[llvm] r196479 - DwarfDebug/DwarfUnit: Push abbreviation structures down into DwarfUnits to reduce duplication
Eric Christopher
echristo at gmail.com
Thu Dec 5 09:33:42 PST 2013
On Thu, Dec 5, 2013 at 9:13 AM, David Blaikie <dblaikie at gmail.com> wrote:
> On Thu, Dec 5, 2013 at 9:05 AM, Eric Christopher <echristo at gmail.com> wrote:
>> Hmm? We only want one FoldingSet per final .o/.dwo
>
> One each for the .o and for the .dwo, or are you expecting/claiming
> there's one shared between both?
>
> As the code was written before, and as it is written now, there's a
> separate set for the .o and the .dwo - which makes sense to me. We
> need the abbreviations for the skeletons to be in the .o, so they
> can't be stored away in the .dwo. But we don't want to put all the
> non-skeletal abbrevations for the .dwo in the .o (because we want to
> keep as much stuff in the dwo as possible - and it's not like there
> are any abbreviations that are likely to appear in both the .o and the
> .dwo)
>
> Previous code had these 4 members in DwarfDebug:
>
> FoldingSet<DIEAbbrev> AbbreviationsSet;
> std::vector<DIEAbbrev *> Abbreviations;
> FoldingSet<DIEAbbrev> SkeletonAbbrevSet;
> std::vector<DIEAbbrev *> SkeletonAbbrevs;
>
> Now we have two members in DwarfUnit:
>
> FoldingSet<DIEAbbrev> AbbreviationsSet;
> std::vector<DIEAbbrev *> Abbreviations;
>
> And two instances of DwarfUnit. So we have the same 4 objects and we
> emit the same abbreviations in the same files, so far as I can tell.
>
Ah right. Naming confusion. I think I'd originally planned for
DwarfUnit to do what you have Unit doing, etc. I'll fix a bit of that
now.
-eric
>> because
>> abbreviations are uniqued across all compile/partial compile/type
>> units. Am I missing something here in this patch?
>>
>> -eric
>>
>> On Wed, Dec 4, 2013 at 11:43 PM, David Blaikie <dblaikie at gmail.com> wrote:
>>> Author: dblaikie
>>> Date: Thu Dec 5 01:43:55 2013
>>> New Revision: 196479
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=196479&view=rev
>>> Log:
>>> DwarfDebug/DwarfUnit: Push abbreviation structures down into DwarfUnits to reduce duplication
>>>
>>> Modified:
>>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
>>>
>>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=196479&r1=196478&r2=196479&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
>>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Thu Dec 5 01:43:55 2013
>>> @@ -114,10 +114,6 @@ static const char *const DbgTimerName =
>>>
>>> //===----------------------------------------------------------------------===//
>>>
>>> -// Configuration values for initial hash set sizes (log2).
>>> -//
>>> -static const unsigned InitAbbreviationsSetSize = 9; // log2(512)
>>> -
>>> namespace llvm {
>>>
>>> /// resolve - Look in the DwarfDebug map for the MDNode that
>>> @@ -182,14 +178,10 @@ static unsigned getDwarfVersionFromModul
>>> }
>>>
>>> DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
>>> - : Asm(A), MMI(Asm->MMI), FirstCU(0),
>>> - AbbreviationsSet(InitAbbreviationsSetSize),
>>> - SourceIdMap(DIEValueAllocator), PrevLabel(NULL), GlobalCUIndexCount(0),
>>> - GlobalRangeCount(0), InfoHolder(A, &AbbreviationsSet, Abbreviations,
>>> - "info_string", DIEValueAllocator),
>>> - SkeletonAbbrevSet(InitAbbreviationsSetSize),
>>> - SkeletonHolder(A, &SkeletonAbbrevSet, SkeletonAbbrevs, "skel_string",
>>> - DIEValueAllocator) {
>>> + : Asm(A), MMI(Asm->MMI), FirstCU(0), SourceIdMap(DIEValueAllocator),
>>> + PrevLabel(NULL), GlobalCUIndexCount(0), GlobalRangeCount(0),
>>> + InfoHolder(A, "info_string", DIEValueAllocator),
>>> + SkeletonHolder(A, "skel_string", DIEValueAllocator) {
>>>
>>> DwarfInfoSectionSym = DwarfAbbrevSectionSym = 0;
>>> DwarfStrSectionSym = TextSectionSym = 0;
>>> @@ -288,7 +280,7 @@ unsigned DwarfUnits::getAddrPoolIndex(co
>>> //
>>> void DwarfUnits::assignAbbrevNumber(DIEAbbrev &Abbrev) {
>>> // Check the set for priors.
>>> - DIEAbbrev *InSet = AbbreviationsSet->GetOrInsertNode(&Abbrev);
>>> + DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev);
>>>
>>> // If it's newly added.
>>> if (InSet == &Abbrev) {
>>> @@ -2162,25 +2154,21 @@ void DwarfDebug::emitDebugInfo() {
>>>
>>> // Emit the abbreviation section.
>>> void DwarfDebug::emitAbbreviations() {
>>> - if (!useSplitDwarf())
>>> - emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection(),
>>> - &Abbreviations);
>>> - else
>>> - emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection(),
>>> - &SkeletonAbbrevs);
>>> + DwarfUnits &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
>>> +
>>> + Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
>>> }
>>>
>>> -void DwarfDebug::emitAbbrevs(const MCSection *Section,
>>> - std::vector<DIEAbbrev *> *Abbrevs) {
>>> +void DwarfUnits::emitAbbrevs(const MCSection *Section) {
>>> // Check to see if it is worth the effort.
