[turbofan] Push TruncateFloat64ToInt32 into phis.

test/unittests/compiler/machine-operator-reducer-unittest.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/base/division-by-constant.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator-reducer.h"
 #include "src/compiler/typer.h"
 #include "test/unittests/compiler/graph-unittest.h"
@@ skipping 437 matching lines @@
 TEST_F(MachineOperatorReducerTest, TruncateFloat64ToInt32WithConstant) {
   TRACED_FOREACH(double, x, kFloat64Values) {
     Reduction reduction = Reduce(graph()->NewNode(
         machine()->TruncateFloat64ToInt32(), Float64Constant(x)));
     ASSERT_TRUE(reduction.Changed());
     EXPECT_THAT(reduction.replacement(), IsInt32Constant(DoubleToInt32(x)));
   }
 }
 
 
+TEST_F(MachineOperatorReducerTest, TruncateFloat64ToInt32WithPhi) {
+  Node* const p0 = Parameter(0);
+  Node* const p1 = Parameter(1);
+  Node* const merge = graph()->start();
+  Reduction reduction = Reduce(graph()->NewNode(
+      machine()->TruncateFloat64ToInt32(),
+      graph()->NewNode(common()->Phi(kMachFloat64, 2), p0, p1, merge)));
+  ASSERT_TRUE(reduction.Changed());
+  EXPECT_THAT(reduction.replacement(),
+              IsPhi(kMachInt32, IsTruncateFloat64ToInt32(p0),
+                    IsTruncateFloat64ToInt32(p1), merge));
+}
+
+
 // -----------------------------------------------------------------------------
 // TruncateInt64ToInt32
 
 
 TEST_F(MachineOperatorReducerTest, TruncateInt64ToInt32WithChangeInt32ToInt64) {
   Node* value = Parameter(0);
   Reduction reduction = Reduce(graph()->NewNode(
       machine()->TruncateInt64ToInt32(),
       graph()->NewNode(machine()->ChangeInt32ToInt64(), value)));
   ASSERT_TRUE(reduction.Changed());
@@ skipping 736 matching lines @@
     Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
     EXPECT_THAT(r.replacement(),
                 IsStore(rep, base, index, value, effect, control));
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8