[turbofan] Introduce new operators Float32SubPreserveNan and Float64SubPreserveNan for wasm.

src/compiler/x64/instruction-selector-x64.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 <algorithm>
 
 #include "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
@@ skipping 1234 matching lines @@
   X64OperandGenerator g(this);
   Float32BinopMatcher m(node);
   if (m.left().IsMinusZero()) {
     VisitFloatUnop(this, node, m.right().node(), kAVXFloat32Neg,
                    kSSEFloat32Neg);
     return;
   }
   VisitFloatBinop(this, node, kAVXFloat32Sub, kSSEFloat32Sub);
 }
 
+void InstructionSelector::VisitFloat32SubPreserveNan(Node* node) {
+  VisitFloatBinop(this, node, kAVXFloat32Sub, kSSEFloat32Sub);
+}
 
 void InstructionSelector::VisitFloat32Mul(Node* node) {
   VisitFloatBinop(this, node, kAVXFloat32Mul, kSSEFloat32Mul);
 }
 
 
 void InstructionSelector::VisitFloat32Div(Node* node) {
   VisitFloatBinop(this, node, kAVXFloat32Div, kSSEFloat32Div);
 }
 
@@ skipping 39 matching lines @@
         }
       }
     }
     VisitFloatUnop(this, node, m.right().node(), kAVXFloat64Neg,
                    kSSEFloat64Neg);
     return;
   }
   VisitFloatBinop(this, node, kAVXFloat64Sub, kSSEFloat64Sub);
 }
 
+void InstructionSelector::VisitFloat64SubPreserveNan(Node* node) {
+  VisitFloatBinop(this, node, kAVXFloat64Sub, kSSEFloat64Sub);
+}
 
 void InstructionSelector::VisitFloat64Mul(Node* node) {
   VisitFloatBinop(this, node, kAVXFloat64Mul, kSSEFloat64Mul);
 }
 
 
 void InstructionSelector::VisitFloat64Div(Node* node) {
   VisitFloatBinop(this, node, kAVXFloat64Div, kSSEFloat64Div);
 }
 
@@ skipping 822 matching lines @@
              MachineOperatorBuilder::kFloat64RoundTruncate |
              MachineOperatorBuilder::kFloat32RoundTiesEven |
              MachineOperatorBuilder::kFloat64RoundTiesEven;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8