| // 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 <deque> |
| #include <queue> |
| |
| #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 { |
| RepTypeUnion use : 14; // Union of all usages for the node. |
| bool queued : 1; // Bookkeeping for the traversal. |
| bool visited : 1; // Bookkeeping for the traversal. |
| RepTypeUnion output : 14; // Output type of the node. |
| }; |
| |
| RepresentationSelector(JSGraph* jsgraph, Zone* zone, |
| RepresentationChanger* changer) |
| : jsgraph_(jsgraph), |
| count_(jsgraph->graph()->NodeCount()), |
| info_(zone->NewArray<NodeInfo>(count_)), |
| nodes_(NodeVector::allocator_type(zone)), |
| replacements_(NodeVector::allocator_type(zone)), |
| contains_js_nodes_(false), |
| phase_(PROPAGATE), |
| changer_(changer), |
| queue_(std::deque<Node*, NodePtrZoneAllocator>( |
| NodePtrZoneAllocator(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, RepTypeUnion 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, RepType use) { |
| Enqueue(node, static_cast<RepTypeUnion>(use)); |
| } |
| |
| void SetOutput(Node* node, RepTypeUnion 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 & rMask) == 0 || IsPowerOf2(output & rMask)); |
| 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, RepTypeUnion 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 & rMask) == 0) return; // No input requirement on the use. |
| RepTypeUnion output = GetInfo(input)->output; |
| if ((output & rMask & 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); |
| } |
| } |
| } |
| |
| static const RepTypeUnion kFloat64 = rFloat64 | tNumber; |
| static const RepTypeUnion kInt32 = rWord32 | tInt32; |
| static const RepTypeUnion kUint32 = rWord32 | tUint32; |
| static const RepTypeUnion kInt64 = rWord64 | tInt64; |
| static const RepTypeUnion kUint64 = rWord64 | tUint64; |
| static const RepTypeUnion kAnyTagged = rTagged | tAny; |
| |
| // The default, most general visitation case. For {node}, process all value, |
| // context, effect, and control inputs, assuming that value inputs should have |
| // {rTagged} representation and can observe all output values {tAny}. |
| void VisitInputs(Node* node) { |
| InputIter i = node->inputs().begin(); |
| for (int j = OperatorProperties::GetValueInputCount(node->op()); j > 0; |
| ++i, j--) { |
| ProcessInput(node, i.index(), kAnyTagged); // Value inputs |
| } |
| for (int j = OperatorProperties::GetContextInputCount(node->op()); j > 0; |
| ++i, j--) { |
| ProcessInput(node, i.index(), kAnyTagged); // 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, kAnyTagged); |
| } |
| |
| // Helper for binops of the I x I -> O variety. |
| void VisitBinop(Node* node, RepTypeUnion input_use, RepTypeUnion 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, RepTypeUnion input_use, RepTypeUnion output) { |
| DCHECK_EQ(1, node->InputCount()); |
| ProcessInput(node, 0, input_use); |
| SetOutput(node, output); |
| } |
| |
| // Helper for leaf nodes. |
| void VisitLeaf(Node* node, RepTypeUnion output) { |
| DCHECK_EQ(0, node->InputCount()); |
| SetOutput(node, output); |
| } |
| |
| // Helpers for specific types of binops. |
| void VisitFloat64Binop(Node* node) { VisitBinop(node, kFloat64, kFloat64); } |
| void VisitInt32Binop(Node* node) { VisitBinop(node, kInt32, kInt32); } |
| void VisitUint32Binop(Node* node) { VisitBinop(node, kUint32, kUint32); } |
| void VisitInt64Binop(Node* node) { VisitBinop(node, kInt64, kInt64); } |
| void VisitUint64Binop(Node* node) { VisitBinop(node, kUint64, kUint64); } |
| void VisitFloat64Cmp(Node* node) { VisitBinop(node, kFloat64, rBit); } |
| void VisitInt32Cmp(Node* node) { VisitBinop(node, kInt32, rBit); } |
| void VisitUint32Cmp(Node* node) { VisitBinop(node, kUint32, rBit); } |
