// 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-lowering.h"
#include "src/base/bits.h"
#include "src/code-factory.h"
#include "src/compiler/common-operator.h"
#include "src/compiler/graph-inl.h"
#include "src/compiler/node-properties-inl.h"
#include "src/compiler/representation-change.h"
#include "src/compiler/simplified-lowering.h"
#include "src/compiler/simplified-operator.h"
#include "src/objects.h"
namespace v8 {
namespace internal {
namespace compiler {
// Macro for outputting trace information from representation inference.
#define TRACE(x) \
if (FLAG_trace_representation) PrintF x
// Representation selection and lowering of {Simplified} operators to machine
// operators are interwined. We use a fixpoint calculation to compute both the
// output representation and the best possible lowering for {Simplified} nodes.
// Representation change insertion ensures that all values are in the correct
// machine representation after this phase, as dictated by the machine
// operators themselves.
enum Phase {
// 1.) PROPAGATE: Traverse the graph from the end, pushing usage information
// backwards from uses to definitions, around cycles in phis, according
// to local rules for each operator.
// During this phase, the usage information for a node determines the best
// possible lowering for each operator so far, and that in turn determines
// the output representation.
// Therefore, to be correct, this phase must iterate to a fixpoint before
// the next phase can begin.
PROPAGATE,
// 2.) LOWER: perform lowering for all {Simplified} nodes by replacing some
// operators for some nodes, expanding some nodes to multiple nodes, or
// removing some (redundant) nodes.
// During this phase, use the {RepresentationChanger} to insert
// representation changes between uses that demand a particular
// representation and nodes that produce a different representation.
LOWER
};
class RepresentationSelector {
public:
// Information for each node tracked during the fixpoint.
struct NodeInfo {
MachineTypeUnion use : 15; // Union of all usages for the node.
bool queued : 1; // Bookkeeping for the traversal.
bool visited : 1; // Bookkeeping for the traversal.
MachineTypeUnion output : 15; // Output type of the node.
};
RepresentationSelector(JSGraph* jsgraph, Zone* zone,
RepresentationChanger* changer)
: jsgraph_(jsgraph),
count_(jsgraph->graph()->NodeCount()),
info_(zone->NewArray<NodeInfo>(count_)),
nodes_(zone),
replacements_(zone),
contains_js_nodes_(false),
phase_(PROPAGATE),
changer_(changer),
queue_(zone) {
memset(info_, 0, sizeof(NodeInfo) * count_);
}
void Run(SimplifiedLowering* lowering) {
// Run propagation phase to a fixpoint.
TRACE(("--{Propagation phase}--\n"));
phase_ = PROPAGATE;
Enqueue(jsgraph_->graph()->end());
// Process nodes from the queue until it is empty.
while (!queue_.empty()) {
Node* node = queue_.front();
NodeInfo* info = GetInfo(node);
queue_.pop();
info->queued = false;
TRACE((" visit #%d: %s\n", node->id(), node->op()->mnemonic()));
VisitNode(node, info->use, NULL);
TRACE((" ==> output "));
PrintInfo(info->output);
TRACE(("\n"));
}
// Run lowering and change insertion phase.
TRACE(("--{Simplified lowering phase}--\n"));
phase_ = LOWER;
// Process nodes from the collected {nodes_} vector.
for (NodeVector::iterator i = nodes_.begin(); i != nodes_.end(); ++i) {
Node* node = *i;
TRACE((" visit #%d: %s\n", node->id(), node->op()->mnemonic()));
// Reuse {VisitNode()} so the representation rules are in one place.
VisitNode(node, GetUseInfo(node), lowering);
}
// Perform the final replacements.
for (NodeVector::iterator i = replacements_.begin();
i != replacements_.end(); ++i) {
Node* node = *i;
Node* replacement = *(++i);
node->ReplaceUses(replacement);
}
}
// Enqueue {node} if the {use} contains new information for that node.
// Add {node} to {nodes_} if this is the first time it's been visited.
void Enqueue(Node* node, MachineTypeUnion use = 0) {
if (phase_ != PROPAGATE) return;
NodeInfo* info = GetInfo(node);
if (!info->visited) {
// First visit of this node.
info->visited = true;
info->queued = true;
nodes_.push_back(node);
queue_.push(node);
TRACE((" initial: "));
info->use |= use;
PrintUseInfo(node);
return;
}
TRACE((" queue?: "));
PrintUseInfo(node);
if ((info->use & use) != use) {
// New usage information for the node is available.
if (!info->queued) {
queue_.push(node);
info->queued = true;
TRACE((" added: "));
} else {
TRACE((" inqueue: "));
}
info->use |= use;
PrintUseInfo(node);
}
}
bool lower() { return phase_ == LOWER; }
void Enqueue(Node* node, MachineType use) {
Enqueue(node, static_cast<MachineTypeUnion>(use));
}
void SetOutput(Node* node, MachineTypeUnion output) {
// Every node should have at most one output representation. Note that
// phis can have 0, if they have not been used in a representation-inducing
// instruction.
