SimplifyCFG: don't remove unreachable default switch destinations

[oota-llvm.git] / test / Transforms / SimplifyCFG / switch-range-to-icmp.ll

diff --git a/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll b/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll
index 8bf2b04520b93e6911255eee95a172a3b6cfba51..a109b317c7320a1fade6030a86e575ff0253f15a 100644 (file)
--- a/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll
+++ b/test/Transforms/SimplifyCFG/switch-range-to-icmp.ll
@@ -48,3 +48,30 @@ b:
   %1 = call i32 @f(i32 1)
   ret i32 %1
 }
+
+
+define i32 @unreachable2(i32 %x) {
+; CHECK-LABEL: @unreachable2
+; CHECK: x.off = add i32 %x, -5
+; CHECK: %switch = icmp ult i32 %x.off, 3
+; CHECK: br i1 %switch, label %a, label %b
+
+entry:
+  ; Note: folding the most popular case destination into the default
+  ; would prevent switch-to-icmp here.
+  switch i32 %x, label %unreachable [
+    i32 5, label %a
+    i32 6, label %a
+    i32 7, label %a
+    i32 10, label %b
+    i32 20, label %b
+  ]
+unreachable:
+  unreachable
+a:
+  %0 = call i32 @f(i32 0)
+  ret i32 %0
+b:
+  %1 = call i32 @f(i32 1)
+  ret i32 %1
+}