| void VisitInt64Cmp(Node* node) { VisitBinop(node, kInt64, rBit); } |
| void VisitUint64Cmp(Node* node) { VisitBinop(node, kUint64, rBit); } |
| |
| // Helper for handling phis. |
| void VisitPhi(Node* node, RepTypeUnion use) { |
| // First, propagate the usage information to inputs of the phi. |
| int values = OperatorProperties::GetValueInputCount(node->op()); |
| Node::Inputs inputs = node->inputs(); |
| for (Node::Inputs::iterator iter(inputs.begin()); iter != inputs.end(); |
| ++iter, --values) { |
| // Propagate {use} of the phi to value inputs, and 0 to control. |
| // 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. |
| RepTypeUnion use_rep = GetUseInfo(node) & rMask; |
| RepTypeUnion use_type = GetUseInfo(node) & tMask; |
| RepTypeUnion rep = 0; |
| if (use_rep & rTagged) { |
| rep = rTagged; // Tagged overrides everything. |
| } else if (use_rep & rFloat64) { |
| rep = rFloat64; |
| } else if (use_rep & rWord64) { |
| rep = rWord64; |
| } else if (use_rep & rWord32) { |
| rep = rWord32; |
| } else if (use_rep & rBit) { |
| rep = rBit; |
| } 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 & tAny) { |
| rep = rTagged; |
| } else if (use_type & tNumber) { |
| rep = rFloat64; |
| } else if (use_type & tInt64 || use_type & tUint64) { |
| rep = rWord64; |
| } else if (use_type & tInt32 || use_type & tUint32) { |
| rep = rWord32; |
| } else if (use_type & tBool) { |
| rep = rBit; |
| } else { |
| UNREACHABLE(); // should have at least a usage type! |
| } |
| } |
| // Preserve the usage type, but set the representation. |
| Type* upper = NodeProperties::GetBounds(node).upper; |
| SetOutput(node, rep | changer_->TypeFromUpperBound(upper)); |
| } |
| |
| Operator* Int32Op(Node* node) { |
| return changer_->Int32OperatorFor(node->opcode()); |
| } |
| |
| Operator* Uint32Op(Node* node) { |
| return changer_->Uint32OperatorFor(node->opcode()); |
| } |
| |
| Operator* Float64Op(Node* node) { |
| return changer_->Float64OperatorFor(node->opcode()); |
| } |
| |
| // 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, RepTypeUnion 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, rTagged | changer_->TypeFromUpperBound(upper)); |
| return; |
| } |
| case IrOpcode::kInt32Constant: |
| return VisitLeaf(node, rWord32); |
| case IrOpcode::kInt64Constant: |
| return VisitLeaf(node, rWord64); |
| case IrOpcode::kFloat64Constant: |
| return VisitLeaf(node, rFloat64); |
| case IrOpcode::kExternalConstant: |
| return VisitLeaf(node, rPtr); |
| case IrOpcode::kNumberConstant: |
| return VisitLeaf(node, rTagged); |
| case IrOpcode::kHeapConstant: |
| return VisitLeaf(node, rTagged); |
| |
| 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, rBit); |
| Enqueue(NodeProperties::GetControlInput(node, 0)); |
| break; |
| case IrOpcode::kPhi: |
| return VisitPhi(node, use); |
| |
| //------------------------------------------------------------------ |
| // 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, rTagged); |
| |
| //------------------------------------------------------------------ |
| // Simplified operators. |
| //------------------------------------------------------------------ |
| case IrOpcode::kBooleanNot: { |
| if (lower()) { |
| RepTypeUnion input = GetInfo(node->InputAt(0))->output; |
| if (input & rBit) { |
| // BooleanNot(x: rBit) => WordEqual(x, #0) |
| node->set_op(lowering->machine()->WordEqual()); |
| node->AppendInput(jsgraph_->zone(), jsgraph_->Int32Constant(0)); |
| } else { |
| // BooleanNot(x: rTagged) => 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, tBool); |
| SetOutput(node, rBit); |
| } |
| 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 & (tUint32 | tNumber | tAny)) == 0) { |
| // => signed Int32Add/Sub |
| VisitInt32Binop(node); |
