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-rw-r--r--include/llvm/Bitcode/BitstreamWriter.h83
1 files changed, 48 insertions, 35 deletions
diff --git a/include/llvm/Bitcode/BitstreamWriter.h b/include/llvm/Bitcode/BitstreamWriter.h
index bfb3a4e..475da13 100644
--- a/include/llvm/Bitcode/BitstreamWriter.h
+++ b/include/llvm/Bitcode/BitstreamWriter.h
@@ -16,13 +16,14 @@
#define BITSTREAM_WRITER_H
#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/Bitcode/BitCodes.h"
#include <vector>
namespace llvm {
class BitstreamWriter {
- std::vector<unsigned char> &Out;
+ SmallVectorImpl<char> &Out;
/// CurBit - Always between 0 and 31 inclusive, specifies the next bit to use.
unsigned CurBit;
@@ -59,8 +60,40 @@ class BitstreamWriter {
};
std::vector<BlockInfo> BlockInfoRecords;
+ // BackpatchWord - Backpatch a 32-bit word in the output with the specified
+ // value.
+ void BackpatchWord(unsigned ByteNo, unsigned NewWord) {
+ Out[ByteNo++] = (unsigned char)(NewWord >> 0);
+ Out[ByteNo++] = (unsigned char)(NewWord >> 8);
+ Out[ByteNo++] = (unsigned char)(NewWord >> 16);
+ Out[ByteNo ] = (unsigned char)(NewWord >> 24);
+ }
+
+ void WriteByte(unsigned char Value) {
+ Out.push_back(Value);
+ }
+
+ void WriteWord(unsigned Value) {
+ unsigned char Bytes[4] = {
+ (unsigned char)(Value >> 0),
+ (unsigned char)(Value >> 8),
+ (unsigned char)(Value >> 16),
+ (unsigned char)(Value >> 24) };
+ Out.append(&Bytes[0], &Bytes[4]);
+ }
+
+ unsigned GetBufferOffset() const {
+ return Out.size();
+ }
+
+ unsigned GetWordIndex() const {
+ unsigned Offset = GetBufferOffset();
+ assert((Offset & 3) == 0 && "Not 32-bit aligned");
+ return Offset / 4;
+ }
+
public:
- explicit BitstreamWriter(std::vector<unsigned char> &O)
+ explicit BitstreamWriter(SmallVectorImpl<char> &O)
: Out(O), CurBit(0), CurValue(0), CurCodeSize(2) {}
~BitstreamWriter() {
@@ -78,10 +111,8 @@ public:
}
}
- std::vector<unsigned char> &getBuffer() { return Out; }
-
/// \brief Retrieve the current position in the stream, in bits.
- uint64_t GetCurrentBitNo() const { return Out.size() * 8 + CurBit; }
+ uint64_t GetCurrentBitNo() const { return GetBufferOffset() * 8 + CurBit; }
//===--------------------------------------------------------------------===//
// Basic Primitives for emitting bits to the stream.
@@ -97,11 +128,7 @@ public:
}
// Add the current word.
- unsigned V = CurValue;
- Out.push_back((unsigned char)(V >> 0));
- Out.push_back((unsigned char)(V >> 8));
- Out.push_back((unsigned char)(V >> 16));
- Out.push_back((unsigned char)(V >> 24));
+ WriteWord(CurValue);
if (CurBit)
CurValue = Val >> (32-CurBit);
@@ -121,11 +148,7 @@ public:
void FlushToWord() {
if (CurBit) {
- unsigned V = CurValue;
- Out.push_back((unsigned char)(V >> 0));
- Out.push_back((unsigned char)(V >> 8));
- Out.push_back((unsigned char)(V >> 16));
- Out.push_back((unsigned char)(V >> 24));
+ WriteWord(CurValue);
CurBit = 0;
CurValue = 0;
}
@@ -164,15 +187,6 @@ public:
Emit(Val, CurCodeSize);
}
- // BackpatchWord - Backpatch a 32-bit word in the output with the specified
- // value.
- void BackpatchWord(unsigned ByteNo, unsigned NewWord) {
- Out[ByteNo++] = (unsigned char)(NewWord >> 0);
- Out[ByteNo++] = (unsigned char)(NewWord >> 8);
- Out[ByteNo++] = (unsigned char)(NewWord >> 16);
- Out[ByteNo ] = (unsigned char)(NewWord >> 24);
- }
-
//===--------------------------------------------------------------------===//
// Block Manipulation
//===--------------------------------------------------------------------===//
@@ -199,7 +213,7 @@ public:
EmitVBR(CodeLen, bitc::CodeLenWidth);
FlushToWord();
- unsigned BlockSizeWordLoc = static_cast<unsigned>(Out.size());
+ unsigned BlockSizeWordIndex = GetWordIndex();
unsigned OldCodeSize = CurCodeSize;
// Emit a placeholder, which will be replaced when the block is popped.
@@ -209,7 +223,7 @@ public:
// 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.push_back(Block(OldCodeSize, BlockSizeWordIndex));
BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
// If there is a blockinfo for this BlockID, add all the predefined abbrevs
@@ -239,7 +253,7 @@ public:
FlushToWord();
// Compute the size of the block, in words, not counting the size field.
- unsigned SizeInWords= static_cast<unsigned>(Out.size())/4-B.StartSizeWord-1;
+ unsigned SizeInWords = GetWordIndex() - B.StartSizeWord - 1;
unsigned ByteNo = B.StartSizeWord*4;
// Update the block size field in the header of this sub-block.
@@ -275,7 +289,7 @@ private:
// Encode the value as we are commanded.
switch (Op.getEncoding()) {
- default: assert(0 && "Unknown encoding!");
+ default: llvm_unreachable("Unknown encoding!");
case BitCodeAbbrevOp::Fixed:
if (Op.getEncodingData())
Emit((unsigned)V, (unsigned)Op.getEncodingData());
@@ -355,25 +369,24 @@ private:
// Flush to a 32-bit alignment boundary.
FlushToWord();
- assert((Out.size() & 3) == 0 && "Not 32-bit aligned");
// Emit each field as a literal byte.
if (BlobData) {
for (unsigned i = 0; i != BlobLen; ++i)
- Out.push_back((unsigned char)BlobData[i]);
+ WriteByte((unsigned char)BlobData[i]);
// Know that blob data is consumed for assertion below.
BlobData = 0;
} else {
for (unsigned e = Vals.size(); RecordIdx != e; ++RecordIdx) {
assert(Vals[RecordIdx] < 256 && "Value too large to emit as blob");
- Out.push_back((unsigned char)Vals[RecordIdx]);
+ WriteByte((unsigned char)Vals[RecordIdx]);
}
}
+
// Align end to 32-bits.
- while (Out.size() & 3)
- Out.push_back(0);
-
+ while (GetBufferOffset() & 3)
+ WriteByte(0);
} else { // Single scalar field.
assert(RecordIdx < Vals.size() && "Invalid abbrev/record");
EmitAbbreviatedField(Op, Vals[RecordIdx]);
@@ -488,7 +501,7 @@ public:
/// EnterBlockInfoBlock - Start emitting the BLOCKINFO_BLOCK.
void EnterBlockInfoBlock(unsigned CodeWidth) {
EnterSubblock(bitc::BLOCKINFO_BLOCK_ID, CodeWidth);
- BlockInfoCurBID = -1U;
+ BlockInfoCurBID = ~0U;
}
private:
/// SwitchToBlockID - If we aren't already talking about the specified block
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