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; 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
}
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