Implement Fast Accessor Builder

src/compiler/fast-accessor-assembler.cc

+// Copyright 2015 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/fast-accessor-assembler.h"
+
+#include "src/base/logging.h"
+#include "src/compiler/graph.h"
+#include "src/compiler/linkage.h"
+#include "src/compiler/pipeline.h"
+#include "src/compiler/raw-machine-assembler.h"
+#include "src/compiler/schedule.h"
+#include "src/compiler/verifier.h"
+#include "src/handles-inl.h"
+#include "src/objects.h"  // For FAA::GetInternalField impl.
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+FastAccessorAssembler::FastAccessorAssembler(Isolate* isolate)
+    : zone_(),
+      assembler_(new RawMachineAssembler(
+          isolate, new (zone()) Graph(zone()),
+          Linkage::GetJSCallDescriptor(&zone_, false, 1,
+                                       CallDescriptor::kNoFlags))),
+      state_(kBuilding) {}
+
+
+FastAccessorAssembler::~FastAccessorAssembler() {}
+
+
+FastAccessorAssembler::ValueId FastAccessorAssembler::IntegerConstant(
+    int const_value) {
+  CHECK_EQ(kBuilding, state_);
+  return FromRaw(assembler_->NumberConstant(const_value));
+}
+
+
+FastAccessorAssembler::ValueId FastAccessorAssembler::GetReceiver() {
+  CHECK_EQ(kBuilding, state_);
+
+  // For JS call descriptor, the receiver is parameter 0. If we use other
+  // call descriptors, this may or may not hold. So let's check.
+  CHECK(assembler_->call_descriptor()->IsJSFunctionCall());
+  return FromRaw(assembler_->Parameter(0));
+}
+
+
+FastAccessorAssembler::ValueId FastAccessorAssembler::LoadInternalField(
+    ValueId value, int field_no) {
+  CHECK_EQ(kBuilding, state_);
+  // Determine the 'value' object's instance type.
+  auto object_map =

[Michael Starzinger, 2015/12/03 13:36:18]

nit: The return type should be "Node*" here AFAICT. Can we write out "Node*"
here and throughout the function here for readability?

[vogelheim, 2015/12/04 09:33:00]

Done.

