[llvm] r247898 - Revert "Function bitcode index in Value Symbol Table and lazy reading support"

Teresa Johnson via llvm-commits llvm-commits at lists.llvm.org
Thu Sep 17 10:20:33 PDT 2015


On Thu, Sep 17, 2015 at 10:10 AM, David Blaikie <dblaikie at gmail.com> wrote:
>
>
> On Thu, Sep 17, 2015 at 10:10 AM, David Blaikie <dblaikie at gmail.com> wrote:
>>
>>
>>
>> On Thu, Sep 17, 2015 at 10:01 AM, Teresa Johnson <tejohnson at google.com>
>> wrote:
>>>
>>> On Thu, Sep 17, 2015 at 9:34 AM, David Blaikie <dblaikie at gmail.com>
>>> wrote:
>>> >
>>> >
>>> > On Thu, Sep 17, 2015 at 9:19 AM, Teresa Johnson via llvm-commits
>>> > <llvm-commits at lists.llvm.org> wrote:
>>> >>
>>> >> Author: tejohnson
>>> >> Date: Thu Sep 17 11:19:10 2015
>>> >> New Revision: 247898
>>> >>
>>> >> URL: http://llvm.org/viewvc/llvm-project?rev=247898&view=rev
>>> >> Log:
>>> >> Revert "Function bitcode index in Value Symbol Table and lazy reading
>>> >> support"
>>> >>
>>> >> Temporarily revert to fix some buildbot issues. One is a minor issue
>>> >> with a variable unused in NDEBUG mode. More concerning are some test
>>> >> failures on win7 that I need to dig into.
>>> >
>>> >
>>> > Thanks for summarizing the reasons for the revert! (sometimes people
>>> > accidentally skip this step & it makes it difficult to understand/look
>>> > back
>>> > over the history, etc)
>>> >
>>> >>
>>> >> This reverts commit 4e66a74543459832cfd571db42b4543580ae1d1d.
>>> >
>>> >
>>> > We try to use the SVN revision numbers, rather than the git hash, as
>>> > the
>>> > authoritative reference when talking about commits (especially in
>>> > commit
>>> > messages). There's a script (llvm/utils/git-svn/git-svnrevert) to help
>>> > with
>>> > this, that will take a git hash, revert it, but produce a commit
>>> > message
>>> > that includes the svn revision instead of the git hash.
>>>
>>> Ah, thanks for the info. Should I amend the commit message for the
>>> revert?
>>
>>
>> Nothing to do once it's committed upstream - I think in theory there's
>> some way we could setup the SVN permissions to enable this, but it's not the
>> case at the moment at least. No worries - just tips for next time.
>>
>> At least it's helpful to follow up in an email and mention the revision
>> (so searching for the revision finds the email threads, so I'll do that
>> here)
>>
>> This commit reverts r247894
>>
>> (also sometimes helpful to reply to the original commit thread with the
>> inverse email "this patch was reverted in r247898" - so that anyone
>> investigating build bot failures who finds the revision, will immediately
>> know it's been reverted, etc (oh, and include the same blurb you did in this
>> commit message about why it was reverted))

Ok, great. Done. Although read this a little too fast the first time
so I didn't include the full details on why, just that there were
buildbot failures. =/

Thanks,
Teresa

>>
>> - Dave
>>
>>>
>>>
>>> Teresa
>>>
>>> >
>>> > - Dave
>>> >
>>> >>
>>> >>
>>> >> Removed:
>>> >>     llvm/trunk/test/Bitcode/vst-forward-declaration.ll
>>> >> Modified:
>>> >>     llvm/trunk/include/llvm/Bitcode/LLVMBitCodes.h
>>> >>     llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp
>>> >>     llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp
>>> >>     llvm/trunk/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
>>> >>
>>> >> Modified: llvm/trunk/include/llvm/Bitcode/LLVMBitCodes.h
>>> >> URL:
>>> >>
>>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Bitcode/LLVMBitCodes.h?rev=247898&r1=247897&r2=247898&view=diff
>>> >>
>>> >>
>>> >> ==============================================================================
>>> >> --- llvm/trunk/include/llvm/Bitcode/LLVMBitCodes.h (original)
>>> >> +++ llvm/trunk/include/llvm/Bitcode/LLVMBitCodes.h Thu Sep 17 11:19:10
>>> >> 2015
>>> >> @@ -42,10 +42,7 @@ namespace bitc {
>>> >>
>>> >>      TYPE_BLOCK_ID_NEW,
>>> >>
>>> >> -    USELIST_BLOCK_ID,
>>> >> -
>>> >> -    MODULE_STRTAB_BLOCK_ID,
>>> >> -    FUNCTION_SUMMARY_BLOCK_ID
>>> >> +    USELIST_BLOCK_ID
>>> >>    };
>>> >>
>>> >>
>>> >> @@ -76,8 +73,6 @@ namespace bitc {
>>> >>
>>> >>      MODULE_CODE_GCNAME      = 11,  // GCNAME: [strchr x N]
>>> >>      MODULE_CODE_COMDAT      = 12,  // COMDAT: [selection_kind, name]
>>> >> -
>>> >> -    MODULE_CODE_VSTOFFSET   = 13,  // VSTOFFSET: [offset]
>>> >>    };
>>> >>
>>> >>    /// PARAMATTR blocks have code for defining a parameter attribute
>>> >> set.
