Revert of [arm] Fix recognition of VNEG. (patchset #3 id:40001 of...

Revert of [arm] Fix recognition of VNEG. (patchset #3 id:40001 of https://codereview.chromium.org/762493006/)

Reason for revert:
Breaks arm compilation.

Original issue's description:
> [arm] Fix recognition of VNEG.
>
> TEST=mjsunit,unittests
> R=svenpanne@chromium.org
>
> Committed: https://chromium.googlesource.com/v8/v8/+/2aed882fe74dbf9210159babe30fedccd900e7cf

TBR=svenpanne@chromium.org,bmeurer@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/751653004

Cr-Commit-Position: refs/heads/master@{#25514}

src/compiler/arm/instruction-selector-arm.cc

@@ -854,16 +854,16 @@ void InstructionSelector::VisitTruncateFloat64ToFloat32(Node* node) {
 
 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()));
@@ -875,14 +875,9 @@ void InstructionSelector::VisitFloat64Add(Node* 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()));
@@ -893,7 +888,13 @@ void InstructionSelector::VisitFloat64Sub(Node* node) {
 
 
 void InstructionSelector::VisitFloat64Mul(Node* 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);
+  }
 }
 
 

src/compiler/node-matchers.h

@@ -5,8 +5,6 @@
 #ifndef V8_COMPILER_NODE_MATCHERS_H_
 #define V8_COMPILER_NODE_MATCHERS_H_
 
-#include <cmath>
-
 #include "src/compiler/generic-node.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/node.h"
@@ -106,7 +104,6 @@ template <typename T, IrOpcode::Value kOpcode>
 struct FloatMatcher FINAL : public ValueMatcher<T, kOpcode> {
   explicit FloatMatcher(Node* node) : ValueMatcher<T, kOpcode>(node) {}
 
-  bool IsMinusZero() const { return this->Is(0.0) && signbit(this->Value()); }
   bool IsNaN() const { return this->HasValue() && std::isnan(this->Value()); }
 };
 
@@ -170,7 +167,6 @@ typedef BinopMatcher<UintPtrMatcher, UintPtrMatcher> UintPtrBinopMatcher;
 typedef BinopMatcher<Float64Matcher, Float64Matcher> Float64BinopMatcher;
 typedef BinopMatcher<NumberMatcher, NumberMatcher> NumberBinopMatcher;
 
-
 template <class BinopMatcher, IrOpcode::Value kAddOpcode,
           IrOpcode::Value kMulOpcode, IrOpcode::Value kShiftOpcode>
 struct AddMatcher : public BinopMatcher {

test/mjsunit/asm/float64mul.js

@@ -12,32 +12,22 @@ function Module(stdlib, foreign, heap) {
     i = +i;
     return +(-1 * i);
   }
-  function f3(i) {
-    i = +i;
-    return +(-i);
-  }
-  return { f1: f1, f2: f2, f3: f3 };
+  return { f1: f1, f2: f2 };
 }
 
 var m = Module(this, {}, new ArrayBuffer(64 * 1024));
 
 assertEquals(NaN, m.f1(NaN));
 assertEquals(NaN, m.f2(NaN));
-assertEquals(NaN, m.f3(NaN));
 assertEquals(Infinity, 1 / m.f1(-0));
 assertEquals(Infinity, 1 / m.f2(-0));
-assertEquals(Infinity, 1 / m.f3(-0));
 assertEquals(Infinity, m.f1(-Infinity));
 assertEquals(Infinity, m.f2(-Infinity));
-assertEquals(Infinity, m.f3(-Infinity));
 assertEquals(-Infinity, 1 / m.f1(0));
 assertEquals(-Infinity, 1 / m.f2(0));
-assertEquals(-Infinity, 1 / m.f3(0));
 assertEquals(-Infinity, m.f1(Infinity));
 assertEquals(-Infinity, m.f2(Infinity));
-assertEquals(-Infinity, m.f3(Infinity));
 for (var i = -2147483648; i < 2147483648; i += 3999777) {
   assertEquals(-i, m.f1(i));
   assertEquals(-i, m.f2(i));
-  assertEquals(-i, m.f3(i));
 }

test/unittests/compiler/arm/instruction-selector-arm-unittest.cc

@@ -1482,21 +1482,6 @@ INSTANTIATE_TEST_CASE_P(InstructionSelectorTest,
 // Miscellaneous.
 
 
-TEST_F(InstructionSelectorTest, Float64SubWithMinusZero) {
-  StreamBuilder m(this, kMachFloat64, kMachFloat64);
-  Node* const p0 = m.Parameter(0);
-  Node* const n = m.Float64Sub(m.Float64Constant(-0.0), p0);
-  m.Return(n);
-  Stream s = m.Build();
-  ASSERT_EQ(1U, s.size());
-  EXPECT_EQ(kArmVnegF64, s[0]->arch_opcode());
-  ASSERT_EQ(1U, s[0]->InputCount());
-  EXPECT_EQ(s.ToVreg(p0), s.ToVreg(s[0]->InputAt(0)));
-  ASSERT_EQ(1U, s[0]->OutputCount());
-  EXPECT_EQ(s.ToVreg(n), s.ToVreg(s[0]->Output()));
-}
-
-
 TEST_F(InstructionSelectorTest, Int32AddWithInt32Mul) {
   {
     StreamBuilder m(this, kMachInt32, kMachInt32, kMachInt32, kMachInt32);