+      assembler_->Load(kMachPtr, FromId(value),
+                       assembler_->IntPtrConstant(
+                           Internals::kHeapObjectMapOffset - kHeapObjectTag));
+  auto instance_type = assembler_->WordAnd(
+      assembler_->Load(
+          kMachUint16, object_map,
+          assembler_->IntPtrConstant(
+              Internals::kMapInstanceTypeAndBitFieldOffset - kHeapObjectTag)),
+      assembler_->IntPtrConstant(0xff));
+
+  // Check whether we have a proper JSObject.
+  RawMachineLabel is_jsobject, is_not_jsobject, merge;
+  assembler_->Branch(
+      assembler_->WordEqual(
+          instance_type, assembler_->IntPtrConstant(Internals::kJSObjectType)),
+      &is_jsobject, &is_not_jsobject);
+
+  // JSObject? Then load the internal field field_no.
+  assembler_->Bind(&is_jsobject);
+  auto internal_field = assembler_->Load(
+      kMachPtr, FromId(value),
+      assembler_->IntPtrConstant(JSObject::kHeaderSize - kHeapObjectTag +
+                                 kPointerSize * field_no));
+  assembler_->Goto(&merge);
+
+  // No JSObject? Return undefined.
+  assembler_->Bind(&is_not_jsobject);
+  auto fail_value = assembler_->UndefinedConstant();
+  assembler_->Goto(&merge);
+
+  // Return.
+  assembler_->Bind(&merge);
+  auto phi = assembler_->Phi(kMachAnyTagged, internal_field, fail_value);
+  return FromRaw(phi);
+}
+
+
+FastAccessorAssembler::ValueId FastAccessorAssembler::LoadValue(
+    FastAccessorAssembler::ValueId value, int offset) {
+  CHECK_EQ(kBuilding, state_);
+  return FromRaw(assembler_->Load(kMachIntPtr, FromId(value),
+                                  assembler_->IntPtrConstant(offset)));
+}
+
+
+FastAccessorAssembler::ValueId FastAccessorAssembler::LoadObject(
+    FastAccessorAssembler::ValueId value, int offset) {
+  CHECK_EQ(kBuilding, state_);
+  return FromRaw(assembler_->Load(
+      kMachAnyTagged, assembler_->Load(kMachPtr, FromId(value),
+                                       assembler_->IntPtrConstant(offset))));
+}
+
+
+void FastAccessorAssembler::ReturnValue(ValueId value) {
+  CHECK_EQ(kBuilding, state_);
+  assembler_->Return(FromId(value));
+}
+
+
+void FastAccessorAssembler::CheckFlagSetOrReturnNull(
+    FastAccessorAssembler::ValueId value, int mask) {
+  CHECK_EQ(kBuilding, state_);
+  RawMachineLabel pass, fail;
+  assembler_->Branch(
+      assembler_->Word32Equal(
+          assembler_->Word32And(FromId(value), assembler_->Int32Constant(mask)),
+          assembler_->Int32Constant(0)),
+      &pass, &fail);
+  assembler_->Bind(&fail);
+  assembler_->Return(assembler_->NullConstant());
+  assembler_->Bind(&pass);
+}
+
+
+void FastAccessorAssembler::CheckNotZeroOrReturnNull(ValueId value) {
+  CHECK_EQ(kBuilding, state_);
+  RawMachineLabel is_null, not_null;
+  assembler_->Branch(
+      assembler_->IntPtrEqual(FromId(value), assembler_->IntPtrConstant(0)),
+      &is_null, &not_null);
+  assembler_->Bind(&is_null);
+  assembler_->Return(assembler_->NullConstant());
+  assembler_->Bind(&not_null);
+}
+
+
+FastAccessorAssembler::LabelId FastAccessorAssembler::MakeLabel() {
+  CHECK_EQ(kBuilding, state_);
+  RawMachineLabel* label =
+      new (zone()->New(sizeof(RawMachineLabel))) RawMachineLabel;
+  return FromRaw(label);
+}
+
+
+void FastAccessorAssembler::SetLabel(LabelId label_id) {
+  CHECK_EQ(kBuilding, state_);
+  assembler_->Bind(FromId(label_id));
+}
+
+
+void FastAccessorAssembler::CheckNotZeroOrJump(ValueId value_id,
+                                               LabelId label_id) {
+  CHECK_EQ(kBuilding, state_);
+  RawMachineLabel pass;
+  assembler_->Branch(
+      assembler_->IntPtrEqual(FromId(value_id), assembler_->IntPtrConstant(0)),
+      &pass, FromId(label_id));
+  assembler_->Bind(&pass);
+}
+
+
+MaybeHandle<Code> FastAccessorAssembler::Build() {
+  CHECK_EQ(kBuilding, state_);
+
+  // Cleanup: We no longer need this.
+  nodes_.clear();
+  labels_.clear();
+
+  // Export the schedule and call the compiler.
+  CompilationInfo info("FastAccessorAssembler", assembler_->isolate(), zone());
+  Schedule* schedule = assembler_->Export();
+
+  // TODO(vogelheim): Pipeline should have a dedicated entry point for this
+  //                  assembler.
+  MaybeHandle<Code> code = Pipeline::GenerateCodeForTesting(
+      &info, assembler_->call_descriptor(), assembler_->graph(), schedule);
+
+  // Update state & return.
+  state_ = !code.is_null() ? kBuilt : kError;
+  return code;
+}
+
+
+FastAccessorAssembler::ValueId FastAccessorAssembler::FromRaw(Node* node) {
+  nodes_.push_back(node);
+  ValueId value = {nodes_.size() - 1};
+  return value;
+}
+
+
+FastAccessorAssembler::LabelId FastAccessorAssembler::FromRaw(
+    RawMachineLabel* label) {
+  labels_.push_back(label);
+  LabelId label_id = {labels_.size() - 1};
+  return label_id;
+}
+
+
+Node* FastAccessorAssembler::FromId(
+    FastAccessorAssembler::ValueId value) const {

[Michael Starzinger, 2015/12/03 13:36:18]

nit: Just "ValueId" without the namespace prefix should work for arguments IIRC.

[vogelheim, 2015/12/04 09:33:00]

Done.

+  CHECK_LT(value.value_id, nodes_.size());
+  CHECK_NOT_NULL(nodes_.at(value.value_id));
+  return nodes_.at(value.value_id);
+}
+
+
+RawMachineLabel* FastAccessorAssembler::FromId(
+    FastAccessorAssembler::LabelId label) const {

[Michael Starzinger, 2015/12/03 13:36:18]

Likewise.

[vogelheim, 2015/12/04 09:33:00]

Done.

+  CHECK_LT(label.label_id, labels_.size());
+  CHECK_NOT_NULL(labels_.at(label.label_id));
+  return labels_.at(label.label_id);
+}
+
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8