Index: llvm/include/llvm/IR/User.h
===================================================================
--- llvm/include/llvm/IR/User.h
+++ llvm/include/llvm/IR/User.h
@@ -218,6 +218,11 @@
     NumUserOperands = NumOps;
   }
 
+  /// A droppable user is a user for which uses can be dropped without affecting
+  /// correctness and should be dropped rather than preventing a transformation
+  /// from happening.
+  bool isDroppable() const;
+
   // ---------------------------------------------------------------------------
   // Operand Iterator interface...
   //
Index: llvm/include/llvm/IR/Value.h
===================================================================
--- llvm/include/llvm/IR/Value.h
+++ llvm/include/llvm/IR/Value.h
@@ -444,6 +444,34 @@
   /// This is logically equivalent to getNumUses() >= N.
   bool hasNUsesOrMore(unsigned N) const;
 
+  /// Return true if there is exactly one user of this value that cannot be
+  /// dropped.
+  ///
+  /// This is specialized because it is a common request and does not require
+  /// traversing the whole use list.
+  Use *getSingleUndroppableUse();
+
+  /// Return true if there this value.
+  ///
+  /// This is specialized because it is a common request and does not require
+  /// traversing the whole use list.
+  bool hasNUndroppableUses(unsigned N) const;
+
+  /// Return true if this value has N users or more.
+  ///
+  /// This is logically equivalent to getNumUses() >= N.
+  bool hasNUndroppableUsesOrMore(unsigned N) const;
+
+  /// Remove every uses that can safely be removed.
+  ///
+  /// This will remove for example uses in llvm.assume.
+  /// This should be used when performing want to perform a tranformation but
+  /// some Droppable uses pervent it.
+  /// This function optionally takes a filter to only remove some droppable
+  /// uses.
+  void dropDroppableUses(llvm::function_ref<bool(const Use *)> ShouldDrop =
+                             [](const Use *) { return true; });
+
   /// Check if this value is used in the specified basic block.
   bool isUsedInBasicBlock(const BasicBlock *BB) const;
 
Index: llvm/lib/IR/User.cpp
===================================================================
--- llvm/lib/IR/User.cpp
+++ llvm/lib/IR/User.cpp
@@ -9,6 +9,7 @@
 #include "llvm/IR/User.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/IntrinsicInst.h"
 
 namespace llvm {
 class BasicBlock;
@@ -105,6 +106,12 @@
       reinterpret_cast<uint8_t *>(DI) - DI->SizeInBytes, DI->SizeInBytes);
 }
 
+bool User::isDroppable() const {
+  if (const auto *Intr = dyn_cast<IntrinsicInst>(this))
+    return Intr->getIntrinsicID() == Intrinsic::assume;
+  return false;
+}
+
 //===----------------------------------------------------------------------===//
 //                         User operator new Implementations
 //===----------------------------------------------------------------------===//
Index: llvm/lib/IR/Value.cpp
===================================================================
--- llvm/lib/IR/Value.cpp
+++ llvm/lib/IR/Value.cpp
@@ -141,6 +141,51 @@
   return hasNItemsOrMore(use_begin(), use_end(), N);
 }
 
+static bool isUnDroppableUser(const User *U) { return !U->isDroppable(); }
+
+Use *Value::getSingleUndroppableUse() {
+  Use *Result = nullptr;
+  for (Use &U : uses()) {
+    if (!U.getUser()->isDroppable()) {
+      if (Result)
+        return nullptr;
+      Result = &U;
+    }
+  }
+  return Result;
+}
+
+bool Value::hasNUndroppableUses(unsigned int N) const {
+  return hasNItems(user_begin(), user_end(), N, isUnDroppableUser);
+}
+
+bool Value::hasNUndroppableUsesOrMore(unsigned int N) const {
+  return hasNItemsOrMore(user_begin(), user_end(), N, isUnDroppableUser);
+}
+
+void Value::dropDroppableUses(
+    llvm::function_ref<bool(const Use *)> ShouldDrop) {
+  SmallVector<Use *, 8> ToBeEdited;
+  for (Use &U : uses())
+    if (U.getUser()->isDroppable() && ShouldDrop(&U))
+      ToBeEdited.push_back(&U);
+  for (Use *U : ToBeEdited) {
+    Value *V = U->get();
+    (void)V;
+    if (auto *Assume = dyn_cast<IntrinsicInst>(U->getUser())) {
+      assert(Assume->getIntrinsicID() == Intrinsic::assume);
+      unsigned OpNo = U->getOperandNo();
+      if (OpNo == 0)
+        Assume->setOperand(0, ConstantInt::getTrue(Assume->getContext()));
+      else
+        Assume->setOperand(OpNo, nullptr);
+    } else
+      llvm_unreachable("add special handeling here");
+    assert(V != U->get() && "the value should have been changed");
+    U->removeFromList();
+  }
+}
+
 bool Value::isUsedInBasicBlock(const BasicBlock *BB) const {
   // This can be computed either by scanning the instructions in BB, or by
   // scanning the use list of this Value. Both lists can be very long, but