[PATCH] zlib_inflate: Upgrade library code to a recent version

Upgrade the zlib_inflate implementation in the kernel from a patched
version 1.1.3/4 to a patched 1.2.3.

The code in the kernel is about seven years old and I noticed that the
external zlib library's inflate performance was significantly faster (~50%)
than the code in the kernel on ARM (and faster again on x86_32).

For comparison the newer deflate code is 20% slower on ARM and 50% slower
on x86_32 but gives an approx 1% compression ratio improvement.  I don't
consider this to be an improvement for kernel use so have no plans to
change the zlib_deflate code.

Various changes have been made to the zlib code in the kernel, the most
significant being the extra functions/flush option used by ppp_deflate.
This update reimplements the features PPP needs to ensure it continues to
work.

This code has been tested on ARM under both JFFS2 (with zlib compression
enabled) and ppp_deflate and on x86_32.  JFFS2 sees an approx.  10% real
world file read speed improvement.

This patch also removes ZLIB_VERSION as it no longer has a correct value.
We don't need version checks anyway as the kernel's module handling will
take care of that for us.  This removal is also more in keeping with the
zlib author's wishes (http://www.zlib.net/zlib_faq.html#faq24) and I've
added something to the zlib.h header to note its a modified version.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Joern Engel <joern@wh.fh-wedel.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 202 deletions

