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llvm / llvm-project / 359c704004ec0826059578c79974d9ea29a8fbff
commit359c704004ec0826059578c79974d9ea29a8fbff[log] [tgz]
authorShubham Sandeep Rastogi <srastogi22@apple.com>Wed Aug 21 17:52:37 2024 -0700
committerGitHub <noreply@github.com>Wed Aug 21 17:52:37 2024 -0700
tree2df8c8a16bfd2221a0b40167b989af08dbe4013d
parente2b97f3802ac5a75a603c9cacd2f3ab19b6cf9b5 [diff]
Handle #dbg_values in SROA. (#94070)

This patch properly handles #dbg_values in SROA by making sure that any
#dbg_values get moved to before a store just like #dbg_declares do, or
the #dbg_value is correctly updated with the right alloca after an
aggregate alloca is broken up.

The issue stems from swift where #dbg_values are emitted and not
dbg.declares, the SROA pass doesn't handle the #dbg_values correctly and
it causes them to all have undefs

If we look at this simple-ish testcase (This is all I could reduce it
down to, and I am still relatively bad at writing llvm IR by hand so I
apologize in advance):

```
%T4main1TV13TangentVectorV = type <{ %T4main1UV13TangentVectorV, [7 x i8], %T4main1UV13TangentVectorV }>
%T4main1UV13TangentVectorV = type <{ %T1M1SVySfG, [7 x i8], %T4main1VV13TangentVectorV }>
%T1M1SVySfG = type <{ ptr, %Ts4Int8V }>
%Ts4Int8V = type <{ i8 }>
%T4main1VV13TangentVectorV = type <{ %T1M1SVySfG }>
define hidden swiftcc void @"$s4main1TV13TangentVectorV1poiyA2E_AEtFZ"(ptr noalias nocapture sret(%T4main1TV13TangentVectorV) %0, ptr noalias nocapture dereferenceable(57) %1, ptr noalias nocapture dereferenceable(57) %2) #0 !dbg !44 {
entry:
  %3 = alloca %T4main1VV13TangentVectorV
  %4 = alloca %T4main1UV13TangentVectorV
  %5 = alloca %T4main1VV13TangentVectorV
  %6 = alloca %T4main1UV13TangentVectorV
  %7 = alloca %T4main1VV13TangentVectorV
  %8 = alloca %T4main1UV13TangentVectorV
  %9 = alloca %T4main1VV13TangentVectorV
  %10 = alloca %T4main1UV13TangentVectorV
  call void @llvm.lifetime.start.p0(i64 9, ptr %3)
  call void @llvm.lifetime.start.p0(i64 25, ptr %4)
  call void @llvm.lifetime.start.p0(i64 9, ptr %5)
  call void @llvm.lifetime.start.p0(i64 25, ptr %6)
  call void @llvm.lifetime.start.p0(i64 9, ptr %7)
  call void @llvm.lifetime.start.p0(i64 25, ptr %8)
  call void @llvm.lifetime.start.p0(i64 9, ptr %9)
  call void @llvm.lifetime.start.p0(i64 25, ptr %10)
  %.u1 = getelementptr inbounds %T4main1TV13TangentVectorV, ptr %1, i32 0, i32 0
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %4, ptr align 8 %.u1, i64 25, i1 false)
  %.u11 = getelementptr inbounds %T4main1TV13TangentVectorV, ptr %2, i32 0, i32 0
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %6, ptr align 8 %.u11, i64 25, i1 false)
  call void @llvm.dbg.value(metadata ptr %4, metadata !62, metadata !DIExpression(DW_OP_deref)), !dbg !75
  %.s = getelementptr inbounds %T4main1UV13TangentVectorV, ptr %4, i32 0, i32 0
  %.s.c = getelementptr inbounds %T1M1SVySfG, ptr %.s, i32 0, i32 0
  %11 = load ptr, ptr %.s.c
  %.s.b = getelementptr inbounds %T1M1SVySfG, ptr %.s, i32 0, i32 1
  %.s.b._value = getelementptr inbounds %Ts4Int8V, ptr %.s.b, i32 0, i32 0
  %12 = load i8, ptr %.s.b._value
  %.s2 = getelementptr inbounds %T4main1UV13TangentVectorV, ptr %6, i32 0, i32 0
  %.s2.c = getelementptr inbounds %T1M1SVySfG, ptr %.s2, i32 0, i32 0
  %13 = load ptr, ptr %.s2.c
  %.s2.b = getelementptr inbounds %T1M1SVySfG, ptr %.s2, i32 0, i32 1
  %.s2.b._value = getelementptr inbounds %Ts4Int8V, ptr %.s2.b, i32 0, i32 0
  %14 = load i8, ptr %.s2.b._value
  %.v = getelementptr inbounds %T4main1UV13TangentVectorV, ptr %4, i32 0, i32 2
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %3, ptr align 8 %.v, i64 9, i1 false)
  %.v3 = getelementptr inbounds %T4main1UV13TangentVectorV, ptr %6, i32 0, i32 2
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %5, ptr align 8 %.v3, i64 9, i1 false)
  %.s4 = getelementptr inbounds %T4main1VV13TangentVectorV, ptr %3, i32 0, i32 0
