33 lines
970 B
LLVM
33 lines
970 B
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; 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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; CHECK-NEXT: entry:
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; CHECK-NEXT: br label [[BACKEDGE:%.*]]
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; CHECK: backedge:
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; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE]] ]
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; CHECK-NEXT: [[IV_NEXT]] = add nsw i32 [[IV]], 1
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; CHECK-NEXT: [[CONT:%.*]] = icmp slt i32 [[IV_NEXT]], 400
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; CHECK-NEXT: br i1 [[CONT]], label [[BACKEDGE]], label [[EXIT:%.*]]
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; CHECK: exit:
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; CHECK-NEXT: ret i8 0
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;
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entry:
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br label %loop
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loop:
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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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