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Revert "Bitcode: Collect all MDString records into a single blob"

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This reverts commit r264409 since it failed to bootstrap:
http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_build/8302/

llvm-svn: 264410
This commit is contained in:
Duncan P. N. Exon Smith
2016-03-25 15:22:27 +00:00
parent fdbf0a5af8
commit fc8110041f
11 changed files with 50 additions and 142 deletions
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85
llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
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@@ -1347,78 +1347,31 @@ static void writeNamedMetadata(const Module &M, const ValueEnumerator &VE,
}
}
static unsigned createMDStringDataAbbrev(BitstreamWriter &Stream) {
BitCodeAbbrev *Abbv = new BitCodeAbbrev();
Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_BULK_STRING_DATA));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
return Stream.EmitAbbrev(Abbv);
}
static void emitMDStringBlob(unsigned DataAbbrev,
ArrayRef<const Metadata *> Strings,
BitstreamWriter &Stream,
SmallVectorImpl<uint64_t> &Record,
SmallString<4096> &Blob) {
for (const Metadata *MD : Strings) {
StringRef S = cast<MDString>(MD)->getString();
Record.push_back(S.size());
Blob.append(S.begin(), S.end());
}
Stream.EmitRecord(bitc::METADATA_BULK_STRING_SIZES, Record);
Record.clear();
Record.push_back(bitc::METADATA_BULK_STRING_DATA);
Stream.EmitRecordWithBlob(DataAbbrev, Record, Blob);
Record.clear();
}
/// Write out a section of records for MDString.
///
/// All the MDString elements in a metadata block are emitted in bulk. They're
/// grouped into blocks, and each block is emitted with pair of records:
///
/// - SIZES: a list of the sizes of the strings in the block.
/// - DATA: the blob itself.
static void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
BitstreamWriter &Stream,
SmallVectorImpl<uint64_t> &Record) {
if (Strings.empty())
return;
// Emit strings in large blocks to reduce record overhead. Somewhat
// arbitrarily, limit this to 512 strings per blob:
// - big enough to eliminate overhead;
// - small enough that the reader's SIZES record will stay within a page.
const size_t NumStringsPerBlob = 512;
Record.reserve(std::min(NumStringsPerBlob, Strings.size()));
unsigned DataAbbrev = createMDStringDataAbbrev(Stream);
SmallString<4096> Blob;
while (Strings.size() > NumStringsPerBlob) {
emitMDStringBlob(DataAbbrev, Strings.slice(0, NumStringsPerBlob), Stream,
Record, Blob);
Strings = Strings.slice(NumStringsPerBlob);
}
if (!Strings.empty())
emitMDStringBlob(DataAbbrev, Strings, Stream, Record, Blob);
}
static void WriteModuleMetadata(const Module &M,
const ValueEnumerator &VE,
BitstreamWriter &Stream) {
if (VE.getMDs().empty() && M.named_metadata_empty())
const auto &MDs = VE.getMDs();
if (MDs.empty() && M.named_metadata_empty())
return;
Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
unsigned MDSAbbrev = 0;
if (VE.hasMDString()) {
// Abbrev for METADATA_STRING.
BitCodeAbbrev *Abbv = new BitCodeAbbrev();
Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
MDSAbbrev = Stream.EmitAbbrev(Abbv);
}
// Initialize MDNode abbreviations.
#define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
#include "llvm/IR/Metadata.def"
SmallVector<uint64_t, 64> Record;
writeMetadataStrings(VE.getMDStrings(), Stream, Record);
for (const Metadata *MD : VE.getNonMDStrings()) {
for (const Metadata *MD : MDs) {
if (const MDNode *N = dyn_cast<MDNode>(MD)) {
assert(N->isResolved() && "Expected forward references to be resolved");
@@ -1432,7 +1385,17 @@ static void WriteModuleMetadata(const Module &M,
#include "llvm/IR/Metadata.def"
}
}
WriteValueAsMetadata(cast<ConstantAsMetadata>(MD), VE, Stream, Record);
if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
WriteValueAsMetadata(MDC, VE, Stream, Record);
continue;
}
const MDString *MDS = cast<MDString>(MD);
// Code: [strchar x N]
Record.append(MDS->bytes_begin(), MDS->bytes_end());
// Emit the finished record.
Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
Record.clear();
}
writeNamedMetadata(M, VE, Stream, Record);