[turbofan] Remove dead code from simplified lowering.

Review URL: https://codereview.chromium.org/1418423007

Cr-Commit-Position: refs/heads/master@{#31602}

src/compiler/simplified-lowering.cc

@@ -1153,14 +1153,6 @@ class RepresentationSelector {
 };
 
 
-Node* SimplifiedLowering::IsTagged(Node* node) {
-  // TODO(titzer): factor this out to a TaggingScheme abstraction.
-  STATIC_ASSERT(kSmiTagMask == 1);  // Only works if tag is the low bit.
-  return graph()->NewNode(machine()->WordAnd(), node,
-                          jsgraph()->Int32Constant(kSmiTagMask));
-}
-
-
 SimplifiedLowering::SimplifiedLowering(JSGraph* jsgraph, Zone* zone,
                                        SourcePositionTable* source_positions)
     : jsgraph_(jsgraph),
@@ -1177,25 +1169,6 @@ void SimplifiedLowering::LowerAllNodes() {
 }
 
 
-Node* SimplifiedLowering::Untag(Node* node) {
-  // TODO(titzer): factor this out to a TaggingScheme abstraction.
-  Node* shift_amount = jsgraph()->Int32Constant(kSmiTagSize + kSmiShiftSize);
-  return graph()->NewNode(machine()->WordSar(), node, shift_amount);
-}
-
-
-Node* SimplifiedLowering::SmiTag(Node* node) {
-  // TODO(titzer): factor this out to a TaggingScheme abstraction.
-  Node* shift_amount = jsgraph()->Int32Constant(kSmiTagSize + kSmiShiftSize);
-  return graph()->NewNode(machine()->WordShl(), node, shift_amount);
-}
-
-
-Node* SimplifiedLowering::OffsetMinusTagConstant(int32_t offset) {
-  return jsgraph()->Int32Constant(offset - kHeapObjectTag);
-}
-
-
 namespace {
 
 WriteBarrierKind ComputeWriteBarrierKind(BaseTaggedness base_is_tagged,

src/compiler/simplified-lowering.h

@@ -54,10 +54,6 @@ class SimplifiedLowering final {
   // position information via the SourcePositionWrapper like all other reducers.
   SourcePositionTable* source_positions_;
 
-  Node* SmiTag(Node* node);
-  Node* IsTagged(Node* node);
-  Node* Untag(Node* node);
-  Node* OffsetMinusTagConstant(int32_t offset);
   Node* ComputeIndex(const ElementAccess& access, Node* const key);
   Node* StringComparison(Node* node);
   Node* Int32Div(Node* const node);