diff options
Diffstat (limited to 'lib/zlib/src/adler32.c')
| -rw-r--r-- | lib/zlib/src/adler32.c | 44 |
1 files changed, 35 insertions, 9 deletions
diff --git a/lib/zlib/src/adler32.c b/lib/zlib/src/adler32.c index e19806c..72cbb87 100644 --- a/lib/zlib/src/adler32.c +++ b/lib/zlib/src/adler32.c @@ -1,13 +1,14 @@ /* adler32.c -- compute the Adler-32 checksum of a data stream - * Copyright (C) 1995-2002 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h + * Copyright (C) 1995-2003 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h */ -/* @(#) $Id: adler32.c,v 1.3 2004-11-27 21:46:13 pixel Exp $ */ +/* @(#) $Id: adler32.c,v 1.4 2005-06-06 11:16:16 pixel Exp $ */ +#define ZLIB_INTERNAL #include "zlib.h" -#define BASE 65521L /* largest prime smaller than 65536 */ +#define BASE 65521UL /* largest prime smaller than 65536 */ #define NMAX 5552 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ @@ -17,6 +18,31 @@ #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4); #define DO16(buf) DO8(buf,0); DO8(buf,8); +#ifdef NO_DIVIDE +# define MOD(a) \ + do { \ + if (a >= (BASE << 16)) a -= (BASE << 16); \ + if (a >= (BASE << 15)) a -= (BASE << 15); \ + if (a >= (BASE << 14)) a -= (BASE << 14); \ + if (a >= (BASE << 13)) a -= (BASE << 13); \ + if (a >= (BASE << 12)) a -= (BASE << 12); \ + if (a >= (BASE << 11)) a -= (BASE << 11); \ + if (a >= (BASE << 10)) a -= (BASE << 10); \ + 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; \ + } while (0) +#else +# define MOD(a) a %= BASE +#endif + /* ========================================================================= */ uLong ZEXPORT adler32(adler, buf, len) uLong adler; @@ -30,19 +56,19 @@ uLong ZEXPORT adler32(adler, buf, len) if (buf == Z_NULL) return 1L; while (len > 0) { - k = len < NMAX ? len : NMAX; + k = len < NMAX ? (int)len : NMAX; len -= k; while (k >= 16) { DO16(buf); - buf += 16; + buf += 16; k -= 16; } if (k != 0) do { s1 += *buf++; - s2 += s1; + s2 += s1; } while (--k); - s1 %= BASE; - s2 %= BASE; + MOD(s1); + MOD(s2); } return (s2 << 16) | s1; } |