRepresentation::kWord64) {
Node* high_node = graph()->NewNode(
common()->Projection(new_index + 1), node,
graph()->start());
ReplaceNode(use_node, use_node, high_node);
++new_index;
}
}
}
}
break;
}
case IrOpcode::kWord64And: {
DCHECK_EQ(2, node->InputCount());
Node* left = node->InputAt(0);
Node* right = node->InputAt(1);
Node* low_node =
graph()->NewNode(machine()->Word32And(), GetReplacementLow(left),
GetReplacementLow(right));
Node* high_node =
graph()->NewNode(machine()->Word32And(), GetReplacementHigh(left),
GetReplacementHigh(right));
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kTruncateInt64ToInt32: {
DCHECK_EQ(1, node->InputCount());
Node* input = node->InputAt(0);
ReplaceNode(node, GetReplacementLow(input), nullptr);
node->NullAllInputs();
break;
}
case IrOpcode::kInt64Add: {
DCHECK_EQ(2, node->InputCount());
Node* right = node->InputAt(1);
node->ReplaceInput(1, GetReplacementLow(right));
node->AppendInput(zone(), GetReplacementHigh(right));
Node* left = node->InputAt(0);
node->ReplaceInput(0, GetReplacementLow(left));
node->InsertInput(zone(), 1, GetReplacementHigh(left));
NodeProperties::ChangeOp(node, machine()->Int32PairAdd());
// We access the additional return values through projections.
Node* low_node =
graph()->NewNode(common()->Projection(0), node, graph()->start());
Node* high_node =
graph()->NewNode(common()->Projection(1), node, graph()->start());
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kInt64Sub: {
DCHECK_EQ(2, node->InputCount());
Node* right = node->InputAt(1);
node->ReplaceInput(1, GetReplacementLow(right));
node->AppendInput(zone(), GetReplacementHigh(right));
Node* left = node->InputAt(0);
node->ReplaceInput(0, GetReplacementLow(left));
node->InsertInput(zone(), 1, GetReplacementHigh(left));
NodeProperties::ChangeOp(node, machine()->Int32PairSub());
// We access the additional return values through projections.
Node* low_node =
graph()->NewNode(common()->Projection(0), node, graph()->start());
Node* high_node =
graph()->NewNode(common()->Projection(1), node, graph()->start());
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kInt64Mul: {
DCHECK_EQ(2, node->InputCount());
Node* right = node->InputAt(1);
node->ReplaceInput(1, GetReplacementLow(right));
node->AppendInput(zone(), GetReplacementHigh(right));
Node* left = node->InputAt(0);
node->ReplaceInput(0, GetReplacementLow(left));
node->InsertInput(zone(), 1, GetReplacementHigh(left));
NodeProperties::ChangeOp(node, machine()->Int32PairMul());
// We access the additional return values through projections.
Node* low_node =
graph()->NewNode(common()->Projection(0), node, graph()->start());
Node* high_node =
graph()->NewNode(common()->Projection(1), node, graph()->start());
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kWord64Or: {
DCHECK_EQ(2, node->InputCount());
Node* left = node->InputAt(0);
Node* right = node->InputAt(1);
Node* low_node =
graph()->NewNode(machine()->Word32Or(), GetReplacementLow(left),
GetReplacementLow(right));
Node* high_node =
graph()->NewNode(machine()->Word32Or(), GetReplacementHigh(left),
GetReplacementHigh(right));
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kWord64Xor: {
DCHECK_EQ(2, node->InputCount());
Node* left = node->InputAt(0);
Node* right = node->InputAt(1);
Node* low_node =
graph()->NewNode(machine()->Word32Xor(), GetReplacementLow(left),
GetReplacementLow(right));
Node* high_node =
graph()->NewNode(machine()->Word32Xor(), GetReplacementHigh(left),
GetReplacementHigh(right));
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kWord64Shl: {
// TODO(turbofan): if the shift count >= 32, then we can set the low word
// of the output to 0 and just calculate the high word.
DCHECK_EQ(2, node->InputCount());
Node* shift = node->InputAt(1);
if (HasReplacementLow(shift)) {
// We do not have to care about the high word replacement, because
// the shift can only be between 0 and 63 anyways.
node->ReplaceInput(1, GetReplacementLow(shift));
}
Node* value = node->InputAt(0);
node->ReplaceInput(0, GetReplacementLow(value));
node->InsertInput(zone(), 1, GetReplacementHigh(value));
NodeProperties::ChangeOp(node, machine()->Word32PairShl());
// We access the additional return values through projections.
