[mlir] Move the Operation use iteration utilities to ResultRange

[rriddle]

Summary

This allows for iterating and interacting with the uses of a specific subset of
results as opposed to just the full range.

[rriddle]

update

mlir/include/mlir/IR/Operation.h

public:
   //===--------------------------------------------------------------------===//
 
   /// Drop all uses of results of this operation.
   void dropAllUses() {
     for (OpResult result : getOpResults())
       result.dropAllUses();
   }
 
-  /// This class implements a use iterator for the Operation. This iterates over
-  /// all uses of all results.
-  class UseIterator final
-      : public llvm::iterator_facade_base<
-            UseIterator, std::forward_iterator_tag, OpOperand> {
-  public:
-    /// Initialize UseIterator for op, specify end to return iterator to last
-    /// use.
-    explicit UseIterator(Operation *op, bool end = false);
-
-    using llvm::iterator_facade_base<UseIterator, std::forward_iterator_tag,
-                                     OpOperand>::operator++;
-    UseIterator &operator++();
-    OpOperand *operator->() const { return use.getOperand(); }
-    OpOperand &operator*() const { return *use.getOperand(); }
-
-    bool operator==(const UseIterator &rhs) const { return use == rhs.use; }
-    bool operator!=(const UseIterator &rhs) const { return !(*this == rhs); }
+  using use_iterator = result_range::use_iterator;
+  using use_range = result_range::use_range;
 
-  private:
-    void skipOverResultsWithNoUsers();
-
-    /// The operation whose uses are being iterated over.
-    Operation *op;
-    /// The result of op who's uses are being iterated over.
-    Operation::result_iterator res;
-    /// The use of the result.
-    Value::use_iterator use;
-  };
-  using use_iterator = UseIterator;
-  using use_range = iterator_range<use_iterator>;
-
-  use_iterator use_begin() { return use_iterator(this); }
-  use_iterator use_end() { return use_iterator(this, /*end=*/true); }
+  use_iterator use_begin() { return getResults().use_begin(); }
+  use_iterator use_end() { return getResults().use_end(); }
 
   /// Returns a range of all uses, which is useful for iterating over all uses.
-  use_range getUses() { return {use_begin(), use_end()}; }
+  use_range getUses() { return getResults().getUses(); }
 
   /// Returns true if this operation has exactly one use.
   bool hasOneUse() { return llvm::hasSingleElement(getUses()); }
 
   /// Returns true if this operation has no uses.
-  bool use_empty() {
-    return llvm::all_of(getOpResults(),
-                        [](OpResult result) { return result.use_empty(); });
-  }
+  bool use_empty() { return getResults().use_empty(); }
 
   /// Returns true if the results of this operation are used outside of the
   /// given block.
   bool isUsedOutsideOfBlock(Block *block) {
     return llvm::any_of(getOpResults(), [block](OpResult result) {
       return result.isUsedOutsideOfBlock(block);
     });
   }

mlir/include/mlir/IR/OperationSupport.h

 
 /// This class implements the result iterators for the Operation class.
 class ResultRange final
     : public llvm::detail::indexed_accessor_range_base<
           ResultRange, detail::OpResultImpl *, OpResult, OpResult, OpResult> {
 public:
   using RangeBaseT::RangeBaseT;
 
+  //===--------------------------------------------------------------------===//
+  // Types
+  //===--------------------------------------------------------------------===//
+
   /// Returns the types of the values within this range.
   using type_iterator = ValueTypeIterator<iterator>;
   using type_range = ValueTypeRange<ResultRange>;
   type_range getTypes() const { return {begin(), end()}; }
   auto getType() const { return getTypes(); }
 
+  //===--------------------------------------------------------------------===//
+  // Uses
+  //===--------------------------------------------------------------------===//
+
+  class UseIterator;
+  using use_iterator = UseIterator;
+  using use_range = iterator_range<use_iterator>;
+
+  /// Returns a range of all uses of results within this range, which is useful
+  /// for iterating over all uses.
+  use_range getUses() const;
+  use_iterator use_begin() const;
+  use_iterator use_end() const;
+
+  /// Returns true if no results in this range have uses.
+  bool use_empty() const {
+    return llvm::all_of(*this,
+                        [](OpResult result) { return result.use_empty(); });
+  }
+
+  //===--------------------------------------------------------------------===//
+  // Users
+  //===--------------------------------------------------------------------===//
+
+  using user_iterator = ValueUserIterator<use_iterator, OpOperand>;
+  using user_range = iterator_range<user_iterator>;
+
+  /// Returns a range of all users.
+  user_range getUsers();
+  user_iterator user_begin();
+  user_iterator user_end();
+
 private:
   /// See `llvm::detail::indexed_accessor_range_base` for details.
   static detail::OpResultImpl *offset_base(detail::OpResultImpl *object,
                                            ptrdiff_t index) {
     return object->getNextResultAtOffset(index);
   }
   /// See `llvm::detail::indexed_accessor_range_base` for details.
   static OpResult dereference_iterator(detail::OpResultImpl *object,
                                        ptrdiff_t index) {
     return offset_base(object, index);
   }
 
   /// Allow access to `offset_base` and `dereference_iterator`.
   friend RangeBaseT;
 };
 
