xref: /llvm-project/llvm/test/CodeGen/BPF/preserve-static-offset/load-undo-chain.ll (revision 030b8cb1561db4161b108b59044717d89026cf70)
1; RUN: opt --bpf-check-and-opt-ir -mtriple=bpf-pc-linux -S -o - %s | FileCheck %s
2;
3; Check unroll of getelementptr.and.load when several field indexes
4; are specified in a chain.
5;
6; Source:
7;    #define __ctx __attribute__((preserve_static_offset))
8;
9;    struct bar {
10;      int aa;
11;      int bb;
12;    };
13;
14;    struct foo {
15;      int a;
16;      struct bar b;
17;    } __ctx;
18;
19;    extern void consume(int);
20;
21;    void buz(struct foo *p) {
22;      consume(p->b.bb);
23;    }
24;
25; Compilation flag:
26;   clang -cc1 -O2 -triple bpf -S -emit-llvm -disable-llvm-passes -o - \
27;       | opt -passes=sroa,bpf-preserve-static-offset -S -o -
28
29%struct.foo = type { i32, %struct.bar }
30%struct.bar = type { i32, i32 }
31
32; Function Attrs: nounwind
33define dso_local void @buz(ptr noundef %p) #0 {
34entry:
35  %bb1 = call i32 (ptr, i1, i8, i8, i8, i1, ...)
36    @llvm.bpf.getelementptr.and.load.i32
37      (ptr readonly elementtype(%struct.foo) %p,
38       i1 false, i8 0, i8 1, i8 2, i1 true, i32 immarg 0, i32 immarg 1, i32 immarg 1)
39    #4, !tbaa !2
40  call void @consume(i32 noundef %bb1)
41  ret void
42}
43
44; CHECK: define dso_local void @buz(ptr noundef %[[p:.*]])
45; CHECK:   %[[bb11:.*]] = getelementptr inbounds %struct.foo, ptr %[[p]], i32 0, i32 1, i32 1
46; CHECK:   %[[v2:.*]] = load i32, ptr %[[bb11]], align 4
47; CHECK:   call void @consume(i32 noundef %[[v2]])
48
49declare void @consume(i32 noundef) #1
50
51; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
52declare ptr @llvm.preserve.static.offset(ptr readnone) #2
53
54; Function Attrs: nocallback nofree nounwind willreturn
55declare i32 @llvm.bpf.getelementptr.and.load.i32(ptr nocapture, i1 immarg, i8 immarg, i8 immarg, i8 immarg, i1 immarg, ...) #3
56
57attributes #0 = { nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
58attributes #1 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
59attributes #2 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
60attributes #3 = { nocallback nofree nounwind willreturn }
61attributes #4 = { memory(argmem: read) }
62
63!llvm.module.flags = !{!0}
64!llvm.ident = !{!1}
65
66!0 = !{i32 1, !"wchar_size", i32 4}
67!1 = !{!"clang"}
68!2 = !{!3, !4, i64 8}
69!3 = !{!"foo", !4, i64 0, !7, i64 4}
70!4 = !{!"int", !5, i64 0}
71!5 = !{!"omnipotent char", !6, i64 0}
72!6 = !{!"Simple C/C++ TBAA"}
73!7 = !{!"bar", !4, i64 0, !4, i64 4}
74