1; RUN: opt -indvars < %s 2; PR9424: Attempt to use a SCEVCouldNotCompute object! 3; The inner loop computes the Step and Start of the outer loop. 4; Call that Vexit. The outer End value is max(2,Vexit), because 5; the condition "icmp %4 < 2" does not guard the outer loop. 6; SCEV knows that Vexit has range [2,4], so End == Vexit == Start. 7; Now we have ExactBECount == 0. However, MinStart == 2 and MaxEnd == 4. 8; Since the stride is variable and may wrap, we cannot compute 9; MaxBECount. SCEV should override MaxBECount with ExactBECount. 10 11define void @bar() nounwind { 12entry: 13 %. = select i1 undef, i32 2, i32 1 14 br label %"5.preheader" 15 16"4": ; preds = %"5.preheader", %"4" 17 %0 = phi i32 [ 0, %"5.preheader" ], [ %1, %"4" ] 18 %1 = add nsw i32 %0, 1 19 %2 = icmp sgt i32 %., %1 20 br i1 %2, label %"4", label %"9" 21 22"9": ; preds = %"4" 23 %3 = add i32 %6, 1 24 %4 = add i32 %3, %1 25 %5 = icmp slt i32 %4, 2 26 br i1 %5, label %"5.preheader", label %return 27 28"5.preheader": ; preds = %"9", %entry 29 %6 = phi i32 [ 0, %entry ], [ %4, %"9" ] 30 br label %"4" 31 32return: ; preds = %"9" 33 ret void 34} 35