+/// This class implements a use iterator for a range of operation results.
+/// This iterates over all uses of all results within the given result range.
+class ResultRange::UseIterator final
+    : public llvm::iterator_facade_base<UseIterator, std::forward_iterator_tag,
+                                        OpOperand> {
+public:
+  /// Initialize the UseIterator. Specify `end` to return iterator to last
+  /// use, otherwise this is an iterator to the first use.
+  explicit UseIterator(ResultRange results, bool end = false);
+
+  using llvm::iterator_facade_base<UseIterator, std::forward_iterator_tag,
+                                   OpOperand>::operator++;
+  UseIterator &operator++();
+  OpOperand *operator->() const { return use.getOperand(); }
+  OpOperand &operator*() const { return *use.getOperand(); }
+
+  bool operator==(const UseIterator &rhs) const { return use == rhs.use; }
+  bool operator!=(const UseIterator &rhs) const { return !(*this == rhs); }
+
+private:
+  void skipOverResultsWithNoUsers();
+
+  /// The range of results being iterated over.
+  ResultRange::iterator it, endIt;
+  /// The use of the result.
+  Value::use_iterator use;
+};
+
 //===----------------------------------------------------------------------===//
 // ValueRange
 
 /// This class provides an abstraction over the different types of ranges over
 /// Values. In many cases, this prevents the need to explicitly materialize a
 /// SmallVector/std::vector. This class should be used in places that are not
 /// suitable for a more derived type (e.g. ArrayRef) or a template range
 /// parameter.

mlir/lib/IR/Operation.cpp

 /// Create a simple OpBuilder and forward to the OpBuilder version of this
 /// function.
 void impl::ensureRegionTerminator(
     Region &region, Builder &builder, Location loc,
     function_ref<Operation *(OpBuilder &, Location)> buildTerminatorOp) {
   OpBuilder opBuilder(builder.getContext());
   ensureRegionTerminator(region, opBuilder, loc, buildTerminatorOp);
 }
-
-//===----------------------------------------------------------------------===//
-// UseIterator
-//===----------------------------------------------------------------------===//
-
-Operation::UseIterator::UseIterator(Operation *op, bool end)
-    : op(op), res(end ? op->result_end() : op->result_begin()) {
-  // Only initialize current use if there are results/can be uses.
-  if (op->getNumResults())
-    skipOverResultsWithNoUsers();
-}
-
-Operation::UseIterator &Operation::UseIterator::operator++() {
-  // We increment over uses, if we reach the last use then move to next
-  // result.
-  if (use != (*res).use_end())
-    ++use;
-  if (use == (*res).use_end()) {
-    ++res;
-    skipOverResultsWithNoUsers();
-  }
-  return *this;
-}
-
-void Operation::UseIterator::skipOverResultsWithNoUsers() {
-  while (res != op->result_end() && (*res).use_empty())
-    ++res;
-
-  // If we are at the last result, then set use to first use of
-  // first result (sentinel value used for end).
-  if (res == op->result_end())
-    use = {};
-  else
-    use = (*res).use_begin();
-}

mlir/lib/IR/OperationSupport.cpp

MutableOperandRange MutableOperandRangeRange::dereference(const OwnerT &object,
   uint32_t startIndex =
       std::accumulate(sizeData.begin(), sizeData.begin() + index, 0);
   return object.first.slice(
       startIndex, *(sizeData.begin() + index),
       MutableOperandRange::OperandSegment(index, object.second));
 }
 
 //===----------------------------------------------------------------------===//
+// ResultRange
+
+ResultRange::use_range ResultRange::getUses() const {
+  return {use_begin(), use_end()};
+}
+ResultRange::use_iterator ResultRange::use_begin() const {
+  return use_iterator(*this);
+}
+ResultRange::use_iterator ResultRange::use_end() const {
+  return use_iterator(*this, /*end=*/true);
+}
+ResultRange::user_range ResultRange::getUsers() {
+  return {user_begin(), user_end()};
+}
+ResultRange::user_iterator ResultRange::user_begin() {
+  return user_iterator(use_begin());
+}
+ResultRange::user_iterator ResultRange::user_end() {
+  return user_iterator(use_end());
+}
+
+ResultRange::UseIterator::UseIterator(ResultRange results, bool end)
+    : it(end ? results.end() : results.begin()), endIt(results.end()) {
+  // Only initialize current use if there are results/can be uses.
+  if (it != endIt)
+    skipOverResultsWithNoUsers();
+}
+
+ResultRange::UseIterator &ResultRange::UseIterator::operator++() {
+  // We increment over uses, if we reach the last use then move to next
+  // result.
+  if (use != (*it).use_end())
+    ++use;
+  if (use == (*it).use_end()) {
+    ++it;
+    skipOverResultsWithNoUsers();
+  }
+  return *this;
+}
+
+void ResultRange::UseIterator::skipOverResultsWithNoUsers() {
+  while (it != endIt && (*it).use_empty())
+    ++it;
+
+  // If we are at the last result, then set use to first use of
+  // first result (sentinel value used for end).
+  if (it == endIt)
+    use = {};
+  else
+    use = (*it).use_begin();
+}
+
+//===----------------------------------------------------------------------===//
 // ValueRange
 
 ValueRange::ValueRange(ArrayRef<Value> values)
     : ValueRange(values.data(), values.size()) {}
 ValueRange::ValueRange(OperandRange values)
     : ValueRange(values.begin().getBase(), values.size()) {}
 ValueRange::ValueRange(ResultRange values)
     : ValueRange(values.getBase(), values.size()) {}