Revert of [turbofan] Run everything after representation selection concurrently.

src/compiler/change-lowering.cc

 // 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/change-lowering.h"
 
 #include "src/address-map.h"
 #include "src/code-factory.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/operator-properties.h"
 #include "src/compiler/simplified-operator.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 ChangeLowering::~ChangeLowering() {}
 
 
 Reduction ChangeLowering::Reduce(Node* node) {
   Node* control = graph()->start();
   switch (node->opcode()) {
     case IrOpcode::kChangeBitToBool:
-      return ReduceChangeBitToBool(node->InputAt(0), control);
+      return ChangeBitToBool(node->InputAt(0), control);
     case IrOpcode::kChangeBoolToBit:
-      return ReduceChangeBoolToBit(node->InputAt(0));
+      return ChangeBoolToBit(node->InputAt(0));
     case IrOpcode::kChangeInt31ToTagged:
-      return ReduceChangeInt31ToTagged(node->InputAt(0), control);
+      return ChangeInt31ToTagged(node->InputAt(0), control);
     case IrOpcode::kChangeTaggedSignedToInt32:
-      return ReduceChangeTaggedSignedToInt32(node->InputAt(0));
+      return ChangeTaggedSignedToInt32(node->InputAt(0));
     case IrOpcode::kLoadField:
-      return ReduceLoadField(node);
+      return LoadField(node);
     case IrOpcode::kStoreField:
-      return ReduceStoreField(node);
+      return StoreField(node);
     case IrOpcode::kLoadElement:
-      return ReduceLoadElement(node);
+      return LoadElement(node);
     case IrOpcode::kStoreElement:
-      return ReduceStoreElement(node);
+      return StoreElement(node);
     case IrOpcode::kAllocate:
-      return ReduceAllocate(node);
+      return Allocate(node);
     case IrOpcode::kObjectIsSmi:
-      return ReduceObjectIsSmi(node);
+      return ObjectIsSmi(node);
+    case IrOpcode::kChangeInt32ToTagged:
+    case IrOpcode::kChangeUint32ToTagged:
+    case IrOpcode::kChangeFloat64ToTagged:
+      FATAL("Changes should be already lowered during effect linearization.");
+      break;
     default:
       return NoChange();
   }
   UNREACHABLE();
   return NoChange();
 }
 
+
+Node* ChangeLowering::HeapNumberValueIndexConstant() {
+  return jsgraph()->IntPtrConstant(HeapNumber::kValueOffset - kHeapObjectTag);
+}
+
 Node* ChangeLowering::SmiShiftBitsConstant() {
   return jsgraph()->IntPtrConstant(kSmiShiftSize + kSmiTagSize);
 }
 
+Node* ChangeLowering::ChangeInt32ToFloat64(Node* value) {
+  return graph()->NewNode(machine()->ChangeInt32ToFloat64(), value);
+}
+
 Node* ChangeLowering::ChangeInt32ToSmi(Node* value) {
   if (machine()->Is64()) {
     value = graph()->NewNode(machine()->ChangeInt32ToInt64(), value);
   }
   return graph()->NewNode(machine()->WordShl(), value, SmiShiftBitsConstant());
 }
 
+
+Node* ChangeLowering::ChangeSmiToFloat64(Node* value) {
+  return ChangeInt32ToFloat64(ChangeSmiToWord32(value));
+}
+
 Node* ChangeLowering::ChangeSmiToWord32(Node* value) {
   value = graph()->NewNode(machine()->WordSar(), value, SmiShiftBitsConstant());
   if (machine()->Is64()) {
     value = graph()->NewNode(machine()->TruncateInt64ToInt32(), value);
   }
   return value;
 }
 
 
 Node* ChangeLowering::ChangeUint32ToFloat64(Node* value) {
   return graph()->NewNode(machine()->ChangeUint32ToFloat64(), value);
 }
 
-Reduction ChangeLowering::ReduceChangeBitToBool(Node* value, Node* control) {
+
+Node* ChangeLowering::ChangeUint32ToSmi(Node* value) {
+  if (machine()->Is64()) {
+    value = graph()->NewNode(machine()->ChangeUint32ToUint64(), value);
+  }
+  return graph()->NewNode(machine()->WordShl(), value, SmiShiftBitsConstant());
+}
+
+
+Node* ChangeLowering::LoadHeapNumberValue(Node* value, Node* control) {
+  return graph()->NewNode(machine()->Load(MachineType::Float64()), value,
+                          HeapNumberValueIndexConstant(), graph()->start(),
+                          control);
+}
+
+
+Node* ChangeLowering::TestNotSmi(Node* value) {
+  STATIC_ASSERT(kSmiTag == 0);
+  STATIC_ASSERT(kSmiTagMask == 1);
+  return graph()->NewNode(machine()->WordAnd(), value,
+                          jsgraph()->IntPtrConstant(kSmiTagMask));
+}
+
+
+Reduction ChangeLowering::ChangeBitToBool(Node* value, Node* control) {
   return Replace(
       graph()->NewNode(common()->Select(MachineRepresentation::kTagged), value,
                        jsgraph()->TrueConstant(), jsgraph()->FalseConstant()));
 }
 
