Index: llvm/lib/Transforms/Scalar/LoopDeletion.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopDeletion.cpp
+++ llvm/lib/Transforms/Scalar/LoopDeletion.cpp
@@ -393,11 +393,16 @@
   if (!L->getLoopLatch())
     return LoopDeletionResult::Unmodified;
 
-  auto *BTC = SE.getBackedgeTakenCount(L);
-  if (!isa<SCEVCouldNotCompute>(BTC) && SE.isKnownNonZero(BTC))
-    return LoopDeletionResult::Unmodified;
-  if (!BTC->isZero() && !canProveExitOnFirstIteration(L, DT, LI))
-    return LoopDeletionResult::Unmodified;
+  auto *BTCMax = SE.getConstantMaxBackedgeTakenCount(L);
+  if (!BTCMax->isZero()) {
+    auto *BTC = SE.getBackedgeTakenCount(L);
+    if (!BTC->isZero()) {
+      if (!isa<SCEVCouldNotCompute>(BTC) && SE.isKnownNonZero(BTC))
+        return LoopDeletionResult::Unmodified;
+      if (!canProveExitOnFirstIteration(L, DT, LI))
+        return LoopDeletionResult::Unmodified;
+    }
+  }
 
   breakLoopBackedge(L, DT, SE, LI, MSSA);
   return LoopDeletionResult::Deleted;
Index: llvm/test/Transforms/LoopDeletion/switch.ll
===================================================================
--- llvm/test/Transforms/LoopDeletion/switch.ll
+++ llvm/test/Transforms/LoopDeletion/switch.ll
@@ -41,3 +41,38 @@
 unreachable:
   unreachable
 }
+
+define void @func_2() {
+; CHECK-LABEL: @func_2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LBL_2368:%.*]]
+; CHECK:       lbl_2368:
+; CHECK-NEXT:    br i1 false, label [[CLEANUP967:%.*]], label [[UNREACHABLE:%.*]]
+; CHECK:       cleanup967:
+; CHECK-NEXT:    switch i32 undef, label [[CLEANUP1169:%.*]] [
+; CHECK-NEXT:    i32 20, label [[CLEANUP967_LBL_2368_CRIT_EDGE:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       cleanup967.lbl_2368_crit_edge:
+; CHECK-NEXT:    unreachable
+; CHECK:       cleanup1169:
+; CHECK-NEXT:    ret void
+; CHECK:       unreachable:
+; CHECK-NEXT:    unreachable
+;
+entry:
+  br label %lbl_2368
+
+lbl_2368:
+  br i1 false, label %cleanup967, label %unreachable
+
+cleanup967:
+  switch i32 undef, label %cleanup1169 [
+  i32 20, label %lbl_2368
+  ]
+
+cleanup1169:
+  ret void
+
+unreachable:
+  unreachable
+}
Index: llvm/test/Transforms/LoopDeletion/zero-btc.ll
===================================================================
--- llvm/test/Transforms/LoopDeletion/zero-btc.ll
+++ llvm/test/Transforms/LoopDeletion/zero-btc.ll
@@ -239,6 +239,42 @@
   ret void
 }
 
+declare i1 @unknown()
+
+; We can't compute an exit count for the latch, but we know the upper
+; bound on the trip count is zero anyways.
+define void @test_dead_latch1() {
+; CHECK-LABEL: @test_dead_latch1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    store i32 0, i32* @G, align 4
+; CHECK-NEXT:    br i1 false, label [[LATCH:%.*]], label [[EXIT1:%.*]]
+; CHECK:       latch:
+; CHECK-NEXT:    [[LATCHCOND:%.*]] = call i1 @unknown()
+; CHECK-NEXT:    br label [[EXIT2:%.*]]
+; CHECK:       exit1:
+; CHECK-NEXT:    ret void
+; CHECK:       exit2:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  store i32 0, i32* @G
+  br i1 false, label %latch, label %exit1
+latch:
+  %latchcond = call i1 @unknown()
+  br i1 %latchcond, label %loop, label %exit2
+
+exit1:
+  ret void
+exit2:
+  ret void
+}
+
+
 define void @test_live_inner() {
 ; CHECK-LABEL: @test_live_inner(
 ; CHECK-NEXT:  entry: