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1; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
2
3target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
4target triple = "x86_64-unknown-linux-gnu"
5
6; Previously in this case the max backedge count would be computed as 1/0, which
7; is correct but undesirable.  It would also not fold as a constant, tripping
8; asserts in SCEV.
9
10define void @pluto(i32 %arg) {
11; CHECK-LABEL: Classifying expressions for: @pluto
12; CHECK: Loop %bb2: max backedge-taken count is 2
13bb:
14  %tmp = ashr i32 %arg, 31
15  %tmp1 = add nsw i32 %tmp, 2
16  br label %bb2
17
18bb2:                                              ; preds = %bb2, %bb
19  %tmp3 = phi i32 [ 0, %bb ], [ %tmp4, %bb2 ]
20  %tmp4 = add nuw nsw i32 %tmp1, %tmp3
21  %tmp5 = icmp ult i32 %tmp4, 2
22  br i1 %tmp5, label %bb2, label %bb6
23
24bb6:                                              ; preds = %bb2
25  ret void
26}
27