release/src/router/zlib/contrib/masmx64/inffas8664.c

   1 /* inffas8664.c is a hand tuned assembler version of inffast.c - fast decoding
   2  * version for AMD64 on Windows using Microsoft C compiler
   3  *
   4  * Copyright (C) 1995-2003 Mark Adler
   5  * For conditions of distribution and use, see copyright notice in zlib.h
   6  *
   7  * Copyright (C) 2003 Chris Anderson <christop@charm.net>
   8  * Please use the copyright conditions above.
   9  *
  10  * 2005 - Adaptation to Microsoft C Compiler for AMD64 by Gilles Vollant
  11  *
  12  * inffas8664.c call function inffas8664fnc in inffasx64.asm
  13  *  inffasx64.asm is automatically convert from AMD64 portion of inffas86.c
  14  *
  15  * Dec-29-2003 -- I added AMD64 inflate asm support.  This version is also
  16  * slightly quicker on x86 systems because, instead of using rep movsb to copy
  17  * data, it uses rep movsw, which moves data in 2-byte chunks instead of single
  18  * bytes.  I've tested the AMD64 code on a Fedora Core 1 + the x86_64 updates
  19  * from http://fedora.linux.duke.edu/fc1_x86_64
  20  * which is running on an Athlon 64 3000+ / Gigabyte GA-K8VT800M system with
  21  * 1GB ram.  The 64-bit version is about 4% faster than the 32-bit version,
  22  * when decompressing mozilla-source-1.3.tar.gz.
  23  *
  24  * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
  25  * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
  26  * the moment.  I have successfully compiled and tested this code with gcc2.96,
  27  * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
  28  * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
  29  * enabled.  I will attempt to merge the MMX code into this version.  Newer
  30  * versions of this and inffast.S can be found at
  31  * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
  32  *
  33  */
  34
  35 #include <stdio.h>
  36 #include "zutil.h"
  37 #include "inftrees.h"
  38 #include "inflate.h"
  39 #include "inffast.h"
  40
  41 /* Mark Adler's comments from inffast.c: */
  42
  43 /*
  44    Decode literal, length, and distance codes and write out the resulting
  45    literal and match bytes until either not enough input or output is
  46    available, an end-of-block is encountered, or a data error is encountered.
  47    When large enough input and output buffers are supplied to inflate(), for
  48    example, a 16K input buffer and a 64K output buffer, more than 95% of the
  49    inflate execution time is spent in this routine.
  50
  51    Entry assumptions:
  52
  53         state->mode == LEN
  54         strm->avail_in >= 6
  55         strm->avail_out >= 258
  56         start >= strm->avail_out
  57         state->bits < 8
  58
  59    On return, state->mode is one of:
  60
  61         LEN -- ran out of enough output space or enough available input
  62         TYPE -- reached end of block code, inflate() to interpret next block
  63         BAD -- error in block data
  64
  65    Notes:
  66
  67     - The maximum input bits used by a length/distance pair is 15 bits for the
  68       length code, 5 bits for the length extra, 15 bits for the distance code,
  69       and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
  70       Therefore if strm->avail_in >= 6, then there is enough input to avoid
  71       checking for available input while decoding.
  72
  73     - The maximum bytes that a single length/distance pair can output is 258
  74       bytes, which is the maximum length that can be coded.  inflate_fast()
  75       requires strm->avail_out >= 258 for each loop to avoid checking for
  76       output space.