DCHECK((output & kRepMask) == 0 ||
base::bits::IsPowerOfTwo32(output & kRepMask));
GetInfo(node)->output = output;
}
bool BothInputsAre(Node* node, Type* type) {
DCHECK_EQ(2, node->InputCount());
return NodeProperties::GetBounds(node->InputAt(0)).upper->Is(type) &&
NodeProperties::GetBounds(node->InputAt(1)).upper->Is(type);
}
void ProcessInput(Node* node, int index, MachineTypeUnion use) {
Node* input = node->InputAt(index);
if (phase_ == PROPAGATE) {
// In the propagate phase, propagate the usage information backward.
Enqueue(input, use);
} else {
// In the change phase, insert a change before the use if necessary.
if ((use & kRepMask) == 0) return; // No input requirement on the use.
MachineTypeUnion output = GetInfo(input)->output;
if ((output & kRepMask & use) == 0) {
// Output representation doesn't match usage.
TRACE((" change: #%d:%s(@%d #%d:%s) ", node->id(),
node->op()->mnemonic(), index, input->id(),
input->op()->mnemonic()));
TRACE((" from "));
PrintInfo(output);
TRACE((" to "));
PrintInfo(use);
TRACE(("\n"));
Node* n = changer_->GetRepresentationFor(input, output, use);
node->ReplaceInput(index, n);
}
}
}
void ProcessRemainingInputs(Node* node, int index) {
DCHECK_GE(index, NodeProperties::PastValueIndex(node));
DCHECK_GE(index, NodeProperties::PastContextIndex(node));
for (int i = std::max(index, NodeProperties::FirstEffectIndex(node));
i < NodeProperties::PastEffectIndex(node); ++i) {
Enqueue(node->InputAt(i)); // Effect inputs: just visit
}
for (int i = std::max(index, NodeProperties::FirstControlIndex(node));
i < NodeProperties::PastControlIndex(node); ++i) {
Enqueue(node->InputAt(i)); // Control inputs: just visit
}
}
// The default, most general visitation case. For {node}, process all value,
// context, effect, and control inputs, assuming that value inputs should have
// {kRepTagged} representation and can observe all output values {kTypeAny}.
void VisitInputs(Node* node) {
InputIter i = node->inputs().begin();
for (int j = OperatorProperties::GetValueInputCount(node->op()); j > 0;
++i, j--) {
ProcessInput(node, i.index(), kMachAnyTagged); // Value inputs
}
for (int j = OperatorProperties::GetContextInputCount(node->op()); j > 0;
++i, j--) {
ProcessInput(node, i.index(), kMachAnyTagged); // Context inputs
}
for (int j = OperatorProperties::GetEffectInputCount(node->op()); j > 0;
++i, j--) {
Enqueue(*i); // Effect inputs: just visit
}
for (int j = OperatorProperties::GetControlInputCount(node->op()); j > 0;
++i, j--) {
Enqueue(*i); // Control inputs: just visit
}
SetOutput(node, kMachAnyTagged);
}
// Helper for binops of the I x I -> O variety.
void VisitBinop(Node* node, MachineTypeUnion input_use,
MachineTypeUnion output) {
DCHECK_EQ(2, node->InputCount());
ProcessInput(node, 0, input_use);
ProcessInput(node, 1, input_use);
SetOutput(node, output);
}
// Helper for unops of the I -> O variety.
void VisitUnop(Node* node, MachineTypeUnion input_use,
MachineTypeUnion output) {
DCHECK_EQ(1, node->InputCount());
ProcessInput(node, 0, input_use);
SetOutput(node, output);
}
// Helper for leaf nodes.
void VisitLeaf(Node* node, MachineTypeUnion output) {
DCHECK_EQ(0, node->InputCount());
SetOutput(node, output);
}
// Helpers for specific types of binops.
