|  | ; RUN: opt < %s -passes='function(loop-simplify),loop-extract<single>' -disable-output | 
|  |  | 
|  | define void @ab() { | 
|  | entry: | 
|  | br label %codeReplTail | 
|  |  | 
|  | then.1:         ; preds = %codeReplTail | 
|  | br label %loopentry.1 | 
|  |  | 
|  | loopentry.1:            ; preds = %no_exit.1, %then.1 | 
|  | br i1 false, label %no_exit.1, label %loopexit.0.loopexit1 | 
|  |  | 
|  | no_exit.1:              ; preds = %loopentry.1 | 
|  | br label %loopentry.1 | 
|  |  | 
|  | loopexit.0.loopexit:            ; preds = %codeReplTail | 
|  | ret void | 
|  |  | 
|  | loopexit.0.loopexit1:           ; preds = %loopentry.1 | 
|  | ret void | 
|  |  | 
|  | codeReplTail:           ; preds = %codeReplTail, %entry | 
|  | switch i16 0, label %codeReplTail [ | 
|  | i16 0, label %loopexit.0.loopexit | 
|  | i16 1, label %then.1 | 
|  | ] | 
|  | } | 
|  |  |