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-rw-r--r--libs/zlib/src/inffast.c599
1 files changed, 308 insertions, 291 deletions
diff --git a/libs/zlib/src/inffast.c b/libs/zlib/src/inffast.c
index 0dbd1dbc09..8b2d311a5a 100644
--- a/libs/zlib/src/inffast.c
+++ b/libs/zlib/src/inffast.c
@@ -1,5 +1,5 @@
/* inffast.c -- fast decoding
- * Copyright (C) 1995-2017 Mark Adler
+ * Copyright (C) 1995-2008, 2010, 2013 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
@@ -8,316 +8,333 @@
#include "inflate.h"
#include "inffast.h"
-#ifdef ASMINF
-# pragma message("Assembler code may have bugs -- use at your own risk")
+#ifndef ASMINF
+
+ /* Allow machine dependent optimization for post-increment or pre-increment.
+ Based on testing to date,
+ Pre-increment preferred for:
+ - PowerPC G3 (Adler)
+ - MIPS R5000 (Randers-Pehrson)
+ Post-increment preferred for:
+ - none
+ No measurable difference:
+ - Pentium III (Anderson)
+ - M68060 (Nikl)
+ */
+#ifdef POSTINC
+# define OFF 0
+# define PUP(a) *(a)++
#else
+# define OFF 1
+# define PUP(a) *++(a)
+#endif
-/*
- Decode literal, length, and distance codes and write out the resulting
- literal and match bytes until either not enough input or output is
- available, an end-of-block is encountered, or a data error is encountered.
- When large enough input and output buffers are supplied to inflate(), for
- example, a 16K input buffer and a 64K output buffer, more than 95% of the
- inflate execution time is spent in this routine.
+ /*
+ Decode literal, length, and distance codes and write out the resulting
+ literal and match bytes until either not enough input or output is
+ available, an end-of-block is encountered, or a data error is encountered.
+ When large enough input and output buffers are supplied to inflate(), for
+ example, a 16K input buffer and a 64K output buffer, more than 95% of the
+ inflate execution time is spent in this routine.
- Entry assumptions:
+ Entry assumptions:
- state->mode == LEN
- strm->avail_in >= 6
- strm->avail_out >= 258
- start >= strm->avail_out
- state->bits < 8
+ state->mode == LEN
+ strm->avail_in >= 6
+ strm->avail_out >= 258
+ start >= strm->avail_out
+ state->bits < 8
- On return, state->mode is one of:
+ On return, state->mode is one of:
- LEN -- ran out of enough output space or enough available input
- TYPE -- reached end of block code, inflate() to interpret next block
- BAD -- error in block data
+ LEN -- ran out of enough output space or enough available input
+ TYPE -- reached end of block code, inflate() to interpret next block
+ BAD -- error in block data
- Notes:
+ Notes:
- - The maximum input bits used by a length/distance pair is 15 bits for the
- length code, 5 bits for the length extra, 15 bits for the distance code,
- and 13 bits for the distance extra. This totals 48 bits, or six bytes.
- Therefore if strm->avail_in >= 6, then there is enough input to avoid
- checking for available input while decoding.
+ - The maximum input bits used by a length/distance pair is 15 bits for the
+ length code, 5 bits for the length extra, 15 bits for the distance code,
+ and 13 bits for the distance extra. This totals 48 bits, or six bytes.
+ Therefore if strm->avail_in >= 6, then there is enough input to avoid
+ checking for available input while decoding.
- - The maximum bytes that a single length/distance pair can output is 258
- bytes, which is the maximum length that can be coded. inflate_fast()
- requires strm->avail_out >= 258 for each loop to avoid checking for
- output space.
- */
+ - The maximum bytes that a single length/distance pair can output is 258
+ bytes, which is the maximum length that can be coded. inflate_fast()
+ requires strm->avail_out >= 258 for each loop to avoid checking for
+ output space.