void VisitFloat64Binop(Node* node) {
VisitBinop(node, kMachFloat64, kMachFloat64);
}
void VisitInt32Binop(Node* node) { VisitBinop(node, kMachInt32, kMachInt32); }
void VisitUint32Binop(Node* node) {
VisitBinop(node, kMachUint32, kMachUint32);
}
void VisitInt64Binop(Node* node) { VisitBinop(node, kMachInt64, kMachInt64); }
void VisitUint64Binop(Node* node) {
VisitBinop(node, kMachUint64, kMachUint64);
}
void VisitFloat64Cmp(Node* node) { VisitBinop(node, kMachFloat64, kRepBit); }
void VisitInt32Cmp(Node* node) { VisitBinop(node, kMachInt32, kRepBit); }
void VisitUint32Cmp(Node* node) { VisitBinop(node, kMachUint32, kRepBit); }
void VisitInt64Cmp(Node* node) { VisitBinop(node, kMachInt64, kRepBit); }
void VisitUint64Cmp(Node* node) { VisitBinop(node, kMachUint64, kRepBit); }
// Helper for handling phis.
void VisitPhi(Node* node, MachineTypeUnion use,
SimplifiedLowering* lowering) {
// First, propagate the usage information to inputs of the phi.
if (!lower()) {
int values = OperatorProperties::GetValueInputCount(node->op());
// Propagate {use} of the phi to value inputs, and 0 to control.
Node::Inputs inputs = node->inputs();
for (Node::Inputs::iterator iter(inputs.begin()); iter != inputs.end();
++iter, --values) {
// TODO(titzer): it'd be nice to have distinguished edge kinds here.
ProcessInput(node, iter.index(), values > 0 ? use : 0);
}
}
// Phis adapt to whatever output representation their uses demand,
// pushing representation changes to their inputs.
MachineTypeUnion use_rep = GetUseInfo(node) & kRepMask;
MachineTypeUnion use_type = GetUseInfo(node) & kTypeMask;
MachineTypeUnion rep = 0;
if (use_rep & kRepTagged) {
rep = kRepTagged; // Tagged overrides everything.
} else if (use_rep & kRepFloat64) {
rep = kRepFloat64;
} else if (use_rep & kRepWord64) {
rep = kRepWord64;
} else if (use_rep & kRepWord32) {
rep = kRepWord32;
} else if (use_rep & kRepBit) {
rep = kRepBit;
} else {
// There was no representation associated with any of the uses.
// TODO(titzer): Select the best rep using phi's type, not the usage type?
if (use_type & kTypeAny) {
rep = kRepTagged;
} else if (use_type & kTypeNumber) {
rep = kRepFloat64;
} else if (use_type & kTypeInt64 || use_type & kTypeUint64) {
rep = kRepWord64;
} else if (use_type & kTypeInt32 || use_type & kTypeUint32) {
rep = kRepWord32;
} else if (use_type & kTypeBool) {
rep = kRepBit;
} else {
UNREACHABLE(); // should have at least a usage type!
}
}
// Preserve the usage type, but set the representation.
Type* upper = NodeProperties::GetBounds(node).upper;
MachineTypeUnion output_type = rep | changer_->TypeFromUpperBound(upper);
SetOutput(node, output_type);
if (lower()) {
int values = OperatorProperties::GetValueInputCount(node->op());
// Update the phi operator.
MachineType type = static_cast<MachineType>(output_type);
if (type != OpParameter<MachineType>(node)) {
node->set_op(lowering->common()->Phi(type, values));
}
// Convert inputs to the output representation of this phi.
Node::Inputs inputs = node->inputs();
for (Node::Inputs::iterator iter(inputs.begin()); iter != inputs.end();
++iter, --values) {
// TODO(titzer): it'd be nice to have distinguished edge kinds here.
ProcessInput(node, iter.index(), values > 0 ? output_type : 0);
}
}
}
const Operator* Int32Op(Node* node) {
return changer_->Int32OperatorFor(node->opcode());
}
const Operator* Uint32Op(Node* node) {
return changer_->Uint32OperatorFor(node->opcode());
}
const Operator* Float64Op(Node* node) {
return changer_->Float64OperatorFor(node->opcode());
}
static MachineType AssumeImplicitFloat32Change(MachineType type) {
// TODO(titzer): Assume loads of float32 change representation to float64.
// Fix this with full support for float32 representations.
if (type & kRepFloat32) {
return static_cast<MachineType>((type & ~kRepFloat32) | kRepFloat64);
}
return type;
}
// Dispatching routine for visiting the node {node} with the usage {use}.
// Depending on the operator, propagate new usage info to the inputs.
void VisitNode(Node* node, MachineTypeUnion use,
SimplifiedLowering* lowering) {
switch (node->opcode()) {
//------------------------------------------------------------------
// Common operators.
//------------------------------------------------------------------
case IrOpcode::kStart:
case IrOpcode::kDead:
return VisitLeaf(node, 0);
case IrOpcode::kParameter: {
// TODO(titzer): use representation from linkage.
