[csa] Re-introduce automatic constant folding for IntPtrAdd and IntPtrSub

src/code-stub-assembler.cc

 // Copyright 2016 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-stub-assembler.h"
 #include "src/code-factory.h"
 #include "src/frames-inl.h"
 #include "src/frames.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 146 matching lines @@
 
 Node* CodeStubAssembler::IntPtrOrSmiConstant(int value, ParameterMode mode) {
   if (mode == SMI_PARAMETERS) {
     return SmiConstant(Smi::FromInt(value));
   } else {
     DCHECK_EQ(INTPTR_PARAMETERS, mode);
     return IntPtrConstant(value);
   }
 }
 
-Node* CodeStubAssembler::IntPtrAddFoldConstants(Node* left, Node* right) {
-  int32_t left_constant;
-  bool is_left_constant = ToInt32Constant(left, left_constant);
-  int32_t right_constant;
-  bool is_right_constant = ToInt32Constant(right, right_constant);
-  if (is_left_constant) {
-    if (is_right_constant) {
-      return IntPtrConstant(left_constant + right_constant);
-    }
-    if (left_constant == 0) {
-      return right;
-    }
-  } else if (is_right_constant) {
-    if (right_constant == 0) {
-      return left;
-    }
-  }
-  return IntPtrAdd(left, right);
-}
-
-Node* CodeStubAssembler::IntPtrSubFoldConstants(Node* left, Node* right) {
-  int32_t left_constant;
-  bool is_left_constant = ToInt32Constant(left, left_constant);
-  int32_t right_constant;
-  bool is_right_constant = ToInt32Constant(right, right_constant);
-  if (is_left_constant) {
-    if (is_right_constant) {
-      return IntPtrConstant(left_constant - right_constant);
-    }
-  } else if (is_right_constant) {
-    if (right_constant == 0) {
-      return left;
-    }
-  }
-  return IntPtrSub(left, right);
-}
-
 Node* CodeStubAssembler::IntPtrRoundUpToPowerOfTwo32(Node* value) {
   Comment("IntPtrRoundUpToPowerOfTwo32");
   CSA_ASSERT(this, UintPtrLessThanOrEqual(value, IntPtrConstant(0x80000000u)));
   value = IntPtrSub(value, IntPtrConstant(1));
   for (int i = 1; i <= 16; i *= 2) {
     value = WordOr(value, WordShr(value, IntPtrConstant(i)));
   }
   return IntPtrAdd(value, IntPtrConstant(1));
 }
 
@@ skipping 1292 matching lines @@
   ParameterMode mode = OptimalParameterMode();
   Variable var_length(this, OptimalParameterRepresentation());
   var_length.Bind(TaggedToParameter(LoadJSArrayLength(array), mode));
   var_elements.Bind(LoadElements(array));
   Node* capacity =
       TaggedToParameter(LoadFixedArrayBaseLength(var_elements.value()), mode);
 
   // Resize the capacity of the fixed array if it doesn't fit.
   Label fits(this, &var_elements);
   Node* first = arg_index.value();
-  Node* growth = IntPtrSubFoldConstants(args.GetLength(), first);
+  Node* growth = IntPtrSub(args.GetLength(), first);
   Node* new_length =
       IntPtrOrSmiAdd(WordToParameter(growth, mode), var_length.value(), mode);
   GotoUnless(IntPtrOrSmiGreaterThanOrEqual(new_length, capacity, mode), &fits);
   Node* new_capacity = CalculateNewElementsCapacity(
       IntPtrOrSmiAdd(new_length, IntPtrOrSmiConstant(1, mode), mode), mode);
   var_elements.Bind(GrowElementsCapacity(array, var_elements.value(), kind,
                                          kind, capacity, new_capacity, mode,
                                          &pre_bailout));
   Goto(&fits);
   Bind(&fits);
@@ skipping 361 matching lines @@
 Node* CodeStubAssembler::AllocateNameDictionary(Node* at_least_space_for) {
   CSA_ASSERT(this, UintPtrLessThanOrEqual(
                        at_least_space_for,
                        IntPtrConstant(NameDictionary::kMaxCapacity)));
 
   Node* capacity = HashTableComputeCapacity(at_least_space_for);
   CSA_ASSERT(this, WordIsPowerOfTwo(capacity));
 