  %.s4.c = getelementptr inbounds %T1M1SVySfG, ptr %.s4, i32 0, i32 0
  %18 = load ptr, ptr %.s4.c
  %.s5 = getelementptr inbounds %T4main1VV13TangentVectorV, ptr %5, i32 0, i32 0
  %.s5.c = getelementptr inbounds %T1M1SVySfG, ptr %.s5, i32 0, i32 0
  %20 = load ptr, ptr %.s5.c
  %.u2 = getelementptr inbounds %T4main1TV13TangentVectorV, ptr %1, i32 0, i32 2
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %8, ptr align 8 %.u2, i64 25, i1 false)
  %.u26 = getelementptr inbounds %T4main1TV13TangentVectorV, ptr %2, i32 0, i32 2
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %10, ptr align 8 %.u26, i64 25, i1 false)
  %.s7 = getelementptr inbounds %T4main1UV13TangentVectorV, ptr %8, i32 0, i32 0
  %.s7.c = getelementptr inbounds %T1M1SVySfG, ptr %.s7, i32 0, i32 0
  %25 = load ptr, ptr %.s7.c
  %.s7.b = getelementptr inbounds %T1M1SVySfG, ptr %.s7, i32 0, i32 1
  %.s7.b._value = getelementptr inbounds %Ts4Int8V, ptr %.s7.b, i32 0, i32 0
  %26 = load i8, ptr %.s7.b._value
  %.s8 = getelementptr inbounds %T4main1UV13TangentVectorV, ptr %10, i32 0, i32 0
  %.s8.c = getelementptr inbounds %T1M1SVySfG, ptr %.s8, i32 0, i32 0
  %27 = load ptr, ptr %.s8.c
  %.s8.b = getelementptr inbounds %T1M1SVySfG, ptr %.s8, i32 0, i32 1
  %.s8.b._value = getelementptr inbounds %Ts4Int8V, ptr %.s8.b, i32 0, i32 0
  %28 = load i8, ptr %.s8.b._value
  %.v9 = getelementptr inbounds %T4main1UV13TangentVectorV, ptr %8, i32 0, i32 2
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %7, ptr align 8 %.v9, i64 9, i1 false)
  %.v10 = getelementptr inbounds %T4main1UV13TangentVectorV, ptr %10, i32 0, i32 2
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %9, ptr align 8 %.v10, i64 9, i1 false)
  %.s11 = getelementptr inbounds %T4main1VV13TangentVectorV, ptr %7, i32 0, i32 0
  %.s11.c = getelementptr inbounds %T1M1SVySfG, ptr %.s11, i32 0, i32 0
  %32 = load ptr, ptr %.s11.c
  %.s12 = getelementptr inbounds %T4main1VV13TangentVectorV, ptr %9, i32 0, i32 0
  %.s12.c = getelementptr inbounds %T1M1SVySfG, ptr %.s12, i32 0, i32 0
  %34 = load ptr, ptr %.s12.c
  call void @llvm.lifetime.end.p0(i64 25, ptr %10)
  call void @llvm.lifetime.end.p0(i64 9, ptr %9)
  call void @llvm.lifetime.end.p0(i64 25, ptr %8)
  call void @llvm.lifetime.end.p0(i64 9, ptr %7)
  call void @llvm.lifetime.end.p0(i64 25, ptr %6)
  call void @llvm.lifetime.end.p0(i64 9, ptr %5)
  call void @llvm.lifetime.end.p0(i64 25, ptr %4)
  call void @llvm.lifetime.end.p0(i64 9, ptr %3)
  ret void
}
!llvm.module.flags = !{!0, !1, !2, !3, !4, !6, !7, !8, !9, !10, !11, !12, !13, !14, !15}
!swift.module.flags = !{!33}
!llvm.linker.options = !{!34, !35, !36, !37, !38, !39, !40, !41, !42, !43}
!0 = !{i32 2, !"SDK Version", [2 x i32] [i32 14, i32 4]}
!1 = !{i32 1, !"Objective-C Version", i32 2}
!2 = !{i32 1, !"Objective-C Image Info Version", i32 0}
!3 = !{i32 1, !"Objective-C Image Info Section", !"__DATA, no_dead_strip"}
!4 = !{i32 1, !"Objective-C Garbage Collection", i8 0}
!6 = !{i32 7, !"Dwarf Version", i32 4}
!7 = !{i32 2, !"Debug Info Version", i32 3}
!8 = !{i32 1, !"wchar_size", i32 4}
!9 = !{i32 8, !"PIC Level", i32 2}
!10 = !{i32 7, !"uwtable", i32 1}
!11 = !{i32 7, !"frame-pointer", i32 1}
!12 = !{i32 1, !"Swift Version", i32 7}
!13 = !{i32 1, !"Swift ABI Version", i32 7}
!14 = !{i32 1, !"Swift Major Version", i8 6}
!15 = !{i32 1, !"Swift Minor Version", i8 0}
!16 = distinct !DICompileUnit(language: DW_LANG_Swift, file: !17, imports: !18, sdk: "MacOSX14.4.sdk")
!17 = !DIFile(filename: "/Users/emilpedersen/swift2/swift/test/IRGen/debug_scope_distinct.swift", directory: "/Users/emilpedersen/swift2")
!18 = !{!19, !21, !23, !25, !27, !29, !31}
!19 = !DIImportedEntity(tag: DW_TAG_imported_module, scope: !17, entity: !20, file: !17)
!20 = !DIModule(scope: null, name: "main", includePath: "/Users/emilpedersen/swift2/swift/test/IRGen")
!21 = !DIImportedEntity(tag: DW_TAG_imported_module, scope: !17, entity: !22, file: !17)