Type* upper = NodeProperties::GetBounds(node).upper;
ProcessInput(node, 0, 0);
SetOutput(node, kRepTagged | changer_->TypeFromUpperBound(upper));
return;
}
case IrOpcode::kInt32Constant:
return VisitLeaf(node, kRepWord32);
case IrOpcode::kInt64Constant:
return VisitLeaf(node, kRepWord64);
case IrOpcode::kFloat64Constant:
return VisitLeaf(node, kRepFloat64);
case IrOpcode::kExternalConstant:
return VisitLeaf(node, kMachPtr);
case IrOpcode::kNumberConstant:
return VisitLeaf(node, kRepTagged);
case IrOpcode::kHeapConstant:
return VisitLeaf(node, kRepTagged);
case IrOpcode::kEnd:
case IrOpcode::kIfTrue:
case IrOpcode::kIfFalse:
case IrOpcode::kReturn:
case IrOpcode::kMerge:
case IrOpcode::kThrow:
return VisitInputs(node); // default visit for all node inputs.
case IrOpcode::kBranch:
ProcessInput(node, 0, kRepBit);
Enqueue(NodeProperties::GetControlInput(node, 0));
break;
case IrOpcode::kPhi:
return VisitPhi(node, use, lowering);
//------------------------------------------------------------------
// JavaScript operators.
//------------------------------------------------------------------
// For now, we assume that all JS operators were too complex to lower
// to Simplified and that they will always require tagged value inputs
// and produce tagged value outputs.
// TODO(turbofan): it might be possible to lower some JSOperators here,
// but that responsibility really lies in the typed lowering phase.
#define DEFINE_JS_CASE(x) case IrOpcode::k##x:
JS_OP_LIST(DEFINE_JS_CASE)
#undef DEFINE_JS_CASE
contains_js_nodes_ = true;
VisitInputs(node);
return SetOutput(node, kRepTagged);
//------------------------------------------------------------------
// Simplified operators.
//------------------------------------------------------------------
case IrOpcode::kBooleanNot: {
if (lower()) {
MachineTypeUnion input = GetInfo(node->InputAt(0))->output;
if (input & kRepBit) {
// BooleanNot(x: kRepBit) => WordEqual(x, #0)
node->set_op(lowering->machine()->WordEqual());
node->AppendInput(jsgraph_->zone(), jsgraph_->Int32Constant(0));
} else {
// BooleanNot(x: kRepTagged) => WordEqual(x, #false)
node->set_op(lowering->machine()->WordEqual());
node->AppendInput(jsgraph_->zone(), jsgraph_->FalseConstant());
}
} else {
// No input representation requirement; adapt during lowering.
ProcessInput(node, 0, kTypeBool);
SetOutput(node, kRepBit);
}
break;
}
case IrOpcode::kBooleanToNumber: {
if (lower()) {
MachineTypeUnion input = GetInfo(node->InputAt(0))->output;
if (input & kRepBit) {
// BooleanToNumber(x: kRepBit) => x
DeferReplacement(node, node->InputAt(0));
} else {
// BooleanToNumber(x: kRepTagged) => WordEqual(x, #true)
node->set_op(lowering->machine()->WordEqual());
node->AppendInput(jsgraph_->zone(), jsgraph_->TrueConstant());
}
} else {
// No input representation requirement; adapt during lowering.
ProcessInput(node, 0, kTypeBool);
SetOutput(node, kMachInt32);
}
break;
}
case IrOpcode::kNumberEqual:
case IrOpcode::kNumberLessThan:
case IrOpcode::kNumberLessThanOrEqual: {
// Number comparisons reduce to integer comparisons for integer inputs.
if (BothInputsAre(node, Type::Signed32())) {
// => signed Int32Cmp
VisitInt32Cmp(node);
if (lower()) node->set_op(Int32Op(node));
} else if (BothInputsAre(node, Type::Unsigned32())) {
// => unsigned Int32Cmp
VisitUint32Cmp(node);
if (lower()) node->set_op(Uint32Op(node));
} else {
// => Float64Cmp
VisitFloat64Cmp(node);
if (lower()) node->set_op(Float64Op(node));
}
break;
}
case IrOpcode::kNumberAdd:
case IrOpcode::kNumberSubtract: {
// Add and subtract reduce to Int32Add/Sub if the inputs
// are already integers and all uses are truncating.