Node* low_node =
graph()->NewNode(common()->Projection(0), node, graph()->start());
Node* high_node =
graph()->NewNode(common()->Projection(1), node, graph()->start());
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kWord64Shr: {
// TODO(turbofan): if the shift count >= 32, then we can set the low word
// of the output to 0 and just calculate the high word.
DCHECK_EQ(2, node->InputCount());
Node* shift = node->InputAt(1);
if (HasReplacementLow(shift)) {
// We do not have to care about the high word replacement, because
// the shift can only be between 0 and 63 anyways.
node->ReplaceInput(1, GetReplacementLow(shift));
}
Node* value = node->InputAt(0);
node->ReplaceInput(0, GetReplacementLow(value));
node->InsertInput(zone(), 1, GetReplacementHigh(value));
NodeProperties::ChangeOp(node, machine()->Word32PairShr());
// We access the additional return values through projections.
Node* low_node =
graph()->NewNode(common()->Projection(0), node, graph()->start());
Node* high_node =
graph()->NewNode(common()->Projection(1), node, graph()->start());
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kWord64Sar: {
// TODO(turbofan): if the shift count >= 32, then we can set the low word
// of the output to 0 and just calculate the high word.
DCHECK_EQ(2, node->InputCount());
Node* shift = node->InputAt(1);
if (HasReplacementLow(shift)) {
// We do not have to care about the high word replacement, because
// the shift can only be between 0 and 63 anyways.
node->ReplaceInput(1, GetReplacementLow(shift));
}
Node* value = node->InputAt(0);
node->ReplaceInput(0, GetReplacementLow(value));
node->InsertInput(zone(), 1, GetReplacementHigh(value));
NodeProperties::ChangeOp(node, machine()->Word32PairSar());
// We access the additional return values through projections.
Node* low_node =
graph()->NewNode(common()->Projection(0), node, graph()->start());
Node* high_node =
graph()->NewNode(common()->Projection(1), node, graph()->start());
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kWord64Equal: {
DCHECK_EQ(2, node->InputCount());
Node* left = node->InputAt(0);
Node* right = node->InputAt(1);
// TODO(wasm): Use explicit comparisons and && here?
Node* replacement = graph()->NewNode(
machine()->Word32Equal(),
graph()->NewNode(
machine()->Word32Or(),
graph()->NewNode(machine()->Word32Xor(), GetReplacementLow(left),
GetReplacementLow(right)),
graph()->NewNode(machine()->Word32Xor(), GetReplacementHigh(left),
GetReplacementHigh(right))),
graph()->NewNode(common()->Int32Constant(0)));
ReplaceNode(node, replacement, nullptr);
break;
}
case IrOpcode::kInt64LessThan: {
LowerComparison(node, machine()->Int32LessThan(),
machine()->Uint32LessThan());
break;
}
case IrOpcode::kInt64LessThanOrEqual: {
LowerComparison(node, machine()->Int32LessThan(),
machine()->Uint32LessThanOrEqual());
break;
}
case IrOpcode::kUint64LessThan: {
LowerComparison(node, machine()->Uint32LessThan(),
machine()->Uint32LessThan());
break;
}
case IrOpcode::kUint64LessThanOrEqual: {
LowerComparison(node, machine()->Uint32LessThan(),
machine()->Uint32LessThanOrEqual());
break;
}
case IrOpcode::kChangeInt32ToInt64: {
DCHECK_EQ(1, node->InputCount());
Node* input = node->InputAt(0);
if (HasReplacementLow(input)) {
input = GetReplacementLow(input);
}
// We use SAR to preserve the sign in the high word.
