diff options
Diffstat (limited to 'dep/src/zlib/adler32.c')
| -rw-r--r-- | dep/src/zlib/adler32.c | 15 |
1 files changed, 0 insertions, 15 deletions
diff --git a/dep/src/zlib/adler32.c b/dep/src/zlib/adler32.c index 007ba26277c..483da9c58c0 100644 --- a/dep/src/zlib/adler32.c +++ b/dep/src/zlib/adler32.c @@ -2,22 +2,17 @@ * 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) \ @@ -52,7 +47,6 @@ # define MOD(a) a %= BASE # define MOD4(a) a %= BASE #endif - /* ========================================================================= */ uLong ZEXPORT adler32(adler, buf, len) uLong adler; @@ -61,11 +55,9 @@ uLong ZEXPORT adler32(adler, buf, 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]; @@ -76,11 +68,9 @@ uLong ZEXPORT adler32(adler, buf, len) 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--) { @@ -92,7 +82,6 @@ uLong ZEXPORT adler32(adler, buf, len) 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; @@ -104,7 +93,6 @@ uLong ZEXPORT adler32(adler, buf, len) MOD(adler); MOD(sum2); } - /* do remaining bytes (less than NMAX, still just one modulo) */ if (len) { /* avoid modulos if none remaining */ while (len >= 16) { @@ -119,11 +107,9 @@ uLong ZEXPORT adler32(adler, buf, len) MOD(adler); MOD(sum2); } - /* return recombined sums */ return adler | (sum2 << 16); } - /* ========================================================================= */ uLong ZEXPORT adler32_combine(adler1, adler2, len2) uLong adler1; @@ -133,7 +119,6 @@ uLong ZEXPORT adler32_combine(adler1, adler2, len2) unsigned long sum1; unsigned long sum2; unsigned rem; - /* the derivation of this formula is left as an exercise for the reader */ rem = (unsigned)(len2 % BASE); sum1 = adler1 & 0xffff; |