[llvm-commits] [llvm] r151749 - /llvm/trunk/include/llvm/Bitcode/BitstreamWriter.h
Daniel Dunbar
daniel at zuster.org
Wed Feb 29 12:31:05 PST 2012
Author: ddunbar
Date: Wed Feb 29 14:31:05 2012
New Revision: 151749
URL: http://llvm.org/viewvc/llvm-project?rev=151749&view=rev
Log:
BitstreamWriter: Isolate access to the underlying buffer.
Modified:
llvm/trunk/include/llvm/Bitcode/BitstreamWriter.h
Modified: llvm/trunk/include/llvm/Bitcode/BitstreamWriter.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Bitcode/BitstreamWriter.h?rev=151749&r1=151748&r2=151749&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Bitcode/BitstreamWriter.h (original)
+++ llvm/trunk/include/llvm/Bitcode/BitstreamWriter.h Wed Feb 29 14:31:05 2012
@@ -68,6 +68,27 @@
Out[ByteNo ] = (unsigned char)(NewWord >> 24);
}
+ void WriteByte(unsigned char Value) {
+ Out.push_back(Value);
+ }
+
+ void WriteWord(unsigned Value) {
+ Out.push_back((unsigned char)(Value >> 0));
+ Out.push_back((unsigned char)(Value >> 8));
+ Out.push_back((unsigned char)(Value >> 16));
+ Out.push_back((unsigned char)(Value >> 24));
+ }
+
+ 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)
: Out(O), CurBit(0), CurValue(0), CurCodeSize(2) {}
@@ -88,7 +109,7 @@
}
/// \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.
@@ -104,11 +125,7 @@
}
// 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);
@@ -128,11 +145,7 @@
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;
}
@@ -197,7 +210,7 @@
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.
@@ -207,7 +220,7 @@
// 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
@@ -237,7 +250,7 @@
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.
@@ -353,25 +366,24 @@
// 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]);
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