>>> >> @@ -136,11 +131,10 @@ namespace bitc {
>>> >>      TST_CODE_ENTRY = 1     // TST_ENTRY: [typeid, namechar x N]
>>> >>    };
>>> >>
>>> >> -  // Value symbol table codes.
>>> >> +  // The value symbol table only has one code (VST_ENTRY_CODE).
>>> >>    enum ValueSymtabCodes {
>>> >> -    VST_CODE_ENTRY   = 1,   // VST_ENTRY: [valueid, namechar x N]
>>> >> -    VST_CODE_BBENTRY = 2,   // VST_BBENTRY: [bbid, namechar x N]
>>> >> -    VST_CODE_FNENTRY = 3,   // VST_FNENTRY: [valueid, offset,
>>> >> namechar x
>>> >> N]
>>> >> +    VST_CODE_ENTRY   = 1,  // VST_ENTRY: [valid, namechar x N]
>>> >> +    VST_CODE_BBENTRY = 2   // VST_BBENTRY: [bbid, namechar x N]
>>> >>    };
>>> >>
>>> >>    enum MetadataCodes {
>>> >>
>>> >> Modified: llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp
>>> >> URL:
>>> >>
>>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp?rev=247898&r1=247897&r2=247898&view=diff
>>> >>
>>> >>
>>> >> ==============================================================================
>>> >> --- llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp (original)
>>> >> +++ llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp Thu Sep 17
>>> >> 11:19:10
>>> >> 2015
>>> >> @@ -147,7 +147,6 @@ class BitcodeReader : public GVMateriali
>>> >>    BitstreamCursor Stream;
>>> >>    uint64_t NextUnreadBit = 0;
>>> >>    bool SeenValueSymbolTable = false;
>>> >> -  unsigned VSTOffset = 0;
>>> >>
>>> >>    std::vector<Type*> TypeList;
>>> >>    BitcodeReaderValueList ValueList;
>>> >> @@ -371,9 +370,7 @@ private:
>>> >>    std::error_code parseTypeTable();
>>> >>    std::error_code parseTypeTableBody();
>>> >>
>>> >> -  ErrorOr<Value *> recordValue(SmallVectorImpl<uint64_t> &Record,
>>> >> -                               unsigned NameIndex, Triple &TT);
>>> >> -  std::error_code parseValueSymbolTable(unsigned Offset = 0);
>>> >> +  std::error_code parseValueSymbolTable();
>>> >>    std::error_code parseConstants();
>>> >>    std::error_code rememberAndSkipFunctionBody();
>>> >>    /// Save the positions of the Metadata blocks and skip parsing the
>>> >> blocks.
>>> >> @@ -1586,61 +1583,7 @@ std::error_code BitcodeReader::parseType
>>> >>    }
>>> >>  }
>>> >>
>>> >> -/// Associate a value with its name from the given index in the
>>> >> provided
>>> >> record.
>>> >> -ErrorOr<Value *> BitcodeReader::recordValue(SmallVectorImpl<uint64_t>
>>> >> &Record,
>>> >> -                                            unsigned NameIndex,
>>> >> Triple
>>> >> &TT) {
>>> >> -  SmallString<128> ValueName;
>>> >> -  if (convertToString(Record, NameIndex, ValueName))
>>> >> -    return error("Invalid record");
>>> >> -  unsigned ValueID = Record[0];
>>> >> -  if (ValueID >= ValueList.size() || !ValueList[ValueID])
>>> >> -    return error("Invalid record");
>>> >> -  Value *V = ValueList[ValueID];
>>> >> -
>>> >> -  V->setName(StringRef(ValueName.data(), ValueName.size()));
>>> >> -  auto *GO = dyn_cast<GlobalObject>(V);
>>> >> -  if (GO) {
>>> >> -    if (GO->getComdat() == reinterpret_cast<Comdat *>(1)) {
>>> >> -      if (TT.isOSBinFormatMachO())
>>> >> -        GO->setComdat(nullptr);
>>> >> -      else
>>> >> -        GO->setComdat(TheModule->getOrInsertComdat(V->getName()));
>>> >> -    }
>>> >> -  }
>>> >> -  return V;
>>> >> -}
>>> >> -
>>> >> -/// Parse the value symbol table at either the current parsing
>>> >> location
>>> >> or
>>> >> -/// at the given bit offset if provided.
>>> >> -std::error_code BitcodeReader::parseValueSymbolTable(unsigned Offset)
>>> >> {
>>> >> -  uint64_t CurrentBit;
>>> >> -  // Pass in the Offset to distinguish between calling for the
>>> >> module-level
>>> >> -  // VST (where we want to jump to the VST offset) and the
>>> >> function-level
>>> >> -  // VST (where we don't).
