// Don't remove loops for which we can't solve the trip count.
// They could be infinite, in which case we'd be changing program behavior.
ScalarEvolution& SE = getAnalysis<ScalarEvolution>();
- const SCEV *S = SE.getBackedgeTakenCount(L);
+ const SCEV *S = SE.getMaxBackedgeTakenCount(L);
if (isa<SCEVCouldNotCompute>(S))
return Changed;
--- /dev/null
+; RUN: opt < %s -loop-deletion -S | FileCheck %s
+
+; ScalarEvolution can prove the loop iteration is finite, even though
+; it can't represent the exact trip count as an expression. That's
+; good enough to let the loop be deleted.
+
+; CHECK: entry:
+; CHECK-NEXT: br label %return
+
+; CHECK: return:
+; CHECK-NEXT: ret void
+
+define void @foo(i64 %n, i64 %m) nounwind {
+entry:
+ br label %bb
+
+bb:
+ %x.0 = phi i64 [ 0, %entry ], [ %t0, %bb ]
+ %t0 = add i64 %x.0, 1
+ %t1 = icmp slt i64 %x.0, %n
+ %t3 = icmp sgt i64 %x.0, %m
+ %t4 = and i1 %t1, %t3
+ br i1 %t4, label %bb, label %return
+
+return:
+ ret void
+}