187 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			187 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* inffas8664.c is a hand tuned assembler version of inffast.c - fast decoding
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|  * version for AMD64 on Windows using Microsoft C compiler
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|  *
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|  * Copyright (C) 1995-2003 Mark Adler
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|  * For conditions of distribution and use, see copyright notice in zlib.h
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|  *
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|  * Copyright (C) 2003 Chris Anderson <christop@charm.net>
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|  * Please use the copyright conditions above.
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|  *
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|  * 2005 - Adaptation to Microsoft C Compiler for AMD64 by Gilles Vollant
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|  *
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|  * inffas8664.c call function inffas8664fnc in inffasx64.asm
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|  *  inffasx64.asm is automatically convert from AMD64 portion of inffas86.c
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|  *
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|  * Dec-29-2003 -- I added AMD64 inflate asm support.  This version is also
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|  * slightly quicker on x86 systems because, instead of using rep movsb to copy
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|  * data, it uses rep movsw, which moves data in 2-byte chunks instead of single
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|  * bytes.  I've tested the AMD64 code on a Fedora Core 1 + the x86_64 updates
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|  * from http://fedora.linux.duke.edu/fc1_x86_64
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|  * which is running on an Athlon 64 3000+ / Gigabyte GA-K8VT800M system with
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|  * 1GB ram.  The 64-bit version is about 4% faster than the 32-bit version,
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|  * when decompressing mozilla-source-1.3.tar.gz.
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|  *
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|  * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
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|  * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
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|  * the moment.  I have successfully compiled and tested this code with gcc2.96,
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|  * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
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|  * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
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|  * enabled.  I will attempt to merge the MMX code into this version.  Newer
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|  * versions of this and inffast.S can be found at
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|  * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
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|  *
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|  */
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| 
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| #include <stdio.h>
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| #include "zutil.h"
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| #include "inftrees.h"
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| #include "inflate.h"
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| #include "inffast.h"
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| 
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| /* Mark Adler's comments from inffast.c: */
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| 
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| /*
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|    Decode literal, length, and distance codes and write out the resulting
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|    literal and match bytes until either not enough input or output is
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|    available, an end-of-block is encountered, or a data error is encountered.
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|    When large enough input and output buffers are supplied to inflate(), for
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|    example, a 16K input buffer and a 64K output buffer, more than 95% of the
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|    inflate execution time is spent in this routine.
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| 
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|    Entry assumptions:
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| 
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|         state->mode == LEN
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|         strm->avail_in >= 6
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|         strm->avail_out >= 258
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|         start >= strm->avail_out
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|         state->bits < 8
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| 
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|    On return, state->mode is one of:
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| 
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|         LEN -- ran out of enough output space or enough available input
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|         TYPE -- reached end of block code, inflate() to interpret next block
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|         BAD -- error in block data
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| 
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|    Notes:
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| 
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|     - The maximum input bits used by a length/distance pair is 15 bits for the
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|       length code, 5 bits for the length extra, 15 bits for the distance code,
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|       and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
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|       Therefore if strm->avail_in >= 6, then there is enough input to avoid
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|       checking for available input while decoding.
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| 
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|     - The maximum bytes that a single length/distance pair can output is 258
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|       bytes, which is the maximum length that can be coded.  inflate_fast()
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|       requires strm->avail_out >= 258 for each loop to avoid checking for
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|       output space.