+ */
void ZLIB_INTERNAL inflate_fast(strm, start)
z_streamp strm;
unsigned start; /* inflate()'s starting value for strm->avail_out */
{
- struct inflate_state FAR *state;
- z_const unsigned char FAR *in; /* local strm->next_in */
- z_const unsigned char FAR *last; /* have enough input while in < last */
- unsigned char FAR *out; /* local strm->next_out */
- unsigned char FAR *beg; /* inflate()'s initial strm->next_out */
- unsigned char FAR *end; /* while out < end, enough space available */
-#ifdef INFLATE_STRICT
- unsigned dmax; /* maximum distance from zlib header */
-#endif
- unsigned wsize; /* window size or zero if not using window */
- unsigned whave; /* valid bytes in the window */
- 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 */
- code const FAR *lcode; /* local strm->lencode */
- 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 here; /* retrieved table entry */
- unsigned op; /* code bits, operation, extra bits, or */
- /* window position, window bytes to copy */
- unsigned len; /* match length, unused bytes */
- unsigned dist; /* match distance */
- unsigned char FAR *from; /* where to copy match from */
+ struct inflate_state FAR *state;
+ z_const unsigned char FAR *in; /* local strm->next_in */
+ z_const unsigned char FAR *last; /* have enough input while in < last */
+ unsigned char FAR *out; /* local strm->next_out */
+ unsigned char FAR *beg; /* inflate()'s initial strm->next_out */
+ unsigned char FAR *end; /* while out < end, enough space available */
+ #ifdef INFLATE_STRICT
+ unsigned dmax; /* maximum distance from zlib header */
+ #endif
+ unsigned wsize; /* window size or zero if not using window */
+ unsigned whave; /* valid bytes in the window */
+ 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 */
+ code const FAR *lcode; /* local strm->lencode */
+ 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 here; /* retrieved table entry */
+ unsigned op; /* code bits, operation, extra bits, or */
+ /* window position, window bytes to copy */
+ unsigned len; /* match length, unused bytes */
+ unsigned dist; /* match distance */
+ unsigned char FAR *from; /* where to copy match from */
- /* copy state to local variables */
- state = (struct inflate_state FAR *)strm->state;
- in = strm->next_in;
- last = in + (strm->avail_in - 5);
- out = strm->next_out;
- beg = out - (start - strm->avail_out);
- end = out + (strm->avail_out - 257);
-#ifdef INFLATE_STRICT
- dmax = state->dmax;
-#endif
- wsize = state->wsize;
- whave = state->whave;
- wnext = state->wnext;
- window = state->window;
- hold = state->hold;
- bits = state->bits;
- lcode = state->lencode;
- dcode = state->distcode;
- lmask = (1U << state->lenbits) - 1;
- dmask = (1U << state->distbits) - 1;
+ /* copy state to local variables */
+ state = (struct inflate_state FAR *)strm->state;
+ in = strm->next_in - OFF;
+ last = in + (strm->avail_in - 5);
+ out = strm->next_out - OFF;
+ beg = out - (start - strm->avail_out);
+ end = out + (strm->avail_out - 257);
+ #ifdef INFLATE_STRICT
+ dmax = state->dmax;
+ #endif
+ wsize = state->wsize;
+ whave = state->whave;
+ wnext = state->wnext;
+ window = state->window;
+ hold = state->hold;
+ bits = state->bits;
+ lcode = state->lencode;
+ dcode = state->distcode;
+ lmask = (1U << state->lenbits) - 1;
+ dmask = (1U << state->distbits) - 1;
- /* decode literals and length/distances until end-of-block or not enough
- input data or output space */
- do {
- if (bits < 15) {
- hold += (unsigned long)(*in++) << bits;
- bits += 8;
- hold += (unsigned long)(*in++) << bits;
- bits += 8;
- }
- here = lcode[hold & lmask];
- dolen:
- op = (unsigned)(here.bits);
- hold >>= op;
- bits -= op;
- op = (unsigned)(here.op);
- if (op == 0) { /* literal */
- Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
- "inflate: literal '%c'\n" :
- "inflate: literal 0x%02x\n", here.val));
- *out++ = (unsigned char)(here.val);
- }
- else if (op & 16) { /* length base */
- len = (unsigned)(here.val);
- op &= 15; /* number of extra bits */
- if (op) {
- if (bits < op) {
- hold += (unsigned long)(*in++) << bits;
- bits += 8;
- }
- len += (unsigned)hold & ((1U << op) - 1);
- hold >>= op;
- bits -= op;
- }
