Index: llvm/include/llvm/Analysis/ScalarEvolution.h
===================================================================
--- llvm/include/llvm/Analysis/ScalarEvolution.h
+++ llvm/include/llvm/Analysis/ScalarEvolution.h
@@ -677,6 +677,13 @@
   bool isLoopEntryGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
                                 const SCEV *LHS, const SCEV *RHS);
 
+  /// Test whether entry to the basic block is protected by a conditional
+  /// between LHS
+  /// and RHS.
+  bool isBasicBlockEntryGuardedByCond(const BasicBlock *BB,
+                                      ICmpInst::Predicate Pred, const SCEV *LHS,
+                                      const SCEV *RHS);
+
   /// Test whether the backedge of the loop is protected by a conditional
   /// between LHS and RHS.  This is used to eliminate casts.
   bool isLoopBackedgeGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
Index: llvm/lib/Analysis/ScalarEvolution.cpp
===================================================================
--- llvm/lib/Analysis/ScalarEvolution.cpp
+++ llvm/lib/Analysis/ScalarEvolution.cpp
@@ -9451,24 +9451,14 @@
   return false;
 }
 
-bool
-ScalarEvolution::isLoopEntryGuardedByCond(const Loop *L,
-                                          ICmpInst::Predicate Pred,
-                                          const SCEV *LHS, const SCEV *RHS) {
-  // Interpret a null as meaning no loop, where there is obviously no guard
-  // (interprocedural conditions notwithstanding).
-  if (!L) return false;
-
+bool ScalarEvolution::isBasicBlockEntryGuardedByCond(const BasicBlock *BB,
+                                                     ICmpInst::Predicate Pred,
+                                                     const SCEV *LHS,
+                                                     const SCEV *RHS) {
   if (VerifyIR)
-    assert(!verifyFunction(*L->getHeader()->getParent(), &dbgs()) &&
+    assert(!verifyFunction(*BB->getParent(), &dbgs()) &&
            "This cannot be done on broken IR!");
 
-  // Both LHS and RHS must be available at loop entry.
-  assert(isAvailableAtLoopEntry(LHS, L) &&
-         "LHS is not available at Loop Entry");
-  assert(isAvailableAtLoopEntry(RHS, L) &&
-         "RHS is not available at Loop Entry");
-
   if (isKnownViaNonRecursiveReasoning(Pred, LHS, RHS))
     return true;
 
@@ -9528,10 +9518,14 @@
   // Starting at the loop predecessor, climb up the predecessor chain, as long
   // as there are predecessors that can be found that have unique successors
   // leading to the original header.
-  for (std::pair<const BasicBlock *, const BasicBlock *> Pair(
-           L->getLoopPredecessor(), L->getHeader());
+  const Loop *ContainingLoop = LI.getLoopFor(BB);
+  const BasicBlock *PredBB;
+  if (ContainingLoop && ContainingLoop->getHeader() == BB)
+    PredBB = ContainingLoop->getLoopPredecessor();
+  else
+    PredBB = BB->getUniquePredecessor();
+  for (std::pair<const BasicBlock *, const BasicBlock *> Pair(PredBB, BB);
        Pair.first; Pair = getPredecessorWithUniqueSuccessorForBB(Pair.first)) {
-
     if (ProveViaGuard(Pair.first))
       return true;
 
@@ -9551,7 +9545,7 @@
     if (!AssumeVH)
       continue;
     auto *CI = cast<CallInst>(AssumeVH);
-    if (!DT.dominates(CI, L->getHeader()))
+    if (!DT.dominates(CI, BB))
       continue;
 
     if (ProveViaCond(CI->getArgOperand(0), false))
@@ -9561,6 +9555,23 @@
   return false;
 }
 
+bool ScalarEvolution::isLoopEntryGuardedByCond(const Loop *L,
+                                               ICmpInst::Predicate Pred,
+                                               const SCEV *LHS,
+                                               const SCEV *RHS) {
+  // Interpret a null as meaning no loop, where there is obviously no guard
+  // (interprocedural conditions notwithstanding).
+  if (!L)
+    return false;
+
+  // Both LHS and RHS must be available at loop entry.
+  assert(isAvailableAtLoopEntry(LHS, L) &&
+         "LHS is not available at Loop Entry");
+  assert(isAvailableAtLoopEntry(RHS, L) &&
+         "RHS is not available at Loop Entry");
+  return isBasicBlockEntryGuardedByCond(L->getHeader(), Pred, LHS, RHS);
+}
+
 bool ScalarEvolution::isImpliedCond(ICmpInst::Predicate Pred, const SCEV *LHS,
                                     const SCEV *RHS,
                                     const Value *FoundCondValue, bool Inverse) {