linux-imx

/* inffast.c -- fast decoding

 * Copyright (C) 1995-2004 Mark Adler

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

 */

​

#include <linux/zutil.h>

#include "inftrees.h"

#include "inflate.h"

#include "inffast.h"

​

#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)

 */

union uu {

    unsigned short us;

    unsigned char b[2];

};

​

/* Endian independed version */

static inline unsigned short

get_unaligned16(const unsigned short *p)

{

    union uu  mm;

    unsigned char *b = (unsigned char *)p;

​

    mm.b[0] = b[0];

    mm.b[1] = b[1];

    return mm.us;

}

​

#ifdef POSTINC

#  define OFF 0

#  define PUP(a) *(a)++

#  define UP_UNALIGNED(a) get_unaligned16((a)++)

#else

#  define OFF 1

#  define PUP(a) *++(a)

#  define UP_UNALIGNED(a) get_unaligned16(++(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.

​

   Entry assumptions:

​

        state->mode == LEN

        strm->avail_in >= 6

        strm->avail_out >= 258