Revert of [arm] Fix recognition of VNEG.

src/compiler/arm/instruction-selector-arm.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/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 836 matching lines @@
 
 void InstructionSelector::VisitTruncateFloat64ToFloat32(Node* node) {
   ArmOperandGenerator g(this);
   Emit(kArmVcvtF32F64, g.DefineAsRegister(node),
        g.UseRegister(node->InputAt(0)));
 }
 
 
 void InstructionSelector::VisitFloat64Add(Node* node) {
   ArmOperandGenerator g(this);
-  Float64BinopMatcher m(node);
+  Int32BinopMatcher m(node);
   if (m.left().IsFloat64Mul() && CanCover(node, m.left().node())) {
-    Float64BinopMatcher mleft(m.left().node());
+    Int32BinopMatcher mleft(m.left().node());
     Emit(kArmVmlaF64, g.DefineSameAsFirst(node),
          g.UseRegister(m.right().node()), g.UseRegister(mleft.left().node()),
          g.UseRegister(mleft.right().node()));
     return;
   }
   if (m.right().IsFloat64Mul() && CanCover(node, m.right().node())) {
-    Float64BinopMatcher mright(m.right().node());
+    Int32BinopMatcher mright(m.right().node());
     Emit(kArmVmlaF64, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()),
          g.UseRegister(mright.left().node()),
          g.UseRegister(mright.right().node()));
     return;
   }
   VisitRRRFloat64(this, kArmVaddF64, node);
 }
 
 
 void InstructionSelector::VisitFloat64Sub(Node* node) {
   ArmOperandGenerator g(this);
-  Float64BinopMatcher m(node);
-  if (m.left().IsMinusZero()) {
-    Emit(kArmVnegF64, g.DefineAsRegister(node),
-         g.UseRegister(m.right().node()));
-    return;
-  }
+  Int32BinopMatcher m(node);
   if (m.right().IsFloat64Mul() && CanCover(node, m.right().node())) {
-    Float64BinopMatcher mright(m.right().node());
+    Int32BinopMatcher mright(m.right().node());
     Emit(kArmVmlsF64, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()),
          g.UseRegister(mright.left().node()),
          g.UseRegister(mright.right().node()));
     return;
   }
   VisitRRRFloat64(this, kArmVsubF64, node);
 }
 
 
 void InstructionSelector::VisitFloat64Mul(Node* node) {
-  VisitRRRFloat64(this, kArmVmulF64, node);
+  ArmOperandGenerator g(this);
+  Float64BinopMatcher m(node);
+  if (m.right().Is(-1.0)) {
+    Emit(kArmVnegF64, g.DefineAsRegister(node), g.UseRegister(m.left().node()));
+  } else {
+    VisitRRRFloat64(this, kArmVmulF64, node);
+  }
 }
 
 
 void InstructionSelector::VisitFloat64Div(Node* node) {
   VisitRRRFloat64(this, kArmVdivF64, node);
 }
 
 
 void InstructionSelector::VisitFloat64Mod(Node* node) {
   ArmOperandGenerator g(this);
@@ skipping 350 matching lines @@
              MachineOperatorBuilder::kFloat64Ceil |
              MachineOperatorBuilder::kFloat64RoundTruncate |
              MachineOperatorBuilder::kFloat64RoundTiesAway;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8