-Reduction ChangeLowering::ReduceChangeBoolToBit(Node* value) {
+
+Reduction ChangeLowering::ChangeBoolToBit(Node* value) {
   return Replace(graph()->NewNode(machine()->WordEqual(), value,
                                   jsgraph()->TrueConstant()));
 }
 
-Reduction ChangeLowering::ReduceChangeInt31ToTagged(Node* value,
-                                                    Node* control) {
+Reduction ChangeLowering::ChangeInt31ToTagged(Node* value, Node* control) {
   return Replace(ChangeInt32ToSmi(value));
 }
 
-Reduction ChangeLowering::ReduceChangeTaggedSignedToInt32(Node* value) {
+Reduction ChangeLowering::ChangeTaggedSignedToInt32(Node* value) {
   return Replace(ChangeSmiToWord32(value));
 }
 
 namespace {
 
 WriteBarrierKind ComputeWriteBarrierKind(BaseTaggedness base_is_tagged,
-                                         MachineRepresentation representation) {
-  // TODO(bmeurer): Optimize write barriers based on input.
+                                         MachineRepresentation representation,
+                                         Type* field_type, Type* input_type) {
+  if (field_type->Is(Type::TaggedSigned()) ||
+      input_type->Is(Type::TaggedSigned())) {
+    // Write barriers are only for writes of heap objects.
+    return kNoWriteBarrier;
+  }
+  if (input_type->Is(Type::BooleanOrNullOrUndefined())) {
+    // Write barriers are not necessary when storing true, false, null or
+    // undefined, because these special oddballs are always in the root set.
+    return kNoWriteBarrier;
+  }
   if (base_is_tagged == kTaggedBase &&
       representation == MachineRepresentation::kTagged) {
+    if (input_type->IsConstant() &&
+        input_type->AsConstant()->Value()->IsHeapObject()) {
+      Handle<HeapObject> input =
+          Handle<HeapObject>::cast(input_type->AsConstant()->Value());
+      if (input->IsMap()) {
+        // Write barriers for storing maps are cheaper.
+        return kMapWriteBarrier;
+      }
+      Isolate* const isolate = input->GetIsolate();
+      RootIndexMap root_index_map(isolate);
+      int root_index = root_index_map.Lookup(*input);
+      if (root_index != RootIndexMap::kInvalidRootIndex &&
+          isolate->heap()->RootIsImmortalImmovable(root_index)) {
+        // Write barriers are unnecessary for immortal immovable roots.
+        return kNoWriteBarrier;
+      }
+    }
+    if (field_type->Is(Type::TaggedPointer()) ||
+        input_type->Is(Type::TaggedPointer())) {
+      // Write barriers for heap objects don't need a Smi check.
+      return kPointerWriteBarrier;
+    }
+    // Write barriers are only for writes into heap objects (i.e. tagged base).
     return kFullWriteBarrier;
   }
   return kNoWriteBarrier;
 }
 
+
 WriteBarrierKind ComputeWriteBarrierKind(BaseTaggedness base_is_tagged,
                                          MachineRepresentation representation,
-                                         int field_offset) {
+                                         int field_offset, Type* field_type,
+                                         Type* input_type) {
   if (base_is_tagged == kTaggedBase && field_offset == HeapObject::kMapOffset) {
     // Write barriers for storing maps are cheaper.
     return kMapWriteBarrier;
   }
-  return ComputeWriteBarrierKind(base_is_tagged, representation);
+  return ComputeWriteBarrierKind(base_is_tagged, representation, field_type,
+                                 input_type);
 }
 
 }  // namespace
 
-Reduction ChangeLowering::ReduceLoadField(Node* node) {
+
+Reduction ChangeLowering::LoadField(Node* node) {
   const FieldAccess& access = FieldAccessOf(node->op());
   Node* offset = jsgraph()->IntPtrConstant(access.offset - access.tag());
   node->InsertInput(graph()->zone(), 1, offset);
   NodeProperties::ChangeOp(node, machine()->Load(access.machine_type));
   return Changed(node);
 }
 
-Reduction ChangeLowering::ReduceStoreField(Node* node) {
+
+Reduction ChangeLowering::StoreField(Node* node) {
   const FieldAccess& access = FieldAccessOf(node->op());
+  Type* type = NodeProperties::GetType(node->InputAt(1));
   WriteBarrierKind kind = ComputeWriteBarrierKind(
       access.base_is_tagged, access.machine_type.representation(),
-      access.offset);
+      access.offset, access.type, type);
   Node* offset = jsgraph()->IntPtrConstant(access.offset - access.tag());
   node->InsertInput(graph()->zone(), 1, offset);
   NodeProperties::ChangeOp(node,
                            machine()->Store(StoreRepresentation(
                                access.machine_type.representation(), kind)));
   return Changed(node);
 }
 
