[llvm] r266548 - IR: Use ODR to unique DICompositeType members
David Blaikie via llvm-commits
llvm-commits at lists.llvm.org
Sun Apr 17 15:08:18 PDT 2016
On Sat, Apr 16, 2016 at 7:30 PM, Duncan P. N. Exon Smith via llvm-commits <
llvm-commits at lists.llvm.org> wrote:
> Author: dexonsmith
> Date: Sat Apr 16 21:30:20 2016
> New Revision: 266548
>
> URL: http://llvm.org/viewvc/llvm-project?rev=266548&view=rev
> Log:
> IR: Use ODR to unique DICompositeType members
>
> Merge members that are describing the same member of the same ODR type,
> even if other bits differ. If the file or line differ, we don't care;
> if anything else differs, it's an ODR violation (and we still don't
> really care).
>
> For DISubprogram declarations, this looks at the LinkageName and Scope.
> For DW_TAG_member instances of DIDerivedType, this looks at the Name and
> Scope. In both cases, we know that the Scope follows ODR rules if it
> has a non-empty identifier.
>
Not quite following this paragraph ^ why does this need to look at
subprograms and members, rather than just the 'identifier' of the
DICompositeType itself?
>
> Added:
> llvm/trunk/test/Assembler/dicompositetype-members.ll
> Modified:
> llvm/trunk/docs/LangRef.rst
> llvm/trunk/lib/IR/LLVMContextImpl.h
> llvm/trunk/test/Linker/type-unique-odr-a.ll
>
> Modified: llvm/trunk/docs/LangRef.rst
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.rst?rev=266548&r1=266547&r2=266548&view=diff
>
> ==============================================================================
> --- llvm/trunk/docs/LangRef.rst (original)
> +++ llvm/trunk/docs/LangRef.rst Sat Apr 16 21:30:20 2016
> @@ -3976,7 +3976,10 @@ The following ``tag:`` values are valid:
>
> ``DW_TAG_member`` is used to define a member of a :ref:`composite type
> <DICompositeType>`. The type of the member is the ``baseType:``. The
> -``offset:`` is the member's bit offset.
> +``offset:`` is the member's bit offset. If the composite type has a
> non-empty
> +``identifier:``, then it respects ODR rules. In that case, the ``scope:``
> +reference will be a :ref:`metadata string <metadata-string>`, and the
> member
> +will be uniqued solely based on its ``name:`` and ``scope:``.
>
> ``DW_TAG_inheritance`` and ``DW_TAG_friend`` are used in the ``elements:``
> field of :ref:`composite types <DICompositeType>` to describe parents and
> @@ -4125,6 +4128,12 @@ metadata. The ``variables:`` field point
> that must be retained, even if their IR counterparts are optimized out of
> the IR. The ``type:`` field must point at an :ref:`DISubroutineType`.
>
> +When ``isDefinition: false``, subprograms describe a declaration in the
> type
> +tree as opposed to a definition of a funciton. If the scope is a
> +:ref:`metadata string <metadata-string>` then the composite type follows
> ODR
> +rules, and the subprogram declaration is uniqued based only on its
> +``linkageName:`` and ``scope:``.
> +
> .. code-block:: llvm
>
> define void @_Z3foov() !dbg !0 {
> @@ -4133,7 +4142,7 @@ the IR. The ``type:`` field must point a
>
> !0 = distinct !DISubprogram(name: "foo", linkageName: "_Zfoov",
> scope: !1,
> file: !2, line: 7, type: !3, isLocal:
> true,
> - isDefinition: false, scopeLine: 8,
> + isDefinition: true, scopeLine: 8,
> containingType: !4,
> virtuality: DW_VIRTUALITY_pure_virtual,
> virtualIndex: 10, flags: DIFlagPrototyped,
>
> Modified: llvm/trunk/lib/IR/LLVMContextImpl.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/LLVMContextImpl.h?rev=266548&r1=266547&r2=266548&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/IR/LLVMContextImpl.h (original)
> +++ llvm/trunk/lib/IR/LLVMContextImpl.h Sat Apr 16 21:30:20 2016
> @@ -32,6 +32,7 @@
> #include "llvm/IR/LLVMContext.h"
> #include "llvm/IR/Metadata.h"
> #include "llvm/IR/ValueHandle.h"
> +#include "llvm/Support/Dwarf.h"
> #include <vector>
>
> namespace llvm {
> @@ -376,6 +377,12 @@ template <> struct MDNodeKeyImpl<DIDeriv
> ExtraData == RHS->getRawExtraData();
> }
> unsigned getHashValue() const {
> + // If this is a member inside an ODR type, only hash the type and the
> name.