diff --git a/lib/zlib_inflate/infcodes.c b/lib/zlib_inflate/infcodes.c
deleted file mode 100644
index 07cd7591cbb..00000000000
--- a/lib/zlib_inflate/infcodes.c
+++ /dev/null
@@ -1,202 +0,0 @@
-/* infcodes.c -- process literals and length/distance pairs
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h 
- */
-
-#include <linux/zutil.h>
-#include "inftrees.h"
-#include "infblock.h"
-#include "infcodes.h"
-#include "infutil.h"
-#include "inffast.h"
-
-/* simplify the use of the inflate_huft type with some defines */
-#define exop word.what.Exop
-#define bits word.what.Bits
-
-inflate_codes_statef *zlib_inflate_codes_new(
-	uInt bl,
-	uInt bd,
-	inflate_huft *tl,
-	inflate_huft *td, /* need separate declaration for Borland C++ */
-	z_streamp z
-)
-{
-  inflate_codes_statef *c;
-
-  c = &WS(z)->working_state;
-  {
-    c->mode = START;
-    c->lbits = (Byte)bl;
-    c->dbits = (Byte)bd;
-    c->ltree = tl;
-    c->dtree = td;
-  }
-  return c;
-}
-
-
-int zlib_inflate_codes(
-	inflate_blocks_statef *s,
-	z_streamp z,
-	int r
-)
-{
-  uInt j;               /* temporary storage */
-  inflate_huft *t;      /* temporary pointer */
-  uInt e;               /* extra bits or operation */
-  uLong b;              /* bit buffer */
-  uInt k;               /* bits in bit buffer */
-  Byte *p;              /* input data pointer */
-  uInt n;               /* bytes available there */
-  Byte *q;              /* output window write pointer */
-  uInt m;               /* bytes to end of window or read pointer */
-  Byte *f;              /* pointer to copy strings from */
-  inflate_codes_statef *c = s->sub.decode.codes;  /* codes state */
-
-  /* copy input/output information to locals (UPDATE macro restores) */
-  LOAD
-
-  /* process input and output based on current state */
-  while (1) switch (c->mode)
-  {             /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
-    case START:         /* x: set up for LEN */
-#ifndef SLOW
-      if (m >= 258 && n >= 10)
-      {
-        UPDATE
-        r = zlib_inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
-        LOAD
-        if (r != Z_OK)
-        {
-          c->mode = r == Z_STREAM_END ? WASH : BADCODE;
-          break;
-        }
-      }
-#endif /* !SLOW */
-      c->sub.code.need = c->lbits;
-      c->sub.code.tree = c->ltree;
-      c->mode = LEN;
-    case LEN:           /* i: get length/literal/eob next */
-      j = c->sub.code.need;
-      NEEDBITS(j)
-      t = c->sub.code.tree + ((uInt)b & zlib_inflate_mask[j]);
-      DUMPBITS(t->bits)
-      e = (uInt)(t->exop);
-      if (e == 0)               /* literal */
-      {
-        c->sub.lit = t->base;
-        c->mode = LIT;
-        break;
-      }
-      if (e & 16)               /* length */
-      {
-        c->sub.copy.get = e & 15;
-        c->len = t->base;
-        c->mode = LENEXT;
-        break;
-      }
-      if ((e & 64) == 0)        /* next table */
-      {
-        c->sub.code.need = e;
-        c->sub.code.tree = t + t->base;
-        break;
-      }
-      if (e & 32)               /* end of block */
-      {
-        c->mode = WASH;
-        break;
-      }
-      c->mode = BADCODE;        /* invalid code */
-      z->msg = (char*)"invalid literal/length code";
-      r = Z_DATA_ERROR;
-      LEAVE
-    case LENEXT:        /* i: getting length extra (have base) */
-      j = c->sub.copy.get;
-      NEEDBITS(j)
-      c->len += (uInt)b & zlib_inflate_mask[j];
-      DUMPBITS(j)
-      c->sub.code.need = c->dbits;
-      c->sub.code.tree = c->dtree;
-      c->mode = DIST;
-    case DIST:          /* i: get distance next */
-      j = c->sub.code.need;
-      NEEDBITS(j)
-      t = c->sub.code.tree + ((uInt)b & zlib_inflate_mask[j]);
-      DUMPBITS(t->bits)
-      e = (uInt)(t->exop);
-      if (e & 16)               /* distance */
-      {
-        c->sub.copy.get = e & 15;
-        c->sub.copy.dist = t->base;
-        c->mode = DISTEXT;
-        break;
-      }
-      if ((e & 64) == 0)        /* next table */
-      {
-        c->sub.code.need = e;
-        c->sub.code.tree = t + t->base;
-        break;
-      }
-      c->mode = BADCODE;        /* invalid code */
-      z->msg = (char*)"invalid distance code";
-      r = Z_DATA_ERROR;
-      LEAVE
-    case DISTEXT:       /* i: getting distance extra */
-      j = c->sub.copy.get;
-      NEEDBITS(j)
-      c->sub.copy.dist += (uInt)b & zlib_inflate_mask[j];
-      DUMPBITS(j)
-      c->mode = COPY;
-    case COPY:          /* o: copying bytes in window, waiting for space */
-      f = q - c->sub.copy.dist;
-      while (f < s->window)             /* modulo window size-"while" instead */
-        f += s->end - s->window;        /* of "if" handles invalid distances */
-      while (c->len)
-      {
-        NEEDOUT
-        OUTBYTE(*f++)
-        if (f == s->end)
-          f = s->window;
-        c->len--;
-      }
-      c->mode = START;
-      break;
-    case LIT:           /* o: got literal, waiting for output space */
-      NEEDOUT
-      OUTBYTE(c->sub.lit)
-      c->mode = START;
-      break;
-    case WASH:          /* o: got eob, possibly more output */
-      if (k > 7)        /* return unused byte, if any */
-      {
-        k -= 8;
-        n++;
-        p--;            /* can always return one */
-      }
-      FLUSH
-      if (s->read != s->write)
-        LEAVE
-      c->mode = END;
-    case END:
-      r = Z_STREAM_END;
-      LEAVE
-    case BADCODE:       /* x: got error */
-      r = Z_DATA_ERROR;
-      LEAVE
-    default:
-      r = Z_STREAM_ERROR;
-      LEAVE
-  }
-#ifdef NEED_DUMMY_RETURN
-  return Z_STREAM_ERROR;  /* Some dumb compilers complain without this */
-#endif
-}
-
-
-void zlib_inflate_codes_free(
-	inflate_codes_statef *c,
-	z_streamp z
-)
-{
-}