X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FBitcode%2FBitstreamWriter.h;h=70acc019c545a659f0bac99ae66c2478e081de37;hb=fc82fabe00b0b820e3c0d7fc9e289bace0295f11;hp=5de8293278452347c66421e0e331b820a5903968;hpb=a0c96a068ca7027644b5f1972f9c388fa542d278;p=oota-llvm.git

diff --git a/include/llvm/Bitcode/BitstreamWriter.h b/include/llvm/Bitcode/BitstreamWriter.h
index 5de82932784..70acc019c54 100644
--- a/include/llvm/Bitcode/BitstreamWriter.h
+++ b/include/llvm/Bitcode/BitstreamWriter.h
@@ -2,8 +2,8 @@
 //
 //                     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.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -16,9 +16,6 @@
 #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 {
@@ -32,25 +29,51 @@ class BitstreamWriter {
   /// 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.
@@ -137,6 +160,19 @@ public:
   // 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]
@@ -144,17 +180,38 @@ public:
     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>]
@@ -171,20 +228,81 @@ public:
     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.
@@ -195,23 +313,83 @@ public:
         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;
+  }
 };