> + // Otherwise the hash will be stronger than
> + // MDNodeSubsetEqualImpl::isODRMember().
> + if (Tag == dwarf::DW_TAG_member && Name && Scope &&
> isa<MDString>(Scope))
> + return hash_combine(Name, Scope);
> +
> // Intentionally computes the hash on a subset of the operands for
> // performance reason. The subset has to be significant enough to
> avoid
> // collision "most of the time". There is no correctness issue in
> case of
> @@ -384,6 +391,30 @@ template <> struct MDNodeKeyImpl<DIDeriv
> }
> };
>
> +template <> struct MDNodeSubsetEqualImpl<DIDerivedType> {
> + typedef MDNodeKeyImpl<DIDerivedType> KeyTy;
> + static bool isSubsetEqual(const KeyTy &LHS, const DIDerivedType *RHS) {
> + return isODRMember(LHS.Tag, LHS.Scope, LHS.Name, RHS);
> + }
> + static bool isSubsetEqual(const DIDerivedType *LHS, const DIDerivedType
> *RHS) {
> + return isODRMember(LHS->getTag(), LHS->getRawScope(),
> LHS->getRawName(),
> + RHS);
> + }
> +
> + /// Subprograms compare equal if they declare the same function in an
> ODR
> + /// type.
> + static bool isODRMember(unsigned Tag, const Metadata *Scope,
> + const MDString *Name, const DIDerivedType *RHS)
> {
> + // Check whether the LHS is eligible.
> + if (Tag != dwarf::DW_TAG_member || !Name || !Scope ||
> !isa<MDString>(Scope))
> + return false;
> +
> + // Compare to the RHS.
> + return Tag == RHS->getTag() && Name == RHS->getRawName() &&
> + Scope == RHS->getRawScope();
> + }
> +};
> +
> template <> struct MDNodeKeyImpl<DICompositeType> {
> unsigned Tag;
> MDString *Name;
> @@ -537,6 +568,12 @@ template <> struct MDNodeKeyImpl<DISubpr
> Variables == RHS->getRawVariables();
> }
> unsigned getHashValue() const {
> + // If this is a declaration inside an ODR type, only hash the type
> and the
> + // name. Otherwise the hash will be stronger than
> + // MDNodeSubsetEqualImpl::isDeclarationOfODRMember().
> + if (!IsDefinition && LinkageName && Scope && isa<MDString>(Scope))
> + return hash_combine(LinkageName, Scope);
> +
> // Intentionally computes the hash on a subset of the operands for
> // performance reason. The subset has to be significant enough to
> avoid
> // collision "most of the time". There is no correctness issue in
> case of
> @@ -545,6 +582,33 @@ template <> struct MDNodeKeyImpl<DISubpr
> }
> };
>
> +template <> struct MDNodeSubsetEqualImpl<DISubprogram> {
> + typedef MDNodeKeyImpl<DISubprogram> KeyTy;
> + static bool isSubsetEqual(const KeyTy &LHS, const DISubprogram *RHS) {
> + return isDeclarationOfODRMember(LHS.IsDefinition, LHS.Scope,
> + LHS.LinkageName, RHS);
> + }
> + static bool isSubsetEqual(const DISubprogram *LHS, const DISubprogram
> *RHS) {
> + return isDeclarationOfODRMember(LHS->isDefinition(),
> LHS->getRawScope(),
> + LHS->getRawLinkageName(), RHS);
> + }
> +
> + /// Subprograms compare equal if they declare the same function in an
> ODR
> + /// type.
