1 files changed, 10 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index c63618d9dd12..09461e65e2dc 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -7885,6 +7885,13 @@ static bool passingValueIsAlwaysUndefined(Value *V, Instruction *I, bool PtrValu
       case Instruction::Call:
       case Instruction::CallBr:
       case Instruction::Invoke:
+      case Instruction::UDiv:
+      case Instruction::URem:
+        // Note: signed div/rem of INT_MIN / -1 is also immediate UB, not
+        // implemented to avoid code complexity as it is unclear how useful such
+        // logic is.
+      case Instruction::SDiv:
+      case Instruction::SRem:
         return true;
       }
     });
@@ -7986,6 +7993,9 @@ static bool passingValueIsAlwaysUndefined(Value *V, Instruction *I, bool PtrValu
           }
       }
     }
+    // Div/Rem by zero is immediate UB
+    if (match(Use, m_BinOp(m_Value(), m_Specific(I))) && Use->isIntDivRem())
+      return true;
   }
   return false;
 }