ext/zstdruby/libzstd/common/bitstream.h in zstd-ruby-1.3.1.1 vs ext/zstdruby/libzstd/common/bitstream.h in zstd-ruby-1.3.2.0
- old
+ new
@@ -167,38 +167,44 @@
/*-**************************************************************
* Internal functions
****************************************************************/
MEM_STATIC unsigned BIT_highbit32 (register U32 val)
{
+ assert(val != 0);
+ {
# if defined(_MSC_VER) /* Visual */
- unsigned long r=0;
- _BitScanReverse ( &r, val );
- return (unsigned) r;
+ unsigned long r=0;
+ _BitScanReverse ( &r, val );
+ return (unsigned) r;
# elif defined(__GNUC__) && (__GNUC__ >= 3) /* Use GCC Intrinsic */
- return 31 - __builtin_clz (val);
+ return 31 - __builtin_clz (val);
# else /* Software version */
- static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29,
- 11, 14, 16, 18, 22, 25, 3, 30,
- 8, 12, 20, 28, 15, 17, 24, 7,
- 19, 27, 23, 6, 26, 5, 4, 31 };
- U32 v = val;
- v |= v >> 1;
- v |= v >> 2;
- v |= v >> 4;
- v |= v >> 8;
- v |= v >> 16;
- return DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
+ static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29,
+ 11, 14, 16, 18, 22, 25, 3, 30,
+ 8, 12, 20, 28, 15, 17, 24, 7,
+ 19, 27, 23, 6, 26, 5, 4, 31 };
+ U32 v = val;
+ v |= v >> 1;
+ v |= v >> 2;
+ v |= v >> 4;
+ v |= v >> 8;
+ v |= v >> 16;
+ return DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
# endif
+ }
}
/*===== Local Constants =====*/
-static const unsigned BIT_mask[] = { 0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F,
- 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF,
- 0xFFFF, 0x1FFFF, 0x3FFFF, 0x7FFFF, 0xFFFFF, 0x1FFFFF, 0x3FFFFF, 0x7FFFFF,
- 0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF }; /* up to 26 bits */
+static const unsigned BIT_mask[] = {
+ 0, 1, 3, 7, 0xF, 0x1F,
+ 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF,
+ 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0x1FFFF,
+ 0x3FFFF, 0x7FFFF, 0xFFFFF, 0x1FFFFF, 0x3FFFFF, 0x7FFFFF,
+ 0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF, 0x7FFFFFF, 0xFFFFFFF, 0x1FFFFFFF,
+ 0x3FFFFFFF, 0x7FFFFFFF}; /* up to 31 bits */
+#define BIT_MASK_SIZE (sizeof(BIT_mask) / sizeof(BIT_mask[0]))
-
/*-**************************************************************
* bitStream encoding
****************************************************************/
/*! BIT_initCStream() :
* `dstCapacity` must be > sizeof(size_t)
@@ -215,36 +221,40 @@
if (dstCapacity <= sizeof(bitC->bitContainer)) return ERROR(dstSize_tooSmall);
return 0;
}
/*! BIT_addBits() :
- * can add up to 26 bits into `bitC`.
+ * can add up to 31 bits into `bitC`.
* Note : does not check for register overflow ! */
MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC,
size_t value, unsigned nbBits)
{
+ MEM_STATIC_ASSERT(BIT_MASK_SIZE == 32);
+ assert(nbBits < BIT_MASK_SIZE);
+ assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
bitC->bitContainer |= (value & BIT_mask[nbBits]) << bitC->bitPos;
bitC->bitPos += nbBits;
}
/*! BIT_addBitsFast() :
* works only if `value` is _clean_, meaning all high bits above nbBits are 0 */
MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC,
size_t value, unsigned nbBits)
{
assert((value>>nbBits) == 0);
+ assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
bitC->bitContainer |= value << bitC->bitPos;
bitC->bitPos += nbBits;
}
/*! BIT_flushBitsFast() :
* assumption : bitContainer has not overflowed
* unsafe version; does not check buffer overflow */
MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC)
{
size_t const nbBytes = bitC->bitPos >> 3;
- assert( bitC->bitPos <= (sizeof(bitC->bitContainer)*8) );
+ assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
MEM_writeLEST(bitC->ptr, bitC->bitContainer);
bitC->ptr += nbBytes;
assert(bitC->ptr <= bitC->endPtr);
bitC->bitPos &= 7;
bitC->bitContainer >>= nbBytes*8;
@@ -256,11 +266,11 @@
* note : does not signal buffer overflow.
* overflow will be revealed later on using BIT_closeCStream() */
MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC)
{
size_t const nbBytes = bitC->bitPos >> 3;
- assert( bitC->bitPos <= (sizeof(bitC->bitContainer)*8) );
+ assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
MEM_writeLEST(bitC->ptr, bitC->bitContainer);
bitC->ptr += nbBytes;
if (bitC->ptr > bitC->endPtr) bitC->ptr = bitC->endPtr;
bitC->bitPos &= 7;
bitC->bitContainer >>= nbBytes*8;
@@ -348,15 +358,17 @@
return _bextr_u64(bitContainer, start, nbBits);
else
# endif
return _bextr_u32(bitContainer, start, nbBits);
#else
+ assert(nbBits < BIT_MASK_SIZE);
return (bitContainer >> start) & BIT_mask[nbBits];
#endif
}
MEM_STATIC size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits)
{
+ assert(nbBits < BIT_MASK_SIZE);
return bitContainer & BIT_mask[nbBits];
}
/*! BIT_lookBits() :
* Provides next n bits from local register.