Write the identifier offsets array into the PCH file as a blob, so
that the PCH reader does not have to decode the VBR encoding at PCH
load time.
Also, reduce the size of the identifier offsets from 64 bits down to
32 bits. The identifier table itself isn't going to grow to more than
4GB :)
Overall, this results in a 13% speedup in the Cocoa-prefixed "Hello,
World" benchmark.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70063 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 91ddbf4..4ac8364 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -2119,7 +2119,18 @@
}
// Write the offsets table for identifier IDs.
- Stream.EmitRecord(pch::IDENTIFIER_OFFSET, IdentifierOffsets);
+ BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
+ Abbrev->Add(BitCodeAbbrevOp(pch::IDENTIFIER_OFFSET));
+ Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
+ Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
+ unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
+
+ RecordData Record;
+ Record.push_back(pch::IDENTIFIER_OFFSET);
+ Record.push_back(IdentifierOffsets.size());
+ Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
+ (const char *)&IdentifierOffsets.front(),
+ IdentifierOffsets.size() * sizeof(uint32_t));
}
/// \brief Write a record containing the given attributes.
@@ -2253,7 +2264,7 @@
/// \brief Note that the identifier II occurs at the given offset
/// within the identifier table.
void PCHWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
- IdentifierOffsets[IdentifierIDs[II] - 1] = (Offset << 1) | 0x01;
+ IdentifierOffsets[IdentifierIDs[II] - 1] = Offset;
}
/// \brief Note that the selector Sel occurs at the given offset