!22 = !DIModule(scope: null, name: "Swift", includePath: "/Users/emilpedersen/swift2/_build/Ninja-RelWithDebInfoAssert+stdlib-RelWithDebInfo/swift-macosx-arm64/lib/swift/macosx/Swift.swiftmodule/arm64-apple-macos.swiftmodule")
!23 = !DIImportedEntity(tag: DW_TAG_imported_module, scope: !17, entity: !24, line: 60)
!24 = !DIModule(scope: null, name: "_Differentiation", includePath: "/Users/emilpedersen/swift2/_build/Ninja-RelWithDebInfoAssert+stdlib-RelWithDebInfo/swift-macosx-arm64/lib/swift/macosx/_Differentiation.swiftmodule/arm64-apple-macos.swiftmodule")
!25 = !DIImportedEntity(tag: DW_TAG_imported_module, scope: !17, entity: !26, line: 61)
!26 = !DIModule(scope: null, name: "M", includePath: "/Users/emilpedersen/swift2/_build/Ninja-RelWithDebInfoAssert+stdlib-RelWithDebInfo/swift-macosx-arm64/test-macosx-arm64/IRGen/Output/debug_scope_distinct.swift.tmp/M.swiftmodule")
!27 = !DIImportedEntity(tag: DW_TAG_imported_module, scope: !17, entity: !28, file: !17)
!28 = !DIModule(scope: null, name: "_StringProcessing", includePath: "/Users/emilpedersen/swift2/_build/Ninja-RelWithDebInfoAssert+stdlib-RelWithDebInfo/swift-macosx-arm64/lib/swift/macosx/_StringProcessing.swiftmodule/arm64-apple-macos.swiftmodule")
!29 = !DIImportedEntity(tag: DW_TAG_imported_module, scope: !17, entity: !30, file: !17)
!30 = !DIModule(scope: null, name: "_SwiftConcurrencyShims", includePath: "/Users/emilpedersen/swift2/_build/Ninja-RelWithDebInfoAssert+stdlib-RelWithDebInfo/swift-macosx-arm64/lib/swift/shims")
!31 = !DIImportedEntity(tag: DW_TAG_imported_module, scope: !17, entity: !32, file: !17)
!32 = !DIModule(scope: null, name: "_Concurrency", includePath: "/Users/emilpedersen/swift2/_build/Ninja-RelWithDebInfoAssert+stdlib-RelWithDebInfo/swift-macosx-arm64/lib/swift/macosx/_Concurrency.swiftmodule/arm64-apple-macos.swiftmodule")
!33 = !{i1 false}
!34 = !{!"-lswiftCore"}
!35 = !{!"-lswift_StringProcessing"}
!36 = !{!"-lswift_Differentiation"}
!37 = !{!"-lswiftDarwin"}
!38 = !{!"-lswift_Concurrency"}
!39 = !{!"-lswiftSwiftOnoneSupport"}
!40 = !{!"-lobjc"}
!41 = !{!"-lswiftCompatibilityConcurrency"}
!42 = !{!"-lswiftCompatibility56"}
!43 = !{!"-lswiftCompatibilityPacks"}
!44 = distinct !DISubprogram( unit: !16, declaration: !52, retainedNodes: !53)
!45 = !DIFile(filename: "<compiler-generated>", directory: "/")
!46 = !DICompositeType(tag: DW_TAG_structure_type, scope: !47, elements: !48, identifier: "$s4main1TV13TangentVectorVD")
!47 = !DICompositeType(tag: DW_TAG_structure_type, identifier: "$s4main1TVD")
!48 = !{}
!49 = !DISubroutineType(types: !50)
!50 = !{!51}
!51 = !DICompositeType(tag: DW_TAG_structure_type, identifier: "$s4main1TV13TangentVectorVXMtD")
!52 = !DISubprogram( file: !45, type: !49, spFlags: DISPFlagOptimized)
!53 = !{!54, !56, !57}
!54 = !DILocalVariable( scope: !44, type: !55, flags: DIFlagArtificial)
!55 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !46)
!56 = !DILocalVariable( scope: !44, flags: DIFlagArtificial)
!57 = !DILocalVariable( scope: !44, type: !58, flags: DIFlagArtificial)
!58 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !51)
!62 = !DILocalVariable( scope: !63, type: !72, flags: DIFlagArtificial)
!63 = distinct !DISubprogram( type: !66, unit: !16, declaration: !69, retainedNodes: !70)
!64 = !DICompositeType(tag: DW_TAG_structure_type, scope: !65, identifier: "$s4main1UV13TangentVectorVD")
!65 = !DICompositeType(tag: DW_TAG_structure_type, identifier: "$s4main1UVD")
!66 = !DISubroutineType(types: !67)
!67 = !{!68}
!68 = !DICompositeType(tag: DW_TAG_structure_type, identifier: "$s4main1UV13TangentVectorVXMtD")
!69 = !DISubprogram( spFlags: DISPFlagOptimized)
!70 = !{!71, !73}
!71 = !DILocalVariable( scope: !63, flags: DIFlagArtificial)
!72 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !64)
!73 = !DILocalVariable( scope: !63, type: !74, flags: DIFlagArtificial)
!74 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !68)
!75 = !DILocation( scope: !63, inlinedAt: !76)
!76 = distinct !DILocation( scope: !44)

