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Diff for /embedaddon/rsync/zlib/adler32.c between versions 1.1 and 1.1.1.2

version 1.1, 2012/02/17 15:09:30 version 1.1.1.2, 2013/10/14 07:51:14
Line 1 Line 1
 /* adler32.c -- compute the Adler-32 checksum of a data stream  /* adler32.c -- compute the Adler-32 checksum of a data stream
 * Copyright (C) 1995-2004 Mark Adler * Copyright (C) 1995-2011 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h   * For conditions of distribution and use, see copyright notice in zlib.h
  */   */
   
 /* @(#) $Id$ */  /* @(#) $Id$ */
   
#define ZLIB_INTERNAL#include "zutil.h"
#include "zlib.h" 
   
#define BASE 65521UL    /* largest prime smaller than 65536 */#define local static
 
 local uLong adler32_combine_ OF((uLong adler1, uLong adler2, z_off64_t len2));
 
 #define BASE 65521      /* largest prime smaller than 65536 */
 #define NMAX 5552  #define NMAX 5552
 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */  /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
   
Line 18 Line 21
 #define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);  #define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
 #define DO16(buf)   DO8(buf,0); DO8(buf,8);  #define DO16(buf)   DO8(buf,0); DO8(buf,8);
   
/* use NO_DIVIDE if your processor does not do division in hardware *//* use NO_DIVIDE if your processor does not do division in hardware --
    try it both ways to see which is faster */
 #ifdef NO_DIVIDE  #ifdef NO_DIVIDE
#  define MOD(a) \/* note that this assumes BASE is 65521, where 65536 % 65521 == 15
    (thank you to John Reiser for pointing this out) */
 #  define CHOP(a) \
     do { \      do { \
        if (a >= (BASE << 16)) a -= (BASE << 16); \        unsigned long tmp = a >> 16; \
        if (a >= (BASE << 15)) a -= (BASE << 15); \        a &= 0xffffUL; \
        if (a >= (BASE << 14)) a -= (BASE << 14); \        a += (tmp << 4) - tmp; \
        if (a >= (BASE << 13)) a -= (BASE << 13); \    } while (0)
        if (a >= (BASE << 12)) a -= (BASE << 12); \#  define MOD28(a) \
        if (a >= (BASE << 11)) a -= (BASE << 11); \    do { \
        if (a >= (BASE << 10)) a -= (BASE << 10); \        CHOP(a); \
        if (a >= (BASE << 9)) a -= (BASE << 9); \ 
        if (a >= (BASE << 8)) a -= (BASE << 8); \ 
        if (a >= (BASE << 7)) a -= (BASE << 7); \ 
        if (a >= (BASE << 6)) a -= (BASE << 6); \ 
        if (a >= (BASE << 5)) a -= (BASE << 5); \ 
        if (a >= (BASE << 4)) a -= (BASE << 4); \ 
        if (a >= (BASE << 3)) a -= (BASE << 3); \ 
        if (a >= (BASE << 2)) a -= (BASE << 2); \ 
        if (a >= (BASE << 1)) a -= (BASE << 1); \ 
         if (a >= BASE) a -= BASE; \          if (a >= BASE) a -= BASE; \
     } while (0)      } while (0)
#  define MOD4(a) \#  define MOD(a) \
     do { \      do { \
        if (a >= (BASE << 4)) a -= (BASE << 4); \        CHOP(a); \
        if (a >= (BASE << 3)) a -= (BASE << 3); \        MOD28(a); \
        if (a >= (BASE << 2)) a -= (BASE << 2); \    } while (0)
        if (a >= (BASE << 1)) a -= (BASE << 1); \#  define MOD63(a) \
     do { /* this assumes a is not negative */ \
         z_off64_t tmp = a >> 32; \
         a &= 0xffffffffL; \
         a += (tmp << 8) - (tmp << 5) + tmp; \
         tmp = a >> 16; \
         a &= 0xffffL; \
         a += (tmp << 4) - tmp; \
         tmp = a >> 16; \
         a &= 0xffffL; \
         a += (tmp << 4) - tmp; \
         if (a >= BASE) a -= BASE; \          if (a >= BASE) a -= BASE; \
     } while (0)      } while (0)
 #else  #else
 #  define MOD(a) a %= BASE  #  define MOD(a) a %= BASE
#  define MOD4(a) a %= BASE#  define MOD28(a) a %= BASE
 #  define MOD63(a) a %= BASE
 #endif  #endif
   
 /* ========================================================================= */  /* ========================================================================= */
Line 89  uLong ZEXPORT adler32(adler, buf, len) Line 97  uLong ZEXPORT adler32(adler, buf, len)
         }          }
         if (adler >= BASE)          if (adler >= BASE)
             adler -= BASE;              adler -= BASE;
        MOD4(sum2);             /* only added so many BASE's */        MOD28(sum2);            /* only added so many BASE's */
         return adler | (sum2 << 16);          return adler | (sum2 << 16);
     }      }
   
Line 125  uLong ZEXPORT adler32(adler, buf, len) Line 133  uLong ZEXPORT adler32(adler, buf, len)
 }  }
   
 /* ========================================================================= */  /* ========================================================================= */
uLong ZEXPORT adler32_combine(adler1, adler2, len2)local uLong adler32_combine_(adler1, adler2, len2)
     uLong adler1;      uLong adler1;
     uLong adler2;      uLong adler2;
    z_off_t len2;    z_off64_t len2;
 {  {
     unsigned long sum1;      unsigned long sum1;
     unsigned long sum2;      unsigned long sum2;
     unsigned rem;      unsigned rem;
   
       /* for negative len, return invalid adler32 as a clue for debugging */
       if (len2 < 0)
           return 0xffffffffUL;
   
     /* the derivation of this formula is left as an exercise for the reader */      /* the derivation of this formula is left as an exercise for the reader */
    rem = (unsigned)(len2 % BASE);    MOD63(len2);                /* assumes len2 >= 0 */
     rem = (unsigned)len2;
     sum1 = adler1 & 0xffff;      sum1 = adler1 & 0xffff;
     sum2 = rem * sum1;      sum2 = rem * sum1;
     MOD(sum2);      MOD(sum2);
     sum1 += (adler2 & 0xffff) + BASE - 1;      sum1 += (adler2 & 0xffff) + BASE - 1;
     sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;      sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;
    if (sum1 > BASE) sum1 -= BASE;    if (sum1 >= BASE) sum1 -= BASE;
    if (sum1 > BASE) sum1 -= BASE;    if (sum1 >= BASE) sum1 -= BASE;
    if (sum2 > (BASE << 1)) sum2 -= (BASE << 1);    if (sum2 >= (BASE << 1)) sum2 -= (BASE << 1);
    if (sum2 > BASE) sum2 -= BASE;    if (sum2 >= BASE) sum2 -= BASE;
     return sum1 | (sum2 << 16);      return sum1 | (sum2 << 16);
   }
   
   /* ========================================================================= */
   uLong ZEXPORT adler32_combine(adler1, adler2, len2)
       uLong adler1;
       uLong adler2;
       z_off_t len2;
   {
       return adler32_combine_(adler1, adler2, len2);
   }
   
   uLong ZEXPORT adler32_combine64(adler1, adler2, len2)
       uLong adler1;
       uLong adler2;
       z_off64_t len2;
   {
       return adler32_combine_(adler1, adler2, len2);
 }  }
Removed from v.1.1  
changed lines
  Added in v.1.1.1.2

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