| if (lower()) node->set_op(Int32Op(node)); |
| } else if (BothInputsAre(node, Type::Unsigned32()) && |
| (use & (tInt32 | tNumber | tAny)) == 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: { |
| RepTypeUnion use_rep = use & rMask; |
| if (lower()) { |
| RepTypeUnion in = GetInfo(node->InputAt(0))->output; |
| if ((in & tMask) == tInt32 || (in & rMask) == rWord32) { |
| // If the input has type int32, or is already a word32, just change |
| // representation if necessary. |
| VisitUnop(node, tInt32 | use_rep, tInt32 | use_rep); |
| DeferReplacement(node, node->InputAt(0)); |
| } else { |
| // Require the input in float64 format and perform truncation. |
| // TODO(turbofan): could also avoid the truncation with a tag check. |
| VisitUnop(node, tInt32 | rFloat64, tInt32 | rWord32); |
| // TODO(titzer): should be a truncation. |
| node->set_op(lowering->machine()->ChangeFloat64ToInt32()); |
| } |
| } else { |
| // Propagate a type to the input, but pass through representation. |
| VisitUnop(node, tInt32, tInt32 | use_rep); |
| } |
| break; |
| } |
| case IrOpcode::kNumberToUint32: { |
| RepTypeUnion use_rep = use & rMask; |
| if (lower()) { |
| RepTypeUnion in = GetInfo(node->InputAt(0))->output; |
| if ((in & tMask) == tUint32 || (in & rMask) == rWord32) { |
| // The input has type int32, just change representation. |
| VisitUnop(node, tUint32 | use_rep, tUint32 | use_rep); |
| DeferReplacement(node, node->InputAt(0)); |
| } else { |
| // Require the input in float64 format to perform truncation. |
| // TODO(turbofan): could also avoid the truncation with a tag check. |
| VisitUnop(node, tUint32 | rFloat64, tUint32 | rWord32); |
| // TODO(titzer): should be a truncation. |
| node->set_op(lowering->machine()->ChangeFloat64ToUint32()); |
| } |
| } else { |
| // Propagate a type to the input, but pass through representation. |
| VisitUnop(node, tUint32, tUint32 | use_rep); |
| } |
| break; |
| } |
| case IrOpcode::kReferenceEqual: { |
| VisitBinop(node, kAnyTagged, rBit); |
| if (lower()) node->set_op(lowering->machine()->WordEqual()); |
| break; |
| } |
| case IrOpcode::kStringEqual: { |
| VisitBinop(node, kAnyTagged, rBit); |
| // TODO(titzer): lower StringEqual to stub/runtime call. |
| break; |
| } |
| case IrOpcode::kStringLessThan: { |
| VisitBinop(node, kAnyTagged, rBit); |
| // TODO(titzer): lower StringLessThan to stub/runtime call. |
| break; |
| } |
| case IrOpcode::kStringLessThanOrEqual: { |
| VisitBinop(node, kAnyTagged, rBit); |
| // TODO(titzer): lower StringLessThanOrEqual to stub/runtime call. |
| break; |
| } |
| case IrOpcode::kStringAdd: { |
| VisitBinop(node, kAnyTagged, kAnyTagged); |
| // TODO(titzer): lower StringAdd to stub/runtime call. |
| break; |
| } |
| case IrOpcode::kLoadField: { |
| FieldAccess access = FieldAccessOf(node->op()); |
| ProcessInput(node, 0, changer_->TypeForBasePointer(access)); |
| SetOutput(node, changer_->TypeForField(access)); |
| if (lower()) lowering->DoLoadField(node); |
| break; |
| } |
| case IrOpcode::kStoreField: { |
| FieldAccess access = FieldAccessOf(node->op()); |
| ProcessInput(node, 0, changer_->TypeForBasePointer(access)); |
| ProcessInput(node, 1, changer_->TypeForField(access)); |
| 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, kInt32); // element index |
| SetOutput(node, changer_->TypeForElement(access)); |
| if (lower()) lowering->DoLoadElement(node); |
| break; |
| } |
| case IrOpcode::kStoreElement: { |
| ElementAccess access = ElementAccessOf(node->op()); |
| ProcessInput(node, 0, changer_->TypeForBasePointer(access)); |
| ProcessInput(node, 1, kInt32); // element index |
| ProcessInput(node, 2, changer_->TypeForElement(access)); |
| SetOutput(node, 0); |
| if (lower()) lowering->DoStoreElement(node); |
| break; |
| } |
| |
