1; Test that the backend does not mess up the I/R in case of a use of an undef 2; register. This typically happens while expanding a pseudo or otherwise 3; replacing an instruction for another. 4; 5; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z13 -verify-machineinstrs | FileCheck %s 6 7; LLCRMux 8define void @f1(i8*) { 9; CHECK-LABEL: f1: 10; CHECK-NOT: *** Bad machine code: Using an undefined physical register *** 11BB: 12 %L5 = load i8, i8* %0 13 %B9 = lshr i8 %L5, -1 14 br label %CF 15 16CF: ; preds = %CF, %BB 17 %Cmp25 = icmp ne i8 27, %B9 18 br i1 %Cmp25, label %CF, label %CF34 19 20CF34: ; preds = %CF 21 ret void 22} 23