xref: /llvm-project/llvm/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll (revision 29441e4f5fa5f5c7709f7cf180815ba97f611297)
1; RUN: opt < %s -aa-pipeline=tbaa,basic-aa -passes=function-attrs -S | FileCheck %s
2
3; FunctionAttrs should make use of TBAA.
4
5; Add the readnone attribute, since the only access is a store which TBAA
6; says is to constant memory.
7;
8; It's unusual to see a store to constant memory, but it isn't necessarily
9; invalid, as it's possible that this only happens after optimization on a
10; code path which isn't ever executed.
11
12; CHECK: define void @test0_yes(ptr captures(none) %p) #0 {
13define void @test0_yes(ptr %p) nounwind {
14  store i32 0, ptr %p, !tbaa !1
15  ret void
16}
17
18; CHECK: define void @test0_no(ptr writeonly captures(none) initializes((0, 4)) %p) #1 {
19define void @test0_no(ptr %p) nounwind {
20  store i32 0, ptr %p, !tbaa !2
21  ret void
22}
23
24; Add the readnone attribute, since there's just a call to a function which
25; TBAA says only accesses constant memory.
26
27; CHECK: define void @test1_yes(ptr captures(none) %p) #2 {
28define void @test1_yes(ptr %p) nounwind {
29  call void @callee(ptr %p), !tbaa !1
30  ret void
31}
32
33; CHECK: define void @test1_no(ptr %p) #3 {
34define void @test1_no(ptr %p) nounwind {
35  call void @callee(ptr %p), !tbaa !2
36  ret void
37}
38
39; Add the readonly attribute, as above, but this time BasicAA will say
40; that the function accesses memory through its arguments, which TBAA
41; still says that the function doesn't write to memory.
42;
43; This is unusual, since the function is memcpy, but as above, this
44; isn't necessarily invalid.
45
46; CHECK: define void @test2_yes(ptr captures(none) %p, ptr captures(none) %q, i64 %n) #0 {
47define void @test2_yes(ptr %p, ptr %q, i64 %n) nounwind {
48  call void @llvm.memcpy.p0.p0.i64(ptr %p, ptr %q, i64 %n, i1 false), !tbaa !1
49  ret void
50}
51
52; CHECK: define void @test2_no(ptr writeonly captures(none) %p, ptr readonly captures(none) %q, i64 %n) #4 {
53define void @test2_no(ptr %p, ptr %q, i64 %n) nounwind {
54  call void @llvm.memcpy.p0.p0.i64(ptr %p, ptr %q, i64 %n, i1 false), !tbaa !2
55  ret void
56}
57
58; Similar to the others, va_arg only accesses memory through its operand.
59
60; CHECK: define i32 @test3_yes(ptr captures(none) %p) #0 {
61define i32 @test3_yes(ptr %p) nounwind {
62  %t = va_arg ptr %p, i32, !tbaa !1
63  ret i32 %t
64}
65
66; CHECK: define i32 @test3_no(ptr captures(none) %p) #4 {
67define i32 @test3_no(ptr %p) nounwind {
68  %t = va_arg ptr %p, i32, !tbaa !2
69  ret i32 %t
70}
71
72declare void @callee(ptr %p) nounwind
73declare void @llvm.memcpy.p0.p0.i64(ptr, ptr, i64, i1) nounwind
74
75; CHECK: attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(none) }
76; CHECK: attributes #1 = { mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: write) }
77; CHECK: attributes #2 = { nofree nosync nounwind memory(none) }
78; CHECK: attributes #3 = { nounwind }
79; CHECK: attributes #4 = { mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: readwrite) }
80; CHECK: attributes #5 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
81
82; Root note.
83!0 = !{ }
84
85; Invariant memory.
86!1 = !{!3, !3, i64 0, i1 1 }
87; Not invariant memory.
88!2 = !{!3, !3, i64 0, i1 0 }
89!3 = !{ !"foo", !0 }
90