   Node* length = EntryToIndex<NameDictionary>(capacity);
   Node* store_size =
-      IntPtrAddFoldConstants(WordShl(length, IntPtrConstant(kPointerSizeLog2)),
-                             IntPtrConstant(NameDictionary::kHeaderSize));
+      IntPtrAdd(WordShl(length, IntPtrConstant(kPointerSizeLog2)),
+                IntPtrConstant(NameDictionary::kHeaderSize));
 
   Node* result = Allocate(store_size);
   Comment("Initialize NameDictionary");
   // Initialize FixedArray fields.
   DCHECK(Heap::RootIsImmortalImmovable(Heap::kHashTableMapRootIndex));
   StoreMapNoWriteBarrier(result, Heap::kHashTableMapRootIndex);
   StoreObjectFieldNoWriteBarrier(result, FixedArray::kLengthOffset,
                                  SmiFromWord(length));
   // Initialized HashTable fields.
   Node* zero = SmiConstant(0);
@@ skipping 11 matching lines @@
                          SmiConstant(PropertyDetails::kInitialIndex),
                          SKIP_WRITE_BARRIER);
 
   // Initialize NameDictionary elements.
   Node* result_word = BitcastTaggedToWord(result);
   Node* start_address = IntPtrAdd(
       result_word, IntPtrConstant(NameDictionary::OffsetOfElementAt(
                                       NameDictionary::kElementsStartIndex) -
                                   kHeapObjectTag));
   Node* end_address = IntPtrAdd(
-      result_word,
-      IntPtrSubFoldConstants(store_size, IntPtrConstant(kHeapObjectTag)));
+      result_word, IntPtrSub(store_size, IntPtrConstant(kHeapObjectTag)));
   StoreFieldsNoWriteBarrier(start_address, end_address, filler);
   return result;
 }
 
 Node* CodeStubAssembler::AllocateJSObjectFromMap(Node* map, Node* properties,
                                                  Node* elements,
                                                  AllocationFlags flags) {
   CSA_ASSERT(this, IsMap(map));
   Node* size =
       IntPtrMul(LoadMapInstanceSize(map), IntPtrConstant(kPointerSize));
@@ skipping 352 matching lines @@
 
   ElementsKind from_kind = from_one_byte ? UINT8_ELEMENTS : UINT16_ELEMENTS;
   ElementsKind to_kind = to_one_byte ? UINT8_ELEMENTS : UINT16_ELEMENTS;
   STATIC_ASSERT(SeqOneByteString::kHeaderSize == SeqTwoByteString::kHeaderSize);
   int header_size = SeqOneByteString::kHeaderSize - kHeapObjectTag;
   Node* from_offset =
       ElementOffsetFromIndex(from_index, from_kind, mode, header_size);
   Node* to_offset =
       ElementOffsetFromIndex(to_index, to_kind, mode, header_size);
   Node* byte_count = ElementOffsetFromIndex(character_count, from_kind, mode);
-  Node* limit_offset = IntPtrAddFoldConstants(from_offset, byte_count);
+  Node* limit_offset = IntPtrAdd(from_offset, byte_count);
 
   // Prepare the fast loop
   MachineType type =
       from_one_byte ? MachineType::Uint8() : MachineType::Uint16();
   MachineRepresentation rep = to_one_byte ? MachineRepresentation::kWord8
                                           : MachineRepresentation::kWord16;
   int from_increment = 1 << ElementsKindToShiftSize(from_kind);
   int to_increment = 1 << ElementsKindToShiftSize(to_kind);
 
   Variable current_to_offset(this, MachineType::PointerRepresentation());
@@ skipping 3150 matching lines @@
   if (constant_index) {
     return IntPtrConstant(base_size + element_size * index);
   }
 
   Node* shifted_index =
       (element_size_shift == 0)
           ? index_node
           : ((element_size_shift > 0)
                  ? WordShl(index_node, IntPtrConstant(element_size_shift))
                  : WordShr(index_node, IntPtrConstant(-element_size_shift)));
-  return IntPtrAddFoldConstants(IntPtrConstant(base_size), shifted_index);
+  return IntPtrAdd(IntPtrConstant(base_size), shifted_index);
 }
 
 Node* CodeStubAssembler::LoadTypeFeedbackVectorForStub() {
   Node* function =
       LoadFromParentFrame(JavaScriptFrameConstants::kFunctionOffset);
   Node* literals = LoadObjectField(function, JSFunction::kLiteralsOffset);
   return LoadObjectField(literals, LiteralsArray::kFeedbackVectorOffset);
 }
 
 void CodeStubAssembler::UpdateFeedback(Node* feedback,
@@ skipping 2718 matching lines @@
 