- Tracevv((stderr, "inflate: length %u\n", len));
- if (bits < 15) {
- hold += (unsigned long)(*in++) << bits;
- bits += 8;
- hold += (unsigned long)(*in++) << bits;
- bits += 8;
- }
- here = dcode[hold & dmask];
- dodist:
- op = (unsigned)(here.bits);
- hold >>= op;
- bits -= op;
- op = (unsigned)(here.op);
- if (op & 16) { /* distance base */
- dist = (unsigned)(here.val);
- op &= 15; /* number of extra bits */
- if (bits < op) {
- hold += (unsigned long)(*in++) << bits;
- bits += 8;
- if (bits < op) {
- hold += (unsigned long)(*in++) << bits;
- bits += 8;
- }
- }
- dist += (unsigned)hold & ((1U << op) - 1);
-#ifdef INFLATE_STRICT
- if (dist > dmax) {
- strm->msg = (char *)"invalid distance too far back";
- state->mode = BAD;
- break;
- }
-#endif
- hold >>= op;
- bits -= op;
- Tracevv((stderr, "inflate: distance %u\n", dist));
- op = (unsigned)(out - beg); /* max distance in output */
- if (dist > op) { /* see if copy from window */
- op = dist - op; /* distance back in window */
- if (op > whave) {
- 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 {
- *out++ = 0;
- } while (--len);
- continue;
- }
- len -= op - whave;
- do {
- *out++ = 0;
- } while (--op > whave);
- if (op == 0) {
- from = out - dist;
- do {
- *out++ = *from++;
- } while (--len);
- continue;
- }
-#endif
- }
- from = window;
- if (wnext == 0) { /* very common case */
- from += wsize - op;
- if (op < len) { /* some from window */
- len -= op;
- do {
- *out++ = *from++;
- } while (--op);
- from = out - dist; /* rest from output */
- }
- }
- else if (wnext < op) { /* wrap around window */
- from += wsize + wnext - op;
- op -= wnext;
- if (op < len) { /* some from end of window */
- len -= op;
- do {
- *out++ = *from++;
- } while (--op);
- from = window;
- if (wnext < len) { /* some from start of window */
- op = wnext;
- len -= op;
- do {
- *out++ = *from++;
- } while (--op);
- from = out - dist; /* rest from output */
- }
- }
- }
- else { /* contiguous in window */
- from += wnext - op;
- if (op < len) { /* some from window */
- len -= op;
- do {
- *out++ = *from++;
- } while (--op);
- from = out - dist; /* rest from output */
- }
- }
- while (len > 2) {
- *out++ = *from++;
- *out++ = *from++;
- *out++ = *from++;
- len -= 3;
- }
- if (len) {
- *out++ = *from++;
- if (len > 1)
- *out++ = *from++;
- }
- }
- else {
- from = out - dist; /* copy direct from output */
- do { /* minimum length is three */
- *out++ = *from++;
- *out++ = *from++;
- *out++ = *from++;
- len -= 3;
- } while (len > 2);
- if (len) {
- *out++ = *from++;
- if (len > 1)
- *out++ = *from++;
- }
- }
- }
- else if ((op & 64) == 0) { /* 2nd level distance code */
- here = dcode[here.val + (hold & ((1U << op) - 1))];
- goto dodist;
- }
- else {
- strm->msg = (char *)"invalid distance code";
- state->mode = BAD;
- break;
- }
- }
- else if ((op & 64) == 0) { /* 2nd level length code */
- here = lcode[here.val + (hold & ((1U << op) - 1))];
- goto dolen;
- }
- else if (op & 32) { /* end-of-block */
- Tracevv((stderr, "inflate: end of block\n"));
- state->mode = TYPE;
- break;
- }
- else {
- strm->msg = (char *)"invalid literal/length code";
- state->mode = BAD;
- break;
- }
- } while (in < last && out < end);
+ /* decode literals and length/distances until end-of-block or not enough
+ input data or output space */
+ do {
+ if (bits < 15) {
+ hold += (unsigned long)(PUP(in)) << bits;
+ bits += 8;
+ hold += (unsigned long)(PUP(in)) << bits;
+ bits += 8;
+ }
+ here = lcode[hold & lmask];
+ dolen:
+ op = (unsigned)(here.bits);
+ hold >>= op;
+ bits -= op;
+ op = (unsigned)(here.op);
+ if (op == 0) { /* literal */
+ Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+ "inflate: literal '%c'\n" :
+ "inflate: literal 0x%02x\n", here.val));
+ PUP(out) = (unsigned char)(here.val);
+ }
+ else if (op & 16) { /* length base */
+ len = (unsigned)(here.val);
+ op &= 15; /* number of extra bits */
+ if (op) {
+ if (bits < op) {
+ hold += (unsigned long)(PUP(in)) << bits;
+ bits += 8;
+ }
+ len += (unsigned)hold & ((1U << op) - 1);
+ hold >>= op;
+ bits -= op;
+ }
+ Tracevv((stderr, "inflate: length %u\n", len));
+ if (bits < 15) {
+ hold += (unsigned long)(PUP(in)) << bits;
+ bits += 8;