 
 Node* ChangeLowering::ComputeIndex(const ElementAccess& access,
@@ skipping 12 matching lines @@
   }
   if (machine()->Is64()) {
     // TODO(turbofan): This is probably only correct for typed arrays, and only
     // if the typed arrays are at most 2GiB in size, which happens to match
     // exactly our current situation.
     index = graph()->NewNode(machine()->ChangeUint32ToUint64(), index);
   }
   return index;
 }
 
-Reduction ChangeLowering::ReduceLoadElement(Node* node) {
+
+Reduction ChangeLowering::LoadElement(Node* node) {
   const ElementAccess& access = ElementAccessOf(node->op());
   node->ReplaceInput(1, ComputeIndex(access, node->InputAt(1)));
   NodeProperties::ChangeOp(node, machine()->Load(access.machine_type));
   return Changed(node);
 }
 
-Reduction ChangeLowering::ReduceStoreElement(Node* node) {
+
+Reduction ChangeLowering::StoreElement(Node* node) {
   const ElementAccess& access = ElementAccessOf(node->op());
+  Type* type = NodeProperties::GetType(node->InputAt(2));
   node->ReplaceInput(1, ComputeIndex(access, node->InputAt(1)));
   NodeProperties::ChangeOp(
-      node,
-      machine()->Store(StoreRepresentation(
-          access.machine_type.representation(),
-          ComputeWriteBarrierKind(access.base_is_tagged,
-                                  access.machine_type.representation()))));
+      node, machine()->Store(StoreRepresentation(
+                access.machine_type.representation(),
+                ComputeWriteBarrierKind(access.base_is_tagged,
+                                        access.machine_type.representation(),
+                                        access.type, type))));
   return Changed(node);
 }
 
-Reduction ChangeLowering::ReduceAllocate(Node* node) {
+
+Reduction ChangeLowering::Allocate(Node* node) {
   PretenureFlag pretenure = OpParameter<PretenureFlag>(node->op());
   Callable callable = CodeFactory::Allocate(isolate(), pretenure);
   Node* target = jsgraph()->HeapConstant(callable.code());
   CallDescriptor* descriptor = Linkage::GetStubCallDescriptor(
       isolate(), jsgraph()->zone(), callable.descriptor(), 0,
       CallDescriptor::kNoFlags, Operator::kNoThrow);
   const Operator* op = common()->Call(descriptor);
   node->InsertInput(graph()->zone(), 0, target);
   node->InsertInput(graph()->zone(), 2, jsgraph()->NoContextConstant());
   NodeProperties::ChangeOp(node, op);
   return Changed(node);
 }
 
-Reduction ChangeLowering::ReduceObjectIsSmi(Node* node) {
+Node* ChangeLowering::IsSmi(Node* value) {
+  return graph()->NewNode(
+      machine()->WordEqual(),
+      graph()->NewNode(machine()->WordAnd(), value,
+                       jsgraph()->IntPtrConstant(kSmiTagMask)),
+      jsgraph()->IntPtrConstant(kSmiTag));
+}
+
+Node* ChangeLowering::LoadHeapObjectMap(Node* object, Node* control) {
+  return graph()->NewNode(
+      machine()->Load(MachineType::AnyTagged()), object,
+      jsgraph()->IntPtrConstant(HeapObject::kMapOffset - kHeapObjectTag),
+      graph()->start(), control);
+}
+
+Node* ChangeLowering::LoadMapBitField(Node* map) {
+  return graph()->NewNode(
+      machine()->Load(MachineType::Uint8()), map,
+      jsgraph()->IntPtrConstant(Map::kBitFieldOffset - kHeapObjectTag),
+      graph()->start(), graph()->start());
+}
+
+Node* ChangeLowering::LoadMapInstanceType(Node* map) {
+  return graph()->NewNode(
+      machine()->Load(MachineType::Uint8()), map,
+      jsgraph()->IntPtrConstant(Map::kInstanceTypeOffset - kHeapObjectTag),
+      graph()->start(), graph()->start());
+}
+
+Reduction ChangeLowering::ObjectIsSmi(Node* node) {
   node->ReplaceInput(0,
                      graph()->NewNode(machine()->WordAnd(), node->InputAt(0),
                                       jsgraph()->IntPtrConstant(kSmiTagMask)));
   node->AppendInput(graph()->zone(), jsgraph()->IntPtrConstant(kSmiTag));
   NodeProperties::ChangeOp(node, machine()->WordEqual());
   return Changed(node);
 }
 
 Isolate* ChangeLowering::isolate() const { return jsgraph()->isolate(); }
 
 
 Graph* ChangeLowering::graph() const { return jsgraph()->graph(); }
 
 
 CommonOperatorBuilder* ChangeLowering::common() const {
   return jsgraph()->common();
 }
 
 
 MachineOperatorBuilder* ChangeLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8