diff --git a/src/compiler/x87/instruction-selector-x87.cc b/src/compiler/x87/instruction-selector-x87.cc
index e4d085e..a99e7a6 100644
--- a/src/compiler/x87/instruction-selector-x87.cc
+++ b/src/compiler/x87/instruction-selector-x87.cc
@@ -27,11 +27,15 @@
     return DefineAsRegister(node);
   }
 
-  bool CanBeMemoryOperand(InstructionCode opcode, Node* node, Node* input) {
+  bool CanBeMemoryOperand(InstructionCode opcode, Node* node, Node* input,
+                          int effect_level) {
     if (input->opcode() != IrOpcode::kLoad ||
         !selector()->CanCover(node, input)) {
       return false;
     }
+    if (effect_level != selector()->GetEffectLevel(input)) {
+      return false;
+    }
     MachineRepresentation rep =
         LoadRepresentationOf(input->op()).representation();
     switch (opcode) {
@@ -60,13 +64,20 @@
       case IrOpcode::kInt32Constant:
       case IrOpcode::kNumberConstant:
       case IrOpcode::kExternalConstant:
+      case IrOpcode::kRelocatableInt32Constant:
+      case IrOpcode::kRelocatableInt64Constant:
         return true;
       case IrOpcode::kHeapConstant: {
+// TODO(bmeurer): We must not dereference handles concurrently. If we
+// really have to this here, then we need to find a way to put this
+// information on the HeapConstant node already.
+#if 0
         // Constants in new space cannot be used as immediates in V8 because
         // the GC does not scan code objects when collecting the new generation.
         Handle<HeapObject> value = OpParameter<Handle<HeapObject>>(node);
         Isolate* isolate = value->GetIsolate();
         return !isolate->heap()->InNewSpace(*value);
+#endif
       }
       default:
         return false;
@@ -842,21 +853,15 @@
        g.Use(node->InputAt(0)));
 }
 
-
-void InstructionSelector::VisitTruncateFloat64ToInt32(Node* node) {
+void InstructionSelector::VisitTruncateFloat64ToWord32(Node* node) {
   X87OperandGenerator g(this);
+  Emit(kArchTruncateDoubleToI, g.DefineAsRegister(node),
+       g.Use(node->InputAt(0)));
+}
 
-  switch (TruncationModeOf(node->op())) {
-    case TruncationMode::kJavaScript:
-      Emit(kArchTruncateDoubleToI, g.DefineAsRegister(node),
-           g.Use(node->InputAt(0)));
-      return;
-    case TruncationMode::kRoundToZero:
-      Emit(kX87Float64ToInt32, g.DefineAsRegister(node),
-           g.Use(node->InputAt(0)));
-      return;
-  }
-  UNREACHABLE();
+void InstructionSelector::VisitRoundFloat64ToInt32(Node* node) {
+  X87OperandGenerator g(this);
+  Emit(kX87Float64ToInt32, g.DefineAsRegister(node), g.Use(node->InputAt(0)));
 }
 
 
@@ -896,6 +901,12 @@
   Emit(kX87Float32Sub, g.DefineAsFixed(node, stX_0), 0, nullptr);
 }
 
+void InstructionSelector::VisitFloat32SubPreserveNan(Node* node) {
+  X87OperandGenerator g(this);
+  Emit(kX87PushFloat32, g.NoOutput(), g.Use(node->InputAt(0)));
+  Emit(kX87PushFloat32, g.NoOutput(), g.Use(node->InputAt(1)));
+  Emit(kX87Float32Sub, g.DefineAsFixed(node, stX_0), 0, nullptr);
+}
 
 void InstructionSelector::VisitFloat64Sub(Node* node) {
   X87OperandGenerator g(this);
@@ -904,6 +915,13 @@
   Emit(kX87Float64Sub, g.DefineAsFixed(node, stX_0), 0, nullptr);
 }
 