```

if we run
` opt -S -passes=sroa file.ll  -o -`

With this patch we will see
```
%.sroa.5.sroa.021 = alloca [7 x i8], align 8
tail call void @llvm.dbg.value(metadata ptr %.sroa.5.sroa.021, metadata !59, metadata !DIExpression(DW_OP_deref, DW_OP_LLVM_fragment, 72, 56)), !dbg !72
%.sroa.5.sroa.014 = alloca [7 x i8], align 8
 ```
 
 Without this patch we will see:
 
```
%.sroa.5.sroa.021 = alloca [7 x i8], align 8
%.sroa.5.sroa.014 = alloca [7 x i8], align 8
```

Thus this patch ensures that llvm.dbg.values that use allocas that are broken up still have the correct metadata and debug information is preserved

This is part of a stack of patches and is preceded by: https://github.com/llvm/llvm-project/pull/94068
12 files changed
tree: 2df8c8a16bfd2221a0b40167b989af08dbe4013d
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. libc/
  11. libclc/
  12. libcxx/
  13. libcxxabi/
  14. libunwind/
  15. lld/
  16. lldb/
  17. llvm/
  18. llvm-libgcc/
  19. mlir/
  20. offload/
  21. openmp/
  22. polly/
  23. pstl/
  24. runtimes/
  25. third-party/
  26. utils/
  27. .clang-format
  28. .clang-tidy
  29. .git-blame-ignore-revs
  30. .gitattributes
  31. .gitignore
  32. .mailmap
  33. CODE_OF_CONDUCT.md
  34. CONTRIBUTING.md
  35. LICENSE.TXT
  36. pyproject.toml
  37. README.md
  38. SECURITY.md
README.md

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