Index: llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
+++ llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
@@ -588,7 +588,7 @@
         PrevBB = BB;
       }
 
-      if (TPath.isExitValueSet())
+      if (TPath.isExitValueSet() && isSupported(TPath))
         TPaths.push_back(TPath);
     }
   }
@@ -683,6 +683,62 @@
     return Res;
   }
 
+  /// The determinator BB should precede the switch-defining BB.
+  ///
+  /// Otherwise, it is possible that the state defined in the determinator block
+  /// defines the state for the next iteration of the loop, rather than for the
+  /// current one.
+  ///
+  /// Currently supported paths:
+  /// \code
+  /// < switch bb1 determ def > [ 42, determ ]
+  /// < switch_and_def bb1 determ > [ 42, determ ]
+  /// < switch_and_def_and_determ bb1 > [ 42, switch_and_def_and_determ ]
+  /// \endcode
+  ///
+  /// Unsupported paths:
+  /// \code
+  /// < switch bb1 def determ > [ 43, determ ]
+  /// < switch_and_determ bb1 def > [ 43, switch_and_determ ]
+  /// \endcode
+  bool isSupported(const ThreadingPath &TPath) {
+    Instruction *SwitchCondI = dyn_cast<Instruction>(Switch->getCondition());
+    assert(SwitchCondI);
+    if (!SwitchCondI)
+      return false;
+
+    const BasicBlock *SwitchCondDefBB = SwitchCondI->getParent();
+    const BasicBlock *SwitchCondUseBB = Switch->getParent();
+    const BasicBlock *DeterminatorBB = TPath.getDeterminatorBB();
+
+    assert(
+        SwitchCondUseBB == TPath.getPath().front() &&
+        "The first BB in a threading path should have the switch instruction");
+    if (SwitchCondUseBB != TPath.getPath().front())
+      return false;
+
+    // Make DeterminatorBB the first element in Path.
+    PathType Path = TPath.getPath();
+    auto ItDet = std::find(Path.begin(), Path.end(), DeterminatorBB);
+    std::rotate(Path.begin(), ItDet, Path.end());
+
+    bool IsDetBBSeen = false;
+    bool IsDefBBSeen = false;
+    bool IsUseBBSeen = false;
+    for (BasicBlock *BB : Path) {
+      if (BB == DeterminatorBB)
+        IsDetBBSeen = true;
+      if (BB == SwitchCondDefBB)
+        IsDefBBSeen = true;
+      if (BB == SwitchCondUseBB)
+        IsUseBBSeen = true;
+      if (IsDetBBSeen && IsUseBBSeen && !IsDefBBSeen)
+        return false;
+    }
+
+    return true;
+  }
+
   SwitchInst *Switch;
   BasicBlock *SwitchBlock;
   OptimizationRemarkEmitter *ORE;
Index: llvm/test/Transforms/DFAJumpThreading/dfa-jump-threading-analysis.ll
===================================================================
--- llvm/test/Transforms/DFAJumpThreading/dfa-jump-threading-analysis.ll
+++ llvm/test/Transforms/DFAJumpThreading/dfa-jump-threading-analysis.ll
@@ -109,10 +109,16 @@
 
 declare void @baz()
 
-; Verify that having the switch block as a determinator is handled correctly.
-define i32 @main() {
-; CHECK: < bb43 bb59 bb3 bb31 bb41 > [ 77, bb43 ]
-; CHECK-NEXT: < bb43 bb49 bb59 bb3 bb31 bb41 > [ 77, bb43 ]
+; Do not jump-thread those paths where the determinator basic block does not
+; precede the basic block that defines the switch condition.
+;
+; Otherwise, it is possible that the state defined in the determinator block
+; defines the state for the next iteration of the loop, rather than for the
+; current one.
+define i32 @wrong_bb_order() {
+; CHECK-LABEL: DFA Jump threading: wrong_bb_order
+; CHECK-NOT: < bb43 bb59 bb3 bb31 bb41 > [ 77, bb43 ]
+; CHECK-NOT: < bb43 bb49 bb59 bb3 bb31 bb41 > [ 77, bb43 ]
 bb:
   %i = alloca [420 x i8], align 1
   %i2 = getelementptr inbounds [420 x i8], [420 x i8]* %i, i64 0, i64 390