if (BothInputsAre(node, Type::Signed32()) &&
(use & (kTypeUint32 | kTypeNumber | kTypeAny)) == 0) {
// => signed Int32Add/Sub
VisitInt32Binop(node);
if (lower()) node->set_op(Int32Op(node));
} else if (BothInputsAre(node, Type::Unsigned32()) &&
(use & (kTypeInt32 | kTypeNumber | kTypeAny)) == 0) {
// => unsigned Int32Add/Sub
VisitUint32Binop(node);
if (lower()) node->set_op(Uint32Op(node));
} else {
// => Float64Add/Sub
VisitFloat64Binop(node);
if (lower()) node->set_op(Float64Op(node));
}
break;
}
case IrOpcode::kNumberMultiply:
case IrOpcode::kNumberDivide:
case IrOpcode::kNumberModulus: {
// Float64Mul/Div/Mod
VisitFloat64Binop(node);
if (lower()) node->set_op(Float64Op(node));
break;
}
case IrOpcode::kNumberToInt32: {
MachineTypeUnion use_rep = use & kRepMask;
if (lower()) {
MachineTypeUnion in = GetInfo(node->InputAt(0))->output;
if ((in & kTypeMask) == kTypeInt32 || (in & kRepMask) == kRepWord32) {
// If the input has type int32, or is already a word32, just change
// representation if necessary.
VisitUnop(node, kTypeInt32 | use_rep, kTypeInt32 | use_rep);
DeferReplacement(node, node->InputAt(0));
} else {
// Require the input in float64 format and perform truncation.
// TODO(turbofan): avoid a truncation with a smi check.
VisitUnop(node, kTypeInt32 | kRepFloat64, kTypeInt32 | kRepWord32);
node->set_op(lowering->machine()->TruncateFloat64ToInt32());
}
} else {
// Propagate a type to the input, but pass through representation.
VisitUnop(node, kTypeInt32, kTypeInt32 | use_rep);
}
break;
}
case IrOpcode::kNumberToUint32: {
MachineTypeUnion use_rep = use & kRepMask;
if (lower()) {
MachineTypeUnion in = GetInfo(node->InputAt(0))->output;
if ((in & kTypeMask) == kTypeUint32 ||
(in & kRepMask) == kRepWord32) {
// The input has type int32, just change representation.
VisitUnop(node, kTypeUint32 | use_rep, kTypeUint32 | use_rep);
DeferReplacement(node, node->InputAt(0));
} else {
// Require the input in float64 format to perform truncation.
// TODO(turbofan): avoid the truncation with a smi check.
VisitUnop(node, kTypeUint32 | kRepFloat64,
kTypeUint32 | kRepWord32);
node->set_op(lowering->machine()->TruncateFloat64ToInt32());
}
} else {
// Propagate a type to the input, but pass through representation.
VisitUnop(node, kTypeUint32, kTypeUint32 | use_rep);
}
break;
}
case IrOpcode::kReferenceEqual: {
VisitBinop(node, kMachAnyTagged, kRepBit);
if (lower()) node->set_op(lowering->machine()->WordEqual());
break;
}
case IrOpcode::kStringEqual: {
VisitBinop(node, kMachAnyTagged, kRepBit);
if (lower()) lowering->DoStringEqual(node);
break;
}
case IrOpcode::kStringLessThan: {
VisitBinop(node, kMachAnyTagged, kRepBit);
if (lower()) lowering->DoStringLessThan(node);
break;
}
case IrOpcode::kStringLessThanOrEqual: {
VisitBinop(node, kMachAnyTagged, kRepBit);
if (lower()) lowering->DoStringLessThanOrEqual(node);
break;
}
case IrOpcode::kStringAdd: {
VisitBinop(node, kMachAnyTagged, kMachAnyTagged);
if (lower()) lowering->DoStringAdd(node);
break;
}
case IrOpcode::kLoadField: {
FieldAccess access = FieldAccessOf(node->op());
ProcessInput(node, 0, changer_->TypeForBasePointer(access));
ProcessRemainingInputs(node, 1);
SetOutput(node, AssumeImplicitFloat32Change(access.machine_type));
if (lower()) lowering->DoLoadField(node);
break;
}
case IrOpcode::kStoreField: {
FieldAccess access = FieldAccessOf(node->op());
ProcessInput(node, 0, changer_->TypeForBasePointer(access));
ProcessInput(node, 1, AssumeImplicitFloat32Change(access.machine_type));
ProcessRemainingInputs(node, 2);
SetOutput(node, 0);
if (lower()) lowering->DoStoreField(node);
break;
}
case IrOpcode::kLoadElement: {
ElementAccess access = ElementAccessOf(node->op());
ProcessInput(node, 0, changer_->TypeForBasePointer(access));
ProcessInput(node, 1, kMachInt32); // element index
ProcessInput(node, 2, kMachInt32); // length
ProcessRemainingInputs(node, 3);
SetOutput(node, AssumeImplicitFloat32Change(access.machine_type));
if (lower()) lowering->DoLoadElement(node);
break;
}
case IrOpcode::kStoreElement: {
ElementAccess access = ElementAccessOf(node->op());
ProcessInput(node, 0, changer_->TypeForBasePointer(access));
ProcessInput(node, 1, kMachInt32); // element index
ProcessInput(node, 2, kMachInt32); // length
ProcessInput(node, 3, AssumeImplicitFloat32Change(access.machine_type));
ProcessRemainingInputs(node, 4);
SetOutput(node, 0);
if (lower()) lowering->DoStoreElement(node);
break;
}
//------------------------------------------------------------------
// Machine-level operators.
