diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -2567,22 +2567,6 @@
   Value *FalseVal = SI.getFalseValue();
   Type *SelType = SI.getType();
 
-  // FIXME: Remove this workaround when freeze related patches are done.
-  // For select with undef operand which feeds into an equality comparison,
-  // don't simplify it so loop unswitch can know the equality comparison
-  // may have an undef operand. This is a workaround for PR31652 caused by
-  // descrepancy about branch on undef between LoopUnswitch and GVN.
-  if (match(TrueVal, m_Undef()) || match(FalseVal, m_Undef())) {
-    if (llvm::any_of(SI.users(), [&](User *U) {
-          ICmpInst *CI = dyn_cast<ICmpInst>(U);
-          if (CI && CI->isEquality())
-            return true;
-          return false;
-        })) {
-      return nullptr;
-    }
-  }
-
   if (Value *V = SimplifySelectInst(CondVal, TrueVal, FalseVal,
                                     SQ.getWithInstruction(&SI)))
     return replaceInstUsesWith(SI, V);