| ; 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 |
| } |
| |