>>> >> -  if (Offset > 0) {
>>> >> -    // Save the current parsing location so we can jump back at the
>>> >> end
>>> >> -    // of the VST read.
>>> >> -    CurrentBit = Stream.GetCurrentBitNo();
>>> >> -    Stream.JumpToBit(Offset * 32);
>>> >> -    BitstreamEntry Entry = Stream.advance();
>>> >> -    assert(Entry.Kind == BitstreamEntry::SubBlock);
>>> >> -    assert(Entry.ID == bitc::VALUE_SYMTAB_BLOCK_ID);
>>> >> -  }
>>> >> -
>>> >> -  // Compute the delta between the bitcode indices in the VST (the
>>> >> word
>>> >> offset
>>> >> -  // to the word-aligned ENTER_SUBBLOCK for the function block, and
>>> >> that
>>> >> -  // expected by the lazy reader. The reader's EnterSubBlock expects
>>> >> to
>>> >> have
>>> >> -  // already read the ENTER_SUBBLOCK code (size getAbbrevIDWidth) and
>>> >> BlockID
>>> >> -  // (size BlockIDWidth). Note that we access the stream's AbbrevID
>>> >> width
>>> >> here
>>> >> -  // just before entering the VST subblock because: 1) the
>>> >> EnterSubBlock
>>> >> -  // changes the AbbrevID width; 2) the VST block is nested within
>>> >> the
>>> >> same
>>> >> -  // outer MODULE_BLOCK as the FUNCTION_BLOCKs and therefore have the
>>> >> same
>>> >> -  // AbbrevID width before calling EnterSubBlock; and 3) when we want
>>> >> to
>>> >> -  // jump to the FUNCTION_BLOCK using this offset later, we don't
>>> >> want
>>> >> -  // to rely on the stream's AbbrevID width being that of the
>>> >> MODULE_BLOCK.
>>> >> -  unsigned FuncBitcodeOffsetDelta =
>>> >> -      Stream.getAbbrevIDWidth() + bitc::BlockIDWidth;
>>> >> -
>>> >> +std::error_code BitcodeReader::parseValueSymbolTable() {
>>> >>    if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
>>> >>      return error("Invalid record");
>>> >>
>>> >> @@ -1658,8 +1601,6 @@ std::error_code BitcodeReader::parseValu
>>> >>      case BitstreamEntry::Error:
>>> >>        return error("Malformed block");
>>> >>      case BitstreamEntry::EndBlock:
>>> >> -      if (Offset > 0)
>>> >> -        Stream.JumpToBit(CurrentBit);
>>> >>        return std::error_code();
>>> >>      case BitstreamEntry::Record:
>>> >>        // The interesting case.
>>> >> @@ -1672,39 +1613,23 @@ std::error_code BitcodeReader::parseValu
>>> >>      default:  // Default behavior: unknown type.
>>> >>        break;
>>> >>      case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x
>>> >> N]
>>> >> -      ErrorOr<Value *> ValOrErr = recordValue(Record, 1, TT);
>>> >> -      if (std::error_code EC = ValOrErr.getError())
>>> >> -        return EC;
>>> >> -      ValOrErr.get();
>>> >> -      break;
>>> >> -    }
>>> >> -    case bitc::VST_CODE_FNENTRY: {
>>> >> -      // VST_FNENTRY: [valueid, offset, namechar x N]
>>> >> -      ErrorOr<Value *> ValOrErr = recordValue(Record, 2, TT);
>>> >> -      if (std::error_code EC = ValOrErr.getError())
>>> >> -        return EC;
>>> >> -      Value *V = ValOrErr.get();
>>> >> +      if (convertToString(Record, 1, ValueName))
>>> >> +        return error("Invalid record");
>>> >> +      unsigned ValueID = Record[0];
>>> >> +      if (ValueID >= ValueList.size() || !ValueList[ValueID])
>>> >> +        return error("Invalid record");
>>> >> +      Value *V = ValueList[ValueID];
>>> >>
>>> >> -      auto *GO = dyn_cast<GlobalObject>(V);
>>> >> -      if (!GO) {
>>> >> -        // If this is an alias, need to get the actual Function
>>> >> object
>>> >> -        // it aliases, in order to set up the DeferredFunctionInfo
>>> >> entry
>>> >> below.
>>> >> -        auto *GA = dyn_cast<GlobalAlias>(V);
>>> >> -        if (GA)
>>> >> -          GO = GA->getBaseObject();
>>> >> -        assert(GO);
>>> >> -      }
>>> >> -
>>> >> -      uint64_t FuncWordOffset = Record[1];
>>> >> -      Function *F = dyn_cast<Function>(GO);
>>> >> -      assert(F);
>>> >> -      uint64_t FuncBitOffset = FuncWordOffset * 32;
>>> >> -      DeferredFunctionInfo[F] = FuncBitOffset +
>>> >> FuncBitcodeOffsetDelta;
>>> >> -      // Set the NextUnreadBit to point to the last function block.
