62 lines
1.9 KiB
LLVM
62 lines
1.9 KiB
LLVM
; RUN: opt -tbaa -gvn -S < %s | FileCheck %s
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%struct.t = type { i32* }
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; The loaded address and the location of the address itself are not aliased,
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; so the second reload is not necessary. Check that it can be eliminated.
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; CHECK-LABEL: test1
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; CHECK: load
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; CHECK-NOT: load
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define void @test1(%struct.t* nocapture readonly %p, i32 %v) #0 {
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entry:
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%m = getelementptr inbounds %struct.t, %struct.t* %p, i32 0, i32 0
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%0 = load i32*, i32** %m, align 4, !tbaa !1
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store volatile i32 %v, i32* %0, align 4, !tbaa !6
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%1 = load i32*, i32** %m, align 4, !tbaa !1
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store volatile i32 %v, i32* %1, align 4, !tbaa !6
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ret void
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}
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; The store via the loaded address may overwrite the address itself.
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; Make sure that both loads remain.
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; CHECK-LABEL: test2
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; CHECK: load
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; CHECK: store
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; CHECK: load
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define void @test2(%struct.t* nocapture readonly %p, i32 %v) #0 {
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entry:
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%m = getelementptr inbounds %struct.t, %struct.t* %p, i32 0, i32 0
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%0 = load i32*, i32** %m, align 4, !tbaa !1
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store volatile i32 %v, i32* %0, align 4, !tbaa !1
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%1 = load i32*, i32** %m, align 4, !tbaa !1
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store volatile i32 %v, i32* %1, align 4, !tbaa !1
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ret void
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}
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; The loads are ordered and non-monotonic. Although they are not aliased to
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; the stores, make sure both are preserved.
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; CHECK-LABEL: test3
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; CHECK: load
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; CHECK: store
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; CHECK: load
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define void @test3(%struct.t* nocapture readonly %p, i32 %v) #0 {
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entry:
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%m = getelementptr inbounds %struct.t, %struct.t* %p, i32 0, i32 0
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%0 = load atomic i32*, i32** %m acquire, align 4, !tbaa !1
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store volatile i32 %v, i32* %0, align 4, !tbaa !6
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%1 = load atomic i32*, i32** %m acquire, align 4, !tbaa !1
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store volatile i32 %v, i32* %1, align 4, !tbaa !6
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ret void
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}
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attributes #0 = { norecurse nounwind }
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!1 = !{!2, !3, i64 0}
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!2 = !{!"", !3, i64 0}
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!3 = !{!"any pointer", !4, i64 0}
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!4 = !{!"omnipotent char", !5, i64 0}
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!5 = !{!"Simple C/C++ TBAA"}
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!6 = !{!7, !7, i64 0}
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!7 = !{!"int", !4, i64 0}
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