[turbofan] Optimize tagged conversion based on type.

test/cctest/compiler/test-representation-change.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 <limits>
 
 #include "test/cctest/cctest.h"
 #include "test/cctest/compiler/codegen-tester.h"
 #include "test/cctest/compiler/graph-builder-tester.h"
 #include "test/cctest/compiler/value-helper.h"
@@ skipping 426 matching lines @@
   CHECK_EQ(n, c2->InputAt(0));
 }
 
 
 TEST(SingleChanges) {
   CheckChange(IrOpcode::kChangeBoolToBit, MachineRepresentation::kTagged,
               Type::None(), MachineRepresentation::kBit);
   CheckChange(IrOpcode::kChangeBitToBool, MachineRepresentation::kBit,
               Type::None(), MachineRepresentation::kTagged);
 
+  CheckChange(IrOpcode::kChangeInt31ToTagged, MachineRepresentation::kWord32,
+              Type::Signed31(), MachineRepresentation::kTagged);
   CheckChange(IrOpcode::kChangeInt32ToTagged, MachineRepresentation::kWord32,
               Type::Signed32(), MachineRepresentation::kTagged);
   CheckChange(IrOpcode::kChangeUint32ToTagged, MachineRepresentation::kWord32,
               Type::Unsigned32(), MachineRepresentation::kTagged);
   CheckChange(IrOpcode::kChangeFloat64ToTagged, MachineRepresentation::kFloat64,
-              Type::None(), MachineRepresentation::kTagged);
+              Type::Number(), MachineRepresentation::kTagged);
+  CheckTwoChanges(IrOpcode::kChangeFloat64ToInt32,
+                  IrOpcode::kChangeInt31ToTagged,
+                  MachineRepresentation::kFloat64, Type::Signed31(),
+                  MachineRepresentation::kTagged);
+  CheckTwoChanges(IrOpcode::kChangeFloat64ToInt32,
+                  IrOpcode::kChangeInt32ToTagged,
+                  MachineRepresentation::kFloat64, Type::Signed32(),
+                  MachineRepresentation::kTagged);
+  CheckTwoChanges(IrOpcode::kChangeFloat64ToUint32,
+                  IrOpcode::kChangeUint32ToTagged,
+                  MachineRepresentation::kFloat64, Type::Unsigned32(),
+                  MachineRepresentation::kTagged);
 
   CheckChange(IrOpcode::kChangeTaggedToInt32, MachineRepresentation::kTagged,
               Type::Signed32(), MachineRepresentation::kWord32);
   CheckChange(IrOpcode::kChangeTaggedToUint32, MachineRepresentation::kTagged,
               Type::Unsigned32(), MachineRepresentation::kWord32);
   CheckChange(IrOpcode::kChangeTaggedToFloat64, MachineRepresentation::kTagged,
               Type::None(), MachineRepresentation::kFloat64);
 
   // Int32,Uint32 <-> Float64 are actually machine conversions.
   CheckChange(IrOpcode::kChangeInt32ToFloat64, MachineRepresentation::kWord32,
@@ skipping 158 matching lines @@
                    MachineRepresentation::kWord64);
   r.CheckTypeError(MachineRepresentation::kWord32, Type::Signed32(),
                    MachineRepresentation::kWord64);
   r.CheckTypeError(MachineRepresentation::kWord32, Type::Unsigned32(),
                    MachineRepresentation::kWord64);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8