Support for function summary index bitcode sections and files.

[oota-llvm.git] / include / llvm / Bitcode / BitstreamWriter.h

diff --git a/include/llvm/Bitcode/BitstreamWriter.h b/include/llvm/Bitcode/BitstreamWriter.h
index 1fded87295d7e612e7a0eb4ff20d7a44e0293fb8..bac6c57470840128c0e4c89f95f25c42406ff3b6 100644 (file)
--- a/include/llvm/Bitcode/BitstreamWriter.h
+++ b/include/llvm/Bitcode/BitstreamWriter.h
@@ -63,12 +63,6 @@ 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) {
-    support::endian::write32le(&Out[ByteNo], NewWord);
-  }
-
   void WriteByte(unsigned char Value) {
     Out.push_back(Value);
   }
@@ -101,10 +95,25 @@ public:
   /// \brief Retrieve the current position in the stream, in bits.
   uint64_t GetCurrentBitNo() const { return GetBufferOffset() * 8 + CurBit; }
 
+  /// \brief Retrieve the number of bits currently used to encode an abbrev ID.
+  unsigned GetAbbrevIDWidth() const { return CurCodeSize; }
+
   //===--------------------------------------------------------------------===//
   // Basic Primitives for emitting bits to the stream.
   //===--------------------------------------------------------------------===//
 
+  /// Backpatch a 32-bit word in the output at the given bit offset
+  /// with the specified value.
+  void BackpatchWord(uint64_t BitNo, unsigned NewWord) {
+    using namespace llvm::support;
+    unsigned ByteNo = BitNo / 8;
+    assert((!endian::readAtBitAlignment<uint32_t, little, unaligned>(
+               &Out[ByteNo], BitNo & 7)) &&
+           "Expected to be patching over 0-value placeholders");
+    endian::writeAtBitAlignment<uint32_t, little, unaligned>(
+        &Out[ByteNo], NewWord, BitNo & 7);
+  }
+
   void Emit(uint32_t Val, unsigned NumBits) {
     assert(NumBits && NumBits <= 32 && "Invalid value size!");
     assert((Val & ~(~0U >> (32-NumBits))) == 0 && "High bits set!");
@@ -234,10 +243,10 @@ public:
 
     // Compute the size of the block, in words, not counting the size field.
     unsigned SizeInWords = GetWordIndex() - B.StartSizeWord - 1;
-    unsigned ByteNo = B.StartSizeWord*4;
+    uint64_t BitNo = B.StartSizeWord * 32;
 
     // Update the block size field in the header of this sub-block.
-    BackpatchWord(ByteNo, SizeInWords);
+    BackpatchWord(BitNo, SizeInWords);
 
     // Restore the inner block's code size and abbrev table.
     CurCodeSize = B.PrevCodeSize;
@@ -399,16 +408,16 @@ public:
 
   /// EmitRecord - Emit the specified record to the stream, using an abbrev if
   /// we have one to compress the output.
-  template<typename uintty>
-  void EmitRecord(unsigned Code, SmallVectorImpl<uintty> &Vals,
-                  unsigned Abbrev = 0) {
+  template <typename Container>
+  void EmitRecord(unsigned Code, const Container &Vals, unsigned Abbrev = 0) {
     if (!Abbrev) {
       // If we don't have an abbrev to use, emit this in its fully unabbreviated
       // form.
+      auto Count = static_cast<uint32_t>(makeArrayRef(Vals).size());
       EmitCode(bitc::UNABBREV_RECORD);
       EmitVBR(Code, 6);
-      EmitVBR(static_cast<uint32_t>(Vals.size()), 6);
-      for (unsigned i = 0, e = static_cast<unsigned>(Vals.size()); i != e; ++i)
+      EmitVBR(Count, 6);
+      for (unsigned i = 0, e = Count; i != e; ++i)
         EmitVBR64(Vals[i], 6);
       return;
     }