embedaddon/rsync/zlib/inffast.c - diff

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Diff for /embedaddon/rsync/zlib/inffast.c between versions 1.1 and 1.1.1.2

version 1.1, 2012/02/17 15:09:30	version 1.1.1.2, 2013/10/14 07:51:14
Line 1	Line 1
/* inffast.c -- fast decoding	/* inffast.c -- fast decoding
* Copyright (C) 1995-2004 Mark Adler	* Copyright (C) 1995-2008, 2010, 2013 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h	* For conditions of distribution and use, see copyright notice in zlib.h
*/	*/

Line 64	Line 64
requires strm->avail_out >= 258 for each loop to avoid checking for	requires strm->avail_out >= 258 for each loop to avoid checking for
output space.	output space.
*/	*/
void inflate_fast(strm, start)	void ZLIB_INTERNAL inflate_fast(strm, start)
z_streamp strm;	z_streamp strm;
unsigned start; /* inflate()'s starting value for strm->avail_out */	unsigned start; /* inflate()'s starting value for strm->avail_out */
{	{
struct inflate_state FAR *state;	struct inflate_state FAR *state;
unsigned char FAR in; / local strm->next_in */	z_const unsigned char FAR in; / local strm->next_in */
unsigned char FAR last; / while in < last, enough input available */	z_const unsigned char FAR last; / have enough input while in < last */
unsigned char FAR out; / local strm->next_out */	unsigned char FAR out; / local strm->next_out */
unsigned char FAR beg; / inflate()'s initial strm->next_out */	unsigned char FAR beg; / inflate()'s initial strm->next_out */
unsigned char FAR end; / while out < end, enough space available */	unsigned char FAR end; / while out < end, enough space available */
Line 79 unsigned start; /* inflate()'s starting value	Line 79 unsigned start; /* inflate()'s starting value
#endif	#endif
unsigned wsize; /* window size or zero if not using window */	unsigned wsize; /* window size or zero if not using window */
unsigned whave; /* valid bytes in the 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 char FAR window; / allocated sliding window, if wsize != 0 */
unsigned long hold; /* local strm->hold */	unsigned long hold; /* local strm->hold */
unsigned bits; /* local strm->bits */	unsigned bits; /* local strm->bits */
Line 87 unsigned start; /* inflate()'s starting value	Line 87 unsigned start; /* inflate()'s starting value
code const FAR dcode; / local strm->distcode */	code const FAR dcode; / local strm->distcode */
unsigned lmask; /* mask for first level of length codes */	unsigned lmask; /* mask for first level of length codes */
unsigned dmask; /* mask for first level of distance codes */	unsigned dmask; /* mask for first level of distance codes */
code this; /* retrieved table entry */	code here; /* retrieved table entry */
unsigned op; /* code bits, operation, extra bits, or */	unsigned op; /* code bits, operation, extra bits, or */
/* window position, window bytes to copy */	/* window position, window bytes to copy */
unsigned len; /* match length, unused bytes */	unsigned len; /* match length, unused bytes */
Line 106 unsigned start; /* inflate()'s starting value	Line 106 unsigned start; /* inflate()'s starting value
#endif	#endif
wsize = state->wsize;	wsize = state->wsize;
whave = state->whave;	whave = state->whave;
write = state->write;	wnext = state->wnext;
window = state->window;	window = state->window;
hold = state->hold;	hold = state->hold;
bits = state->bits;	bits = state->bits;
Line 124 unsigned start; /* inflate()'s starting value	Line 124 unsigned start; /* inflate()'s starting value
hold += (unsigned long)(PUP(in)) << bits;	hold += (unsigned long)(PUP(in)) << bits;
bits += 8;	bits += 8;
}	}
this = lcode[hold & lmask];	here = lcode[hold & lmask];
dolen:	dolen:
op = (unsigned)(this.bits);	op = (unsigned)(here.bits);
hold >>= op;	hold >>= op;
bits -= op;	bits -= op;
op = (unsigned)(this.op);	op = (unsigned)(here.op);
if (op == 0) { /* literal */	if (op == 0) { /* literal */
Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?	Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
"inflate: literal '%c'\n" :	"inflate: literal '%c'\n" :
"inflate: literal 0x%02x\n", this.val));	"inflate: literal 0x%02x\n", here.val));
PUP(out) = (unsigned char)(this.val);	PUP(out) = (unsigned char)(here.val);
}	}
else if (op & 16) { /* length base */	else if (op & 16) { /* length base */
len = (unsigned)(this.val);	len = (unsigned)(here.val);
op &= 15; /* number of extra bits */	op &= 15; /* number of extra bits */
if (op) {	if (op) {
if (bits < op) {	if (bits < op) {
Line 155 unsigned start; /* inflate()'s starting value	Line 155 unsigned start; /* inflate()'s starting value
