diff --git a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
--- a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
@@ -361,9 +361,17 @@
 
   Value *Op0;
   bool IsKnownNonNegative = false;
+  int64_t UpperBoundVal = MaxConstraintValue;
   if (match(V, m_ZExt(m_Value(Op0)))) {
     IsKnownNonNegative = true;
     V = Op0;
+    if (!llvm::any_of(V->users(),
+                      [&](User *User) { return isa<SExtInst>(User); })) {
+      TypeSize PreZextWidth =
+          DL.getTypeSizeInBits(V->getType()->getScalarType());
+      if (PreZextWidth <= 64)
+        UpperBoundVal = APInt::getMaxValue(PreZextWidth).getZExtValue();
+    }
   }
 
   Value *Op1;
@@ -416,7 +424,7 @@
   if (match(V, m_NUWSub(m_Value(Op0), m_Value(Op1))))
     return {0, {{1, Op0}, {-1, Op1}}};
 
-  return {V, IsKnownNonNegative};
+  return {V, IsKnownNonNegative, UpperBoundVal};
 }
 
 ConstraintTy
diff --git a/llvm/test/Transforms/ConstraintElimination/type-bounds.ll b/llvm/test/Transforms/ConstraintElimination/type-bounds.ll
--- a/llvm/test/Transforms/ConstraintElimination/type-bounds.ll
+++ b/llvm/test/Transforms/ConstraintElimination/type-bounds.ll
@@ -14,7 +14,7 @@
 ; CHECK-NEXT:    br i1 [[CMP_1]], label [[COND:%.*]], label [[EXIT]]
 ; CHECK:       cond:
 ; CHECK-NEXT:    [[CMP_2:%.*]] = icmp ult i32 [[A_EXT]], [[B]]
-; CHECK-NEXT:    call void @use(i1 [[CMP_2]])
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret void
@@ -242,7 +242,7 @@
 ; CHECK-NEXT:    br i1 [[CMP_1]], label [[COND:%.*]], label [[EXIT]]
 ; CHECK:       cond:
 ; CHECK-NEXT:    [[CMP_2:%.*]] = icmp ult i32 [[A_EXT]], [[B]]
-; CHECK-NEXT:    call void @use(i1 [[CMP_2]])
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret void
@@ -349,8 +349,8 @@
 ; CHECK:       cond:
 ; CHECK-NEXT:    [[CMP_3:%.*]] = icmp ult i32 [[A_EXT]], [[B]]
 ; CHECK-NEXT:    [[CMP_4:%.*]] = icmp ult i32 [[A2_EXT]], [[B2]]
-; CHECK-NEXT:    call void @use(i1 [[CMP_3]])
-; CHECK-NEXT:    call void @use(i1 [[CMP_4]])
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret void