[llvm] [SandboxIR] sandboxir::Use operands (part 1) and uses (part 2) (PR #98251)

[via llvm-commits]

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@@ -123,9 +215,77 @@ class Value {
   virtual ~Value() = default;
   ClassID getSubclassID() const { return SubclassID; }
 
+  using use_iterator = UserUseIterator;
+  using const_use_iterator = UserUseIterator;
+
+  use_iterator use_begin();
+  const_use_iterator use_begin() const {
+    return const_cast<Value *>(this)->use_begin();
+  }
+  use_iterator use_end() { return use_iterator(Use(nullptr, nullptr, Ctx)); }
+  const_use_iterator use_end() const {
+    return const_cast<Value *>(this)->use_end();
+  }
+
+  iterator_range<use_iterator> uses() {
+    return make_range<use_iterator>(use_begin(), use_end());
+  }
+  iterator_range<const_use_iterator> uses() const {
+    return make_range<const_use_iterator>(use_begin(), use_end());
+  }
+
+  /// Helper for mapped_iterator.
+  struct UseToUser {
+    User *operator()(const Use &Use) const { return &*Use.getUser(); }
+  };
+
+  using user_iterator = mapped_iterator<sandboxir::UserUseIterator, UseToUser>;
+  using const_user_iterator = user_iterator;
+
+  user_iterator user_begin();
+  user_iterator user_end() {
+    return user_iterator(Use(nullptr, nullptr, Ctx), UseToUser());
+  }
+  const_user_iterator user_begin() const {
+    return const_cast<Value *>(this)->user_begin();
+  }
+  const_user_iterator user_end() const {
+    return const_cast<Value *>(this)->user_end();
+  }
+
+  iterator_range<user_iterator> users() {
+    return make_range<user_iterator>(user_begin(), user_end());
+  }
+  iterator_range<const_user_iterator> users() const {
+    return make_range<const_user_iterator>(user_begin(), user_end());
+  }
+  /// \Returns the number of user edges (not necessarily to unique users).
+  /// WARNING: This is a linear-time operation.
+  unsigned getNumUses() const;
+  /// Return true if this value has N uses or more.
+  /// This is logically equivalent to getNumUses() >= N.
+  /// WARNING: This can be expensive, as it is linear to the number of users.
+  bool hasNUsesOrMore(unsigned Num) const {
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vporpo wrote:

I think they may be used in the vectorizer to skip instructions with too many uses.

https://github.com/llvm/llvm-project/pull/98251