 CodeStubArguments::CodeStubArguments(CodeStubAssembler* assembler, Node* argc)
     : assembler_(assembler),
       argc_(argc),
       arguments_(nullptr),
       fp_(assembler->LoadFramePointer()) {
   argc_ = assembler->ChangeUint32ToWord(argc_);
   Node* offset = assembler->ElementOffsetFromIndex(
       argc_, FAST_ELEMENTS, CodeStubAssembler::INTPTR_PARAMETERS,
       (StandardFrameConstants::kFixedSlotCountAboveFp - 1) * kPointerSize);
-  arguments_ = assembler_->IntPtrAddFoldConstants(fp_, offset);
+  arguments_ = assembler_->IntPtrAdd(fp_, offset);
 }
 
 Node* CodeStubArguments::GetReceiver() const {
   return assembler_->Load(MachineType::AnyTagged(), arguments_,
                           assembler_->IntPtrConstant(kPointerSize));
 }
 
 Node* CodeStubArguments::AtIndex(Node* index,
                                  CodeStubAssembler::ParameterMode mode) const {
   typedef compiler::Node Node;
-  Node* negated_index = assembler_->IntPtrSubFoldConstants(
-      assembler_->IntPtrOrSmiConstant(0, mode), index);
+  Node* negated_index =
+      assembler_->IntPtrSub(assembler_->IntPtrOrSmiConstant(0, mode), index);
   Node* offset =
       assembler_->ElementOffsetFromIndex(negated_index, FAST_ELEMENTS, mode, 0);
   return assembler_->Load(MachineType::AnyTagged(), arguments_, offset);
 }
 
 Node* CodeStubArguments::AtIndex(int index) const {
   return AtIndex(assembler_->IntPtrConstant(index));
 }
 
 void CodeStubArguments::ForEach(
     const CodeStubAssembler::VariableList& vars,
     const CodeStubArguments::ForEachBodyFunction& body, Node* first, Node* last,
     CodeStubAssembler::ParameterMode mode) {
   assembler_->Comment("CodeStubArguments::ForEach");
   DCHECK_IMPLIES(first == nullptr || last == nullptr,
                  mode == CodeStubAssembler::INTPTR_PARAMETERS);
   if (first == nullptr) {
     first = assembler_->IntPtrOrSmiConstant(0, mode);
   }
   if (last == nullptr) {
     last = argc_;
   }
-  Node* start = assembler_->IntPtrSubFoldConstants(
+  Node* start = assembler_->IntPtrSub(
       arguments_,
       assembler_->ElementOffsetFromIndex(first, FAST_ELEMENTS, mode));
-  Node* end = assembler_->IntPtrSubFoldConstants(
+  Node* end = assembler_->IntPtrSub(
       arguments_,
       assembler_->ElementOffsetFromIndex(last, FAST_ELEMENTS, mode));
   assembler_->BuildFastLoop(
       vars, MachineType::PointerRepresentation(), start, end,
       [this, &body](Node* current) {
         Node* arg = assembler_->Load(MachineType::AnyTagged(), current);
         body(arg);
       },
       -kPointerSize, CodeStubAssembler::IndexAdvanceMode::kPost);
 }
 
 void CodeStubArguments::PopAndReturn(Node* value) {
   assembler_->PopAndReturn(
-      assembler_->IntPtrAddFoldConstants(argc_, assembler_->IntPtrConstant(1)),
-      value);
+      assembler_->IntPtrAdd(argc_, assembler_->IntPtrConstant(1)), value);
 }
 
 Node* CodeStubAssembler::IsFastElementsKind(Node* elements_kind) {
   return Uint32LessThanOrEqual(elements_kind,
                                Int32Constant(LAST_FAST_ELEMENTS_KIND));
 }
 
 Node* CodeStubAssembler::IsHoleyFastElementsKind(Node* elements_kind) {
   CSA_ASSERT(this, IsFastElementsKind(elements_kind));
 
@@ skipping 89 matching lines @@
                        Heap::kUndefinedValueRootIndex);
   StoreObjectFieldRoot(result, PromiseReactionJobInfo::kDebugNameOffset,
                        Heap::kUndefinedValueRootIndex);
   StoreObjectFieldNoWriteBarrier(result, PromiseReactionJobInfo::kContextOffset,
                                  context);
   return result;
 }
 
 }  // namespace internal
 }  // namespace v8