hold += (unsigned long)(PUP(in)) << bits;	hold += (unsigned long)(PUP(in)) << bits;
bits += 8;	bits += 8;
}	}
this = dcode[hold & dmask];	here = dcode[hold & dmask];
dodist:	dodist:
op = (unsigned)(this.bits);	op = (unsigned)(here.bits);
hold >>= op;	hold >>= op;
bits -= op;	bits -= op;
op = (unsigned)(this.op);	op = (unsigned)(here.op);
if (op & 16) { /* distance base */	if (op & 16) { /* distance base */
dist = (unsigned)(this.val);	dist = (unsigned)(here.val);
op &= 15; /* number of extra bits */	op &= 15; /* number of extra bits */
if (bits < op) {	if (bits < op) {
hold += (unsigned long)(PUP(in)) << bits;	hold += (unsigned long)(PUP(in)) << bits;
Line 187 unsigned start; /* inflate()'s starting value	Line 187 unsigned start; /* inflate()'s starting value
if (dist > op) { /* see if copy from window */	if (dist > op) { /* see if copy from window */
op = dist - op; /* distance back in window */	op = dist - op; /* distance back in window */
if (op > whave) {	if (op > whave) {
strm->msg = (char *)"invalid distance too far back";	if (state->sane) {
state->mode = BAD;	strm->msg =
break;	(char *)"invalid distance too far back";
	state->mode = BAD;
	break;
	}
	#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
	if (len <= op - whave) {
	do {
	PUP(out) = 0;
	} while (--len);
	continue;
	}
	len -= op - whave;
	do {
	PUP(out) = 0;
	} while (--op > whave);
	if (op == 0) {
	from = out - dist;
	do {
	PUP(out) = PUP(from);
	} while (--len);
	continue;
	}
	#endif
}	}
from = window - OFF;	from = window - OFF;
if (write == 0) { /* very common case */	if (wnext == 0) { /* very common case */
from += wsize - op;	from += wsize - op;
if (op < len) { /* some from window */	if (op < len) { /* some from window */
len -= op;	len -= op;
Line 202 unsigned start; /* inflate()'s starting value	Line 224 unsigned start; /* inflate()'s starting value
from = out - dist; /* rest from output */	from = out - dist; /* rest from output */
}	}
}	}
else if (write < op) { /* wrap around window */	else if (wnext < op) { /* wrap around window */
from += wsize + write - op;	from += wsize + wnext - op;
op -= write;	op -= wnext;
if (op < len) { /* some from end of window */	if (op < len) { /* some from end of window */
len -= op;	len -= op;
do {	do {
PUP(out) = PUP(from);	PUP(out) = PUP(from);
} while (--op);	} while (--op);
from = window - OFF;	from = window - OFF;
if (write < len) { /* some from start of window */	if (wnext < len) { /* some from start of window */
op = write;	op = wnext;
len -= op;	len -= op;
do {	do {
PUP(out) = PUP(from);	PUP(out) = PUP(from);
Line 222 unsigned start; /* inflate()'s starting value	Line 244 unsigned start; /* inflate()'s starting value
}	}
}	}
else { /* contiguous in window */	else { /* contiguous in window */
from += write - op;	from += wnext - op;
if (op < len) { /* some from window */	if (op < len) { /* some from window */
len -= op;	len -= op;
do {	do {
Line 259 unsigned start; /* inflate()'s starting value	Line 281 unsigned start; /* inflate()'s starting value
}	}
}	}
else if ((op & 64) == 0) { /* 2nd level distance code */	else if ((op & 64) == 0) { /* 2nd level distance code */
this = dcode[this.val + (hold & ((1U << op) - 1))];	here = dcode[here.val + (hold & ((1U << op) - 1))];
goto dodist;	goto dodist;
}	}
else {	else {
Line 269 unsigned start; /* inflate()'s starting value	Line 291 unsigned start; /* inflate()'s starting value
}	}
}	}
else if ((op & 64) == 0) { /* 2nd level length code */	else if ((op & 64) == 0) { /* 2nd level length code */
this = lcode[this.val + (hold & ((1U << op) - 1))];	here = lcode[here.val + (hold & ((1U << op) - 1))];
goto dolen;	goto dolen;
}	}
else if (op & 32) { /* end-of-block */	else if (op & 32) { /* end-of-block */
Line 305 unsigned start; /* inflate()'s starting value	Line 327 unsigned start; /* inflate()'s starting value
inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):	inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):
- Using bit fields for code structure	- Using bit fields for code structure
- Different op definition to avoid & for extra bits (do & for table bits)	- 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	- Special case for distance > 1 copies to do overlapped load and store copy
- Explicit branch predictions (based on measured branch probabilities)	- Explicit branch predictions (based on measured branch probabilities)
- Deferring match copy and interspersed it with decoding subsequent codes	- Deferring match copy and interspersed it with decoding subsequent codes

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Removed from v.1.1
changed lines
	Added in v.1.1.1.2