1; RUN: opt -S < %s -passes=loop-unroll -unroll-allow-partial=1 | FileCheck %s 2; 3; Bugpointed test that triggered UB while cleaning up dead 4; instructions after simplifying indvars 5 6; We just check that some unrolling happened here - the assert we've 7; added to ValueHandleBase::operator* would fire if the bug was still 8; present. 9; CHECK: atomicrmw volatile add ptr 10; CHECK: atomicrmw volatile add ptr 11; CHECK: atomicrmw volatile add ptr 12 13@global = external global i32, align 4 14 15define void @widget() { 16bb: 17 br label %bb1 18 19bb1: 20 br label %bb2 21 22bb2: 23 %tmp = phi i32 [ 0, %bb1 ], [ %tmp34, %bb33 ] 24 %tmp3 = phi i32 [ 0, %bb1 ], [ %tmp34, %bb33 ] 25 %tmp26 = and i32 %tmp, 1073741823 26 %tmp27 = getelementptr inbounds i32, ptr @global, i32 %tmp26 27 %tmp28 = atomicrmw volatile add ptr %tmp27, i32 1 monotonic 28 %tmp29 = icmp ugt i32 %tmp28, 23 29 %tmp30 = shl i32 %tmp, 6 30 %tmp31 = add i32 %tmp30, undef 31 %tmp32 = add i32 %tmp31, %tmp28 32 store i32 undef, ptr undef, align 4 33 br label %bb33 34 35bb33: 36 %tmp34 = add nuw nsw i32 %tmp3, 1 37 %tmp35 = icmp ult i32 %tmp3, 15 38 br i1 %tmp35, label %bb2, label %bb36 39 40bb36: 41 br label %bb1 42} 43