[x64] Match -0 - x with sign bit flip.

test/unittests/compiler/x64/instruction-selector-x64-unittest.cc

Index: test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
diff --git a/test/unittests/compiler/x64/instruction-selector-x64-unittest.cc b/test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
index ebdf02448f4413cd955ebedc64739e2a3e1af330..6d0e589e3bf04d4607229e8cbfe64d1ade73943c 100644
--- a/test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
+++ b/test/unittests/compiler/x64/instruction-selector-x64-unittest.cc
@@ -75,6 +75,7 @@ TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithParameter) {
 // -----------------------------------------------------------------------------
 // Loads and stores
 
+
 namespace {
 
 struct MemoryAccess {
@@ -137,6 +138,7 @@ INSTANTIATE_TEST_CASE_P(InstructionSelectorTest,
                         InstructionSelectorMemoryAccessTest,
                         ::testing::ValuesIn(kMemoryAccesses));
 
+
 // -----------------------------------------------------------------------------
 // ChangeUint32ToUint64.
 
@@ -1026,6 +1028,22 @@ TEST_F(InstructionSelectorTest, Float64BinopArithmetic) {
 }
 
 
+TEST_F(InstructionSelectorTest, Float64SubWithMinusZeroAndParameter) {
+  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(kSSEFloat64Neg, 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()));
+  EXPECT_EQ(kFlags_none, s[0]->flags_mode());
+}
+
+
 // -----------------------------------------------------------------------------
 // Miscellaneous.