1 ; RUN: opt < %s -analyze -scalar-evolution \ 2 ; RUN: | grep {Loop %bb: Unpredictable backedge-taken count\\.} 3 4 ; ScalarEvolution can't compute a trip count because it doesn't know if 5 ; dividing by the stride will have a remainder. This could theoretically 6 ; be teaching it how to use a more elaborate trip count computation. 7 8 define i32 @f(i32 %x) nounwind readnone { 9 entry: 10 %0 = icmp ugt i32 %x, 4 ; <i1> [#uses=1] 11 br i1 %0, label %bb.nph, label %bb2 12 13 bb.nph: ; preds = %entry 14 br label %bb 15 16 bb: ; preds = %bb.nph, %bb1 17 %indvar = phi i32 [ 0, %bb.nph ], [ %indvar.next, %bb1 ] ; <i32> [#uses=2] 18 %tmp = mul i32 %indvar, -3 ; <i32> [#uses=1] 19 %x_addr.04 = add i32 %tmp, %x ; <i32> [#uses=1] 20 %1 = add i32 %x_addr.04, -3 ; <i32> [#uses=2] 21 br label %bb1 22 23 bb1: ; preds = %bb 24 %2 = icmp ugt i32 %1, 4 ; <i1> [#uses=1] 25 %indvar.next = add i32 %indvar, 1 ; <i32> [#uses=1] 26 br i1 %2, label %bb, label %bb1.bb2_crit_edge 27 28 bb1.bb2_crit_edge: ; preds = %bb1 29 %.lcssa = phi i32 [ %1, %bb1 ] ; <i32> [#uses=1] 30 br label %bb2 31 32 bb2: ; preds = %bb1.bb2_crit_edge, %entry 33 %x_addr.0.lcssa = phi i32 [ %.lcssa, %bb1.bb2_crit_edge ], [ %x, %entry ] ; <i32> [#uses=1] 34 ret i32 %x_addr.0.lcssa 35 } 36
