static
void fallbackQSort3 ( UInt32* fmap,
UInt32* eclass,
Int32 loSt,
Int32 hiSt )
{
Int32 unLo, unHi, ltLo, gtHi, n, m;
Int32 sp, lo, hi;
UInt32 med, r, r3;
Int32 stackLo[FALLBACK_QSORT_STACK_SIZE];
Int32 stackHi[FALLBACK_QSORT_STACK_SIZE];
r = 0;
sp = 0;
fpush ( loSt, hiSt );
while (sp > 0) {
AssertH ( sp < FALLBACK_QSORT_STACK_SIZE, 1004 );
fpop ( lo, hi );
if (hi - lo < FALLBACK_QSORT_SMALL_THRESH) {
fallbackSimpleSort ( fmap, eclass, lo, hi );
continue;
}
/* Random partitioning. Median of 3 sometimes fails to
avoid bad cases. Median of 9 seems to help but
looks rather expensive. This too seems to work but
is cheaper. Guidance for the magic constants
7621 and 32768 is taken from Sedgewick's algorithms
book, chapter 35.
*/
r = ((r * 7621) + 1) % 32768;
r3 = r % 3;
if (r3 == 0) med = eclass[fmap[lo]]; else
if (r3 == 1) med = eclass[fmap[(lo+hi)>>1]]; else
med = eclass[fmap[hi]];
unLo = ltLo = lo;
unHi = gtHi = hi;
while (1) {
while (1) {
if (unLo > unHi) break;
n = (Int32)eclass[fmap[unLo]] - (Int32)med;
if (n == 0) {
fswap(fmap[unLo], fmap[ltLo]);
ltLo++; unLo++;
continue;
};
if (n > 0) break;
unLo++;
}
while (1) {
if (unLo > unHi) break;
n = (Int32)eclass[fmap[unHi]] - (Int32)med;
if (n == 0) {
fswap(fmap[unHi], fmap[gtHi]);
gtHi--; unHi--;
continue;
};
if (n < 0) break;
unHi--;
}
if (unLo > unHi) break;
fswap(fmap[unLo], fmap[unHi]); unLo++; unHi--;
}
AssertD ( unHi == unLo-1, "fallbackQSort3(2)" );
if (gtHi < ltLo) continue;
n = fmin(ltLo-lo, unLo-ltLo); fvswap(lo, unLo-n, n);
m = fmin(hi-gtHi, gtHi-unHi); fvswap(unLo, hi-m+1, m);
n = lo + unLo - ltLo - 1;
m = hi - (gtHi - unHi) + 1;
if (n - lo > hi - m) {
fpush ( lo, n );
fpush ( m, hi );
} else {
fpush ( m, hi );
fpush ( lo, n );
}
}
/*---------------------------------------------------*/
static
void generateMTFValues ( EState* s )
{
UChar yy[256];
Int32 i, j;
Int32 zPend;
Int32 wr;
Int32 EOB;
/*
After sorting (eg, here),
s->arr1 [ 0 .. s->nblock-1 ] holds sorted order,
and
((UChar*)s->arr2) [ 0 .. s->nblock-1 ]
holds the original block data.
The first thing to do is generate the MTF values,
and put them in
((UInt16*)s->arr1) [ 0 .. s->nblock-1 ].
Because there are strictly fewer or equal MTF values
than block values, ptr values in this area are overwritten
with MTF values only when they are no longer needed.
The final compressed bitstream is generated into the
area starting at
(UChar*) (&((UChar*)s->arr2)[s->nblock])
These storage aliases are set up in bzCompressInit(),
except for the last one, which is arranged in
compressBlock().
*/
UInt32* ptr = s->ptr;
UChar* block = s->block;
UInt16* mtfv = s->mtfv;
makeMaps_e ( s );
EOB = s->nInUse+1;
for (i = 0; i <= EOB; i++) s->mtfFreq[i] = 0;
wr = 0;
zPend = 0;
for (i = 0; i < s->nInUse; i++) yy[i] = (UChar) i;
for (i = 0; i < s->nblock; i++) {
UChar ll_i;
AssertD ( wr <= i, _T("generateMTFValues(1)") );
j = ptr[i]-1; if (j < 0) j += s->nblock;
ll_i = s->unseqToSeq[block[j]];
AssertD ( ll_i < s->nInUse, _T("generateMTFValues(2a)") );
if (yy[0] == ll_i) {
zPend++;
} else {
if (zPend > 0) {
zPend--;
while (True) {
if (zPend & 1) {
mtfv[wr] = BZ_RUNB; wr++;
s->mtfFreq[BZ_RUNB]++;
} else {
mtfv[wr] = BZ_RUNA; wr++;
s->mtfFreq[BZ_RUNA]++;
}
if (zPend < 2) break;
zPend = (zPend - 2) / 2;
};
zPend = 0;
}
{
register UChar rtmp;
register UChar* ryy_j;
register UChar rll_i;
rtmp = yy[1];
yy[1] = yy[0];
ryy_j = &(yy[1]);
rll_i = ll_i;
while ( rll_i != rtmp ) {
register UChar rtmp2;
ryy_j++;
rtmp2 = rtmp;
rtmp = *ryy_j;
*ryy_j = rtmp2;
};
yy[0] = rtmp;
j = ryy_j - &(yy[0]);
mtfv[wr] = j+1; wr++; s->mtfFreq[j+1]++;
}
}
}
if (zPend > 0) {
zPend--;
while (True) {
if (zPend & 1) {
mtfv[wr] = BZ_RUNB; wr++;
s->mtfFreq[BZ_RUNB]++;
} else {
mtfv[wr] = BZ_RUNA; wr++;
s->mtfFreq[BZ_RUNA]++;
}
if (zPend < 2) break;
zPend = (zPend - 2) / 2;
};
zPend = 0;
}
mtfv[wr] = EOB; wr++; s->mtfFreq[EOB]++;
s->nMTF = wr;
}
