static inline size_t lz4hc_commonlength(const u8 *p1, const u8 *p2,
const u8 *const matchlimit)
{
const u8 *p1t = p1;
while (p1t < matchlimit - (STEPSIZE - 1)) {
#if LZ4_ARCH64
u64 diff = A64(p2) ^ A64(p1t);
#else
u32 diff = A32(p2) ^ A32(p1t);
#endif
if (!diff) {
p1t += STEPSIZE;
p2 += STEPSIZE;
continue;
}
p1t += LZ4_NBCOMMONBYTES(diff);
return p1t - p1;
}
#if LZ4_ARCH64
if ((p1t < (matchlimit-3)) && (A32(p2) == A32(p1t))) {
p1t += 4;
p2 += 4;
}
#endif
if ((p1t < (matchlimit - 1)) && (A16(p2) == A16(p1t))) {
p1t += 2;
p2 += 2;
}
if ((p1t < matchlimit) && (*p2 == *p1t))
p1t++;
return p1t - p1;
}
static inline U32 XXH_readLE32_align(const U32* ptr, XXH_endianess endian, XXH_alignment align)
{
if (align==XXH_unaligned)
return endian==XXH_littleEndian ? A32(ptr) : XXH_swap32(A32(ptr));
else
return endian==XXH_littleEndian ? *ptr : XXH_swap32(*ptr);
}
static inline int lz4hc_insertandgetwidermatch(struct lz4hc_data *hc4,
const u8 *ip, const u8 *startlimit, const u8 *matchlimit, int longest,
const u8 **matchpos, const u8 **startpos)
{
u16 *const chaintable = hc4->chaintable;
HTYPE *const hashtable = hc4->hashtable;
#if LZ4_ARCH64
const BYTE * const base = hc4->base;
#else
const int base = 0;
#endif
const u8 *ref;
int nbattempts = MAX_NB_ATTEMPTS;
int delta = (int)(ip - startlimit);
/* First Match */
lz4hc_insert(hc4, ip);
ref = hashtable[HASH_VALUE(ip)] + base;
while ((ref >= ip - MAX_DISTANCE) && (ref >= hc4->base)
&& (nbattempts)) {
nbattempts--;
if (*(startlimit + longest) == *(ref - delta + longest)) {
if (A32(ref) == A32(ip)) {
const u8 *reft = ref + MINMATCH;
const u8 *ipt = ip + MINMATCH;
const u8 *startt = ip;
while (ipt < matchlimit-(STEPSIZE - 1)) {
#if LZ4_ARCH64
u64 diff = A64(reft) ^ A64(ipt);
#else
u32 diff = A32(reft) ^ A32(ipt);
#endif
if (!diff) {
ipt += STEPSIZE;
reft += STEPSIZE;
continue;
}
ipt += LZ4_NBCOMMONBYTES(diff);
goto _endcount;
}
#if LZ4_ARCH64
if ((ipt < (matchlimit - 3))
&& (A32(reft) == A32(ipt))) {
ipt += 4;
reft += 4;
}
ipt += 2;
#endif
if ((ipt < (matchlimit - 1))
&& (A16(reft) == A16(ipt))) {
reft += 2;
}
if ((ipt < matchlimit) && (*reft == *ipt))
ipt++;
_endcount:
reft = ref;
while ((startt > startlimit)
&& (reft > hc4->base)
&& (startt[-1] == reft[-1])) {
startt--;
reft--;
}
if ((ipt - startt) > longest) {
longest = (int)(ipt - startt);
*matchpos = reft;
*startpos = startt;
}
}
}
ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK];
}
return longest;
}
static inline int lz4hc_insertandfindbestmatch(struct lz4hc_data *hc4,
const u8 *ip, const u8 *const matchlimit, const u8 **matchpos)
{
u16 *const chaintable = hc4->chaintable;
HTYPE *const hashtable = hc4->hashtable;
const u8 *ref;
#if LZ4_ARCH64
const BYTE * const base = hc4->base;
#else
const int base = 0;
#endif
int nbattempts = MAX_NB_ATTEMPTS;
size_t repl = 0, ml = 0;
u16 delta;
/* HC4 match finder */
lz4hc_insert(hc4, ip);
ref = hashtable[HASH_VALUE(ip)] + base;
/* potential repetition */
if (ref >= ip-4) {
/* confirmed */
if (A32(ref) == A32(ip)) {
delta = (u16)(ip-ref);
repl = ml = lz4hc_commonlength(ip + MINMATCH,
ref + MINMATCH, matchlimit) + MINMATCH;
*matchpos = ref;
}
ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK];
}
while ((ref >= ip - MAX_DISTANCE) && nbattempts) {
nbattempts--;
if (*(ref + ml) == *(ip + ml)) {
if (A32(ref) == A32(ip)) {
size_t mlt =
lz4hc_commonlength(ip + MINMATCH,
ref + MINMATCH, matchlimit) + MINMATCH;
if (mlt > ml) {
ml = mlt;
*matchpos = ref;
}
}
}
ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK];
}
/* Complete table */
if (repl) {
const BYTE *ptr = ip;
const BYTE *end;
end = ip + repl - (MINMATCH-1);
/* Pre-Load */
while (ptr < end - delta) {
chaintable[(size_t)(ptr) & MAXD_MASK] = delta;
ptr++;
}
do {
chaintable[(size_t)(ptr) & MAXD_MASK] = delta;
/* Head of chain */
hashtable[HASH_VALUE(ptr)] = (ptr) - base;
ptr++;
} while (ptr < end);
hc4->nexttoupdate = end;
}
return (int)ml;
}
