Index: llvm/lib/Analysis/ScalarEvolution.cpp
===================================================================
--- llvm/lib/Analysis/ScalarEvolution.cpp
+++ llvm/lib/Analysis/ScalarEvolution.cpp
@@ -11947,6 +11947,10 @@
   } else {
     MaxBECount = computeMaxBECountForLT(
         Start, Stride, RHS, getTypeSizeInBits(LHS->getType()), IsSigned);
+    // If we prove the max count is zero, so is the symbolic bound.  This can
+    // happen due to differences in how we reason about bounds impied by UB.
+    if (MaxBECount->isZero())
+      BECount = MaxBECount;
   }
 
   if (isa<SCEVCouldNotCompute>(MaxBECount) &&
Index: llvm/test/Analysis/ScalarEvolution/max-trip-count.ll
===================================================================
--- llvm/test/Analysis/ScalarEvolution/max-trip-count.ll
+++ llvm/test/Analysis/ScalarEvolution/max-trip-count.ll
@@ -458,7 +458,7 @@
 
 define void @max_overflow(i8 %n) mustprogress {
 ; CHECK-LABEL: Determining loop execution counts for: @max_overflow
-; CHECK: Loop %loop: backedge-taken count is (-126 + (126 smax %n))<nsw>
+; CHECK: Loop %loop: backedge-taken count is 0
 ; CHECK: Loop %loop: max backedge-taken count is 0
 entry:
   br label %loop