| //------------------------------------------------------------------ |
| // Machine-level operators. |
| //------------------------------------------------------------------ |
| case IrOpcode::kLoad: { |
| // TODO(titzer): machine loads/stores need to know BaseTaggedness!? |
| RepType tBase = rTagged; |
| MachineType rep = OpParameter<MachineType>(node); |
| ProcessInput(node, 0, tBase); // pointer or object |
| ProcessInput(node, 1, kInt32); // index |
| SetOutput(node, changer_->TypeForMachineType(rep)); |
| break; |
| } |
| case IrOpcode::kStore: { |
| // TODO(titzer): machine loads/stores need to know BaseTaggedness!? |
| RepType tBase = rTagged; |
| StoreRepresentation rep = OpParameter<StoreRepresentation>(node); |
| ProcessInput(node, 0, tBase); // pointer or object |
| ProcessInput(node, 1, kInt32); // index |
| ProcessInput(node, 2, changer_->TypeForMachineType(rep.rep)); |
| SetOutput(node, 0); |
| break; |
| } |
| case IrOpcode::kWord32Shr: |
| // We output unsigned int32 for shift right because JavaScript. |
| return VisitBinop(node, rWord32, rWord32 | tUint32); |
| 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, rWord32, rWord32 | tInt32); |
| case IrOpcode::kWord32Equal: |
| return VisitBinop(node, rWord32, rBit); |
| |
| 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, rWord64, rWord64); |
| case IrOpcode::kWord64Equal: |
| return VisitBinop(node, rWord64, rBit); |
| |
| case IrOpcode::kConvertInt32ToInt64: |
| return VisitUnop(node, tInt32 | rWord32, tInt32 | rWord64); |
| case IrOpcode::kConvertInt64ToInt32: |
| return VisitUnop(node, tInt64 | rWord64, tInt32 | rWord32); |
| |
| case IrOpcode::kChangeInt32ToFloat64: |
| return VisitUnop(node, tInt32 | rWord32, tInt32 | rFloat64); |
| case IrOpcode::kChangeUint32ToFloat64: |
| return VisitUnop(node, tUint32 | rWord32, tUint32 | rFloat64); |
| case IrOpcode::kChangeFloat64ToInt32: |
| return VisitUnop(node, tInt32 | rFloat64, tInt32 | rWord32); |
| case IrOpcode::kChangeFloat64ToUint32: |
| return VisitUnop(node, tUint32 | rFloat64, tUint32 | rWord32); |
| |
| case IrOpcode::kFloat64Add: |
| case IrOpcode::kFloat64Sub: |
| case IrOpcode::kFloat64Mul: |
| case IrOpcode::kFloat64Div: |
| case IrOpcode::kFloat64Mod: |
| return VisitFloat64Binop(node); |
| 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(RepTypeUnion info) { |
| if (FLAG_trace_representation) { |
| char buf[REP_TYPE_STRLEN]; |
| RenderRepTypeUnion(buf, info); |
| TRACE(("%s", buf)); |
| } |
| } |
| |
| 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 |
| |
| std::queue<Node*, std::deque<Node*, NodePtrZoneAllocator> > queue_; |
| |
| NodeInfo* GetInfo(Node* node) { |
| DCHECK(node->id() >= 0); |
| DCHECK(node->id() < count_); |
| return &info_[node->id()]; |
| } |
| |
| RepTypeUnion 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, machine(), |
| graph()->zone()->isolate()); |
| RepresentationSelector selector(jsgraph(), zone(), &changer); |
| selector.Run(this); |
| |
| LoweringBuilder::LowerAllNodes(); |
| } |
| |
| |
| 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 void UpdateControlSuccessors(Node* before, Node* node) { |
| DCHECK(IrOpcode::IsControlOpcode(before->opcode())); |
| UseIter iter = before->uses().begin(); |
| while (iter != before->uses().end()) { |
| if (IrOpcode::IsControlOpcode((*iter)->opcode()) && |
| NodeProperties::IsControlEdge(iter.edge())) { |
| iter = iter.UpdateToAndIncrement(node); |
| continue; |
| } |
| ++iter; |
| } |
| } |
| |
| |
| void SimplifiedLowering::DoChangeTaggedToUI32(Node* node, Node* effect, |
| Node* control, bool is_signed) { |
| // if (IsTagged(val)) |
| // ConvertFloat64To(Int32|Uint32)(Load[kMachineFloat64](input, #value_offset)) |
| // else Untag(val) |
| Node* val = node->InputAt(0); |
