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zlib 1.2.3.5

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This commit is contained in:
Mark Adler
2011-09-09 23:26:49 -07:00
parent f6194ef39a
commit d004b04783
74 changed files with 7130 additions and 1865 deletions
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20
inffast.c
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@@ -79,7 +79,7 @@ unsigned start; /* inflate()'s starting value for strm->avail_out */
#endif
unsigned wsize; /* window size or zero if not using window */
unsigned whave; /* valid bytes in the window */
unsigned write; /* window write index */
unsigned wnext; /* window write index */
unsigned char FAR *window; /* allocated sliding window, if wsize != 0 */
unsigned long hold; /* local strm->hold */
unsigned bits; /* local strm->bits */
@@ -106,7 +106,7 @@ unsigned start; /* inflate()'s starting value for strm->avail_out */
#endif
wsize = state->wsize;
whave = state->whave;
write = state->write;
wnext = state->wnext;
window = state->window;
hold = state->hold;
bits = state->bits;
@@ -214,7 +214,7 @@ unsigned start; /* inflate()'s starting value for strm->avail_out */
#endif
}
from = window - OFF;
if (write == 0) { /* very common case */
if (wnext == 0) { /* very common case */
from += wsize - op;
if (op < len) { /* some from window */
len -= op;
@@ -224,17 +224,17 @@ unsigned start; /* inflate()'s starting value for strm->avail_out */
from = out - dist; /* rest from output */
}
}
else if (write < op) { /* wrap around window */
from += wsize + write - op;
op -= write;
else if (wnext < op) { /* wrap around window */
from += wsize + wnext - op;
op -= wnext;
if (op < len) { /* some from end of window */
len -= op;
do {
PUP(out) = PUP(from);
} while (--op);
from = window - OFF;
if (write < len) { /* some from start of window */
op = write;
if (wnext < len) { /* some from start of window */
op = wnext;
len -= op;
do {
PUP(out) = PUP(from);
@@ -244,7 +244,7 @@ unsigned start; /* inflate()'s starting value for strm->avail_out */
}
}
else { /* contiguous in window */
from += write - op;
from += wnext - op;
if (op < len) { /* some from window */
len -= op;
do {
@@ -327,7 +327,7 @@ unsigned start; /* inflate()'s starting value for strm->avail_out */
inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):
- Using bit fields for code structure
- Different op definition to avoid & for extra bits (do & for table bits)
- Three separate decoding do-loops for direct, window, and write == 0
- Three separate decoding do-loops for direct, window, and wnext == 0
- Special case for distance > 1 copies to do overlapped load and store copy
- Explicit branch predictions (based on measured branch probabilities)
- Deferring match copy and interspersed it with decoding subsequent codes