> + static bool isDeclarationOfODRMember(bool IsDefinition, const Metadata
> *Scope,
> + const MDString *LinkageName,
> + const DISubprogram *RHS) {
> + // Check whether the LHS is eligible.
> + if (IsDefinition || !Scope || !LinkageName || !Scope ||
> + !isa<MDString>(Scope))
> + return false;
> +
> + // Compare to the RHS.
> + return IsDefinition == RHS->isDefinition() && Scope ==
> RHS->getRawScope() &&
> + LinkageName == RHS->getRawLinkageName();
> + }
> +};
> +
> template <> struct MDNodeKeyImpl<DILexicalBlock> {
> Metadata *Scope;
> Metadata *File;
>
> Added: llvm/trunk/test/Assembler/dicompositetype-members.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Assembler/dicompositetype-members.ll?rev=266548&view=auto
>
> ==============================================================================
> --- llvm/trunk/test/Assembler/dicompositetype-members.ll (added)
> +++ llvm/trunk/test/Assembler/dicompositetype-members.ll Sat Apr 16
> 21:30:20 2016
> @@ -0,0 +1,54 @@
> +; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
> +; RUN: verify-uselistorder %s
> +
> +; Anchor the order of the nodes.
> +!named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12, !13,
> !14, !15, !16, !17}
> +
> +; Some basic building blocks.
> +; CHECK: !0 = !DIBasicType
> +; CHECK-NEXT: !1 = !DIFile
> +; CHECK-NEXT: !2 = !DIFile
> +!0 = !DIBasicType(tag: DW_TAG_base_type, name: "name", size: 1, align: 2,
> encoding: DW_ATE_unsigned_char)
> +!1 = !DIFile(filename: "path/to/file", directory: "/path/to/dir")
> +!2 = !DIFile(filename: "path/to/other", directory: "/path/to/dir")
> +
> +; Define an identified type with fields and functions.
> +; CHECK-NEXT: !3 = !DICompositeType(tag: DW_TAG_structure_type, name:
> "has-uuid",
> +; CHECK-NEXT: !4 = !DIDerivedType(tag: DW_TAG_member, name: "field1",
> scope: !"has-uuid", file: !1
> +; CHECK-NEXT: !5 = !DIDerivedType(tag: DW_TAG_member, name: "field2",
> scope: !"has-uuid", file: !1
> +; CHECK-NEXT: !6 = !DISubprogram(name: "foo", linkageName: "foo1", scope:
> !"has-uuid", file: !1
> +; CHECK-NEXT: !7 = !DISubprogram(name: "foo", linkageName: "foo2", scope:
> !"has-uuid", file: !1
> +!3 = !DICompositeType(tag: DW_TAG_structure_type, name: "has-uuid", file:
> !1, line: 2, size: 64, align: 32, identifier: "uuid")
> +!4 = !DIDerivedType(tag: DW_TAG_member, name: "field1", scope:
> !"has-uuid", file: !1, line: 4, baseType: !0, size: 32, align: 32, offset:
> 32)
> +!5 = !DIDerivedType(tag: DW_TAG_member, name: "field2", scope:
> !"has-uuid", file: !1, line: 4, baseType: !0, size: 32, align: 32, offset:
> 32)
> +!6 = !DISubprogram(name: "foo", linkageName: "foo1", scope: !"has-uuid",
> file: !1, isDefinition: false)
> +!7 = !DISubprogram(name: "foo", linkageName: "foo2", scope: !"has-uuid",
> file: !1, isDefinition: false)
> +
> +; Define an un-identified type with fields and functions.