| Node* branch = graph()->NewNode(common()->Branch(), IsTagged(val), control); |
| |
| // true branch. |
| Node* tbranch = graph()->NewNode(common()->IfTrue(), branch); |
| Node* loaded = graph()->NewNode( |
| machine()->Load(kMachineFloat64), val, |
| OffsetMinusTagConstant(HeapNumber::kValueOffset), effect); |
| Operator* op = is_signed ? machine()->ChangeFloat64ToInt32() |
| : machine()->ChangeFloat64ToUint32(); |
| Node* converted = graph()->NewNode(op, loaded); |
| |
| // false branch. |
| Node* fbranch = graph()->NewNode(common()->IfFalse(), branch); |
| Node* untagged = Untag(val); |
| |
| // merge. |
| Node* merge = graph()->NewNode(common()->Merge(2), tbranch, fbranch); |
| Node* phi = graph()->NewNode(common()->Phi(2), converted, untagged, merge); |
| UpdateControlSuccessors(control, merge); |
| branch->ReplaceInput(1, control); |
| node->ReplaceUses(phi); |
| } |
| |
| |
| void SimplifiedLowering::DoChangeTaggedToFloat64(Node* node, Node* effect, |
| Node* control) { |
| // if (IsTagged(input)) Load[kMachineFloat64](input, #value_offset) |
| // else ConvertFloat64(Untag(input)) |
| Node* val = node->InputAt(0); |
| Node* branch = graph()->NewNode(common()->Branch(), IsTagged(val), control); |
| |
| // true branch. |
| Node* tbranch = graph()->NewNode(common()->IfTrue(), branch); |
| Node* loaded = graph()->NewNode( |
| machine()->Load(kMachineFloat64), val, |
| OffsetMinusTagConstant(HeapNumber::kValueOffset), effect); |
| |
| // false branch. |
| Node* fbranch = graph()->NewNode(common()->IfFalse(), branch); |
| Node* untagged = Untag(val); |
| Node* converted = |
| graph()->NewNode(machine()->ChangeInt32ToFloat64(), untagged); |
| |
| // merge. |
| Node* merge = graph()->NewNode(common()->Merge(2), tbranch, fbranch); |
| Node* phi = graph()->NewNode(common()->Phi(2), loaded, converted, merge); |
| UpdateControlSuccessors(control, merge); |
| branch->ReplaceInput(1, control); |
| node->ReplaceUses(phi); |
| } |
| |
| |
| void SimplifiedLowering::DoChangeUI32ToTagged(Node* node, Node* effect, |
| Node* control, bool is_signed) { |
| Node* val = node->InputAt(0); |
| Node* is_smi = NULL; |
| if (is_signed) { |
| if (SmiValuesAre32Bits()) { |
| // All int32s fit in this case. |
| DCHECK(kPointerSize == 8); |
| return node->ReplaceUses(SmiTag(val)); |
| } else { |
| // TODO(turbofan): use an Int32AddWithOverflow to tag and check here. |
| Node* lt = graph()->NewNode(machine()->Int32LessThanOrEqual(), val, |
| jsgraph()->Int32Constant(Smi::kMaxValue)); |
| Node* gt = |
| graph()->NewNode(machine()->Int32LessThanOrEqual(), |
| jsgraph()->Int32Constant(Smi::kMinValue), val); |
| is_smi = graph()->NewNode(machine()->Word32And(), lt, gt); |
| } |
| } else { |
| // Check if Uint32 value is in the smi range. |
| is_smi = graph()->NewNode(machine()->Uint32LessThanOrEqual(), val, |
| jsgraph()->Int32Constant(Smi::kMaxValue)); |
| } |
| |
| // TODO(turbofan): fold smi test branch eagerly. |
| // if (IsSmi(input)) SmiTag(input); |
| // else InlineAllocAndInitHeapNumber(ConvertToFloat64(input))) |
| Node* branch = graph()->NewNode(common()->Branch(), is_smi, control); |
| |
| // true branch. |
| Node* tbranch = graph()->NewNode(common()->IfTrue(), branch); |
| Node* smi_tagged = SmiTag(val); |
| |
| // false branch. |
| Node* fbranch = graph()->NewNode(common()->IfFalse(), branch); |
| Node* heap_num = jsgraph()->Constant(0.0); // TODO(titzer): alloc and init |
| |
| // merge. |
| Node* merge = graph()->NewNode(common()->Merge(2), tbranch, fbranch); |
| Node* phi = graph()->NewNode(common()->Phi(2), smi_tagged, heap_num, merge); |
| UpdateControlSuccessors(control, merge); |
| branch->ReplaceInput(1, control); |
| node->ReplaceUses(phi); |
| } |
| |
| |