>>> >> -      // Later when parsing is resumed after function
>>> >> materialization,
>>> >> -      // we can simply skip that last function block.
>>> >> -      if (FuncBitOffset > NextUnreadBit)
>>> >> -        NextUnreadBit = FuncBitOffset;
>>> >> +      V->setName(StringRef(ValueName.data(), ValueName.size()));
>>> >> +      if (auto *GO = dyn_cast<GlobalObject>(V)) {
>>> >> +        if (GO->getComdat() == reinterpret_cast<Comdat *>(1)) {
>>> >> +          if (TT.isOSBinFormatMachO())
>>> >> +            GO->setComdat(nullptr);
>>> >> +          else
>>> >> +
>>> >> GO->setComdat(TheModule->getOrInsertComdat(V->getName()));
>>> >> +        }
>>> >> +      }
>>> >> +      ValueName.clear();
>>> >>        break;
>>> >>      }
>>> >>      case bitc::VST_CODE_BBENTRY: {
>>> >> @@ -2927,23 +2852,9 @@ std::error_code BitcodeReader::parseModu
>>> >>            return EC;
>>> >>          break;
>>> >>        case bitc::VALUE_SYMTAB_BLOCK_ID:
>>> >> -        if (!SeenValueSymbolTable) {
>>> >> -          // Either this is an old form VST without function index
>>> >> and an
>>> >> -          // associated VST forward declaration record (which would
>>> >> have
>>> >> caused
>>> >> -          // the VST to be jumped to and parsed before it was
>>> >> encountered
>>> >> -          // normally in the stream), or there were no function
>>> >> blocks to
>>> >> -          // trigger an earlier parsing of the VST.
>>> >> -          assert(VSTOffset == 0 || FunctionsWithBodies.empty());
>>> >> -          if (std::error_code EC = parseValueSymbolTable())
>>> >> -            return EC;
>>> >> -          SeenValueSymbolTable = true;
>>> >> -        } else {
>>> >> -          // We must have had a VST forward declaration record, which
>>> >> caused
>>> >> -          // the parser to jump to and parse the VST earlier.
>>> >> -          assert(VSTOffset > 0);
>>> >> -          if (Stream.SkipBlock())
>>> >> -            return error("Invalid record");
>>> >> -        }
>>> >> +        if (std::error_code EC = parseValueSymbolTable())
>>> >> +          return EC;
>>> >> +        SeenValueSymbolTable = true;
>>> >>          break;
>>> >>        case bitc::CONSTANTS_BLOCK_ID:
>>> >>          if (std::error_code EC = parseConstants())
>>> >> @@ -2971,32 +2882,6 @@ std::error_code BitcodeReader::parseModu
>>> >>            SeenFirstFunctionBody = true;
>>> >>          }
>>> >>
>>> >> -        if (VSTOffset > 0) {
>>> >> -          // If we have a VST forward declaration record, make sure
>>> >> we
>>> >> -          // parse the VST now if we haven't already. It is needed to
>>> >> -          // set up the DeferredFunctionInfo vector for lazy reading.
>>> >> -          if (!SeenValueSymbolTable) {
>>> >> -            if (std::error_code EC =
>>> >> -                    BitcodeReader::parseValueSymbolTable(VSTOffset))
>>> >> -              return EC;
>>> >> -            SeenValueSymbolTable = true;
>>> >> -            return std::error_code();
>>> >> -          } else {
>>> >> -            // If we have a VST forward declaration record, but have
>>> >> already
>>> >> -            // parsed the VST (just above, when the first function
>>> >> body
>>> >> was
>>> >> -            // encountered here), then we are resuming the parse
>>> >> after
>>> >> -            // materializing functions. The NextUnreadBit points to
>>> >> the
>>> >> start
>>> >> -            // of the last function block recorded in the VST (set
>>> >> when
>>> >> -            // parsing the VST function entries). Skip it.
>>> >> -            if (Stream.SkipBlock())
>>> >> -              return error("Invalid record");
>>> >> -            continue;
>>> >> -          }
>>> >> -        }
>>> >> -
>>> >> -        // Support older bitcode files that did not have the function
>>> >> -        // index in the VST, nor a VST forward declaration record.
>>> >> -        // Build the DeferredFunctionInfo vector on the fly.
>>> >>          if (std::error_code EC = rememberAndSkipFunctionBody())
>>> >>            return EC;
>>> >>          // Suspend parsing when we reach the function bodies.
