xref: /llvm-project/llvm/test/Transforms/RewriteStatepointsForGC/drop-invalid-metadata.ll (revision 20fa198687800fafc4f9fd53683cefc150d79a13)
1; RUN: opt -S -passes=rewrite-statepoints-for-gc < %s | FileCheck %s
2
3; This test checks that metadata that's invalid after RS4GC is dropped.
4; We can miscompile if optimizations scheduled after RS4GC uses the
5; metadata that's infact invalid.
6
7declare void @bar()
8
9declare void @baz(i32)
10; Confirm that loadedval instruction does not contain invariant.load metadata.
11; but contains the range metadata.
12; Since loadedval is not marked invariant, it will prevent incorrectly sinking
13; %loadedval in LICM and avoid creation of an unrelocated use of %baseaddr.
14define void @test_invariant_load(i1 %c) gc "statepoint-example" {
15; CHECK-LABEL: @test_invariant_load
16; CHECK: %loadedval = load i32, ptr addrspace(1) %baseaddr, align 8, !range !0
17bb:
18  br label %outerloopHdr
19
20outerloopHdr:                                              ; preds = %bb6, %bb
21  %baseaddr = phi ptr addrspace(1) [ undef, %bb ], [ %tmp4, %bb6 ]
22; LICM may sink this load to exit block after RS4GC because it's tagged invariant.
23  %loadedval = load i32, ptr addrspace(1) %baseaddr, align 8, !range !0, !invariant.load !1
24  br label %innerloopHdr
25
26innerloopHdr:                                              ; preds = %innerlooplatch, %outerloopHdr
27  %tmp4 = phi ptr addrspace(1) [ %baseaddr, %outerloopHdr ], [ %gep, %innerlooplatch ]
28  br label %innermostloophdr
29
30innermostloophdr:                                              ; preds = %bb6, %innerloopHdr
31  br i1 %c, label %exitblock, label %bb6
32
33bb6:                                              ; preds = %innermostloophdr
34  switch i32 undef, label %innermostloophdr [
35    i32 0, label %outerloopHdr
36    i32 1, label %innerlooplatch
37  ]
38
39innerlooplatch:                                              ; preds = %bb6
40  call void @bar()
41  %gep = getelementptr inbounds i32, ptr addrspace(1) %tmp4, i64 8
42  br label %innerloopHdr
43
44exitblock:                                             ; preds = %innermostloophdr
45  %tmp13 = add i32 42, %loadedval
46  call void @baz(i32 %tmp13)
47  unreachable
48}
49
50; drop the noalias metadata.
51define void @test_noalias(i32 %x, ptr addrspace(1) %p, ptr addrspace(1) %q) gc "statepoint-example" {
52; CHECK-LABEL: test_noalias
53; CHECK: %y = load i32, ptr addrspace(1) %q, align 16
54; CHECK: gc.statepoint
55; CHECK: %p.relocated
56; CHECK-NEXT: store i32 %x, ptr addrspace(1) %p.relocated, align 16
57entry:
58  %y = load i32, ptr addrspace(1) %q, align 16, !noalias !5
59  call void @baz(i32 %x)
60  store i32 %x, ptr addrspace(1) %p, align 16, !noalias !5
61  ret void
62}
63
64; drop the dereferenceable metadata
65define void @test_dereferenceable(ptr addrspace(1) %p, i32 %x, ptr addrspace(1) %q) gc "statepoint-example" {
66; CHECK-LABEL: test_dereferenceable
67; CHECK: %v1 = load ptr addrspace(1), ptr addrspace(1) %p
68; CHECK-NEXT: %v2 = load i32, ptr addrspace(1) %v1
69; CHECK: gc.statepoint
70  %v1 = load ptr addrspace(1), ptr addrspace(1) %p, !dereferenceable !6
71  %v2 = load i32, ptr addrspace(1) %v1
72  call void @baz(i32 %x)
73  store i32 %v2, ptr addrspace(1) %q, align 16
74  ret void
75}
76
77; invariant.start allows us to sink the load past the baz statepoint call into taken block, which is
78; incorrect. remove the invariant.start and RAUW undef.
79define void @test_inv_start(i1 %cond, ptr addrspace(1) %p, i32 %x, ptr addrspace(1) %q) gc "statepoint-example" {
80; CHECK-LABEL: test_inv_start
81; CHECK-NOT: invariant.start
82; CHECK: gc.statepoint
83  %v1 = load ptr addrspace(1), ptr addrspace(1) %p
84  %invst = call ptr @llvm.invariant.start.p1(i64 1, ptr addrspace(1) %v1)
85  %v2 = load i32, ptr addrspace(1) %v1
86  call void @baz(i32 %x)
87  br i1 %cond, label %taken, label %untaken
88
89taken:
90  store i32 %v2, ptr addrspace(1) %q, align 16
91  call void @llvm.invariant.end.p1(ptr %invst, i64 4, ptr addrspace(1) %v1)
92  ret void
93
94; CHECK-LABEL: untaken:
95; CHECK: gc.statepoint
96untaken:
97  %foo = call i32 @escaping.invariant.start(ptr %invst)
98  call void @dummy(i32 %foo)
99  ret void
100}
101
102; invariant.start is removed and the uses are undef'ed.
103define void @test_inv_start2(i1 %cond, ptr addrspace(1) %p, i32 %x, ptr addrspace(1) %q) gc "statepoint-example" {
104; CHECK-LABEL: test_inv_start2
105; CHECK-NOT: invariant.start
106; CHECK: gc.statepoint
107  %v1 = load ptr addrspace(1), ptr addrspace(1) %p
108  %invst = call ptr @llvm.invariant.start.p1(i64 1, ptr addrspace(1) %v1)
109  %v2 = load i32, ptr addrspace(1) %v1
110  call void @baz(i32 %x)
111  br i1 %cond, label %taken, label %untaken
112
113taken:
114  store i32 %v2, ptr addrspace(1) %q, align 16
115  call void @llvm.invariant.end.p1(ptr %invst, i64 4, ptr addrspace(1) %v1)
116  ret void
117
118untaken:
119  ret void
120}
121declare ptr @llvm.invariant.start.p1(i64, ptr addrspace(1)  nocapture) nounwind readonly
122declare void @llvm.invariant.end.p1(ptr, i64, ptr addrspace(1) nocapture) nounwind
123declare i32 @escaping.invariant.start(ptr) nounwind
124declare void @dummy(i32)
125declare token @llvm.experimental.gc.statepoint.p0(i64, i32, ptr, i32, i32, ...)
126
127; Function Attrs: nounwind readonly
128declare ptr addrspace(1) @llvm.experimental.gc.relocate.p1(token, i32, i32) #0
129
130
131attributes #0 = { nounwind readonly }
132
133!0 = !{i32 0, i32 2147483647}
134!1 = !{}
135!2 = !{i32 10, i32 1}
136!3 = !{!3}
137!4 = !{!4, !3}
138!5 = !{!4}
139!6 = !{i64 8}
140