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

src/compiler/ia32/instruction-selector-ia32.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/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
@@ skipping 901 matching lines @@
   IA32OperandGenerator g(this);
   Float32BinopMatcher m(node);
   if (m.left().IsMinusZero()) {
     VisitFloatUnop(this, node, m.right().node(), kAVXFloat32Neg,
                    kSSEFloat32Neg);
     return;
   }
   VisitRROFloat(this, node, kAVXFloat32Sub, kSSEFloat32Sub);
 }
 
+void InstructionSelector::VisitFloat32SubPreserveNan(Node* node) {
+  VisitRROFloat(this, node, kAVXFloat32Sub, kSSEFloat32Sub);
+}
 
 void InstructionSelector::VisitFloat64Sub(Node* node) {
   IA32OperandGenerator g(this);
   Float64BinopMatcher m(node);
   if (m.left().IsMinusZero()) {
     if (m.right().IsFloat64RoundDown() &&
         CanCover(m.node(), m.right().node())) {
       if (m.right().InputAt(0)->opcode() == IrOpcode::kFloat64Sub &&
           CanCover(m.right().node(), m.right().InputAt(0))) {
         Float64BinopMatcher mright0(m.right().InputAt(0));
         if (mright0.left().IsMinusZero()) {
           Emit(kSSEFloat64Round | MiscField::encode(kRoundUp),
                g.DefineAsRegister(node), g.UseRegister(mright0.right().node()));
           return;
         }
       }
     }
     VisitFloatUnop(this, node, m.right().node(), kAVXFloat64Neg,
                    kSSEFloat64Neg);
     return;
   }
   VisitRROFloat(this, node, kAVXFloat64Sub, kSSEFloat64Sub);
 }
 
+void InstructionSelector::VisitFloat64SubPreserveNan(Node* node) {
+  VisitRROFloat(this, node, kAVXFloat64Sub, kSSEFloat64Sub);
+}
 
 void InstructionSelector::VisitFloat32Mul(Node* node) {
   VisitRROFloat(this, node, kAVXFloat32Mul, kSSEFloat32Mul);
 }
 
 
 void InstructionSelector::VisitFloat64Mul(Node* node) {
   VisitRROFloat(this, node, kAVXFloat64Mul, kSSEFloat64Mul);
 }
 
@@ skipping 725 matching lines @@
              MachineOperatorBuilder::kFloat64RoundTruncate |
              MachineOperatorBuilder::kFloat32RoundTiesEven |
              MachineOperatorBuilder::kFloat64RoundTiesEven;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8