[turbofan] Introduce dedicated NumberConvertHoleNaN simplified operator.

src/compiler/simplified-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/simplified-lowering.h"
 
 #include <limits>
 
 #include "src/address-map.h"
 #include "src/base/bits.h"
@@ skipping 1431 matching lines @@
           node->ReplaceInput(
               0, jsgraph_->graph()->NewNode(
                      lowering->machine()->Float64ExtractHighWord32(),
                      node->InputAt(0)));
           node->AppendInput(jsgraph_->zone(),
                             jsgraph_->Int32Constant(kHoleNanUpper32));
           NodeProperties::ChangeOp(node, jsgraph_->machine()->Word32Equal());
         }
         return;
       }
+      case IrOpcode::kNumberConvertHoleNaN: {
+        if (truncation.TruncatesToFloat64()) {
+          // NumberConvertHoleNaN(x) => x
+          VisitUnop(node, UseInfo::TruncatingFloat64(),
+                    MachineRepresentation::kFloat64);
+          if (lower()) DeferReplacement(node, node->InputAt(0));
+        } else {
+          VisitUnop(node, UseInfo::TruncatingFloat64(),
+                    MachineRepresentation::kTagged);
+          if (lower()) {
+            // NumberConvertHoleNaN(x) =>
+            //   Select(Word32Equal(Float64ExtractHighWord32(x),
+            //                      #HoleNanUpper32),
+            //          #Undefined,
+            //          ChangeFloat64ToTagged(x))
+            Node* value = node->InputAt(0);
+            node->ReplaceInput(
+                0,
+                jsgraph_->graph()->NewNode(
+                    jsgraph_->machine()->Word32Equal(),
+                    jsgraph_->graph()->NewNode(
+                        jsgraph_->machine()->Float64ExtractHighWord32(), value),
+                    jsgraph_->Int32Constant(kHoleNanUpper32)));
+            node->AppendInput(jsgraph_->zone(), jsgraph_->UndefinedConstant());
+            node->AppendInput(
+                jsgraph_->zone(),
+                jsgraph_->graph()->NewNode(
+                    jsgraph_->simplified()->ChangeFloat64ToTagged(), value));
+            NodeProperties::ChangeOp(
+                node, jsgraph_->common()->Select(MachineRepresentation::kTagged,
+                                                 BranchHint::kFalse));
+          }
+        }
+        return;
+      }
       case IrOpcode::kReferenceEqual: {
         VisitBinop(node, UseInfo::AnyTagged(), MachineRepresentation::kBit);
         if (lower()) {
           NodeProperties::ChangeOp(node, lowering->machine()->WordEqual());
         }
         return;
       }
       case IrOpcode::kStringEqual: {
         VisitBinop(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged);
         if (lower()) {
@@ skipping 1400 matching lines @@
         isolate(), graph()->zone(), callable.descriptor(), 0, flags,
         Operator::kNoProperties);
     to_number_operator_.set(common()->Call(desc));
   }
   return to_number_operator_.get();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8