u-boot/lib/zlib/adler32.c

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/* adler32.c -- compute the Adler-32 checksum of a data stream
* Copyright (C) 1995-2004 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
/* @(#) $Id$ */
#define ZLIB_INTERNAL
#include "zlib.h"
#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 */
#define DO1(buf,i) {adler += (buf)[i]; sum2 += adler;}
#define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
#define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
#define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
#define DO16(buf) DO8(buf,0); DO8(buf,8);
/* use NO_DIVIDE if your processor does not do division in hardware */
#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)
# define MOD4(a) \
do { \
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
# define MOD4(a) a %= BASE
#endif
/* ========================================================================= */
lib/zlib: sparse fixes define Z_NULL to (void *)0 include/u-boot/zlib.h to get rid of most of the NULL pointer warnings. inflate.c:942:1: warning: non-ANSI definition of function 'inflateEnd' inflate.c:9:1: warning: non-ANSI definition of function 'inflateReset' inflate.c:12:17: warning: Using plain integer as NULL pointer inflate.c:12:42: warning: Using plain integer as NULL pointer inflate.c:15:17: warning: Using plain integer as NULL pointer inflate.c:21:19: warning: Using plain integer as NULL pointer inflate.c:35:1: warning: non-ANSI definition of function 'inflateInit2_' inflate.c:38:20: warning: Using plain integer as NULL pointer inflate.c:41:17: warning: Using plain integer as NULL pointer inflate.c:42:17: warning: Using plain integer as NULL pointer inflate.c:50:18: warning: Using plain integer as NULL pointer inflate.c:65:23: warning: Using plain integer as NULL pointer inflate.c:69:21: warning: Using plain integer as NULL pointer inflate.c:78:1: warning: non-ANSI definition of function 'inflateInit_' inflate.c:86:1: warning: non-ANSI definition of function 'fixedtables' inflate.c:108:26: warning: Using plain integer as NULL pointer inflate.c:109:1: warning: non-ANSI definition of function 'updatewindow' inflate.c:112:30: warning: Using plain integer as NULL pointer inflate.c:339:1: warning: non-ANSI definition of function 'inflate' inflate.c:349:17: warning: Using plain integer as NULL pointer inflate.c:349:42: warning: Using plain integer as NULL pointer inflate.c:350:27: warning: Using plain integer as NULL pointer inflate.c:369:42: warning: Using plain integer as NULL pointer inflate.c:376:32: warning: Using plain integer as NULL pointer inflate.c:401:54: warning: Using plain integer as NULL pointer inflate.c:419:32: warning: Using plain integer as NULL pointer inflate.c:426:32: warning: Using plain integer as NULL pointer inflate.c:433:32: warning: Using plain integer as NULL pointer inflate.c:444:36: warning: Using plain integer as NULL pointer inflate.c:449:37: warning: Using plain integer as NULL pointer inflate.c:450:38: warning: Using plain integer as NULL pointer inflate.c:457:40: warning: Using plain integer as NULL pointer inflate.c:458:47: warning: Using plain integer as NULL pointer inflate.c:480:40: warning: Using plain integer as NULL pointer inflate.c:481:50: warning: Using plain integer as NULL pointer inflate.c:491:37: warning: Using plain integer as NULL pointer inflate.c:492:37: warning: Using plain integer as NULL pointer inflate.c:501:40: warning: Using plain integer as NULL pointer inflate.c:502:53: warning: Using plain integer as NULL pointer inflate.c:512:37: warning: Using plain integer as NULL pointer inflate.c:513:40: warning: Using plain integer as NULL pointer inflate.c:525:32: warning: Using plain integer as NULL pointer inflate.c:529:52: warning: Using plain integer as NULL pointer inflate.c:543:54: warning: Using plain integer as NULL pointer inflate.c:932:17: warning: Using plain integer as NULL pointer inflate.c:932:42: warning: Using plain integer as NULL pointer inflate.c:935:26: warning: Using plain integer as NULL pointer inflate.c:940:19: warning: Using plain integer as NULL pointer adler32.c:58:5: warning: non-ANSI definition of function 'adler32' adler32.c:81:16: warning: Using plain integer as NULL pointer zutil.c:53:9: warning: non-ANSI definition of function 'zcalloc' zutil.c:64:9: warning: non-ANSI definition of function 'zcfree' inffast.c:70:1: warning: non-ANSI definition of function 'inflate_fast' inftrees.c:33:1: warning: non-ANSI definition of function 'inflate_table' Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
2012-10-29 13:34:35 +00:00
uLong ZEXPORT adler32(uLong adler, const Bytef *buf, uInt len)
{
unsigned long sum2;
unsigned n;
/* split Adler-32 into component sums */
sum2 = (adler >> 16) & 0xffff;
adler &= 0xffff;
/* in case user likes doing a byte at a time, keep it fast */
if (len == 1) {
adler += buf[0];
if (adler >= BASE)
adler -= BASE;
sum2 += adler;
if (sum2 >= BASE)
sum2 -= BASE;
return adler | (sum2 << 16);
}
/* initial Adler-32 value (deferred check for len == 1 speed) */
if (buf == Z_NULL)
return 1L;
/* in case short lengths are provided, keep it somewhat fast */
if (len < 16) {
while (len--) {
adler += *buf++;
sum2 += adler;
}
if (adler >= BASE)
adler -= BASE;
MOD4(sum2); /* only added so many BASE's */
return adler | (sum2 << 16);
}
/* do length NMAX blocks -- requires just one modulo operation */
while (len >= NMAX) {
len -= NMAX;
n = NMAX / 16; /* NMAX is divisible by 16 */
do {
DO16(buf); /* 16 sums unrolled */
buf += 16;
} while (--n);
MOD(adler);
MOD(sum2);
}
/* do remaining bytes (less than NMAX, still just one modulo) */
if (len) { /* avoid modulos if none remaining */
while (len >= 16) {
len -= 16;
DO16(buf);
buf += 16;
}
while (len--) {
adler += *buf++;
sum2 += adler;
}
MOD(adler);
MOD(sum2);
}
/* return recombined sums */
return adler | (sum2 << 16);
}