1 ; RUN: opt -tbaa -gvn -S < %s | FileCheck %s 2 3 %struct.t = type { i32* } 4 5 ; The loaded address and the location of the address itself are not aliased, 6 ; so the second reload is not necessary. Check that it can be eliminated. 7 ; CHECK-LABEL: test1 8 ; CHECK: load 9 ; CHECK-NOT: load 10 define void @test1(%struct.t* nocapture readonly %p, i32 %v) #0 { 11 entry: 12 %m = getelementptr inbounds %struct.t, %struct.t* %p, i32 0, i32 0 13 %0 = load i32*, i32** %m, align 4, !tbaa !1 14 store volatile i32 %v, i32* %0, align 4, !tbaa !6 15 %1 = load i32*, i32** %m, align 4, !tbaa !1 16 store volatile i32 %v, i32* %1, align 4, !tbaa !6 17 ret void 18 } 19 20 ; The store via the loaded address may overwrite the address itself. 21 ; Make sure that both loads remain. 22 ; CHECK-LABEL: test2 23 ; CHECK: load 24 ; CHECK: store 25 ; CHECK: load 26 define void @test2(%struct.t* nocapture readonly %p, i32 %v) #0 { 27 entry: 28 %m = getelementptr inbounds %struct.t, %struct.t* %p, i32 0, i32 0 29 %0 = load i32*, i32** %m, align 4, !tbaa !1 30 store volatile i32 %v, i32* %0, align 4, !tbaa !1 31 %1 = load i32*, i32** %m, align 4, !tbaa !1 32 store volatile i32 %v, i32* %1, align 4, !tbaa !1 33 ret void 34 } 35 36 ; The loads are ordered and non-monotonic. Although they are not aliased to 37 ; the stores, make sure both are preserved. 38 ; CHECK-LABEL: test3 39 ; CHECK: load 40 ; CHECK: store 41 ; CHECK: load 42 define void @test3(%struct.t* nocapture readonly %p, i32 %v) #0 { 43 entry: 44 %m = getelementptr inbounds %struct.t, %struct.t* %p, i32 0, i32 0 45 %0 = load atomic i32*, i32** %m acquire, align 4, !tbaa !1 46 store volatile i32 %v, i32* %0, align 4, !tbaa !6 47 %1 = load atomic i32*, i32** %m acquire, align 4, !tbaa !1 48 store volatile i32 %v, i32* %1, align 4, !tbaa !6 49 ret void 50 } 51 52 attributes #0 = { norecurse nounwind } 53 54 !1 = !{!2, !3, i64 0} 55 !2 = !{!"", !3, i64 0} 56 !3 = !{!"any pointer", !4, i64 0} 57 !4 = !{!"omnipotent char", !5, i64 0} 58 !5 = !{!"Simple C/C++ TBAA"} 59 !6 = !{!7, !7, i64 0} 60 !7 = !{!"int", !4, i64 0} 61 62