+void InstructionSelector::VisitFloat64SubPreserveNan(Node* node) {
+  X87OperandGenerator g(this);
+  Emit(kX87PushFloat64, g.NoOutput(), g.Use(node->InputAt(0)));
+  Emit(kX87PushFloat64, g.NoOutput(), g.Use(node->InputAt(1)));
+  Emit(kX87Float64Sub, g.DefineAsFixed(node, stX_0), 0, nullptr);
+}
+
 
 void InstructionSelector::VisitFloat32Mul(Node* node) {
   X87OperandGenerator g(this);
@@ -1254,18 +1272,24 @@
 
   InstructionCode narrowed_opcode = TryNarrowOpcodeSize(opcode, left, right);
 
+  int effect_level = selector->GetEffectLevel(node);
+  if (cont->IsBranch()) {
+    effect_level = selector->GetEffectLevel(
+        cont->true_block()->PredecessorAt(0)->control_input());
+  }
+
   // If one of the two inputs is an immediate, make sure it's on the right, or
   // if one of the two inputs is a memory operand, make sure it's on the left.
   if ((!g.CanBeImmediate(right) && g.CanBeImmediate(left)) ||
-      (g.CanBeMemoryOperand(narrowed_opcode, node, right) &&
-       !g.CanBeMemoryOperand(narrowed_opcode, node, left))) {
+      (g.CanBeMemoryOperand(narrowed_opcode, node, right, effect_level) &&
+       !g.CanBeMemoryOperand(narrowed_opcode, node, left, effect_level))) {
     if (!node->op()->HasProperty(Operator::kCommutative)) cont->Commute();
     std::swap(left, right);
   }
 
   // Match immediates on right side of comparison.
   if (g.CanBeImmediate(right)) {
-    if (g.CanBeMemoryOperand(opcode, node, left)) {
+    if (g.CanBeMemoryOperand(opcode, node, left, effect_level)) {
       // TODO(epertoso): we should use `narrowed_opcode' here once we match
       // immediates too.
       return VisitCompareWithMemoryOperand(selector, opcode, left,
@@ -1276,7 +1300,7 @@
   }
 
   // Match memory operands on left side of comparison.
-  if (g.CanBeMemoryOperand(narrowed_opcode, node, left)) {
+  if (g.CanBeMemoryOperand(narrowed_opcode, node, left, effect_level)) {
     bool needs_byte_register =
         narrowed_opcode == kX87Test8 || narrowed_opcode == kX87Cmp8;
     return VisitCompareWithMemoryOperand(
@@ -1588,6 +1612,52 @@
        g.UseRegister(left), g.UseRegister(right));
 }
 
+void InstructionSelector::VisitAtomicLoad(Node* node) {
+  LoadRepresentation load_rep = LoadRepresentationOf(node->op());
+  DCHECK(load_rep.representation() == MachineRepresentation::kWord8 ||
+         load_rep.representation() == MachineRepresentation::kWord16 ||
+         load_rep.representation() == MachineRepresentation::kWord32);
+  USE(load_rep);
+  VisitLoad(node);
+}
+
+void InstructionSelector::VisitAtomicStore(Node* node) {
+  X87OperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+
+  MachineRepresentation rep = AtomicStoreRepresentationOf(node->op());
+  ArchOpcode opcode = kArchNop;
+  switch (rep) {
+    case MachineRepresentation::kWord8:
+      opcode = kX87Xchgb;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kX87Xchgw;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kX87Xchgl;
+      break;
+    default:
+      UNREACHABLE();
+      break;
+  }
+  AddressingMode addressing_mode;
+  InstructionOperand inputs[4];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  if (g.CanBeImmediate(index)) {
+    inputs[input_count++] = g.UseImmediate(index);
+    addressing_mode = kMode_MRI;
+  } else {
+    inputs[input_count++] = g.UseUniqueRegister(index);
+    addressing_mode = kMode_MR1;
+  }
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  Emit(code, 0, nullptr, input_count, inputs);
+}
 
 // static
 MachineOperatorBuilder::Flags