//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Chris Lattner and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#define BITSTREAM_WRITER_H
#include "llvm/Bitcode/BitCodes.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/DataTypes.h"
-#include <cassert>
#include <vector>
namespace llvm {
/// CurValue - The current value. Only bits < CurBit are valid.
uint32_t CurValue;
- // CurCodeSize - This is the declared size of code values used for the current
- // block, in bits.
+ /// CurCodeSize - This is the declared size of code values used for the
+ /// current block, in bits.
unsigned CurCodeSize;
+
+ /// BlockInfoCurBID - When emitting a BLOCKINFO_BLOCK, this is the currently
+ /// selected BLOCK ID.
+ unsigned BlockInfoCurBID;
+ /// CurAbbrevs - Abbrevs installed at in this block.
+ std::vector<BitCodeAbbrev*> CurAbbrevs;
+
struct Block {
unsigned PrevCodeSize;
unsigned StartSizeWord;
+ std::vector<BitCodeAbbrev*> PrevAbbrevs;
Block(unsigned PCS, unsigned SSW) : PrevCodeSize(PCS), StartSizeWord(SSW) {}
};
/// BlockScope - This tracks the current blocks that we have entered.
std::vector<Block> BlockScope;
+
+ /// BlockInfo - This contains information emitted to BLOCKINFO_BLOCK blocks.
+ /// These describe abbreviations that all blocks of the specified ID inherit.
+ struct BlockInfo {
+ unsigned BlockID;
+ std::vector<BitCodeAbbrev*> Abbrevs;
+ };
+ std::vector<BlockInfo> BlockInfoRecords;
+
public:
- BitstreamWriter(std::vector<unsigned char> &O)
+ explicit BitstreamWriter(std::vector<unsigned char> &O)
: Out(O), CurBit(0), CurValue(0), CurCodeSize(2) {}
~BitstreamWriter() {
assert(CurBit == 0 && "Unflused data remaining");
- assert(BlockScope.empty() && "Block imbalance");
+ assert(BlockScope.empty() && CurAbbrevs.empty() && "Block imbalance");
+
+ // Free the BlockInfoRecords.
+ while (!BlockInfoRecords.empty()) {
+ BlockInfo &Info = BlockInfoRecords.back();
+ // Free blockinfo abbrev info.
+ for (unsigned i = 0, e = Info.Abbrevs.size(); i != e; ++i)
+ Info.Abbrevs[i]->dropRef();
+ BlockInfoRecords.pop_back();
+ }
}
//===--------------------------------------------------------------------===//
// Basic Primitives for emitting bits to the stream.
// Block Manipulation
//===--------------------------------------------------------------------===//
+ /// getBlockInfo - If there is block info for the specified ID, return it,
+ /// otherwise return null.
+ BlockInfo *getBlockInfo(unsigned BlockID) {
+ // Common case, the most recent entry matches BlockID.
+ if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
+ return &BlockInfoRecords.back();
+
+ for (unsigned i = 0, e = BlockInfoRecords.size(); i != e; ++i)
+ if (BlockInfoRecords[i].BlockID == BlockID)
+ return &BlockInfoRecords[i];
+ return 0;
+ }
+
void EnterSubblock(unsigned BlockID, unsigned CodeLen) {
// Block header:
// [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
EmitVBR(BlockID, bitc::BlockIDWidth);
EmitVBR(CodeLen, bitc::CodeLenWidth);
FlushToWord();
- BlockScope.push_back(Block(CurCodeSize, Out.size()/4));
+
+ unsigned BlockSizeWordLoc = Out.size();
+ unsigned OldCodeSize = CurCodeSize;
+
// Emit a placeholder, which will be replaced when the block is popped.
Emit(0, bitc::BlockSizeWidth);
CurCodeSize = CodeLen;
+
+ // Push the outer block's abbrev set onto the stack, start out with an
+ // empty abbrev set.
+ BlockScope.push_back(Block(OldCodeSize, BlockSizeWordLoc/4));
+ BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
+
+ // If there is a blockinfo for this BlockID, add all the predefined abbrevs
+ // to the abbrev list.
