1; RUN: opt < %s -analyze -enable-new-pm=0 -scalar-evolution | FileCheck %s 2; RUN: opt < %s -disable-output "-passes=print<scalar-evolution>" 2>&1 | FileCheck %s 3 4target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" 5target triple = "x86_64-unknown-linux-gnu" 6 7; Previously in this case the max backedge count would be computed as 1/0, which 8; is correct but undesirable. It would also not fold as a constant, tripping 9; asserts in SCEV. 10 11define void @pluto(i32 %arg) { 12; CHECK-LABEL: Classifying expressions for: @pluto 13; CHECK: Loop %bb2: max backedge-taken count is 2 14bb: 15 %tmp = ashr i32 %arg, 31 16 %tmp1 = add nsw i32 %tmp, 2 17 br label %bb2 18 19bb2: ; preds = %bb2, %bb 20 %tmp3 = phi i32 [ 0, %bb ], [ %tmp4, %bb2 ] 21 %tmp4 = add nuw nsw i32 %tmp1, %tmp3 22 %tmp5 = icmp ult i32 %tmp4, 2 23 br i1 %tmp5, label %bb2, label %bb6 24 25bb6: ; preds = %bb2 26 ret void 27} 28