[turbofan] Introduce ChangeTaggedToTaggedSigned operator.

src/compiler/effect-control-linearizer.cc

 // Copyright 2015 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/compiler/effect-control-linearizer.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/compiler-source-position-table.h"
 #include "src/compiler/js-graph.h"
@@ skipping 615 matching lines @@
       break;
     case IrOpcode::kChangeTaggedToInt32:
       result = LowerChangeTaggedToInt32(node);
       break;
     case IrOpcode::kChangeTaggedToUint32:
       result = LowerChangeTaggedToUint32(node);
       break;
     case IrOpcode::kChangeTaggedToFloat64:
       result = LowerChangeTaggedToFloat64(node);
       break;
+    case IrOpcode::kChangeTaggedToTaggedSigned:
+      result = LowerChangeTaggedToTaggedSigned(node);
+      break;
     case IrOpcode::kTruncateTaggedToBit:
       result = LowerTruncateTaggedToBit(node);
       break;
     case IrOpcode::kTruncateTaggedToFloat64:
       result = LowerTruncateTaggedToFloat64(node);
       break;
     case IrOpcode::kCheckBounds:
       result = LowerCheckBounds(node, frame_state);
       break;
     case IrOpcode::kCheckMaps:
@@ skipping 379 matching lines @@
   __ Goto(&done, vfalse);
 
   __ Bind(&done);
   return done.PhiAt(0);
 }
 
 Node* EffectControlLinearizer::LowerChangeTaggedToFloat64(Node* node) {
   return LowerTruncateTaggedToFloat64(node);
 }
 
+Node* EffectControlLinearizer::LowerChangeTaggedToTaggedSigned(Node* node) {
+  Node* value = node->InputAt(0);
+
+  auto if_not_smi = __ MakeDeferredLabel<1>();
+  auto done = __ MakeLabel<2>(MachineRepresentation::kWord32);
+
+  Node* check = ObjectIsSmi(value);
+  __ GotoUnless(check, &if_not_smi);
+  __ Goto(&done, value);
+
+  __ Bind(&if_not_smi);
+  STATIC_ASSERT(HeapNumber::kValueOffset == Oddball::kToNumberRawOffset);
+  Node* vfalse = __ LoadField(AccessBuilder::ForHeapNumberValue(), value);
+  vfalse = __ ChangeFloat64ToInt32(vfalse);
+  vfalse = ChangeInt32ToSmi(vfalse);
+  __ Goto(&done, vfalse);
+
+  __ Bind(&done);
+  return done.PhiAt(0);
+}
+
 Node* EffectControlLinearizer::LowerTruncateTaggedToFloat64(Node* node) {
   Node* value = node->InputAt(0);
 
   auto if_not_smi = __ MakeDeferredLabel<1>();
   auto done = __ MakeLabel<2>(MachineRepresentation::kFloat64);
 
   Node* check = ObjectIsSmi(value);
   __ GotoUnless(check, &if_not_smi);
   Node* vtrue = ChangeSmiToInt32(value);
   vtrue = __ ChangeInt32ToFloat64(vtrue);
@@ skipping 1721 matching lines @@
   return isolate()->factory();
 }
 
 Isolate* EffectControlLinearizer::isolate() const {
   return jsgraph()->isolate();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8