>>> >> Subsequent
>>> >> @@ -3300,12 +3185,6 @@ std::error_code BitcodeReader::parseModu
>>> >>          return error("Invalid record");
>>> >>        ValueList.shrinkTo(Record[0]);
>>> >>        break;
>>> >> -    /// MODULE_CODE_VSTOFFSET: [offset]
>>> >> -    case bitc::MODULE_CODE_VSTOFFSET:
>>> >> -      if (Record.size() < 1)
>>> >> -        return error("Invalid record");
>>> >> -      VSTOffset = Record[0];
>>> >> -      break;
>>> >>      }
>>> >>      Record.clear();
>>> >>    }
>>> >> @@ -4763,11 +4642,6 @@ std::error_code BitcodeReader::findFunct
>>> >>      Function *F,
>>> >>      DenseMap<Function *, uint64_t>::iterator
>>> >> DeferredFunctionInfoIterator) {
>>> >>    while (DeferredFunctionInfoIterator->second == 0) {
>>> >> -    // This is the fallback handling for the old format bitcode that
>>> >> -    // didn't contain the function index in the VST. Assert if we end
>>> >> up
>>> >> -    // here for the new format (which is the only time the VSTOffset
>>> >> would
>>> >> -    // be non-zero).
>>> >> -    assert(VSTOffset == 0);
>>> >>      if (Stream.AtEndOfStream())
>>> >>        return error("Could not find function in stream");
>>> >>      // ParseModule will parse the next body in the stream and set its
>>> >>
>>> >> Modified: llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp
>>> >> URL:
>>> >>
>>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp?rev=247898&r1=247897&r2=247898&view=diff
>>> >>
>>> >>
>>> >> ==============================================================================
>>> >> --- llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp (original)
>>> >> +++ llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp Thu Sep 17
>>> >> 11:19:10
>>> >> 2015
>>> >> @@ -574,40 +574,10 @@ static void writeComdats(const ValueEnum
>>> >>    }
>>> >>  }
>>> >>
>>> >> -/// Write a record that will eventually hold the word offset of the
>>> >> -/// module-level VST. For now the offset is 0, which will be
>>> >> backpatched
>>> >> -/// after the real VST is written. Returns the bit offset to
>>> >> backpatch.
>>> >> -static uint64_t WriteValueSymbolTableForwardDecl(const
>>> >> ValueSymbolTable
>>> >> &VST,
>>> >> -                                                 BitstreamWriter
>>> >> &Stream)
>>> >> {
>>> >> -  if (VST.empty()) return 0;
>>> >> -
>>> >> -  // Write a placeholder value in for the offset of the real VST,
>>> >> -  // which is written after the function blocks so that it can
>>> >> include
>>> >> -  // the offset of each function. The placeholder offset will be
>>> >> -  // updated when the real VST is written.
>>> >> -  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
>>> >> -  Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
>>> >> -  // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
>>> >> -  // hold the real VST offset. Must use fixed instead of VBR as we
>>> >> don't
>>> >> -  // know how many VBR chunks to reserve ahead of time.
>>> >> -  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
>>> >> -  unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(Abbv);
>>> >> -
>>> >> -  // Emit the placeholder
>>> >> -  ArrayRef<unsigned> Vals = {llvm::bitc::MODULE_CODE_VSTOFFSET, 0};
>>> >> -  Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
>>> >> -
>>> >> -  // Compute and return the bit offset to the placeholder, which will
>>> >> be
>>> >> -  // patched when the real VST is written. We can simply subtract the
>>> >> 32-bit
>>> >> -  // fixed size from the current bit number to get the location to
>>> >> backpatch.
>>> >> -  return Stream.GetCurrentBitNo() - 32;
>>> >> -}
>>> >> -
>>> >> -/// Emit top-level description of module, including target triple,
>>> >> inline
>>> >> asm,
>>> >> -/// descriptors for global variables, and function prototype info.
>>> >> -/// Returns the bit offset to backpatch with the location of the real
>>> >> VST.
>>> >> -static uint64_t WriteModuleInfo(const Module *M, const
>>> >> ValueEnumerator
>>> >> &VE,
>>> >> -                                BitstreamWriter &Stream) {
>>> >> +// Emit top-level description of module, including target triple,
>>> >> inline
>>> >> asm,
>>> >> +// descriptors for global variables, and function prototype info.
>>> >> +static void WriteModuleInfo(const Module *M, const ValueEnumerator
>>> >> &VE,
>>> >> +                            BitstreamWriter &Stream) {
>>> >>    // Emit various pieces of data attached to a module.
>>> >>    if (!M->getTargetTriple().empty())
>>> >>      WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
>>> >> @@ -767,10 +737,6 @@ static uint64_t WriteModuleInfo(const Mo
>>> >>      Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
>>> >>      Vals.clear();
>>> >>    }
>>> >> -
>>> >> -  uint64_t VSTOffsetPlaceholder =
>>> >> -      WriteValueSymbolTableForwardDecl(M->getValueSymbolTable(),
>>> >> Stream);
>>> >> -  return VSTOffsetPlaceholder;
>>> >>  }
>>> >>
>>> >>  static uint64_t GetOptimizationFlags(const Value *V) {
>>> >> @@ -2125,119 +2091,32 @@ static StringEncoding getStringEncoding(
>>> >>      return SE_Fixed7;
>>> >>  }
>>> >>
>>> >> -/// Emit names for globals/functions etc. The VSTOffsetPlaceholder,
>>> >> -/// BitcodeStartBit and FunctionIndex are only passed for the
>>> >> module-level
>>> >> -/// VST, where we are including a function bitcode index and need to
>>> >> -/// backpatch the VST forward declaration record.
