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

test/cctest/compiler/test-run-machops.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 <cmath>
 #include <functional>
 #include <limits>
 
 #include "src/base/bits.h"
 #include "src/codegen.h"
@@ skipping 3194 matching lines @@
 
   FOR_FLOAT32_INPUTS(pl) {
     FOR_FLOAT32_INPUTS(pr) {
       float expected = *pl - *pr;
       CheckFloatEq(expected, bt.call(*pl, *pr));
     }
   }
 }
 
 
+TEST(RunFloat32SubImm1) {
+  float input = 0.0f;
+  float output = 0.0f;
+
+  FOR_FLOAT32_INPUTS(i) {
+    RawMachineAssemblerTester<int32_t> m;
+    Node* t0 = m.LoadFromPointer(&input, kMachFloat32);
+    Node* t1 = m.Float32Sub(m.Float32Constant(*i), t0);
+    m.StoreToPointer(&output, kMachFloat32, t1);
+    m.Return(m.Int32Constant(0));
+    FOR_FLOAT32_INPUTS(j) {
+      input = *j;
+      float expected = *i - input;
+      CHECK_EQ(0, m.Call());
+      CheckFloatEq(expected, output);
+    }
+  }
+}
+
+
+TEST(RunFloat32SubImm2) {
+  float input = 0.0f;
+  float output = 0.0f;
+
+  FOR_FLOAT32_INPUTS(i) {
+    RawMachineAssemblerTester<int32_t> m;
+    Node* t0 = m.LoadFromPointer(&input, kMachFloat32);
+    Node* t1 = m.Float32Sub(t0, m.Float32Constant(*i));
+    m.StoreToPointer(&output, kMachFloat32, t1);
+    m.Return(m.Int32Constant(0));
+    FOR_FLOAT32_INPUTS(j) {
+      input = *j;
+      float expected = input - *i;
+      CHECK_EQ(0, m.Call());
+      CheckFloatEq(expected, output);
+    }
+  }
+}
+
+
 TEST(RunFloat64SubP) {
   RawMachineAssemblerTester<int32_t> m;
   Float64BinopTester bt(&m);
 
   bt.AddReturn(m.Float64Sub(bt.param0, bt.param1));
 
   FOR_FLOAT64_INPUTS(pl) {
     FOR_FLOAT64_INPUTS(pr) {
       double expected = *pl - *pr;
       CheckDoubleEq(expected, bt.call(*pl, *pr));
@@ skipping 1844 matching lines @@
   m.Return(m.Int32Constant(0));
   for (size_t i = 0; i < arraysize(kValues); ++i) {
     input = kValues[i];
     CHECK_EQ(0, m.Call());
     double expected = round(kValues[i]);
     CHECK_EQ(expected, result);
   }
 }
 
 #endif  // V8_TURBOFAN_TARGET