> +; CHECK-NEXT: !8 = !DICompositeType(tag: DW_TAG_structure_type, name:
> "no-uuid", file: !1
> +; CHECK-NEXT: !9 = !DIDerivedType(tag: DW_TAG_member, name: "field1",
> scope: !8, file: !1
> +; CHECK-NEXT: !10 = !DIDerivedType(tag: DW_TAG_member, name: "field2",
> scope: !8, file: !1
> +; CHECK-NEXT: !11 = !DISubprogram(name: "foo", linkageName: "foo1",
> scope: !8, file: !1
> +; CHECK-NEXT: !12 = !DISubprogram(name: "foo", linkageName: "foo2",
> scope: !8, file: !1
> +!8 = !DICompositeType(tag: DW_TAG_structure_type, name: "no-uuid", file:
> !1, line: 2, size: 64, align: 32)
> +!9 = !DIDerivedType(tag: DW_TAG_member, name: "field1", scope: !8, file:
> !1, line: 4, baseType: !0, size: 32, align: 32, offset: 32)
> +!10 = !DIDerivedType(tag: DW_TAG_member, name: "field2", scope: !8, file:
> !1, line: 4, baseType: !0, size: 32, align: 32, offset: 32)
> +!11 = !DISubprogram(name: "foo", linkageName: "foo1", scope: !8, file:
> !1, isDefinition: false)
> +!12 = !DISubprogram(name: "foo", linkageName: "foo2", scope: !8, file:
> !1, isDefinition: false)
> +
> +; Add duplicate fields and members of "no-uuid" in a different file.
> These
> +; should stick around, since "no-uuid" does not have an "identifier:"
> field.
> +; CHECK-NEXT: !13 = !DIDerivedType(tag: DW_TAG_member, name: "field1",
> scope: !8, file: !2,
> +; CHECK-NEXT: !14 = !DISubprogram(name: "foo", linkageName: "foo1",
> scope: !8, file: !2,
> +!13 = !DIDerivedType(tag: DW_TAG_member, name: "field1", scope: !8, file:
> !2, line: 4, baseType: !0, size: 32, align: 32, offset: 32)
> +!14 = !DISubprogram(name: "foo", linkageName: "foo1", scope: !8, file:
> !2, isDefinition: false)
> +
> +; Add duplicate fields and members of "has-uuid" in a different file.
> These
> +; should be merged.
> +!15 = !DIDerivedType(tag: DW_TAG_member, name: "field1", scope:
> !"has-uuid", file: !2, line: 4, baseType: !0, size: 32, align: 32, offset:
> 32)
> +!16 = !DISubprogram(name: "foo", linkageName: "foo1", scope: !"has-uuid",
> file: !2, isDefinition: false)
> +
> +; CHECK-NEXT: !15 = !{!4, !6}
> +; CHECK-NOT: !DIDerivedType
> +; CHECK-NOT: !DISubprogram
> +!17 = !{!15, !16}
>
> Modified: llvm/trunk/test/Linker/type-unique-odr-a.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/type-unique-odr-a.ll?rev=266548&r1=266547&r2=266548&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/Linker/type-unique-odr-a.ll (original)
> +++ llvm/trunk/test/Linker/type-unique-odr-a.ll Sat Apr 16 21:30:20 2016
> @@ -4,6 +4,10 @@
> ; RUN: | %llc_dwarf -dwarf-linkage-names=Enable -filetype=obj -O0 \
> ; RUN: | llvm-dwarfdump -debug-dump=info - \
> ; RUN: | FileCheck %s
> +; RUN: llvm-link %p/type-unique-odr-b.ll %s -S -o - \
> +; RUN: | %llc_dwarf -dwarf-linkage-names=Enable -filetype=obj -O0 \
> +; RUN: | llvm-dwarfdump -debug-dump=info - \
> +; RUN: | FileCheck %s
> ;
> ; Test ODR-based type uniquing for C++ class members.
> ; rdar://problem/15851313.
>
>
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