[turbofan] Move simplified alloc, load and store lowering to change lowering.

src/compiler/change-lowering.cc

Index: src/compiler/change-lowering.cc
diff --git a/src/compiler/change-lowering.cc b/src/compiler/change-lowering.cc
index 8552cdf7921b6c5bd62e4d7bbd7091008d5e5eb8..213f7759648635771f9b9fd67f3f97be4723ca7d 100644
--- a/src/compiler/change-lowering.cc
+++ b/src/compiler/change-lowering.cc
@@ -4,12 +4,14 @@
 
 #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 {
@@ -37,6 +39,16 @@ Reduction ChangeLowering::Reduce(Node* node) {
       return ChangeTaggedToUI32(node->InputAt(0), control, kUnsigned);
     case IrOpcode::kChangeUint32ToTagged:
       return ChangeUint32ToTagged(node->InputAt(0), control);
+    case IrOpcode::kLoadField:
+      return LoadField(node);
+    case IrOpcode::kStoreField:
+      return StoreField(node);
+    case IrOpcode::kLoadElement:
+      return LoadElement(node);
+    case IrOpcode::kStoreElement:
+      return StoreElement(node);
+    case IrOpcode::kAllocate:
+      return Allocate(node);
     default:
       return NoChange();
   }
@@ -407,6 +419,153 @@ Reduction ChangeLowering::ChangeUint32ToTagged(Node* value, Node* control) {
 }
 
 
+namespace {
+
+WriteBarrierKind ComputeWriteBarrierKind(BaseTaggedness base_is_tagged,
+                                         MachineType 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 &&
+      RepresentationOf(representation) == kRepTagged) {
+    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;
+}
+
+}  // namespace
+
+
+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::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, 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, kind)));
+  return Changed(node);
+}
+
+
+Node* ChangeLowering::ComputeIndex(const ElementAccess& access,
+                                   Node* const key) {
+  Node* index = key;
+  const int element_size_shift = ElementSizeLog2Of(access.machine_type);
+  if (element_size_shift) {
+    index = graph()->NewNode(machine()->Word32Shl(), index,
+                             jsgraph()->Int32Constant(element_size_shift));
+  }
+  const int fixed_offset = access.header_size - access.tag();
+  if (fixed_offset) {
+    index = graph()->NewNode(machine()->Int32Add(), index,
+                             jsgraph()->Int32Constant(fixed_offset));
+  }
+  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::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::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,
+          ComputeWriteBarrierKind(access.base_is_tagged, access.machine_type,
+                                  access.type, type))));
+  return Changed(node);
+}
+
+
+Reduction ChangeLowering::Allocate(Node* node) {
+  PretenureFlag pretenure = OpParameter<PretenureFlag>(node->op());
+  if (pretenure == NOT_TENURED) {
+    Callable callable = CodeFactory::AllocateInNewSpace(isolate());
+    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);
+  } else {
+    DCHECK_EQ(TENURED, pretenure);
+    AllocationSpace space = OLD_SPACE;
+    Runtime::FunctionId f = Runtime::kAllocateInTargetSpace;
+    Operator::Properties props = node->op()->properties();
+    CallDescriptor* desc =
+        Linkage::GetRuntimeCallDescriptor(jsgraph()->zone(), f, 2, props);
+    ExternalReference ref(f, jsgraph()->isolate());
+    int32_t flags = AllocateTargetSpace::encode(space);
+    node->InsertInput(graph()->zone(), 0, jsgraph()->CEntryStubConstant(1));
+    node->InsertInput(graph()->zone(), 2, jsgraph()->SmiConstant(flags));
+    node->InsertInput(graph()->zone(), 3, jsgraph()->ExternalConstant(ref));
+    node->InsertInput(graph()->zone(), 4, jsgraph()->Int32Constant(2));
+    node->InsertInput(graph()->zone(), 5, jsgraph()->NoContextConstant());
+    NodeProperties::ChangeOp(node, common()->Call(desc));
+  }
+  return Changed(node);
+}
+
+
 Isolate* ChangeLowering::isolate() const { return jsgraph()->isolate(); }