ReplaceNode(
node, input,
graph()->NewNode(machine()->Word32Sar(), input,
graph()->NewNode(common()->Int32Constant(31))));
node->NullAllInputs();
break;
}
case IrOpcode::kChangeUint32ToUint64: {
DCHECK_EQ(1, node->InputCount());
Node* input = node->InputAt(0);
if (HasReplacementLow(input)) {
input = GetReplacementLow(input);
}
ReplaceNode(node, input, graph()->NewNode(common()->Int32Constant(0)));
node->NullAllInputs();
break;
}
case IrOpcode::kBitcastInt64ToFloat64: {
DCHECK_EQ(1, node->InputCount());
Node* input = node->InputAt(0);
Node* stack_slot = graph()->NewNode(
machine()->StackSlot(MachineRepresentation::kWord64));
Node* store_high_word = graph()->NewNode(
machine()->Store(
StoreRepresentation(MachineRepresentation::kWord32,
WriteBarrierKind::kNoWriteBarrier)),
stack_slot,
graph()->NewNode(
common()->Int32Constant(kInt64UpperHalfMemoryOffset)),
GetReplacementHigh(input), graph()->start(), graph()->start());
Node* store_low_word = graph()->NewNode(
machine()->Store(
StoreRepresentation(MachineRepresentation::kWord32,
WriteBarrierKind::kNoWriteBarrier)),
stack_slot,
graph()->NewNode(
common()->Int32Constant(kInt64LowerHalfMemoryOffset)),
GetReplacementLow(input), store_high_word, graph()->start());
Node* load =
graph()->NewNode(machine()->Load(MachineType::Float64()), stack_slot,
graph()->NewNode(common()->Int32Constant(0)),
store_low_word, graph()->start());
ReplaceNode(node, load, nullptr);
break;
}
case IrOpcode::kBitcastFloat64ToInt64: {
DCHECK_EQ(1, node->InputCount());
Node* input = node->InputAt(0);
if (HasReplacementLow(input)) {
input = GetReplacementLow(input);
}
Node* stack_slot = graph()->NewNode(
machine()->StackSlot(MachineRepresentation::kWord64));
Node* store = graph()->NewNode(
machine()->Store(
StoreRepresentation(MachineRepresentation::kFloat64,
WriteBarrierKind::kNoWriteBarrier)),
stack_slot, graph()->NewNode(common()->Int32Constant(0)), input,
graph()->start(), graph()->start());
Node* high_node = graph()->NewNode(
machine()->Load(MachineType::Int32()), stack_slot,
graph()->NewNode(
common()->Int32Constant(kInt64UpperHalfMemoryOffset)),
store, graph()->start());
Node* low_node = graph()->NewNode(
machine()->Load(MachineType::Int32()), stack_slot,
graph()->NewNode(
common()->Int32Constant(kInt64LowerHalfMemoryOffset)),
store, graph()->start());
ReplaceNode(node, low_node, high_node);
break;
}
case IrOpcode::kWord64Ror: {
DCHECK_EQ(2, node->InputCount());
Node* input = node->InputAt(0);
Node* shift = HasReplacementLow(node->InputAt(1))
? GetReplacementLow(node->InputAt(1))
: node->InputAt(1);
Int32Matcher m(shift);
if (m.HasValue()) {
// Precondition: 0 <= shift < 64.
int32_t shift_value = m.Value() & 0x3F;
if (shift_value == 0) {
ReplaceNode(node, GetReplacementLow(input),
GetReplacementHigh(input));
} else if (shift_value == 32) {
ReplaceNode(node, GetReplacementHigh(input),
GetReplacementLow(input));
} else {
Node* low_input;
Node* high_input;
if (shift_value < 32) {
low_input = GetReplacementLow(input);
high_input = GetReplacementHigh(input);
} else {
low_input = GetReplacementHigh(input);
high_input = GetReplacementLow(input);
}
int32_t masked_shift_value = shift_value & 0x1F;
Node* masked_shift =
graph()->NewNode(common()->Int32Constant(masked_shift_value));
Node* inv_shift = graph()->NewNode(
common()->Int32Constant(32 - masked_shift_value));
Node* low_node = graph()->NewNode(
machine()->Word32Or(),
graph()->NewNode(machine()->Word32Shr(), low_input, masked_shift),
graph()->NewNode(machine()->Word32Shl(), high_input, inv_shift));
Node* high_node = graph()->NewNode(
machine()->Word32Or(), graph()->NewNode(machine()->Word32Shr(),
high_input, masked_shift),
graph()->NewNode(machine()->Word32Shl(), low_input, inv_shift));
ReplaceNode(node, low_node, high_node);
}
} else {
Node* safe_shift = shift;
if (!machine()->Word32ShiftIsSafe()) {
safe_shift =
graph()->NewNode(machine()->Word32And(), shift,
graph()->NewNode(common()->Int32Constant(0x1F)));
}
// By creating this bit-mask with SAR and SHL we do not have to deal
// with shift == 0 as a special case.