  77  */
  78
  79
  80
  81     typedef struct inffast_ar {
  82 /* 64   32                               x86  x86_64 */
  83 /* ar offset                              register */
  84 /*  0    0 */ void *esp;                /* esp save */
  85 /*  8    4 */ void *ebp;                /* ebp save */
  86 /* 16    8 */ unsigned char FAR *in;    /* esi rsi  local strm->next_in */
  87 /* 24   12 */ unsigned char FAR *last;  /*     r9   while in < last */
  88 /* 32   16 */ unsigned char FAR *out;   /* edi rdi  local strm->next_out */
  89 /* 40   20 */ unsigned char FAR *beg;   /*          inflate()'s init next_out */
  90 /* 48   24 */ unsigned char FAR *end;   /*     r10  while out < end */
  91 /* 56   28 */ unsigned char FAR *window;/*          size of window, wsize!=0 */
  92 /* 64   32 */ code const FAR *lcode;    /* ebp rbp  local strm->lencode */
  93 /* 72   36 */ code const FAR *dcode;    /*     r11  local strm->distcode */
  94 /* 80   40 */ size_t /*unsigned long */hold;       /* edx rdx  local strm->hold */
  95 /* 88   44 */ unsigned bits;            /* ebx rbx  local strm->bits */
  96 /* 92   48 */ unsigned wsize;           /*          window size */
  97 /* 96   52 */ unsigned write;           /*          window write index */
  98 /*100   56 */ unsigned lmask;           /*     r12  mask for lcode */
  99 /*104   60 */ unsigned dmask;           /*     r13  mask for dcode */
 100 /*108   64 */ unsigned len;             /*     r14  match length */
 101 /*112   68 */ unsigned dist;            /*     r15  match distance */
 102 /*116   72 */ unsigned status;          /*          set when state chng*/
 103     } type_ar;
 104 #ifdef ASMINF
 105
 106 void inflate_fast(strm, start)
 107 z_streamp strm;
 108 unsigned start;         /* inflate()'s starting value for strm->avail_out */
 109 {
 110     struct inflate_state FAR *state;
 111     type_ar ar;
 112     void inffas8664fnc(struct inffast_ar * par);
 113
 114
 115
 116 #if (defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )) || (defined(_MSC_VER) && defined(_M_AMD64))
 117 #define PAD_AVAIL_IN 6
 118 #define PAD_AVAIL_OUT 258
 119 #else
 120 #define PAD_AVAIL_IN 5
 121 #define PAD_AVAIL_OUT 257
 122 #endif
 123
 124     /* copy state to local variables */
 125     state = (struct inflate_state FAR *)strm->state;
 126
 127     ar.in = strm->next_in;
 128     ar.last = ar.in + (strm->avail_in - PAD_AVAIL_IN);
 129     ar.out = strm->next_out;
 130     ar.beg = ar.out - (start - strm->avail_out);
 131     ar.end = ar.out + (strm->avail_out - PAD_AVAIL_OUT);
 132     ar.wsize = state->wsize;
 133     ar.write = state->wnext;
 134     ar.window = state->window;
 135     ar.hold = state->hold;
 136     ar.bits = state->bits;
 137     ar.lcode = state->lencode;
 138     ar.dcode = state->distcode;
 139     ar.lmask = (1U << state->lenbits) - 1;
 140     ar.dmask = (1U << state->distbits) - 1;
 141
 142     /* decode literals and length/distances until end-of-block or not enough
 143        input data or output space */
 144
 145     /* align in on 1/2 hold size boundary */
 146     while (((size_t)(void *)ar.in & (sizeof(ar.hold) / 2 - 1)) != 0) {
 147         ar.hold += (unsigned long)*ar.in++ << ar.bits;
 148         ar.bits += 8;
 149     }
 150
 151     inffas8664fnc(&ar);
 152
 153     if (ar.status > 1) {
 154         if (ar.status == 2)
 155             strm->msg = "invalid literal/length code";
 156         else if (ar.status == 3)
 157             strm->msg = "invalid distance code";
 158         else
 159             strm->msg = "invalid distance too far back";
 160         state->mode = BAD;
 161     }
 162     else if ( ar.status == 1 ) {
 163         state->mode = TYPE;
 164     }
 165
 166     /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
 167     ar.len = ar.bits >> 3;
 168     ar.in -= ar.len;
 169     ar.bits -= ar.len << 3;
 170     ar.hold &= (1U << ar.bits) - 1;
 171
 172     /* update state and return */
 173     strm->next_in = ar.in;
 174     strm->next_out = ar.out;
 175     strm->avail_in = (unsigned)(ar.in < ar.last ?
 176                                 PAD_AVAIL_IN + (ar.last - ar.in) :
 177                                 PAD_AVAIL_IN - (ar.in - ar.last));
 178     strm->avail_out = (unsigned)(ar.out < ar.end ?
 179                                  PAD_AVAIL_OUT + (ar.end - ar.out) :
 180                                  PAD_AVAIL_OUT - (ar.out - ar.end));
 181     state->hold = (unsigned long)ar.hold;
 182     state->bits = ar.bits;
 183     return;
 184 }
 185
 186 #endif