>>> >> -static void WriteValueSymbolTable(
>>> >> -    const ValueSymbolTable &VST, const ValueEnumerator &VE,
>>> >> -    BitstreamWriter &Stream, uint64_t VSTOffsetPlaceholder = 0,
>>> >> -    uint64_t BitcodeStartBit = 0,
>>> >> -    DenseMap<const Function *, uint64_t> *FunctionIndex = nullptr) {
>>> >> -  if (VST.empty()) {
>>> >> -    // WriteValueSymbolTableForwardDecl should have returned early as
>>> >> -    // well. Ensure this handling remains in sync by asserting that
>>> >> -    // the placeholder offset is not set.
>>> >> -    assert(VSTOffsetPlaceholder == 0);
>>> >> -    return;
>>> >> -  }
>>> >> -
>>> >> -  if (VSTOffsetPlaceholder > 0) {
>>> >> -    // Get the offset of the VST we are writing, and backpatch it
>>> >> into
>>> >> -    // the VST forward declaration record.
>>> >> -    uint64_t VSTOffset = Stream.GetCurrentBitNo();
>>> >> -    // The BitcodeStartBit was the stream offset of the actual
>>> >> bitcode
>>> >> -    // (e.g. excluding any initial darwin header).
>>> >> -    VSTOffset -= BitcodeStartBit;
>>> >> -    assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
>>> >> -    Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32);
>>> >> -  }
>>> >> -
>>> >> +// Emit names for globals/functions etc.
>>> >> +static void WriteValueSymbolTable(const ValueSymbolTable &VST,
>>> >> +                                  const ValueEnumerator &VE,
>>> >> +                                  BitstreamWriter &Stream) {
>>> >> +  if (VST.empty()) return;
>>> >>    Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
>>> >>
>>> >> -  // For the module-level VST, add abbrev Ids for the
>>> >> VST_CODE_FNENTRY
>>> >> -  // records, which are not used in the per-function VSTs.
>>> >> -  unsigned FnEntry8BitAbbrev;
>>> >> -  unsigned FnEntry7BitAbbrev;
>>> >> -  unsigned FnEntry6BitAbbrev;
>>> >> -  if (VSTOffsetPlaceholder > 0) {
>>> >> -    // 8-bit fixed-width VST_FNENTRY function strings.
>>> >> -    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
>>> >> -    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // value id
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  //
>>> >> funcoffset
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
>>> >> -    FnEntry8BitAbbrev = Stream.EmitAbbrev(Abbv);
>>> >> -
>>> >> -    // 7-bit fixed width VST_FNENTRY function strings.
>>> >> -    Abbv = new BitCodeAbbrev();
>>> >> -    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // value id
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  //
>>> >> funcoffset
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
>>> >> -    FnEntry7BitAbbrev = Stream.EmitAbbrev(Abbv);
>>> >> -
>>> >> -    // 6-bit char6 VST_FNENTRY function strings.
>>> >> -    Abbv = new BitCodeAbbrev();
>>> >> -    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // value id
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  //
>>> >> funcoffset
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
>>> >> -    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
>>> >> -    FnEntry6BitAbbrev = Stream.EmitAbbrev(Abbv);
>>> >> -  }
>>> >> -
>>> >>    // FIXME: Set up the abbrev, we know how many values there are!
>>> >>    // FIXME: We know if the type names can use 7-bit ascii.
>>> >>    SmallVector<unsigned, 64> NameVals;
>>> >>
>>> >>    for (const ValueName &Name : VST) {
>>> >> +
>>> >>      // Figure out the encoding to use for the name.
>>> >>      StringEncoding Bits =
>>> >>          getStringEncoding(Name.getKeyData(), Name.getKeyLength());
>>> >>
>>> >>      unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
>>> >> -    NameVals.push_back(VE.getValueID(Name.getValue()));
>>> >> -
>>> >> -    Function *F = dyn_cast<Function>(Name.getValue());
>>> >> -    if (!F) {
>>> >> -      // If value is an alias, need to get the aliased base object to
>>> >> -      // see if it is a function.
>>> >> -      auto *GA = dyn_cast<GlobalAlias>(Name.getValue());
>>> >> -      if (GA && GA->getBaseObject())
>>> >> -        F = dyn_cast<Function>(GA->getBaseObject());
>>> >> -    }
>>> >>
>>> >>      // VST_ENTRY:   [valueid, namechar x N]
>>> >> -    // VST_FNENTRY: [valueid, funcoffset, namechar x N]
>>> >>      // VST_BBENTRY: [bbid, namechar x N]
>>> >>      unsigned Code;
>>> >>      if (isa<BasicBlock>(Name.getValue())) {
>>> >>        Code = bitc::VST_CODE_BBENTRY;
>>> >>        if (Bits == SE_Char6)
>>> >>          AbbrevToUse = VST_BBENTRY_6_ABBREV;
>>> >> -    } else if (F && !F->isDeclaration()) {
>>> >> -      // Must be the module-level VST, where we pass in the Index and
>>> >> -      // have a VSTOffsetPlaceholder. The function-level VST should
>>> >> not
>>> >> -      // contain any Function symbols.
