| ; RUN: opt -S -jump-threading < %s | FileCheck %s | |
| define i8 @test(i32 %a, i32 %length) { | |
| ; CHECK-LABEL: @test | |
| entry: | |
| ; CHECK: br label %backedge | |
| br label %loop | |
| loop: | |
| ; CHECK-LABEL: backedge: | |
| ; CHECK: phi i32 | |
| ; CHECK: br i1 %cont, label %backedge, label %exit | |
| %iv = phi i32 [0, %entry], [%iv.next, %backedge] | |
| ;; We can use an inductive argument to prove %iv is always positive | |
| %cnd = icmp sge i32 %iv, 0 | |
| br i1 %cnd, label %backedge, label %exit | |
| backedge: | |
| %iv.next = add nsw i32 %iv, 1 | |
| %cont = icmp slt i32 %iv.next, 400 | |
| br i1 %cont, label %loop, label %exit | |
| exit: | |
| ret i8 0 | |
| } | |