//------------------------------------------------------------------
case IrOpcode::kLoad: {
// TODO(titzer): machine loads/stores need to know BaseTaggedness!?
MachineType tBase = kRepTagged;
LoadRepresentation rep = OpParameter<LoadRepresentation>(node);
ProcessInput(node, 0, tBase); // pointer or object
ProcessInput(node, 1, kMachInt32); // index
ProcessRemainingInputs(node, 2);
SetOutput(node, rep);
break;
}
case IrOpcode::kStore: {
// TODO(titzer): machine loads/stores need to know BaseTaggedness!?
MachineType tBase = kRepTagged;
StoreRepresentation rep = OpParameter<StoreRepresentation>(node);
ProcessInput(node, 0, tBase); // pointer or object
ProcessInput(node, 1, kMachInt32); // index
ProcessInput(node, 2, rep.machine_type());
ProcessRemainingInputs(node, 3);
SetOutput(node, 0);
break;
}
case IrOpcode::kWord32Shr:
// We output unsigned int32 for shift right because JavaScript.
return VisitBinop(node, kRepWord32, kRepWord32 | kTypeUint32);
case IrOpcode::kWord32And:
case IrOpcode::kWord32Or:
case IrOpcode::kWord32Xor:
case IrOpcode::kWord32Shl:
case IrOpcode::kWord32Sar:
// We use signed int32 as the output type for these word32 operations,
// though the machine bits are the same for either signed or unsigned,
// because JavaScript considers the result from these operations signed.
return VisitBinop(node, kRepWord32, kRepWord32 | kTypeInt32);
case IrOpcode::kWord32Equal:
return VisitBinop(node, kRepWord32, kRepBit);
case IrOpcode::kInt32Add:
case IrOpcode::kInt32Sub:
case IrOpcode::kInt32Mul:
case IrOpcode::kInt32Div:
case IrOpcode::kInt32Mod:
return VisitInt32Binop(node);
case IrOpcode::kInt32UDiv:
case IrOpcode::kInt32UMod:
return VisitUint32Binop(node);
case IrOpcode::kInt32LessThan:
case IrOpcode::kInt32LessThanOrEqual:
return VisitInt32Cmp(node);
case IrOpcode::kUint32LessThan:
case IrOpcode::kUint32LessThanOrEqual:
return VisitUint32Cmp(node);
case IrOpcode::kInt64Add:
case IrOpcode::kInt64Sub:
case IrOpcode::kInt64Mul:
case IrOpcode::kInt64Div:
case IrOpcode::kInt64Mod:
return VisitInt64Binop(node);
case IrOpcode::kInt64LessThan:
case IrOpcode::kInt64LessThanOrEqual:
return VisitInt64Cmp(node);
case IrOpcode::kInt64UDiv:
case IrOpcode::kInt64UMod:
return VisitUint64Binop(node);
case IrOpcode::kWord64And:
case IrOpcode::kWord64Or:
case IrOpcode::kWord64Xor:
case IrOpcode::kWord64Shl:
case IrOpcode::kWord64Shr:
case IrOpcode::kWord64Sar:
return VisitBinop(node, kRepWord64, kRepWord64);
case IrOpcode::kWord64Equal:
return VisitBinop(node, kRepWord64, kRepBit);
case IrOpcode::kChangeInt32ToInt64:
return VisitUnop(node, kTypeInt32 | kRepWord32,
kTypeInt32 | kRepWord64);
case IrOpcode::kChangeUint32ToUint64:
return VisitUnop(node, kTypeUint32 | kRepWord32,
kTypeUint32 | kRepWord64);
case IrOpcode::kTruncateInt64ToInt32:
// TODO(titzer): Is kTypeInt32 correct here?