+ hold += (unsigned long)(PUP(in)) << bits;
+ bits += 8;
+ }
+ here = dcode[hold & dmask];
+ dodist:
+ op = (unsigned)(here.bits);
+ hold >>= op;
+ bits -= op;
+ op = (unsigned)(here.op);
+ if (op & 16) { /* distance base */
+ dist = (unsigned)(here.val);
+ op &= 15; /* number of extra bits */
+ if (bits < op) {
+ hold += (unsigned long)(PUP(in)) << bits;
+ bits += 8;
+ if (bits < op) {
+ hold += (unsigned long)(PUP(in)) << bits;
+ bits += 8;
+ }
+ }
+ dist += (unsigned)hold & ((1U << op) - 1);
+ #ifdef INFLATE_STRICT
+ if (dist > dmax) {
+ strm->msg = (char *)"invalid distance too far back";
+ state->mode = BAD;
+ break;
+ }
+ #endif
+ hold >>= op;
+ bits -= op;
+ Tracevv((stderr, "inflate: distance %u\n", dist));
+ op = (unsigned)(out - beg); /* max distance in output */
+ if (dist > op) { /* see if copy from window */
+ op = dist - op; /* distance back in window */
+ if (op > whave) {
+ 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 (wnext == 0) { /* very common case */
+ from += wsize - op;
+ if (op < len) { /* some from window */
+ len -= op;
+ do {
+ PUP(out) = PUP(from);
+ } while (--op);
+ from = out - dist; /* rest from output */
+ }
+ }
+ 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 (wnext < len) { /* some from start of window */
+ op = wnext;
+ len -= op;
+ do {
+ PUP(out) = PUP(from);
+ } while (--op);
+ from = out - dist; /* rest from output */
+ }
+ }
+ }
+ else { /* contiguous in window */
+ from += wnext - op;
+ if (op < len) { /* some from window */
+ len -= op;
+ do {
+ PUP(out) = PUP(from);
+ } while (--op);
+ from = out - dist; /* rest from output */
+ }
+ }
+ while (len > 2) {
+ PUP(out) = PUP(from);
+ PUP(out) = PUP(from);
+ PUP(out) = PUP(from);
+ len -= 3;
+ }
+ if (len) {
+ PUP(out) = PUP(from);
+ if (len > 1)
+ PUP(out) = PUP(from);
+ }
+ }
+ else {
+ from = out - dist; /* copy direct from output */
+ do { /* minimum length is three */
+ PUP(out) = PUP(from);
+ PUP(out) = PUP(from);
+ PUP(out) = PUP(from);
+ len -= 3;
+ } while (len > 2);
+ if (len) {
+ PUP(out) = PUP(from);
+ if (len > 1)
+ PUP(out) = PUP(from);
+ }
+ }
+ }
+ else if ((op & 64) == 0) { /* 2nd level distance code */
+ here = dcode[here.val + (hold & ((1U << op) - 1))];
+ goto dodist;
+ }
+ else {
+ strm->msg = (char *)"invalid distance code";
+ state->mode = BAD;
+ break;
+ }
+ }
+ else if ((op & 64) == 0) { /* 2nd level length code */
+ here = lcode[here.val + (hold & ((1U << op) - 1))];
+ goto dolen;
+ }
+ else if (op & 32) { /* end-of-block */
+ Tracevv((stderr, "inflate: end of block\n"));
+ state->mode = TYPE;
+ break;
+ }
+ else {
+ strm->msg = (char *)"invalid literal/length code";
+ state->mode = BAD;
+ break;
+ }
+ } while (in < last && out < end);
- /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
- len = bits >> 3;
- in -= len;
- bits -= len << 3;
- hold &= (1U << bits) - 1;
+ /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
+ len = bits >> 3;
+ in -= len;
+ bits -= len << 3;
+ hold &= (1U << bits) - 1;
- /* update state and return */
- strm->next_in = in;
- strm->next_out = out;
- strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
- strm->avail_out = (unsigned)(out < end ?
- 257 + (end - out) : 257 - (out - end));
- state->hold = hold;
- state->bits = bits;
- return;
+ /* update state and return */
+ strm->next_in = in + OFF;
+ strm->next_out = out + OFF;
+ strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
+ strm->avail_out = (unsigned)(out < end ?
+ 257 + (end - out) : 257 - (out - end));
+ state->hold = hold;
+ state->bits = bits;
+ return;
}
/*
- 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 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
- - Swapping literal/length else
- - Swapping window/direct else
- - Larger unrolled copy loops (three is about right)
- - Moving len -= 3 statement into middle of loop
+ 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 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
+ - Swapping literal/length else
+ - Swapping window/direct else
+ - Larger unrolled copy loops (three is about right)
+ - Moving len -= 3 statement into middle of loop
*/
#endif /* !ASMINF */
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-27 22:36:11 +0000