|  | ; Test that the backend does not mess up the I/R in case of a use of an undef | 
|  | ; register. This typically happens while expanding a pseudo or otherwise | 
|  | ; replacing an instruction for another. | 
|  | ; | 
|  | ; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z13 -verify-machineinstrs | FileCheck %s | 
|  |  | 
|  | ; LLCRMux | 
|  | define void @f1(i8*) { | 
|  | ; CHECK-LABEL: f1: | 
|  | ; CHECK-NOT: *** Bad machine code: Using an undefined physical register *** | 
|  | BB: | 
|  | %L5 = load i8, i8* %0 | 
|  | %B9 = lshr i8 %L5, -1 | 
|  | br label %CF | 
|  |  | 
|  | CF:                                               ; preds = %CF, %BB | 
|  | %Cmp25 = icmp ne i8 27, %B9 | 
|  | br i1 %Cmp25, label %CF, label %CF34 | 
|  |  | 
|  | CF34:                                             ; preds = %CF | 
|  | ret void | 
|  | } |