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r173072 is causing some regressions on big endian hosts, I don't have…

… time to debug it

so revert it for now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173074 91177308-0d34-0410-b5e6-96231b3b80d8
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1 parent 02b206f commit dc60fc1aa710812be17c5b01f34ef251c87b42b4 @lattner lattner committed Jan 21, 2013
Showing with 21 additions and 49 deletions.
  1. +21 −49 include/llvm/Bitcode/BitstreamReader.h
@@ -170,17 +170,12 @@ class BitstreamCursor {
BitstreamReader *BitStream;
size_t NextChar;
-
- /// CurWord/word_t - This is the current data we have pulled from the stream
- /// but have not returned to the client. This is specifically and
- /// intentionally defined to follow the word size of the host machine for
- /// efficiency. We use word_t in places that are aware of this to make it
- /// perfectly explicit what is going on.
- typedef size_t word_t;
- word_t CurWord;
+ /// CurWord - This is the current data we have pulled from the stream but have
+ /// not returned to the client.
+ uint32_t CurWord;
/// BitsInCurWord - This is the number of bits in CurWord that are valid. This
- /// is always from [0...31/63] inclusive (depending on word size).
+ /// is always from [0...31] inclusive.
unsigned BitsInCurWord;
// CurCodeSize - This is the declared size of code values used for the current
@@ -323,8 +318,8 @@ class BitstreamCursor {
/// JumpToBit - Reset the stream to the specified bit number.
void JumpToBit(uint64_t BitNo) {
- uintptr_t ByteNo = uintptr_t(BitNo/8) & ~(sizeof(word_t)-1);
- unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
+ uintptr_t ByteNo = uintptr_t(BitNo/8) & ~3;
+ uintptr_t WordBitNo = uintptr_t(BitNo) & 31;
assert(canSkipToPos(ByteNo) && "Invalid location");
// Move the cursor to the right word.
@@ -333,20 +328,16 @@ class BitstreamCursor {
CurWord = 0;
// Skip over any bits that are already consumed.
- if (WordBitNo) {
- if (sizeof(word_t) > 4)
- Read64(WordBitNo);
- else
- Read(WordBitNo);
- }
+ if (WordBitNo)
+ Read(static_cast<unsigned>(WordBitNo));
}
uint32_t Read(unsigned NumBits) {
assert(NumBits <= 32 && "Cannot return more than 32 bits!");
// If the field is fully contained by CurWord, return it quickly.
if (BitsInCurWord >= NumBits) {
- uint32_t R = uint32_t(CurWord) & (~0U >> (32-NumBits));
+ uint32_t R = CurWord & ((1U << NumBits)-1);
CurWord >>= NumBits;
BitsInCurWord -= NumBits;
return R;
@@ -359,32 +350,24 @@ class BitstreamCursor {
return 0;
}
- uint32_t R = uint32_t(CurWord);
+ unsigned R = CurWord;
// Read the next word from the stream.
- uint8_t buf[sizeof(word_t)] = {0};
- BitStream->getBitcodeBytes().readBytes(NextChar, sizeof(buf), buf, NULL);
-
- typedef support::detail::packed_endian_specific_integral
- <word_t, support::little, support::unaligned> Endian_T;
- CurWord = *reinterpret_cast<Endian_T*>(buf);
-
- NextChar += sizeof(word_t);
+ CurWord = getWord(NextChar);
+ NextChar += 4;
// Extract NumBits-BitsInCurWord from what we just read.
unsigned BitsLeft = NumBits-BitsInCurWord;
- // Be careful here, BitsLeft is in the range [1..32]/[1..64] inclusive.
- R |= uint32_t((CurWord & (word_t(~0ULL) >> (sizeof(word_t)*8-BitsLeft)))
- << BitsInCurWord);
+ // Be careful here, BitsLeft is in the range [1..32] inclusive.
+ R |= (CurWord & (~0U >> (32-BitsLeft))) << BitsInCurWord;
- // BitsLeft bits have just been used up from CurWord. BitsLeft is in the
- // range [1..32]/[1..64] so be careful how we shift.
- if (BitsLeft != sizeof(word_t)*8)
+ // BitsLeft bits have just been used up from CurWord.
+ if (BitsLeft != 32)
CurWord >>= BitsLeft;
else
CurWord = 0;
- BitsInCurWord = sizeof(word_t)*8-BitsLeft;
+ BitsInCurWord = 32-BitsLeft;
return R;
}
@@ -433,21 +416,10 @@ class BitstreamCursor {
}
}
-private:
void SkipToFourByteBoundary() {
- // If word_t is 64-bits and if we've read less than 32 bits, just dump
- // the bits we have up to the next 32-bit boundary.
- if (sizeof(word_t) > 4 &&
- BitsInCurWord > 32) {
- CurWord >>= BitsInCurWord-32;
- BitsInCurWord = 32;
- return;
- }
-
BitsInCurWord = 0;
CurWord = 0;
}
-public:
unsigned ReadCode() {
return Read(CurCodeSize);
@@ -471,15 +443,15 @@ class BitstreamCursor {
// don't care what code widths are used inside of it.
ReadVBR(bitc::CodeLenWidth);
SkipToFourByteBoundary();
- unsigned NumFourBytes = Read(bitc::BlockSizeWidth);
+ unsigned NumWords = Read(bitc::BlockSizeWidth);
// Check that the block wasn't partially defined, and that the offset isn't
// bogus.
- size_t SkipTo = GetCurrentBitNo() + NumFourBytes*4*8;
- if (AtEndOfStream() || !canSkipToPos(SkipTo/8))
+ size_t SkipTo = NextChar + NumWords*4;
+ if (AtEndOfStream() || !canSkipToPos(SkipTo))
return true;
- JumpToBit(SkipTo);
+ NextChar = SkipTo;
return false;
}

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