>>> >> -      assert(FunctionIndex);
>>> >> -      assert(VSTOffsetPlaceholder > 0);
>>> >> -
>>> >> -      // Save the word offset of the function (from the start of the
>>> >> -      // actual bitcode written to the stream).
>>> >> -      assert(FunctionIndex->count(F) == 1);
>>> >> -      uint64_t BitcodeIndex = (*FunctionIndex)[F] - BitcodeStartBit;
>>> >> -      assert((BitcodeIndex & 31) == 0 && "function block not 32-bit
>>> >> aligned");
>>> >> -      NameVals.push_back(BitcodeIndex / 32);
>>> >> -
>>> >> -      Code = bitc::VST_CODE_FNENTRY;
>>> >> -      AbbrevToUse = FnEntry8BitAbbrev;
>>> >> -      if (Bits == SE_Char6)
>>> >> -        AbbrevToUse = FnEntry6BitAbbrev;
>>> >> -      else if (Bits == SE_Fixed7)
>>> >> -        AbbrevToUse = FnEntry7BitAbbrev;
>>> >>      } else {
>>> >>        Code = bitc::VST_CODE_ENTRY;
>>> >>        if (Bits == SE_Char6)
>>> >> @@ -2246,6 +2125,7 @@ static void WriteValueSymbolTable(
>>> >>          AbbrevToUse = VST_ENTRY_7_ABBREV;
>>> >>      }
>>> >>
>>> >> +    NameVals.push_back(VE.getValueID(Name.getValue()));
>>> >>      for (const char *P = Name.getKeyData(),
>>> >>           *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
>>> >>        NameVals.push_back((unsigned char)*P);
>>> >> @@ -2293,13 +2173,7 @@ static void WriteUseListBlock(const Func
>>> >>
>>> >>  /// WriteFunction - Emit a function body to the module stream.
>>> >>  static void WriteFunction(const Function &F, ValueEnumerator &VE,
>>> >> -                          BitstreamWriter &Stream,
>>> >> -                          DenseMap<const Function *, uint64_t>
>>> >> &FunctionIndex) {
>>> >> -  // Save the bitcode index of the start of this function block for
>>> >> recording
>>> >> -  // in the VST.
>>> >> -  uint64_t BitcodeIndex = Stream.GetCurrentBitNo();
>>> >> -  FunctionIndex[&F] = BitcodeIndex;
>>> >> -
>>> >> +                          BitstreamWriter &Stream) {
>>> >>    Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
>>> >>    VE.incorporateFunction(F);
>>> >>
>>> >> @@ -2547,8 +2421,7 @@ static void WriteBlockInfo(const ValueEn
>>> >>
>>> >>  /// WriteModule - Emit the specified module to the bitstream.
>>> >>  static void WriteModule(const Module *M, BitstreamWriter &Stream,
>>> >> -                        bool ShouldPreserveUseListOrder,
>>> >> -                        uint64_t BitcodeStartBit) {
>>> >> +                        bool ShouldPreserveUseListOrder) {
>>> >>    Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
>>> >>
>>> >>    SmallVector<unsigned, 1> Vals;
>>> >> @@ -2575,7 +2448,7 @@ static void WriteModule(const Module *M,
>>> >>
>>> >>    // Emit top-level description of module, including target triple,
>>> >> inline asm,
>>> >>    // descriptors for global variables, and function prototype info.
>>> >> -  uint64_t VSTOffsetPlaceholder = WriteModuleInfo(M, VE, Stream);
>>> >> +  WriteModuleInfo(M, VE, Stream);
>>> >>
>>> >>    // Emit constants.
>>> >>    WriteModuleConstants(VE, Stream);
>>> >> @@ -2586,18 +2459,17 @@ static void WriteModule(const Module *M,
>>> >>    // Emit metadata.
>>> >>    WriteModuleMetadataStore(M, Stream);
>>> >>
>>> >> +  // Emit names for globals/functions etc.
>>> >> +  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
>>> >> +
>>> >>    // Emit module-level use-lists.
>>> >>    if (VE.shouldPreserveUseListOrder())
>>> >>      WriteUseListBlock(nullptr, VE, Stream);
>>> >>
>>> >>    // Emit function bodies.
>>> >> -  DenseMap<const Function *, uint64_t> FunctionIndex;
>>> >>    for (Module::const_iterator F = M->begin(), E = M->end(); F != E;
>>> >> ++F)
>>> >>      if (!F->isDeclaration())
>>> >> -      WriteFunction(*F, VE, Stream, FunctionIndex);
>>> >> -
>>> >> -  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream,
>>> >> -                        VSTOffsetPlaceholder, BitcodeStartBit,
>>> >> &FunctionIndex);
>>> >> +      WriteFunction(*F, VE, Stream);
>>> >>
>>> >>    Stream.ExitBlock();
>>> >>  }
>>> >> @@ -2688,11 +2560,6 @@ void llvm::WriteBitcodeToFile(const Modu
>>> >>    // Emit the module into the buffer.
