[BACK]Return to adler32.c CVS log [TXT] [DIR] Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / sudo / zlib

Diff for /embedaddon/sudo/zlib/adler32.c between versions 1.1.1.1 and 1.1.1.2

version 1.1.1.1, 2012/02/21 16:23:02 version 1.1.1.2, 2013/07/22 10:46:14
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) 1995-2007 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
  */   */
   
Line 9 Line 9
   
 #define local static  #define local static
   
local uLong adler32_combine_(uLong adler1, uLong adler2, z_off64_t len2);local uLong adler32_combine_ OF((uLong adler1, uLong adler2, z_off64_t len2));
   
#define BASE 65521UL    /* largest prime smaller than 65536 */#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 21  local uLong adler32_combine_(uLong adler1, uLong adler Line 21  local uLong adler32_combine_(uLong adler1, uLong adler
 #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 92  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 137  local uLong adler32_combine_(adler1, adler2, len2) Line 142  local uLong adler32_combine_(adler1, adler2, len2)
     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);
Removed from v.1.1.1.1  
changed lines
  Added in v.1.1.1.2

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>