Index: llvm/include/llvm/IR/PassInstrumentation.h
===================================================================
--- llvm/include/llvm/IR/PassInstrumentation.h
+++ llvm/include/llvm/IR/PassInstrumentation.h
@@ -75,7 +75,10 @@
   // already invalidated IRUnit is unsafe. There are ways to handle invalidated IRUnits
   // in a safe way, and we might pursue that as soon as there is a useful instrumentation
   // that needs it.
+  // For every Before callback called there is either After, AfterInvalidated
+  // or AfterSkipped call with the same pass name and IRUnit if available.
   using BeforePassFunc = bool(StringRef, Any);
+  using AfterPassSkippedFunc = void(StringRef, Any);
   using AfterPassFunc = void(StringRef, Any, const PreservedAnalyses &);
   using AfterPassInvalidatedFunc = void(StringRef, const PreservedAnalyses &);
   using BeforeAnalysisFunc = void(StringRef, Any);
@@ -92,6 +95,11 @@
     BeforePassCallbacks.emplace_back(std::move(C));
   }
 
+  template <typename CallableT>
+  void registerAfterPassSkippedCallback(CallableT C) {
+    AfterPassSkippedCallbacks.emplace_back(std::move(C));
+  }
+
   template <typename CallableT> void registerAfterPassCallback(CallableT C) {
     AfterPassCallbacks.emplace_back(std::move(C));
   }
@@ -115,6 +123,8 @@
   friend class PassInstrumentation;
 
   SmallVector<llvm::unique_function<BeforePassFunc>, 4> BeforePassCallbacks;
+  SmallVector<llvm::unique_function<AfterPassSkippedFunc>, 4>
+      AfterPassSkippedCallbacks;
   SmallVector<llvm::unique_function<AfterPassFunc>, 4> AfterPassCallbacks;
   SmallVector<llvm::unique_function<AfterPassInvalidatedFunc>, 4>
       AfterPassInvalidatedCallbacks;
@@ -169,6 +179,11 @@
     for (auto &C : Callbacks->BeforePassCallbacks)
       ShouldRun &= C(Pass.name(), llvm::Any(&IR));
     ShouldRun = ShouldRun || isRequired(Pass);
+
+    if (!ShouldRun)
+      for (auto &C : Callbacks->AfterPassSkippedCallbacks)
+        C(Pass.name(), llvm::Any(&IR));
+
     return ShouldRun;
   }