>>> >>    {
>>> >>      BitstreamWriter Stream(Buffer);
>>> >> -    // Save the start bit of the actual bitcode, in case there is
>>> >> space
>>> >> -    // saved at the start for the darwin header above. The reader
>>> >> stream
>>> >> -    // will start at the bitcode, and we need the offset of the VST
>>> >> -    // to line up.
>>> >> -    uint64_t BitcodeStartBit = Stream.GetCurrentBitNo();
>>> >>
>>> >>      // Emit the file header.
>>> >>      Stream.Emit((unsigned)'B', 8);
>>> >> @@ -2703,7 +2570,7 @@ void llvm::WriteBitcodeToFile(const Modu
>>> >>      Stream.Emit(0xD, 4);
>>> >>
>>> >>      // Emit the module.
>>> >> -    WriteModule(M, Stream, ShouldPreserveUseListOrder,
>>> >> BitcodeStartBit);
>>> >> +    WriteModule(M, Stream, ShouldPreserveUseListOrder);
>>> >>    }
>>> >>
>>> >>    if (TT.isOSDarwin())
>>> >>
>>> >> Removed: llvm/trunk/test/Bitcode/vst-forward-declaration.ll
>>> >> URL:
>>> >>
>>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/vst-forward-declaration.ll?rev=247897&view=auto
>>> >>
>>> >>
>>> >> ==============================================================================
>>> >> --- llvm/trunk/test/Bitcode/vst-forward-declaration.ll (original)
>>> >> +++ llvm/trunk/test/Bitcode/vst-forward-declaration.ll (removed)
>>> >> @@ -1,29 +0,0 @@
>>> >> -; RUN: llvm-as < %s | llvm-bcanalyzer -dump | FileCheck %s
>>> >> -check-prefix=BC
>>> >> -; Check for VST forward declaration record and VST function index
>>> >> records.
>>> >> -
>>> >> -; BC: <VSTOFFSET
>>> >> -; BC: <FNENTRY
>>> >> -; BC: <FNENTRY
>>> >> -
>>> >> -; RUN: llvm-as < %s | llvm-dis | FileCheck %s
>>> >> -; Check that this round-trips correctly.
>>> >> -
>>> >> -; ModuleID = '<stdin>'
>>> >> -target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
>>> >> -target triple = "x86_64-unknown-linux-gnu"
>>> >> -
>>> >> -; CHECK: define i32 @foo()
>>> >> -
>>> >> -; Function Attrs: nounwind uwtable
>>> >> -define i32 @foo() #0 {
>>> >> -entry:
>>> >> -  ret i32 1
>>> >> -}
>>> >> -
>>> >> -; CHECK: define i32 @bar(i32 %x)
>>> >> -
>>> >> -; Function Attrs: nounwind uwtable
>>> >> -define i32 @bar(i32 %x) #0 {
>>> >> -entry:
>>> >> -  ret i32 %x
>>> >> -}
>>> >>
>>> >> Modified: llvm/trunk/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
>>> >> URL:
>>> >>
>>> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp?rev=247898&r1=247897&r2=247898&view=diff
>>> >>
>>> >>
>>> >> ==============================================================================
>>> >> --- llvm/trunk/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp (original)
>>> >> +++ llvm/trunk/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp Thu Sep 17
>>> >> 11:19:10 2015
>>> >> @@ -165,7 +165,6 @@ static const char *GetCodeName(unsigned
>>> >>        STRINGIFY_CODE(MODULE_CODE, ALIAS)
>>> >>        STRINGIFY_CODE(MODULE_CODE, PURGEVALS)
>>> >>        STRINGIFY_CODE(MODULE_CODE, GCNAME)
>>> >> -      STRINGIFY_CODE(MODULE_CODE, VSTOFFSET)
>>> >>      }
>>> >>    case bitc::PARAMATTR_BLOCK_ID:
>>> >>      switch (CodeID) {
>>> >> @@ -267,7 +266,6 @@ static const char *GetCodeName(unsigned
>>> >>      default: return nullptr;
>>> >>      STRINGIFY_CODE(VST_CODE, ENTRY)
>>> >>      STRINGIFY_CODE(VST_CODE, BBENTRY)
>>> >> -    STRINGIFY_CODE(VST_CODE, FNENTRY)
>>> >>      }
>>> >>    case bitc::METADATA_ATTACHMENT_ID:
>>> >>      switch(CodeID) {
>>> >>
>>> >>
>>> >> _______________________________________________
>>> >> llvm-commits mailing list
>>> >> llvm-commits at lists.llvm.org
>>> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>> >
>>> >
>>>
>>>
>>>
>>> --
>>> Teresa Johnson | Software Engineer | tejohnson at google.com | 408-460-2413
>>
>>
>



-- 
Teresa Johnson | Software Engineer | tejohnson at google.com | 408-460-2413


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