diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -561,22 +561,6 @@
   }
 }
 
-// For a ret instruction followed by a musttail call, we cannot insert anything
-// in between. Instead we use the musttail call instruction as the insertion
-// point.
-static Instruction *adjustForMusttailCall(Instruction *I) {
-  ReturnInst *RI = dyn_cast<ReturnInst>(I);
-  if (!RI)
-    return I;
-  Instruction *Prev = RI->getPrevNode();
-  if (BitCastInst *BCI = dyn_cast_or_null<BitCastInst>(Prev))
-    Prev = BCI->getPrevNode();
-  if (CallInst *CI = dyn_cast_or_null<CallInst>(Prev))
-    if (CI->isMustTailCall())
-      return CI;
-  return RI;
-}
-
 namespace {
 
 /// Module analysis for getting various metadata about the module.
@@ -985,8 +969,14 @@
   void createDynamicAllocasInitStorage();
 
   // ----------------------- Visitors.
-  /// Collect all Ret instructions.
-  void visitReturnInst(ReturnInst &RI) { RetVec.push_back(&RI); }
+  /// Collect all Ret instructions, or the musttail call instruction if it
+  /// precedes the return instruction.
+  void visitReturnInst(ReturnInst &RI) {
+    if (CallInst *CI = RI.getParent()->getTerminatingMustTailCall())
+      RetVec.push_back(CI);
+    else
+      RetVec.push_back(&RI);
+  }
 
   /// Collect all Resume instructions.
   void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
@@ -1021,8 +1011,7 @@
   // Unpoison dynamic allocas redzones.
   void unpoisonDynamicAllocas() {
     for (Instruction *Ret : RetVec)
-      unpoisonDynamicAllocasBeforeInst(adjustForMusttailCall(Ret),
-                                       DynamicAllocaLayout);
+      unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
 
     for (Instruction *StackRestoreInst : StackRestoreVec)
       unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
@@ -3333,8 +3322,7 @@
 
   // (Un)poison the stack before all ret instructions.
   for (Instruction *Ret : RetVec) {
-    Instruction *Adjusted = adjustForMusttailCall(Ret);
-    IRBuilder<> IRBRet(Adjusted);
+    IRBuilder<> IRBRet(Ret);
     // Mark the current frame as retired.
     IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
                        BasePlus0);
@@ -3353,7 +3341,7 @@
       Value *Cmp =
           IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
       Instruction *ThenTerm, *ElseTerm;
-      SplitBlockAndInsertIfThenElse(Cmp, Adjusted, &ThenTerm, &ElseTerm);
+      SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
 
       IRBuilder<> IRBPoison(ThenTerm);
       if (StackMallocIdx <= 4) {
diff --git a/llvm/lib/Transforms/Utils/EntryExitInstrumenter.cpp b/llvm/lib/Transforms/Utils/EntryExitInstrumenter.cpp
--- a/llvm/lib/Transforms/Utils/EntryExitInstrumenter.cpp
+++ b/llvm/lib/Transforms/Utils/EntryExitInstrumenter.cpp
@@ -97,13 +97,8 @@
         continue;
 
       // If T is preceded by a musttail call, that's the real terminator.
-      Instruction *Prev = T->getPrevNode();
-      if (BitCastInst *BCI = dyn_cast_or_null<BitCastInst>(Prev))
-        Prev = BCI->getPrevNode();
-      if (CallInst *CI = dyn_cast_or_null<CallInst>(Prev)) {
-        if (CI->isMustTailCall())
-          T = CI;
-      }
+      if (CallInst *CI = BB.getTerminatingMustTailCall())
+        T = CI;
 
       DebugLoc DL;
       if (DebugLoc TerminatorDL = T->getDebugLoc())
diff --git a/llvm/lib/Transforms/Utils/EscapeEnumerator.cpp b/llvm/lib/Transforms/Utils/EscapeEnumerator.cpp
--- a/llvm/lib/Transforms/Utils/EscapeEnumerator.cpp
+++ b/llvm/lib/Transforms/Utils/EscapeEnumerator.cpp
@@ -41,27 +41,9 @@
     if (!isa<ReturnInst>(TI) && !isa<ResumeInst>(TI))
       continue;
 
-    // If the ret instruction is followed by a musttaill call,
-    // or a bitcast instruction and then a musttail call, we should return
-    // the musttail call as the insertion point to not break the musttail
-    // contract.
-    auto AdjustMustTailCall = [&](Instruction *I) -> Instruction * {
-      auto *RI = dyn_cast<ReturnInst>(I);
-      if (!RI || !RI->getPrevNode())
-        return I;
-      auto *CI = dyn_cast<CallInst>(RI->getPrevNode());
-      if (CI && CI->isMustTailCall())
-        return CI;
-      auto *BI = dyn_cast<BitCastInst>(RI->getPrevNode());
-      if (!BI || !BI->getPrevNode())
-        return I;
-      CI = dyn_cast<CallInst>(BI->getPrevNode());
-      if (CI && CI->isMustTailCall())
-        return CI;
-      return I;
-    };
-
-    Builder.SetInsertPoint(AdjustMustTailCall(TI));
+    if (CallInst *CI = CurBB->getTerminatingMustTailCall())
+      TI = CI;
+    Builder.SetInsertPoint(TI);
     return &Builder;
   }