diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
@@ -225,6 +225,10 @@
   LLVM_NODISCARD std::pair<ProgramStateRef, ProgramStateRef>
   assume(DefinedOrUnknownSVal cond) const;
 
+  LLVM_NODISCARD std::pair<ProgramStateRef, ProgramStateRef>
+  assumeInBoundDual(DefinedOrUnknownSVal idx, DefinedOrUnknownSVal upperBound,
+                    QualType IndexType = QualType()) const;
+
   LLVM_NODISCARD ProgramStateRef
   assumeInBound(DefinedOrUnknownSVal idx, DefinedOrUnknownSVal upperBound,
                 bool assumption, QualType IndexType = QualType()) const;
diff --git a/clang/lib/StaticAnalyzer/Checkers/ArrayBoundChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ArrayBoundChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/ArrayBoundChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ArrayBoundChecker.cpp
@@ -58,8 +58,8 @@
   DefinedOrUnknownSVal ElementCount = getDynamicElementCount(
       state, ER->getSuperRegion(), C.getSValBuilder(), ER->getValueType());
 
-  ProgramStateRef StInBound = state->assumeInBound(Idx, ElementCount, true);
-  ProgramStateRef StOutBound = state->assumeInBound(Idx, ElementCount, false);
+  ProgramStateRef StInBound, StOutBound;
+  std::tie(StInBound, StOutBound) = state->assumeInBoundDual(Idx, ElementCount);
   if (StOutBound && !StInBound) {
     ExplodedNode *N = C.generateErrorNode(StOutBound);
     if (!N)
diff --git a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -355,8 +355,8 @@
   // Get the index of the accessed element.
   DefinedOrUnknownSVal Idx = ER->getIndex().castAs<DefinedOrUnknownSVal>();
 
-  ProgramStateRef StInBound = state->assumeInBound(Idx, Size, true);
-  ProgramStateRef StOutBound = state->assumeInBound(Idx, Size, false);
+  ProgramStateRef StInBound, StOutBound;
+  std::tie(StInBound, StOutBound) = state->assumeInBoundDual(Idx, Size);
   if (StOutBound && !StInBound) {
     // These checks are either enabled by the CString out-of-bounds checker
     // explicitly or implicitly by the Malloc checker.
@@ -2493,4 +2493,4 @@
 REGISTER_CHECKER(CStringOutOfBounds)
 REGISTER_CHECKER(CStringBufferOverlap)
 REGISTER_CHECKER(CStringNotNullTerm)
-REGISTER_CHECKER(CStringUninitializedRead)
\ No newline at end of file
+REGISTER_CHECKER(CStringUninitializedRead)
diff --git a/clang/lib/StaticAnalyzer/Checkers/ObjCContainersChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ObjCContainersChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/ObjCContainersChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ObjCContainersChecker.cpp
@@ -137,8 +137,8 @@
 
     // Now, check if 'Idx in [0, Size-1]'.
     const QualType T = IdxExpr->getType();
-    ProgramStateRef StInBound = State->assumeInBound(Idx, *Size, true, T);
-    ProgramStateRef StOutBound = State->assumeInBound(Idx, *Size, false, T);
+    ProgramStateRef StInBound, StOutBound;
+    std::tie(StInBound, StOutBound) = State->assumeInBoundDual(Idx, *Size, T);
     if (StOutBound && !StInBound) {
       ExplodedNode *N = C.generateErrorNode(StOutBound);
       if (!N)
diff --git a/clang/lib/StaticAnalyzer/Checkers/ReturnPointerRangeChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ReturnPointerRangeChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/ReturnPointerRangeChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ReturnPointerRangeChecker.cpp
@@ -64,8 +64,8 @@
   if (Idx == ElementCount)
     return;
 
-  ProgramStateRef StInBound = state->assumeInBound(Idx, ElementCount, true);
-  ProgramStateRef StOutBound = state->assumeInBound(Idx, ElementCount, false);
+  ProgramStateRef StInBound, StOutBound;
+  std::tie(StInBound, StOutBound) = state->assumeInBoundDual(Idx, ElementCount);
   if (StOutBound && !StInBound) {
     ExplodedNode *N = C.generateErrorNode(StOutBound);
 
diff --git a/clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
@@ -53,8 +53,8 @@
   DefinedOrUnknownSVal Idx = ER->getIndex().castAs<DefinedOrUnknownSVal>();
   DefinedOrUnknownSVal ElementCount = getDynamicElementCount(
       state, ER->getSuperRegion(), C.getSValBuilder(), ER->getValueType());
-  ProgramStateRef StInBound = state->assumeInBound(Idx, ElementCount, true);
-  ProgramStateRef StOutBound = state->assumeInBound(Idx, ElementCount, false);
+  ProgramStateRef StInBound, StOutBound;
+  std::tie(StInBound, StOutBound) = state->assumeInBoundDual(Idx, ElementCount);
   return StOutBound && !StInBound;
 }
 
diff --git a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
--- a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
@@ -314,12 +314,12 @@
   return getStateManager().getPersistentState(NewSt);
 }
 
-ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx,
-                                      DefinedOrUnknownSVal UpperBound,
-                                      bool Assumption,
-                                      QualType indexTy) const {
+LLVM_NODISCARD std::pair<ProgramStateRef, ProgramStateRef>
+ProgramState::assumeInBoundDual(DefinedOrUnknownSVal Idx,
+                                DefinedOrUnknownSVal UpperBound,
+                                QualType indexTy) const {
   if (Idx.isUnknown() || UpperBound.isUnknown())
-    return this;
+    return {this, this};
 
   // Build an expression for 0 <= Idx < UpperBound.
   // This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed.
@@ -338,7 +338,7 @@
   SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add,
                                         Idx.castAs<NonLoc>(), Min, indexTy);
   if (newIdx.isUnknownOrUndef())
-    return this;
+    return {this, this};
 
   // Adjust the upper bound.
   SVal newBound =
@@ -346,17 +346,26 @@
                             Min, indexTy);
 
   if (newBound.isUnknownOrUndef())
-    return this;
+    return {this, this};
 
   // Build the actual comparison.
   SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT, newIdx.castAs<NonLoc>(),
                                          newBound.castAs<NonLoc>(), Ctx.IntTy);
   if (inBound.isUnknownOrUndef())
-    return this;
+    return {this, this};
 
   // Finally, let the constraint manager take care of it.
   ConstraintManager &CM = SM.getConstraintManager();
-  return CM.assume(this, inBound.castAs<DefinedSVal>(), Assumption);
+  return CM.assumeDual(this, inBound.castAs<DefinedSVal>());
+}
+
+ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx,
+                                            DefinedOrUnknownSVal UpperBound,
+                                            bool Assumption,
+                                            QualType indexTy) const {
+  std::pair<ProgramStateRef, ProgramStateRef> R =
+      assumeInBoundDual(Idx, UpperBound, indexTy);
+  return Assumption ? R.first : R.second;
 }
 
 ConditionTruthVal ProgramState::isNonNull(SVal V) const {