[turbofan] Remove the FloatXXSubPreserveNan operators.

src/compiler/arm64/instruction-selector-arm64.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/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 1722 matching lines @@
 
 void InstructionSelector::VisitFloat64Add(Node* node) {
   VisitRRR(this, kArm64Float64Add, node);
 }
 
 
 void InstructionSelector::VisitFloat32Sub(Node* node) {
   VisitRRR(this, kArm64Float32Sub, node);
 }
 
-void InstructionSelector::VisitFloat32SubPreserveNan(Node* node) {
-  VisitRRR(this, kArm64Float32Sub, node);
-}
-
 void InstructionSelector::VisitFloat64Sub(Node* node) {
-  Arm64OperandGenerator 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(kArm64Float64RoundUp, g.DefineAsRegister(node),
-               g.UseRegister(mright0.right().node()));
-          return;
-        }
-      }
-    }
-    Emit(kArm64Float64Neg, g.DefineAsRegister(node),
-         g.UseRegister(m.right().node()));
-    return;
-  }
   VisitRRR(this, kArm64Float64Sub, node);
 }
 
-void InstructionSelector::VisitFloat64SubPreserveNan(Node* node) {
-  VisitRRR(this, kArm64Float64Sub, node);
-}
-
 void InstructionSelector::VisitFloat32Mul(Node* node) {
   VisitRRR(this, kArm64Float32Mul, node);
 }
 
 
 void InstructionSelector::VisitFloat64Mul(Node* node) {
   VisitRRR(this, kArm64Float64Mul, node);
 }
 
 
@@ skipping 965 matching lines @@
 // static
 MachineOperatorBuilder::AlignmentRequirements
 InstructionSelector::AlignmentRequirements() {
   return MachineOperatorBuilder::AlignmentRequirements::
       FullUnalignedAccessSupport();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8