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