[turbofan] Try hard(er) to use smi representation for float64 values.

test/unittests/compiler/change-lowering-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/code-stubs.h"
 #include "src/compiler/change-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/simplified-operator.h"
@@ skipping 103 matching lines @@
 
 TARGET_TEST_P(ChangeLoweringCommonTest, ChangeBoolToBit) {
   Node* value = Parameter(Type::Number());
   Reduction r =
       Reduce(graph()->NewNode(simplified()->ChangeBoolToBit(), value));
   ASSERT_TRUE(r.Changed());
   EXPECT_THAT(r.replacement(), IsWordEqual(value, IsTrueConstant()));
 }
 
 
-TARGET_TEST_P(ChangeLoweringCommonTest, ChangeFloat64ToTagged) {
-  Node* value = Parameter(Type::Number());
-  Reduction r =
-      Reduce(graph()->NewNode(simplified()->ChangeFloat64ToTagged(), value));
-  ASSERT_TRUE(r.Changed());
-  Capture<Node*> heap_number;
-  EXPECT_THAT(
-      r.replacement(),
-      IsFinishRegion(
-          AllOf(CaptureEq(&heap_number),
-                IsAllocateHeapNumber(IsBeginRegion(graph()->start()),
-                                     graph()->start())),
-          IsStore(StoreRepresentation(kMachFloat64, kNoWriteBarrier),
-                  CaptureEq(&heap_number),
-                  IsIntPtrConstant(HeapNumber::kValueOffset - kHeapObjectTag),
-                  value, CaptureEq(&heap_number), graph()->start())));
-}
-
-
 TARGET_TEST_P(ChangeLoweringCommonTest, ChangeInt32ToTaggedWithSignedSmall) {
   Node* value = Parameter(Type::SignedSmall());
   Reduction r =
       Reduce(graph()->NewNode(simplified()->ChangeInt32ToTagged(), value));
   ASSERT_TRUE(r.Changed());
   EXPECT_THAT(r.replacement(), IsChangeInt32ToSmi(value));
 }
 
 
 TARGET_TEST_P(ChangeLoweringCommonTest, ChangeUint32ToTaggedWithUnsignedSmall) {
@@ skipping 307 matching lines @@
                       CaptureEq(&branch),
                       IsBranch(IsUint32LessThanOrEqual(
                                    value, IsInt32Constant(Smi::kMaxValue)),
                                graph()->start()))),
                   AllOf(CaptureEq(&if_false), IsIfFalse(CaptureEq(&branch))))));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8