Node* inv_mask = graph()->NewNode(
machine()->Word32Shl(),
graph()->NewNode(machine()->Word32Sar(),
graph()->NewNode(common()->Int32Constant(
std::numeric_limits<int32_t>::min())),
safe_shift),
graph()->NewNode(common()->Int32Constant(1)));
Node* bit_mask =
graph()->NewNode(machine()->Word32Xor(), inv_mask,
graph()->NewNode(common()->Int32Constant(-1)));
// We have to mask the shift value for this comparison. If
// !machine()->Word32ShiftIsSafe() then the masking should already be
// part of the graph.
Node* masked_shift6 = shift;
if (machine()->Word32ShiftIsSafe()) {
masked_shift6 =
graph()->NewNode(machine()->Word32And(), shift,
graph()->NewNode(common()->Int32Constant(0x3F)));
}
Diamond lt32(
graph(), common(),
graph()->NewNode(machine()->Int32LessThan(), masked_shift6,
graph()->NewNode(common()->Int32Constant(32))));
// The low word and the high word can be swapped either at the input or
// at the output. We swap the inputs so that shift does not have to be
// kept for so long in a register.
Node* input_low =
lt32.Phi(MachineRepresentation::kWord32, GetReplacementLow(input),
GetReplacementHigh(input));
Node* input_high =
lt32.Phi(MachineRepresentation::kWord32, GetReplacementHigh(input),
GetReplacementLow(input));
Node* rotate_low =
graph()->NewNode(machine()->Word32Ror(), input_low, safe_shift);
Node* rotate_high =
graph()->NewNode(machine()->Word32Ror(), input_high, safe_shift);
Node* low_node = graph()->NewNode(
machine()->Word32Or(),
graph()->NewNode(machine()->Word32And(), rotate_low, bit_mask),
graph()->NewNode(machine()->Word32And(), rotate_high, inv_mask));
Node* high_node = graph()->NewNode(
machine()->Word32Or(),
graph()->NewNode(machine()->Word32And(), rotate_high, bit_mask),
graph()->NewNode(machine()->Word32And(), rotate_low, inv_mask));
ReplaceNode(node, low_node, high_node);
}
break;
}
case IrOpcode::kWord64Clz: {
DCHECK_EQ(1, node->InputCount());
Node* input = node->InputAt(0);
Diamond d(
graph(), common(),
graph()->NewNode(machine()->Word32Equal(), GetReplacementHigh(input),
graph()->NewNode(common()->Int32Constant(0))));
Node* low_node = d.Phi(
MachineRepresentation::kWord32,
graph()->NewNode(machine()->Int32Add(),
graph()->NewNode(machine()->Word32Clz(),
GetReplacementLow(input)),
graph()->NewNode(common()->Int32Constant(32))),
graph()->NewNode(machine()->Word32Clz(), GetReplacementHigh(input)));
ReplaceNode(node, low_node, graph()->NewNode(common()->Int32Constant(0)));
break;
}
case IrOpcode::kWord64Ctz: {
DCHECK_EQ(1, node->InputCount());
DCHECK(machine()->Word32Ctz().IsSupported());
Node* input = node->InputAt(0);
Diamond d(
graph(), common(),
graph()->NewNode(machine()->Word32Equal(), GetReplacementLow(input),
graph()->NewNode(common()->Int32Constant(0))));
Node* low_node =
d.Phi(MachineRepresentation::kWord32,
graph()->NewNode(machine()->Int32Add(),
graph()->NewNode(machine()->Word32Ctz().op(),
GetReplacementHigh(input)),
graph()->NewNode(common()->Int32Constant(32))),
graph()->NewNode(machine()->Word32Ctz().op(),
GetReplacementLow(input)));
ReplaceNode(node, low_node, graph()->NewNode(common()->Int32Constant(0)));
break;
}
case IrOpcode::kWord64Popcnt: {
DCHECK_EQ(1, node->InputCount());
Node* input = node->InputAt(0);
// We assume that a Word64Popcnt node only has been created if
// Word32Popcnt is actually supported.
DCHECK(machine()->Word32Popcnt().IsSupported());
ReplaceNode(node, graph()->NewNode(
machine()->Int32Add(),
graph()->NewNode(machine()->Word32Popcnt().op(),
GetReplacementLow(input)),
graph()->NewNode(machine()->Word32Popcnt().op(),
GetReplacementHigh(input))),
graph()->NewNode(common()->Int32Constant(0)));
break;
}
case IrOpcode::kPhi: {
MachineRepresentation rep = PhiRepresentationOf(node->op());
if (rep == MachineRepresentation::kWord64) {
// The replacement nodes have already been created, we only have to
// replace placeholder nodes.
