wean Blob handling logic off of banging on NextChar directly. Instead…

…, make

it reason about the current bit position, which is always independent of the
underlying cursors word size.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173063 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Bitcode/Reader/BitstreamReader.cpp

@@ -184,17 +184,17 @@ void BitstreamCursor::skipRecord(unsigned AbbrevID) {
     SkipToFourByteBoundary();  // 32-bit alignment
 
     // Figure out where the end of this blob will be including tail padding.
-    size_t NewEnd = NextChar+((NumElts+3)&~3);
+    size_t NewEnd = GetCurrentBitNo()+((NumElts+3)&~3)*8;
 
     // If this would read off the end of the bitcode file, just set the
     // record to empty and return.
-    if (!canSkipToPos(NewEnd)) {
+    if (!canSkipToPos(NewEnd/8)) {
       NextChar = BitStream->getBitcodeBytes().getExtent();
       break;
     }
 
     // Skip over the blob.
-    NextChar = NewEnd;
+    JumpToBit(NewEnd);
   }
 }
 
@@ -244,11 +244,12 @@ unsigned BitstreamCursor::readRecord(unsigned AbbrevID,
     SkipToFourByteBoundary();  // 32-bit alignment
 
     // Figure out where the end of this blob will be including tail padding.
-    size_t NewEnd = NextChar+((NumElts+3)&~3);
+    size_t CurBitPos = GetCurrentBitNo();
+    size_t NewEnd = CurBitPos+((NumElts+3)&~3)*8;
 
     // If this would read off the end of the bitcode file, just set the
     // record to empty and return.
-    if (!canSkipToPos(NewEnd)) {
+    if (!canSkipToPos(NewEnd/8)) {
       Vals.append(NumElts, 0);
       NextChar = BitStream->getBitcodeBytes().getExtent();
       break;
@@ -259,14 +260,16 @@ unsigned BitstreamCursor::readRecord(unsigned AbbrevID,
     if (Blob) {
       *Blob =
         StringRef((const char*)BitStream->getBitcodeBytes().getPointer(
-                                                            NextChar, NumElts),
-                NumElts);
+                                                          CurBitPos/8, NumElts),
+                  NumElts);
     } else {
-      for (; NumElts; ++NextChar, --NumElts)
-        Vals.push_back(getByte(NextChar));
+      // FIXME: This is a brutally inefficient way to do this.  Why isn't this
+      // just using getPointer?      
+      for (; NumElts; --NumElts)
+        Vals.push_back(Read(8));
     }
     // Skip over tail padding.
-    NextChar = NewEnd;
+    JumpToBit(NewEnd);
   }
 
   unsigned Code = (unsigned)Vals[0];