| void SimplifiedLowering::DoChangeFloat64ToTagged(Node* node, Node* effect, |
| Node* control) { |
| return; // TODO(titzer): need to call runtime to allocate in one branch |
| } |
| |
| |
| void SimplifiedLowering::DoChangeBoolToBit(Node* node, Node* effect, |
| Node* control) { |
| Node* cmp = graph()->NewNode(machine()->WordEqual(), node->InputAt(0), |
| jsgraph()->TrueConstant()); |
| node->ReplaceUses(cmp); |
| } |
| |
| |
| void SimplifiedLowering::DoChangeBitToBool(Node* node, Node* effect, |
| Node* control) { |
| Node* val = node->InputAt(0); |
| Node* branch = graph()->NewNode(common()->Branch(), val, control); |
| |
| // true branch. |
| Node* tbranch = graph()->NewNode(common()->IfTrue(), branch); |
| // false branch. |
| Node* fbranch = graph()->NewNode(common()->IfFalse(), branch); |
| // merge. |
| Node* merge = graph()->NewNode(common()->Merge(2), tbranch, fbranch); |
| Node* phi = graph()->NewNode(common()->Phi(2), jsgraph()->TrueConstant(), |
| jsgraph()->FalseConstant(), merge); |
| UpdateControlSuccessors(control, merge); |
| branch->ReplaceInput(1, control); |
| node->ReplaceUses(phi); |
| } |
| |
| |
| static WriteBarrierKind ComputeWriteBarrierKind(BaseTaggedness base_is_tagged, |
| MachineType representation, |
| Type* type) { |
| // TODO(turbofan): skip write barriers for Smis, etc. |
| if (base_is_tagged == kTaggedBase && representation == kMachineTagged) { |
| // 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.representation)); |
| 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.representation, access.type); |
| node->set_op(machine_.Store(access.representation, 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 = 0; |
| switch (access.representation) { |
| case kMachineTagged: |
| element_size = kPointerSize; |
| break; |
| case kMachineWord8: |
| element_size = 1; |
| break; |
| case kMachineWord16: |
| element_size = 2; |
| break; |
| case kMachineWord32: |
| element_size = 4; |
| break; |
| case kMachineWord64: |
| case kMachineFloat64: |
| element_size = 8; |
| break; |
| case kMachineLast: |
| UNREACHABLE(); |
| break; |
| } |
| 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.representation)); |
| node->ReplaceInput(1, ComputeIndex(access, node->InputAt(1))); |
| } |
| |
| |
| void SimplifiedLowering::DoStoreElement(Node* node) { |
| const ElementAccess& access = ElementAccessOf(node->op()); |
| WriteBarrierKind kind = ComputeWriteBarrierKind( |
| access.base_is_tagged, access.representation, access.type); |
| node->set_op(machine_.Store(access.representation, kind)); |
| node->ReplaceInput(1, ComputeIndex(access, node->InputAt(1))); |
| } |
| |
| |
| void SimplifiedLowering::Lower(Node* node) {} |
| |
| |
| void SimplifiedLowering::LowerChange(Node* node, Node* effect, Node* control) { |
| switch (node->opcode()) { |
| case IrOpcode::kChangeTaggedToInt32: |
| DoChangeTaggedToUI32(node, effect, control, true); |
| break; |
| case IrOpcode::kChangeTaggedToUint32: |
| DoChangeTaggedToUI32(node, effect, control, false); |
| break; |
| case IrOpcode::kChangeTaggedToFloat64: |
| DoChangeTaggedToFloat64(node, effect, control); |
| break; |
| case IrOpcode::kChangeInt32ToTagged: |
| DoChangeUI32ToTagged(node, effect, control, true); |
| break; |
| case IrOpcode::kChangeUint32ToTagged: |
| DoChangeUI32ToTagged(node, effect, control, false); |
| break; |
| case IrOpcode::kChangeFloat64ToTagged: |
| DoChangeFloat64ToTagged(node, effect, control); |
| break; |
| case IrOpcode::kChangeBoolToBit: |
| DoChangeBoolToBit(node, effect, control); |
| break; |
| case IrOpcode::kChangeBitToBool: |
| DoChangeBitToBool(node, effect, control); |
| break; |
| default: |
| UNREACHABLE(); |
| break; |
| } |
| } |
| |
| } // namespace compiler |
| } // namespace internal |
| } // namespace v8 |
