BitsInCurWord = 0;
// Skip over any bits that are already consumed.
- if (WordBitNo) {
- if (sizeof(word_t) > 4)
- Read64(WordBitNo);
- else
- Read(WordBitNo);
- }
+ if (WordBitNo)
+ Read(WordBitNo);
}
void fillCurWord() {
BitsInCurWord = BytesRead * 8;
}
- uint32_t Read(unsigned NumBits) {
- assert(NumBits && NumBits <= 32 &&
- "Cannot return zero or more than 32 bits!");
+ word_t Read(unsigned NumBits) {
+ static const unsigned BitsInWord = sizeof(word_t) * 8;
+
+ assert(NumBits && NumBits <= BitsInWord &&
+ "Cannot return zero or more than BitsInWord bits!");
static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
// If the field is fully contained by CurWord, return it quickly.
if (BitsInCurWord >= NumBits) {
- uint32_t R = uint32_t(CurWord) & (~0U >> (32-NumBits));
+ word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
// Use a mask to avoid undefined behavior.
CurWord >>= (NumBits & Mask);
return R;
}
- uint32_t R = BitsInCurWord ? uint32_t(CurWord) : 0;
+ word_t R = BitsInCurWord ? CurWord : 0;
unsigned BitsLeft = NumBits - BitsInCurWord;
fillCurWord();
if (BitsLeft > BitsInCurWord)
return 0;
- uint32_t R2 =
- uint32_t(CurWord) & (~word_t(0) >> (sizeof(word_t) * 8 - BitsLeft));
+ word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
// Use a mask to avoid undefined behavior.
CurWord >>= (BitsLeft & Mask);
BitsInCurWord -= BitsLeft;
- R |= uint32_t(R2 << (NumBits - BitsLeft));
+ R |= R2 << (NumBits - BitsLeft);
return R;
}
- uint64_t Read64(unsigned NumBits) {
- if (NumBits <= 32) return Read(NumBits);
-
- uint64_t V = Read(32);
- return V | (uint64_t)Read(NumBits-32) << 32;
- }
-
uint32_t ReadVBR(unsigned NumBits) {
uint32_t Piece = Read(NumBits);
if ((Piece & (1U << (NumBits-1))) == 0)