Node* low_node = GetReplacementLow(node);
Node* high_node = GetReplacementHigh(node);
for (int i = 0; i < node->op()->ValueInputCount(); i++) {
low_node->ReplaceInput(i, GetReplacementLow(node->InputAt(i)));
high_node->ReplaceInput(i, GetReplacementHigh(node->InputAt(i)));
}
} else {
DefaultLowering(node);
}
break;
}
case IrOpcode::kWord64ReverseBytes: {
Node* input = node->InputAt(0);
ReplaceNode(node, graph()->NewNode(machine()->Word32ReverseBytes().op(),
GetReplacementHigh(input)),
graph()->NewNode(machine()->Word32ReverseBytes().op(),
GetReplacementLow(input)));
break;
}
default: { DefaultLowering(node); }
}
} // NOLINT(readability/fn_size)
void Int64Lowering::LowerComparison(Node* node, const Operator* high_word_op,
const Operator* low_word_op) {
DCHECK_EQ(2, node->InputCount());
Node* left = node->InputAt(0);
Node* right = node->InputAt(1);
Node* replacement = graph()->NewNode(
machine()->Word32Or(),
graph()->NewNode(high_word_op, GetReplacementHigh(left),
GetReplacementHigh(right)),
graph()->NewNode(
machine()->Word32And(),
graph()->NewNode(machine()->Word32Equal(), GetReplacementHigh(left),
GetReplacementHigh(right)),
graph()->NewNode(low_word_op, GetReplacementLow(left),
GetReplacementLow(right))));
ReplaceNode(node, replacement, nullptr);
}
bool Int64Lowering::DefaultLowering(Node* node, bool low_word_only) {
bool something_changed = false;
for (int i = NodeProperties::PastValueIndex(node) - 1; i >= 0; i--) {
Node* input = node->InputAt(i);
if (HasReplacementLow(input)) {
something_changed = true;
node->ReplaceInput(i, GetReplacementLow(input));
}
if (!low_word_only && HasReplacementHigh(input)) {
something_changed = true;
node->InsertInput(zone(), i + 1, GetReplacementHigh(input));
}
}
return something_changed;
}
void Int64Lowering::ReplaceNode(Node* old, Node* new_low, Node* new_high) {
// if new_low == nullptr, then also new_high == nullptr.
DCHECK(new_low != nullptr || new_high == nullptr);
replacements_[old->id()].low = new_low;
replacements_[old->id()].high = new_high;
}
bool Int64Lowering::HasReplacementLow(Node* node) {
return replacements_[node->id()].low != nullptr;
}
Node* Int64Lowering::GetReplacementLow(Node* node) {
Node* result = replacements_[node->id()].low;
DCHECK(result);
return result;
}
bool Int64Lowering::HasReplacementHigh(Node* node) {
return replacements_[node->id()].high != nullptr;
}
Node* Int64Lowering::GetReplacementHigh(Node* node) {
Node* result = replacements_[node->id()].high;
DCHECK(result);
return result;
}
void Int64Lowering::PreparePhiReplacement(Node* phi) {
MachineRepresentation rep = PhiRepresentationOf(phi->op());
if (rep == MachineRepresentation::kWord64) {
// We have to create the replacements for a phi node before we actually
// lower the phi to break potential cycles in the graph. The replacements of
// input nodes do not exist yet, so we use a placeholder node to pass the
// graph verifier.
int value_count = phi->op()->ValueInputCount();
Node** inputs_low = zone()->NewArray<Node*>(value_count + 1);
Node** inputs_high = zone()->NewArray<Node*>(value_count + 1);
for (int i = 0; i < value_count; i++) {
inputs_low[i] = placeholder_;
inputs_high[i] = placeholder_;
}
inputs_low[value_count] = NodeProperties::GetControlInput(phi, 0);
inputs_high[value_count] = NodeProperties::GetControlInput(phi, 0);
ReplaceNode(phi,
graph()->NewNode(
common()->Phi(MachineRepresentation::kWord32, value_count),
value_count + 1, inputs_low, false),
graph()->NewNode(
common()->Phi(MachineRepresentation::kWord32, value_count),
value_count + 1, inputs_high, false));
}
}
} // namespace compiler
} // namespace internal
} // namespace v8