1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -S -jump-threading < %s | FileCheck %s
3
4define i8 @test(i32 %a, i32 %length) {
5; CHECK-LABEL: @test(
6; CHECK-NEXT:  entry:
7; CHECK-NEXT:    br label [[BACKEDGE:%.*]]
8; CHECK:       backedge:
9; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE]] ]
10; CHECK-NEXT:    [[IV_NEXT]] = add nsw i32 [[IV]], 1
11; CHECK-NEXT:    [[CONT:%.*]] = icmp slt i32 [[IV_NEXT]], 400
12; CHECK-NEXT:    br i1 [[CONT]], label [[BACKEDGE]], label [[EXIT:%.*]]
13; CHECK:       exit:
14; CHECK-NEXT:    ret i8 0
15;
16entry:
17  br label %loop
18
19loop:
20  %iv = phi i32 [0, %entry], [%iv.next, %backedge]
21  ;; We can use an inductive argument to prove %iv is always positive
22  %cnd = icmp sge i32 %iv, 0
23  br i1 %cnd, label %backedge, label %exit
24
25backedge:
26  %iv.next = add nsw i32 %iv, 1
27  %cont = icmp slt i32 %iv.next, 400
28  br i1 %cont, label %loop, label %exit
29exit:
30  ret i8 0
31}
32
33