third_party/zlib/inffast.c - Issue 8806004: Update zlib to 1.2.5.

Unified Diff: third_party/zlib/inffast.c

Issue 8806004: Update zlib to 1.2.5. (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src/

Patch Set: '' Created 9 years ago

Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.

Jump to:

View side-by-side diff with in-line comments

Index: third_party/zlib/inffast.c

===================================================================

--- third_party/zlib/inffast.c (revision 113739)

+++ third_party/zlib/inffast.c (working copy)

@@ -1,5 +1,5 @@

/* inffast.c -- fast decoding

* For conditions of distribution and use, see copyright notice in zlib.h

@@ -64,7 +64,7 @@

requires strm->avail_out >= 258 for each loop to avoid checking for

output space.

-void inflate_fast(strm, start)

+void ZLIB_INTERNAL inflate_fast(strm, start)

z_streamp strm;

unsigned start; /* inflate()'s starting value for strm->avail_out */

{

@@ -79,7 +79,7 @@

#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 */

@@ -87,7 +87,7 @@

code const FAR *dcode; /* local strm->distcode */

unsigned lmask; /* mask for first level of length 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 */

/* window position, window bytes to copy */

unsigned len; /* match length, unused bytes */

@@ -106,7 +106,7 @@

#endif

wsize = state->wsize;

whave = state->whave;

- write = state->write;

+ wnext = state->wnext;

window = state->window;

hold = state->hold;

bits = state->bits;

@@ -124,20 +124,20 @@

hold += (unsigned long)(PUP(in)) << bits;

bits += 8;

}

- this = lcode[hold & lmask];

+ here = lcode[hold & lmask];

dolen:

- op = (unsigned)(this.bits);

+ op = (unsigned)(here.bits);

hold >>= op;

bits -= op;

- op = (unsigned)(this.op);

+ op = (unsigned)(here.op);

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 0x%02x\n", this.val));

- PUP(out) = (unsigned char)(this.val);

+ "inflate: literal 0x%02x\n", here.val));

+ PUP(out) = (unsigned char)(here.val);

}

else if (op & 16) { /* length base */

- len = (unsigned)(this.val);

+ len = (unsigned)(here.val);

op &= 15; /* number of extra bits */

if (op) {

if (bits < op) {

@@ -155,14 +155,14 @@

hold += (unsigned long)(PUP(in)) << bits;

bits += 8;

}

- this = dcode[hold & dmask];

+ here = dcode[hold & dmask];

dodist:

- op = (unsigned)(this.bits);

+ op = (unsigned)(here.bits);

hold >>= op;

bits -= op;

- op = (unsigned)(this.op);

+ op = (unsigned)(here.op);

if (op & 16) { /* distance base */

- dist = (unsigned)(this.val);

+ dist = (unsigned)(here.val);

op &= 15; /* number of extra bits */

if (bits < op) {

hold += (unsigned long)(PUP(in)) << bits;

@@ -187,12 +187,34 @@

if (dist > op) { /* see if copy from window */

op = dist - op; /* distance back in window */

if (op > whave) {

- strm->msg = (char *)"invalid distance too far back";

- state->mode = BAD;

- break;

+ if (state->sane) {

+ strm->msg =

+ (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;

- if (write == 0) { /* very common case */

+ if (wnext == 0) { /* very common case */

from += wsize - op;

if (op < len) { /* some from window */

len -= op;

@@ -202,17 +224,17 @@

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);

@@ -222,7 +244,7 @@

}

else { /* contiguous in window */

- from += write - op;

+ from += wnext - op;

if (op < len) { /* some from window */

len -= op;

do {

@@ -259,7 +281,7 @@

}

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;

}

else {

@@ -269,7 +291,7 @@

}

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;

}

else if (op & 32) { /* end-of-block */

@@ -305,7 +327,7 @@

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

« no previous file with comments | « third_party/zlib/inffast.h ('k') | third_party/zlib/inflate.h » ('j') | no next file with comments »