[turbofan] Work towards fixing asm.js heap access.

src/compiler/simplified-lowering.cc

Index: src/compiler/simplified-lowering.cc
diff --git a/src/compiler/simplified-lowering.cc b/src/compiler/simplified-lowering.cc
index 39246df24609db6d039b5a78459cf5a97662b701..e832beb7637d6120adc9bcef0b821801e26b7b39 100644
--- a/src/compiler/simplified-lowering.cc
+++ b/src/compiler/simplified-lowering.cc
@@ -739,23 +739,6 @@ class RepresentationSelector {
         }
         break;
       }
-      case IrOpcode::kPlainPrimitiveToNumber: {
-        VisitUnop(node, kMachAnyTagged, kTypeNumber | kRepTagged);
-        if (lower()) {
-          // PlainPrimitiveToNumber(x) => Call(ToNumberStub, x, no-context)
-          Operator::Properties properties = node->op()->properties();
-          Callable callable = CodeFactory::ToNumber(jsgraph_->isolate());
-          CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
-          CallDescriptor* desc = Linkage::GetStubCallDescriptor(
-              jsgraph_->isolate(), jsgraph_->zone(), callable.descriptor(), 0,
-              flags, properties);
-          node->set_op(jsgraph_->common()->Call(desc));
-          node->InsertInput(jsgraph_->zone(), 0,
-                            jsgraph_->HeapConstant(callable.code()));
-          node->AppendInput(jsgraph_->zone(), jsgraph_->NoContextConstant());
-        }
-        break;
-      }
       case IrOpcode::kReferenceEqual: {
         VisitBinop(node, kMachAnyTagged, kRepBit);
         if (lower()) node->set_op(lowering->machine()->WordEqual());
@@ -811,24 +794,8 @@ class RepresentationSelector {
         ProcessInput(node, 1, kMachInt32);  // offset
         ProcessInput(node, 2, kMachInt32);  // length
         ProcessRemainingInputs(node, 3);
-        // Tagged overrides everything if we have to do a typed array bounds
-        // check, because we may need to return undefined then.
-        MachineType output_type;
-        if (use & kRepTagged) {
-          output_type = kMachAnyTagged;
-        } else if (use & kRepFloat64) {
-          if (access.machine_type() & kRepFloat32) {
-            output_type = access.machine_type();
-          } else {
-            output_type = kMachFloat64;
-          }
-        } else if (use & kRepFloat32) {
-          output_type = kMachFloat32;
-        } else {
-          output_type = access.machine_type();
-        }
-        SetOutput(node, output_type);
-        if (lower()) lowering->DoLoadBuffer(node, output_type, changer_);
+        SetOutput(node, access.machine_type());
+        if (lower()) lowering->DoLoadBuffer(node);
         break;
       }
       case IrOpcode::kStoreBuffer: {
@@ -1224,61 +1191,10 @@ Node* SimplifiedLowering::ComputeIndex(const ElementAccess& access,
 }
 
 
-void SimplifiedLowering::DoLoadBuffer(Node* node, MachineType output_type,
-                                      RepresentationChanger* changer) {
+void SimplifiedLowering::DoLoadBuffer(Node* node) {
   DCHECK_EQ(IrOpcode::kLoadBuffer, node->opcode());
-  DCHECK_NE(kMachNone, RepresentationOf(output_type));
   MachineType const type = BufferAccessOf(node->op()).machine_type();
-  if (output_type != type) {
-    Node* const buffer = node->InputAt(0);
-    Node* const offset = node->InputAt(1);
-    Node* const length = node->InputAt(2);
-    Node* const effect = node->InputAt(3);
-    Node* const control = node->InputAt(4);
-    Node* const index =
-        machine()->Is64()
-            ? graph()->NewNode(machine()->ChangeUint32ToUint64(), offset)
-            : offset;
-
-    Node* check = graph()->NewNode(machine()->Uint32LessThan(), offset, length);
-    Node* branch =
-        graph()->NewNode(common()->Branch(BranchHint::kTrue), check, control);
-
-    Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
-    Node* etrue =
-        graph()->NewNode(machine()->Load(type), buffer, index, effect, if_true);
-    Node* vtrue = changer->GetRepresentationFor(etrue, type, output_type);
-
-    Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
-    Node* efalse = effect;
-    Node* vfalse;
-    if (output_type & kRepTagged) {
-      vfalse = jsgraph()->UndefinedConstant();
-    } else if (output_type & kRepFloat64) {
-      vfalse =
-          jsgraph()->Float64Constant(std::numeric_limits<double>::quiet_NaN());
-    } else if (output_type & kRepFloat32) {
-      vfalse =
-          jsgraph()->Float32Constant(std::numeric_limits<float>::quiet_NaN());
-    } else {
-      vfalse = jsgraph()->Int32Constant(0);
-    }
-
-    Node* merge = graph()->NewNode(common()->Merge(2), if_true, if_false);
-    Node* ephi = graph()->NewNode(common()->EffectPhi(2), etrue, efalse, merge);
-
-    // Replace effect uses of {node} with the {ephi}.
-    NodeProperties::ReplaceWithValue(node, node, ephi);
-
-    // Turn the {node} into a Phi.
-    node->set_op(common()->Phi(output_type, 2));
-    node->ReplaceInput(0, vtrue);
-    node->ReplaceInput(1, vfalse);
-    node->ReplaceInput(2, merge);
-    node->TrimInputCount(3);
-  } else {
-    node->set_op(machine()->CheckedLoad(type));
-  }
+  node->set_op(machine()->CheckedLoad(type));
 }