return VisitUnop(node, kTypeInt32 | kRepWord64,
kTypeInt32 | kRepWord32);
case IrOpcode::kChangeInt32ToFloat64:
return VisitUnop(node, kTypeInt32 | kRepWord32,
kTypeInt32 | kRepFloat64);
case IrOpcode::kChangeUint32ToFloat64:
return VisitUnop(node, kTypeUint32 | kRepWord32,
kTypeUint32 | kRepFloat64);
case IrOpcode::kChangeFloat64ToInt32:
return VisitUnop(node, kTypeInt32 | kRepFloat64,
kTypeInt32 | kRepWord32);
case IrOpcode::kChangeFloat64ToUint32:
return VisitUnop(node, kTypeUint32 | kRepFloat64,
kTypeUint32 | kRepWord32);
case IrOpcode::kFloat64Add:
case IrOpcode::kFloat64Sub:
case IrOpcode::kFloat64Mul:
case IrOpcode::kFloat64Div:
case IrOpcode::kFloat64Mod:
return VisitFloat64Binop(node);
case IrOpcode::kFloat64Sqrt:
return VisitUnop(node, kMachFloat64, kMachFloat64);
case IrOpcode::kFloat64Equal:
case IrOpcode::kFloat64LessThan:
case IrOpcode::kFloat64LessThanOrEqual:
return VisitFloat64Cmp(node);
default:
VisitInputs(node);
break;
}
}
void DeferReplacement(Node* node, Node* replacement) {
if (replacement->id() < count_) {
// Replace with a previously existing node eagerly.
node->ReplaceUses(replacement);
} else {
// Otherwise, we are replacing a node with a representation change.
// Such a substitution must be done after all lowering is done, because
// new nodes do not have {NodeInfo} entries, and that would confuse
// the representation change insertion for uses of it.
replacements_.push_back(node);
replacements_.push_back(replacement);
}
// TODO(titzer) node->RemoveAllInputs(); // Node is now dead.
}
void PrintUseInfo(Node* node) {
TRACE(("#%d:%-20s ", node->id(), node->op()->mnemonic()));
PrintInfo(GetUseInfo(node));
TRACE(("\n"));
}
void PrintInfo(MachineTypeUnion info) {
if (FLAG_trace_representation) {
OFStream os(stdout);
os << static_cast<MachineType>(info);
}
}
private:
JSGraph* jsgraph_;
int count_; // number of nodes in the graph
NodeInfo* info_; // node id -> usage information
NodeVector nodes_; // collected nodes
NodeVector replacements_; // replacements to be done after lowering
bool contains_js_nodes_; // {true} if a JS operator was seen
Phase phase_; // current phase of algorithm
RepresentationChanger* changer_; // for inserting representation changes
ZoneQueue<Node*> queue_; // queue for traversing the graph
NodeInfo* GetInfo(Node* node) {
DCHECK(node->id() >= 0);
DCHECK(node->id() < count_);
return &info_[node->id()];
}
MachineTypeUnion GetUseInfo(Node* node) { return GetInfo(node)->use; }
};
Node* SimplifiedLowering::IsTagged(Node* node) {
// TODO(titzer): factor this out to a TaggingScheme abstraction.
STATIC_ASSERT(kSmiTagMask == 1); // Only works if tag is the low bit.
return graph()->NewNode(machine()->WordAnd(), node,
jsgraph()->Int32Constant(kSmiTagMask));
}
void SimplifiedLowering::LowerAllNodes() {
SimplifiedOperatorBuilder simplified(graph()->zone());
RepresentationChanger changer(jsgraph(), &simplified,
graph()->zone()->isolate());
RepresentationSelector selector(jsgraph(), zone(), &changer);
selector.Run(this);
}
Node* SimplifiedLowering::Untag(Node* node) {
// TODO(titzer): factor this out to a TaggingScheme abstraction.
Node* shift_amount = jsgraph()->Int32Constant(kSmiTagSize + kSmiShiftSize);
return graph()->NewNode(machine()->WordSar(), node, shift_amount);
}
Node* SimplifiedLowering::SmiTag(Node* node) {
// TODO(titzer): factor this out to a TaggingScheme abstraction.