>>> - if (!Abbrevs->empty()) {
>>> + if (!Abbreviations.empty()) {
>>> // Start the debug abbrev section.
>>> Asm->OutStreamer.SwitchSection(Section);
>>>
>>> // For each abbrevation.
>>> - for (unsigned i = 0, N = Abbrevs->size(); i < N; ++i) {
>>> + for (unsigned i = 0, N = Abbreviations.size(); i < N; ++i) {
>>> // Get abbreviation data
>>> - const DIEAbbrev *Abbrev = Abbrevs->at(i);
>>> + const DIEAbbrev *Abbrev = Abbreviations[i];
>>>
>>> // Emit the abbrevations code (base 1 index.)
>>> Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
>>> @@ -3031,8 +3019,7 @@ void DwarfDebug::emitDebugInfoDWO() {
>>> // abbreviations for the .debug_info.dwo section.
>>> void DwarfDebug::emitDebugAbbrevDWO() {
>>> assert(useSplitDwarf() && "No split dwarf?");
>>> - emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection(),
>>> - &Abbreviations);
>>> + InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
>>> }
>>>
>>> // Emit the .debug_str.dwo section for separated dwarf. This contains the
>>>
>>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h?rev=196479&r1=196478&r2=196479&view=diff
>>> ==============================================================================
>>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h (original)
>>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h Thu Dec 5 01:43:55 2013
>>> @@ -226,10 +226,10 @@ class DwarfUnits {
>>> AsmPrinter *Asm;
>>>
>>> // Used to uniquely define abbreviations.
>>> - FoldingSet<DIEAbbrev> *AbbreviationsSet;
>>> + FoldingSet<DIEAbbrev> AbbreviationsSet;
>>>
>>> // A list of all the unique abbreviations in use.
>>> - std::vector<DIEAbbrev *> &Abbreviations;
>>> + std::vector<DIEAbbrev *> Abbreviations;
>>>
>>> // A pointer to all units in the section.
>>> SmallVector<Unit *, 1> CUs;
>>> @@ -251,12 +251,9 @@ class DwarfUnits {
>>> unsigned NextAddrPoolNumber;
>>>
>>> public:
>>> - DwarfUnits(AsmPrinter *AP, FoldingSet<DIEAbbrev> *AS,
>>> - std::vector<DIEAbbrev *> &A, const char *Pref,
>>> - BumpPtrAllocator &DA)
>>> - : Asm(AP), AbbreviationsSet(AS), Abbreviations(A), StringPool(DA),
>>> - NextStringPoolNumber(0), StringPref(Pref), AddressPool(),
>>> - NextAddrPoolNumber(0) {}
>>> + DwarfUnits(AsmPrinter *AP, const char *Pref, BumpPtrAllocator &DA)
>>> + : Asm(AP), StringPool(DA), NextStringPoolNumber(0), StringPref(Pref),
>>> + AddressPool(), NextAddrPoolNumber(0) {}
>>>
>>> ~DwarfUnits();
>>>
>>> @@ -279,6 +276,9 @@ public:
>>> void emitUnits(DwarfDebug *DD, const MCSection *USection,
>>> const MCSection *ASection, const MCSymbol *ASectionSym);
>>>
>>> + /// \brief Emit a set of abbreviations to the specific section.
>>> + void emitAbbrevs(const MCSection *);
>>> +
>>> /// \brief Emit all of the strings to the section given.
>>> void emitStrings(const MCSection *StrSection, const MCSection *OffsetSection,
>>> const MCSymbol *StrSecSym);
>>> @@ -347,12 +347,6 @@ class DwarfDebug : public AsmPrinterHand
>>> /// of in CompileUnit.
>>> DenseMap<const MDNode *, DIE *> MDTypeNodeToDieMap;
>>>
>>> - // Used to uniquely define abbreviations.
>>> - FoldingSet<DIEAbbrev> AbbreviationsSet;
>>> -
>>> - // A list of all the unique abbreviations in use.
>>> - std::vector<DIEAbbrev *> Abbreviations;
>>> -
>>> // Stores the current file ID for a given compile unit.
>>> DenseMap <unsigned, unsigned> FileIDCUMap;
>>> // Source id map, i.e. CUID, source filename and directory,
>>> @@ -485,12 +479,6 @@ class DwarfDebug : public AsmPrinterHand
>>> // original object file, rather than things that are meant
>>> // to be in the .dwo sections.
>>>
>>> - // Used to uniquely define abbreviations for the skeleton emission.
>>> - FoldingSet<DIEAbbrev> SkeletonAbbrevSet;
>>> -
>>> - // A list of all the unique abbreviations in use.
>>> - std::vector<DIEAbbrev *> SkeletonAbbrevs;
>>> -
>>> // Holder for the skeleton information.
>>> DwarfUnits SkeletonHolder;
>>>
>>> @@ -553,9 +541,6 @@ class DwarfDebug : public AsmPrinterHand
>>> /// open.
>>> void endSections();
>>>
>>> - /// \brief Emit a set of abbreviations to the specific section.
>>> - void emitAbbrevs(const MCSection *, std::vector<DIEAbbrev*> *);
>>> -
>>> /// \brief Emit the debug info section.
>>> void emitDebugInfo();
>>>
>>>
>>>
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