lzo1a_decompress ( const lzo_byte *in , lzo_uint in_len,
lzo_byte *out, lzo_uint *out_len,
lzo_voidp wrkmem )
{
#if defined(LZO_OPTIMIZE_GNUC_i386)
register lzo_byte *op __asm__("%edi");
register const lzo_byte *ip __asm__("%esi");
register lzo_uint t __asm__("%ecx");
register const lzo_byte *m_pos __asm__("%ebx");
#else
register lzo_byte *op;
register const lzo_byte *ip;
register lzo_uint t;
register const lzo_byte *m_pos;
#endif
const lzo_byte * const ip_end = in + in_len;
LZO_UNUSED(wrkmem);
#if defined(__LZO_QUERY_DECOMPRESS)
if (__LZO_IS_DECOMPRESS_QUERY(in,in_len,out,out_len,wrkmem))
return __LZO_QUERY_DECOMPRESS(in,in_len,out,out_len,wrkmem,0,0);
#endif
op = out;
ip = in;
while (ip < ip_end)
{
t = *ip++; /* get marker */
LZO_STATS(lzo_stats->marker[t]++);
if (t == 0) /* a R0 literal run */
{
t = *ip++;
if (t >= R0FAST - R0MIN) /* a long R0 run */
{
t -= R0FAST - R0MIN;
if (t == 0)
t = R0FAST;
else
{
#if 0
t = 256u << ((unsigned) t);
#else
/* help the optimizer */
lzo_uint tt = 256;
do tt <<= 1; while (--t > 0);
t = tt;
#endif
}
MEMCPY8_DS(op,ip,t);
continue;
}
t += R0MIN;
goto literal;
}
else if (t < R0MIN) /* a short literal run */
{
literal:
MEMCPY_DS(op,ip,t);
/* after a literal a match must follow */
while (ip < ip_end)
{
t = *ip++; /* get R1 marker */
if (t >= R0MIN)
goto match;
/* R1 match - a context sensitive 3 byte match + 1 byte literal */
assert((t & OMASK) == t);
m_pos = op - MIN_OFFSET;
m_pos -= t | (((lzo_uint) *ip++) << OBITS);
assert(m_pos >= out); assert(m_pos < op);
*op++ = *m_pos++;
*op++ = *m_pos++;
*op++ = *m_pos++;
*op++ = *ip++;
}
}
else /* a match */
{
match:
/* get match offset */
m_pos = op - MIN_OFFSET;
m_pos -= (t & OMASK) | (((lzo_uint) *ip++) << OBITS);
assert(m_pos >= out); assert(m_pos < op);
/* get match len */
if (t < ((MSIZE - 1) << OBITS)) /* a short match */
{
t >>= OBITS;
*op++ = *m_pos++;
*op++ = *m_pos++;
MEMMOVE_DS(op,m_pos,t);
}
else /* a long match */
{
#if (LBITS < 8)
t = (MIN_MATCH_LONG - THRESHOLD) + ((lzo_uint)(*ip++) & LMASK);
#else
t = (MIN_MATCH_LONG - THRESHOLD) + (lzo_uint)(*ip++);
#endif
*op++ = *m_pos++;
*op++ = *m_pos++;
MEMMOVE_DS(op,m_pos,t);
#if (LBITS < 8)
/* a very short literal following a long match */
t = ip[-1] >> LBITS;
if (t) do
*op++ = *ip++;
while (--t);
#endif
}
}
lzo1a_decompress ( const lzo_bytep in , lzo_uint in_len,
lzo_bytep out, lzo_uintp out_len,
lzo_voidp wrkmem )
{
register lzo_bytep op;
register const lzo_bytep ip;
register lzo_uint t;
register const lzo_bytep m_pos;
const lzo_bytep const ip_end = in + in_len;
LZO_UNUSED(wrkmem);
op = out;
ip = in;
while (ip < ip_end)
{
t = *ip++; /* get marker */
LZO_STATS(lzo_stats->marker[t]++);
if (t == 0) /* a R0 literal run */
{
t = *ip++;
if (t >= R0FAST - R0MIN) /* a long R0 run */
{
t -= R0FAST - R0MIN;
if (t == 0)
t = R0FAST;
else
{
#if 0
t = 256u << ((unsigned) t);
#else
/* help the optimizer */
lzo_uint tt = 256;
do tt <<= 1; while (--t > 0);
t = tt;
#endif
}
MEMCPY8_DS(op,ip,t);
continue;
}
t += R0MIN;
goto literal;
}
else if (t < R0MIN) /* a short literal run */
{
literal:
MEMCPY_DS(op,ip,t);
/* after a literal a match must follow */
while (ip < ip_end)
{
t = *ip++; /* get R1 marker */
if (t >= R0MIN)
goto match;
/* R1 match - a context sensitive 3 byte match + 1 byte literal */
assert((t & OMASK) == t);
m_pos = op - MIN_OFFSET;
m_pos -= t | (((lzo_uint) *ip++) << OBITS);
assert(m_pos >= out); assert(m_pos < op);
*op++ = m_pos[0];
*op++ = m_pos[1];
*op++ = m_pos[2];
*op++ = *ip++;
}
}
else /* a match */
{
match:
/* get match offset */
m_pos = op - MIN_OFFSET;
m_pos -= (t & OMASK) | (((lzo_uint) *ip++) << OBITS);
assert(m_pos >= out); assert(m_pos < op);
/* get match len */
if (t < ((MSIZE - 1) << OBITS)) /* a short match */
{
t >>= OBITS;
*op++ = *m_pos++;
*op++ = *m_pos++;
MEMCPY_DS(op,m_pos,t);
}
else /* a long match */
{
#if (LBITS < 8)
t = (MIN_MATCH_LONG - THRESHOLD) + ((lzo_uint)(*ip++) & LMASK);
#else
t = (MIN_MATCH_LONG - THRESHOLD) + (lzo_uint)(*ip++);
#endif
*op++ = *m_pos++;
*op++ = *m_pos++;
MEMCPY_DS(op,m_pos,t);
#if (LBITS < 8)
/* a very short literal following a long match */
t = ip[-1] >> LBITS;
if (t) do
*op++ = *ip++;
while (--t);
#endif
}
}