Node* shift_amount = jsgraph()->Int32Constant(kSmiTagSize + kSmiShiftSize);
return graph()->NewNode(machine()->WordShl(), node, shift_amount);
}
Node* SimplifiedLowering::OffsetMinusTagConstant(int32_t offset) {
return jsgraph()->Int32Constant(offset - kHeapObjectTag);
}
static WriteBarrierKind ComputeWriteBarrierKind(BaseTaggedness base_is_tagged,
MachineType representation,
Type* type) {
// TODO(turbofan): skip write barriers for Smis, etc.
if (base_is_tagged == kTaggedBase &&
RepresentationOf(representation) == kRepTagged) {
// Write barriers are only for writes into heap objects (i.e. tagged base).
return kFullWriteBarrier;
}
return kNoWriteBarrier;
}
void SimplifiedLowering::DoLoadField(Node* node) {
const FieldAccess& access = FieldAccessOf(node->op());
node->set_op(machine()->Load(access.machine_type));
Node* offset = jsgraph()->Int32Constant(access.offset - access.tag());
node->InsertInput(zone(), 1, offset);
}
void SimplifiedLowering::DoStoreField(Node* node) {
const FieldAccess& access = FieldAccessOf(node->op());
WriteBarrierKind kind = ComputeWriteBarrierKind(
access.base_is_tagged, access.machine_type, access.type);
node->set_op(
machine()->Store(StoreRepresentation(access.machine_type, kind)));
Node* offset = jsgraph()->Int32Constant(access.offset - access.tag());
node->InsertInput(zone(), 1, offset);
}
Node* SimplifiedLowering::ComputeIndex(const ElementAccess& access,
Node* index) {
int element_size = ElementSizeOf(access.machine_type);
if (element_size != 1) {
index = graph()->NewNode(machine()->Int32Mul(),
jsgraph()->Int32Constant(element_size), index);
}
int fixed_offset = access.header_size - access.tag();
if (fixed_offset == 0) return index;
return graph()->NewNode(machine()->Int32Add(), index,
jsgraph()->Int32Constant(fixed_offset));
}
void SimplifiedLowering::DoLoadElement(Node* node) {
const ElementAccess& access = ElementAccessOf(node->op());
node->set_op(machine()->Load(access.machine_type));
node->ReplaceInput(1, ComputeIndex(access, node->InputAt(1)));
node->RemoveInput(2);
}
void SimplifiedLowering::DoStoreElement(Node* node) {
const ElementAccess& access = ElementAccessOf(node->op());
WriteBarrierKind kind = ComputeWriteBarrierKind(
access.base_is_tagged, access.machine_type, access.type);
node->set_op(
machine()->Store(StoreRepresentation(access.machine_type, kind)));
node->ReplaceInput(1, ComputeIndex(access, node->InputAt(1)));
node->RemoveInput(2);
}
void SimplifiedLowering::DoStringAdd(Node* node) {
Callable callable = CodeFactory::StringAdd(
zone()->isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
CallDescriptor* desc =
Linkage::GetStubCallDescriptor(callable.descriptor(), 0, flags, zone());
node->set_op(common()->Call(desc));
node->InsertInput(zone(), 0, jsgraph()->HeapConstant(callable.code()));
node->AppendInput(zone(), jsgraph()->UndefinedConstant());
node->AppendInput(zone(), graph()->start());
node->AppendInput(zone(), graph()->start());
}
Node* SimplifiedLowering::StringComparison(Node* node, bool requires_ordering) {
CEntryStub stub(zone()->isolate(), 1);
Runtime::FunctionId f =
requires_ordering ? Runtime::kStringCompare : Runtime::kStringEquals;
ExternalReference ref(f, zone()->isolate());
Operator::Properties props = node->op()->properties();
// TODO(mstarzinger): We should call StringCompareStub here instead, once an
// interface descriptor is available for it.
CallDescriptor* desc = Linkage::GetRuntimeCallDescriptor(f, 2, props, zone());
return graph()->NewNode(common()->Call(desc),
jsgraph()->HeapConstant(stub.GetCode()),
NodeProperties::GetValueInput(node, 0),
NodeProperties::GetValueInput(node, 1),
jsgraph()->ExternalConstant(ref),
jsgraph()->Int32Constant(2),
jsgraph()->UndefinedConstant());
}
void SimplifiedLowering::DoStringEqual(Node* node) {
node->set_op(machine()->WordEqual());
node->ReplaceInput(0, StringComparison(node, false));
node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
}
void SimplifiedLowering::DoStringLessThan(Node* node) {
node->set_op(machine()->IntLessThan());
node->ReplaceInput(0, StringComparison(node, true));
node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
}
void SimplifiedLowering::DoStringLessThanOrEqual(Node* node) {
node->set_op(machine()->IntLessThanOrEqual());
node->ReplaceInput(0, StringComparison(node, true));
node->ReplaceInput(1, jsgraph()->SmiConstant(EQUAL));
}
} // namespace compiler
} // namespace internal
} // namespace v8