[turbofan] Remove the FloatXXSubPreserveNan operators.

src/compiler/mips/instruction-selector-mips.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/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 746 matching lines @@
 
 void InstructionSelector::VisitFloat64Add(Node* node) {
   VisitRRR(this, kMipsAddD, node);
 }
 
 
 void InstructionSelector::VisitFloat32Sub(Node* node) {
   VisitRRR(this, kMipsSubS, node);
 }
 
-void InstructionSelector::VisitFloat32SubPreserveNan(Node* node) {
-  VisitRRR(this, kMipsSubPreserveNanS, node);
-}
-
 void InstructionSelector::VisitFloat64Sub(Node* node) {
-  MipsOperandGenerator g(this);
-  Float64BinopMatcher m(node);
-  if (m.left().IsMinusZero() && 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(kMipsFloat64RoundUp, g.DefineAsRegister(node),
-             g.UseRegister(mright0.right().node()));
-        return;
-      }
-    }
-  }
   VisitRRR(this, kMipsSubD, node);
 }
 
-void InstructionSelector::VisitFloat64SubPreserveNan(Node* node) {
-  VisitRRR(this, kMipsSubPreserveNanD, node);
-}
-
 void InstructionSelector::VisitFloat32Mul(Node* node) {
   VisitRRR(this, kMipsMulS, node);
 }
 
 
 void InstructionSelector::VisitFloat64Mul(Node* node) {
   VisitRRR(this, kMipsMulD, node);
 }
 
 
@@ skipping 851 matching lines @@
     DCHECK(IsMipsArchVariant(kLoongson) || IsMipsArchVariant(kMips32r1) ||
            IsMipsArchVariant(kMips32r2));
     return MachineOperatorBuilder::AlignmentRequirements::
         NoUnalignedAccessSupport();
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8