+ if (BlockInfo *Info = getBlockInfo(BlockID)) {
+ for (unsigned i = 0, e = Info->Abbrevs.size(); i != e; ++i) {
+ CurAbbrevs.push_back(Info->Abbrevs[i]);
+ Info->Abbrevs[i]->addRef();
+ }
+ }
}
void ExitBlock() {
assert(!BlockScope.empty() && "Block scope imbalance!");
- Block B = BlockScope.back();
- BlockScope.pop_back();
+
+ // Delete all abbrevs.
+ for (unsigned i = 0, e = CurAbbrevs.size(); i != e; ++i)
+ CurAbbrevs[i]->dropRef();
+
+ const Block &B = BlockScope.back();
// Block tail:
// [END_BLOCK, <align4bytes>]
Out[ByteNo++] = (unsigned char)(SizeInWords >> 16);
Out[ByteNo++] = (unsigned char)(SizeInWords >> 24);
- // Restore the outer block's code size.
+ // Restore the inner block's code size and abbrev table.
CurCodeSize = B.PrevCodeSize;
+ BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
+ BlockScope.pop_back();
}
//===--------------------------------------------------------------------===//
// Record Emission
//===--------------------------------------------------------------------===//
+private:
+ /// EmitAbbreviatedField - Emit a single scalar field value with the specified
+ /// encoding.
+ template<typename uintty>
+ void EmitAbbreviatedField(const BitCodeAbbrevOp &Op, uintty V) {
+ if (Op.isLiteral()) {
+ // If the abbrev specifies the literal value to use, don't emit
+ // anything.
+ assert(V == Op.getLiteralValue() &&
+ "Invalid abbrev for record!");
+ return;
+ }
+
+ // Encode the value as we are commanded.
+ switch (Op.getEncoding()) {
+ default: assert(0 && "Unknown encoding!");
+ case BitCodeAbbrevOp::Fixed:
+ Emit((unsigned)V, (unsigned)Op.getEncodingData());
+ break;
+ case BitCodeAbbrevOp::VBR:
+ EmitVBR64(V, (unsigned)Op.getEncodingData());
+ break;
+ case BitCodeAbbrevOp::Char6:
+ Emit(BitCodeAbbrevOp::EncodeChar6((char)V), 6);
+ break;
+ }
+ }
+public:
+
/// EmitRecord - Emit the specified record to the stream, using an abbrev if
/// we have one to compress the output.
- void EmitRecord(unsigned Code, SmallVectorImpl<uint64_t> &Vals,
+ template<typename uintty>
+ void EmitRecord(unsigned Code, SmallVectorImpl<uintty> &Vals,
unsigned Abbrev = 0) {
if (Abbrev) {
- assert(0 && "abbrevs not implemented yet!");
+ unsigned AbbrevNo = Abbrev-bitc::FIRST_APPLICATION_ABBREV;
+ assert(AbbrevNo < CurAbbrevs.size() && "Invalid abbrev #!");
+ BitCodeAbbrev *Abbv = CurAbbrevs[AbbrevNo];
+
+ EmitCode(Abbrev);
+
+ // Insert the code into Vals to treat it uniformly.
+ Vals.insert(Vals.begin(), Code);
+
+ unsigned RecordIdx = 0;
+ for (unsigned i = 0, e = Abbv->getNumOperandInfos(); i != e; ++i) {
+ const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
+ if (Op.isLiteral() || Op.getEncoding() != BitCodeAbbrevOp::Array) {
+ assert(RecordIdx < Vals.size() && "Invalid abbrev/record");
+ EmitAbbreviatedField(Op, Vals[RecordIdx]);
+ ++RecordIdx;
+ } else {
+ // Array case.
+ assert(i+2 == e && "array op not second to last?");
+ const BitCodeAbbrevOp &EltEnc = Abbv->getOperandInfo(++i);
+
+ // Emit a vbr6 to indicate the number of elements present.
+ EmitVBR(Vals.size()-RecordIdx, 6);
+
+ // Emit each field.
+ for (; RecordIdx != Vals.size(); ++RecordIdx)
+ EmitAbbreviatedField(EltEnc, Vals[RecordIdx]);
+ }
+ }
+ assert(RecordIdx == Vals.size() && "Not all record operands emitted!");
} else {
// If we don't have an abbrev to use, emit this in its fully unabbreviated
// form.
