1; RUN: opt -O2 %s | llvm-dis > %t1 2; RUN: llc -filetype=asm -o - %t1 | FileCheck %s 3; RUN: llc -mattr=+alu32 -filetype=asm -o - %t1 | FileCheck %s 4; 5; Source code: 6; union u { int a; int b; }; 7; #define _(x) (__builtin_preserve_access_index(x)) 8; int get_value(const ptr addr); 9; int test(union u *arg) { return get_value(_(&arg->b)); } 10; Compiler flag to generate IR: 11; clang -target bpf -S -O2 -g -emit-llvm -Xclang -disable-llvm-passes test.c 12 13target triple = "bpf" 14 15%union.u = type { i32 } 16 17; Function Attrs: nounwind 18define dso_local i32 @test(ptr %arg) local_unnamed_addr #0 !dbg !7 { 19entry: 20 call void @llvm.dbg.value(metadata ptr %arg, metadata !17, metadata !DIExpression()), !dbg !18 21 %0 = tail call ptr @llvm.preserve.union.access.index.p0.us.p0.us(ptr %arg, i32 1), !dbg !19, !llvm.preserve.access.index !12 22 %call = tail call i32 @get_value(ptr %0) #4, !dbg !20 23 ret i32 %call, !dbg !21 24} 25; CHECK-LABEL: test 26; CHECK: [[RELOC:.Ltmp[0-9]+]] 27; CHECK: r2 = 0 28; CHECK: r1 += r2 29; CHECK: call get_value 30; CHECK: exit 31 32; CHECK: .section .BTF.ext,"",@progbits 33; CHECK: .long 16 # FieldReloc 34; CHECK-NEXT: .long 20 # Field reloc section string offset=20 35; CHECK-NEXT: .long 1 36; CHECK-NEXT: .long [[RELOC]] 37; CHECK-NEXT: .long 2 38; CHECK-NEXT: .long 26 39; CHECK-NEXT: .long 0 40 41declare dso_local i32 @get_value(ptr) local_unnamed_addr #1 42 43; Function Attrs: nounwind readnone 44declare ptr @llvm.preserve.union.access.index.p0.us.p0.us(ptr, i32 immarg) #2 45 46; Function Attrs: nounwind readnone speculatable 47declare void @llvm.dbg.value(metadata, metadata, metadata) #3 48 49attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "frame-pointer"="all" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" } 50attributes #1 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "frame-pointer"="all" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" } 51attributes #2 = { nounwind readnone } 52attributes #3 = { nounwind readnone speculatable } 53attributes #4 = { nounwind } 54 55!llvm.dbg.cu = !{!0} 56!llvm.module.flags = !{!3, !4, !5} 57!llvm.ident = !{!6} 58 59!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0 (trunk 365789)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None) 60!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core") 61!2 = !{} 62!3 = !{i32 2, !"Dwarf Version", i32 4} 63!4 = !{i32 2, !"Debug Info Version", i32 3} 64!5 = !{i32 1, !"wchar_size", i32 4} 65!6 = !{!"clang version 9.0.0 (trunk 365789)"} 66!7 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !8, scopeLine: 4, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !16) 67!8 = !DISubroutineType(types: !9) 68!9 = !{!10, !11} 69!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) 70!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64) 71!12 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u", file: !1, line: 1, size: 32, elements: !13) 72!13 = !{!14, !15} 73!14 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !12, file: !1, line: 1, baseType: !10, size: 32) 74!15 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !12, file: !1, line: 1, baseType: !10, size: 32) 75!16 = !{!17} 76!17 = !DILocalVariable(name: "arg", arg: 1, scope: !7, file: !1, line: 4, type: !11) 77!18 = !DILocation(line: 0, scope: !7) 78!19 = !DILocation(line: 4, column: 43, scope: !7) 79!20 = !DILocation(line: 4, column: 33, scope: !7) 80!21 = !DILocation(line: 4, column: 26, scope: !7) 81