+; PR16130: clang produces incorrect code with loop/expression at -O2
+; rdar:14036816 loop-unroll makes assumptions about undefined behavior
+;
+; The loop latch is assumed to exit after the first iteration because
+; of the induction variable's NSW flag. However, the loop latch's
+; equality test is skipped and the loop exits after the second
+; iteration via the early exit. So loop unrolling cannot assume that
+; the loop latch's exit count of zero is an upper bound on the number
+; of iterations.
+;
+; CHECK-LABEL: @nsw_latch(
+; CHECK: for.body:
+; CHECK: %b.03 = phi i32 [ 0, %entry ], [ %add, %for.cond ]
+; CHECK: return:
+; CHECK: %b.03.lcssa = phi i32 [ %b.03, %for.body ], [ %b.03, %for.cond ]
+define void @nsw_latch(i32* %a) nounwind {
+entry:
+ br label %for.body
+
+for.body: ; preds = %for.cond, %entry
+ %b.03 = phi i32 [ 0, %entry ], [ %add, %for.cond ]
+ %tobool = icmp eq i32 %b.03, 0
+ %add = add nsw i32 %b.03, 8
+ br i1 %tobool, label %for.cond, label %return
+
+for.cond: ; preds = %for.body
+ %cmp = icmp eq i32 %add, 13
+ br i1 %cmp, label %return, label %for.body
+
+return: ; preds = %for.body, %for.cond
+ %b.03.lcssa = phi i32 [ %b.03, %for.body ], [ %b.03, %for.cond ]
+ %retval.0 = phi i32 [ 1, %for.body ], [ 0, %for.cond ]
+ store i32 %b.03.lcssa, i32* %a, align 4
+ ret void
+}