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|  */
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| 
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| 
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| 
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|     typedef struct inffast_ar {
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| /* 64   32                               x86  x86_64 */
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| /* ar offset                              register */
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| /*  0    0 */ void *esp;                /* esp save */
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| /*  8    4 */ void *ebp;                /* ebp save */
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| /* 16    8 */ unsigned char FAR *in;    /* esi rsi  local strm->next_in */
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| /* 24   12 */ unsigned char FAR *last;  /*     r9   while in < last */
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| /* 32   16 */ unsigned char FAR *out;   /* edi rdi  local strm->next_out */
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| /* 40   20 */ unsigned char FAR *beg;   /*          inflate()'s init next_out */
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| /* 48   24 */ unsigned char FAR *end;   /*     r10  while out < end */
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| /* 56   28 */ unsigned char FAR *window;/*          size of window, wsize!=0 */
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| /* 64   32 */ code const FAR *lcode;    /* ebp rbp  local strm->lencode */
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| /* 72   36 */ code const FAR *dcode;    /*     r11  local strm->distcode */
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| /* 80   40 */ size_t /*unsigned long */hold;       /* edx rdx  local strm->hold */
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| /* 88   44 */ unsigned bits;            /* ebx rbx  local strm->bits */
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| /* 92   48 */ unsigned wsize;           /*          window size */
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| /* 96   52 */ unsigned write;           /*          window write index */
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| /*100   56 */ unsigned lmask;           /*     r12  mask for lcode */
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| /*104   60 */ unsigned dmask;           /*     r13  mask for dcode */
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| /*108   64 */ unsigned len;             /*     r14  match length */
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| /*112   68 */ unsigned dist;            /*     r15  match distance */
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| /*116   72 */ unsigned status;          /*          set when state chng*/
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|     } type_ar;
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| #ifdef ASMINF
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| 
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| void inflate_fast(strm, start)
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| z_streamp strm;
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| unsigned start;         /* inflate()'s starting value for strm->avail_out */
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| {
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|     struct inflate_state FAR *state;
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|     type_ar ar;
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|     void inffas8664fnc(struct inffast_ar * par);
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| 
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| 
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| 
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| #if (defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )) || (defined(_MSC_VER) && defined(_M_AMD64))
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| #define PAD_AVAIL_IN 6
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| #define PAD_AVAIL_OUT 258
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| #else
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| #define PAD_AVAIL_IN 5
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| #define PAD_AVAIL_OUT 257
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| #endif
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| 
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|     /* copy state to local variables */
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|     state = (struct inflate_state FAR *)strm->state;
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| 
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|     ar.in = strm->next_in;
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|     ar.last = ar.in + (strm->avail_in - PAD_AVAIL_IN);
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|     ar.out = strm->next_out;
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|     ar.beg = ar.out - (start - strm->avail_out);
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|     ar.end = ar.out + (strm->avail_out - PAD_AVAIL_OUT);
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|     ar.wsize = state->wsize;
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|     ar.write = state->wnext;
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|     ar.window = state->window;
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|     ar.hold = state->hold;
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|     ar.bits = state->bits;
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|     ar.lcode = state->lencode;
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|     ar.dcode = state->distcode;
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|     ar.lmask = (1U << state->lenbits) - 1;
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|     ar.dmask = (1U << state->distbits) - 1;
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| 
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|     /* decode literals and length/distances until end-of-block or not enough
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|        input data or output space */
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| 
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|     /* align in on 1/2 hold size boundary */
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|     while (((size_t)(void *)ar.in & (sizeof(ar.hold) / 2 - 1)) != 0) {
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|         ar.hold += (unsigned long)*ar.in++ << ar.bits;
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|         ar.bits += 8;
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|     }
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| 
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|     inffas8664fnc(&ar);
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| 
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|     if (ar.status > 1) {
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|         if (ar.status == 2)
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|             strm->msg = "invalid literal/length code";
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|         else if (ar.status == 3)
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|             strm->msg = "invalid distance code";
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|         else
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|             strm->msg = "invalid distance too far back";
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|         state->mode = BAD;
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|     }
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|     else if ( ar.status == 1 ) {
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|         state->mode = TYPE;
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|     }
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| 
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|     /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
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|     ar.len = ar.bits >> 3;
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|     ar.in -= ar.len;
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|     ar.bits -= ar.len << 3;
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|     ar.hold &= (1U << ar.bits) - 1;
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| 
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|     /* update state and return */
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|     strm->next_in = ar.in;
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|     strm->next_out = ar.out;
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|     strm->avail_in = (unsigned)(ar.in < ar.last ?
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|                                 PAD_AVAIL_IN + (ar.last - ar.in) :
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|                                 PAD_AVAIL_IN - (ar.in - ar.last));
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|     strm->avail_out = (unsigned)(ar.out < ar.end ?
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|                                  PAD_AVAIL_OUT + (ar.end - ar.out) :
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|                                  PAD_AVAIL_OUT - (ar.out - ar.end));
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|     state->hold = (unsigned long)ar.hold;
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|     state->bits = ar.bits;
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|     return;
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| }
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| 
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| #endif
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