EmitVBR64(Vals[i], 6);
}
}
+
+ //===--------------------------------------------------------------------===//
+ // Abbrev Emission
+ //===--------------------------------------------------------------------===//
- /// EmitRecord - Emit the specified record to the stream, using an abbrev if
- /// we have one to compress the output.
- void EmitRecord(unsigned Code, SmallVectorImpl<unsigned> &Vals,
- unsigned Abbrev = 0) {
- if (Abbrev) {
- assert(0 && "abbrevs not implemented yet!");
- } else {
- // If we don't have an abbrev to use, emit this in its fully unabbreviated
- // form.
- EmitCode(bitc::UNABBREV_RECORD);
- EmitVBR(Code, 6);
- EmitVBR(Vals.size(), 6);
- for (unsigned i = 0, e = Vals.size(); i != e; ++i)
- EmitVBR(Vals[i], 6);
+private:
+ // Emit the abbreviation as a DEFINE_ABBREV record.
+ void EncodeAbbrev(BitCodeAbbrev *Abbv) {
+ EmitCode(bitc::DEFINE_ABBREV);
+ EmitVBR(Abbv->getNumOperandInfos(), 5);
+ for (unsigned i = 0, e = Abbv->getNumOperandInfos(); i != e; ++i) {
+ const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
+ Emit(Op.isLiteral(), 1);
+ if (Op.isLiteral()) {
+ EmitVBR64(Op.getLiteralValue(), 8);
+ } else {
+ Emit(Op.getEncoding(), 3);
+ if (Op.hasEncodingData())
+ EmitVBR64(Op.getEncodingData(), 5);
+ }
}
}
+public:
+
+ /// EmitAbbrev - This emits an abbreviation to the stream. Note that this
+ /// method takes ownership of the specified abbrev.
+ unsigned EmitAbbrev(BitCodeAbbrev *Abbv) {
+ // Emit the abbreviation as a record.
+ EncodeAbbrev(Abbv);
+ CurAbbrevs.push_back(Abbv);
+ return CurAbbrevs.size()-1+bitc::FIRST_APPLICATION_ABBREV;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // BlockInfo Block Emission
+ //===--------------------------------------------------------------------===//
+
+ /// EnterBlockInfoBlock - Start emitting the BLOCKINFO_BLOCK.
+ void EnterBlockInfoBlock(unsigned CodeWidth) {
+ EnterSubblock(bitc::BLOCKINFO_BLOCK_ID, CodeWidth);
+ BlockInfoCurBID = -1U;
+ }
+private:
+ /// SwitchToBlockID - If we aren't already talking about the specified block
+ /// ID, emit a BLOCKINFO_CODE_SETBID record.
+ void SwitchToBlockID(unsigned BlockID) {
+ if (BlockInfoCurBID == BlockID) return;
+ SmallVector<unsigned, 2> V;
+ V.push_back(BlockID);
+ EmitRecord(bitc::BLOCKINFO_CODE_SETBID, V);
+ BlockInfoCurBID = BlockID;
+ }
+
+ BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
+ if (BlockInfo *BI = getBlockInfo(BlockID))
+ return *BI;
+
+ // Otherwise, add a new record.
+ BlockInfoRecords.push_back(BlockInfo());
+ BlockInfoRecords.back().BlockID = BlockID;
+ return BlockInfoRecords.back();
+ }
+
+public:
+
+ /// EmitBlockInfoAbbrev - Emit a DEFINE_ABBREV record for the specified
+ /// BlockID.
+ unsigned EmitBlockInfoAbbrev(unsigned BlockID, BitCodeAbbrev *Abbv) {
+ SwitchToBlockID(BlockID);
+ EncodeAbbrev(Abbv);
+
+ // Add the abbrev to the specified block record.
+ BlockInfo &Info = getOrCreateBlockInfo(BlockID);
+ Info.Abbrevs.push_back(Abbv);
+
+ return Info.Abbrevs.size()-1+bitc::FIRST_APPLICATION_ABBREV;
+ }
};
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