1; RUN: opt -S %s -value-tracking-dom-conditions -licm -load-combine | FileCheck %s 2; In pr24866.ll, we saw a crash when accessing a nullptr returned when 3; asking for a dominator tree Node. This reproducer is really fragile, 4; but it's currently the best we have. 5 6%struct.c_derived_tbl.2.5.8.11.14.17.23.38.59.80.92.98.104.107.155.183 = type { [256 x i32], [256 x i8] } 7 8 9; Function Attrs: nounwind uwtable 10define void @encode_one_blockX2(%struct.c_derived_tbl.2.5.8.11.14.17.23.38.59.80.92.98.104.107.155.183* nocapture readonly %actbl) #0 { 11; CHECK-LABEL: @encode_one_blockX2 12entry: 13 br i1 false, label %L_KLOOP_01, label %L_KLOOP.preheader 14 15L_KLOOP_01: ; preds = %while.end, %entry 16 br label %L_KLOOP.preheader 17 18L_KLOOP_08: ; preds = %while.end 19 br label %L_KLOOP.preheader 20 21L_KLOOP.preheader: ; preds = %L_KLOOP_08, %L_KLOOP_01, %entry 22 %r.2.ph = phi i32 [ undef, %L_KLOOP_08 ], [ 0, %entry ], [ undef, %L_KLOOP_01 ] 23 br label %L_KLOOP 24 25L_KLOOP: ; preds = %while.end, %L_KLOOP.preheader 26 %r.2 = phi i32 [ 0, %while.end ], [ %r.2.ph, %L_KLOOP.preheader ] 27 br i1 true, label %while.body, label %while.end 28 29while.body: ; preds = %while.body, %L_KLOOP 30 br label %while.body 31 32while.end: ; preds = %L_KLOOP 33 %shl105 = shl i32 %r.2, 4 34 %add106 = add nsw i32 %shl105, undef 35 %idxprom107 = sext i32 %add106 to i64 36 %arrayidx108 = getelementptr inbounds %struct.c_derived_tbl.2.5.8.11.14.17.23.38.59.80.92.98.104.107.155.183, %struct.c_derived_tbl.2.5.8.11.14.17.23.38.59.80.92.98.104.107.155.183* %actbl, i64 0, i32 0, i64 %idxprom107 37 %0 = load i32, i32* %arrayidx108, align 4 38 %arrayidx110 = getelementptr inbounds %struct.c_derived_tbl.2.5.8.11.14.17.23.38.59.80.92.98.104.107.155.183, %struct.c_derived_tbl.2.5.8.11.14.17.23.38.59.80.92.98.104.107.155.183* %actbl, i64 0, i32 1, i64 %idxprom107 39 %1 = load i8, i8* %arrayidx110, align 1 40 indirectbr i8* undef, [label %L_KLOOP_DONE, label %L_KLOOP_01, label %L_KLOOP_08, label %L_KLOOP] 41 42L_KLOOP_DONE: ; preds = %while.end 43 ret void 44} 45