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authorSebastian Huber <sebastian.huber@embedded-brains.de>2023-05-05 10:02:34 +0200
committerSebastian Huber <sebastian.huber@embedded-brains.de>2023-05-09 15:07:09 +0200
commit1f00afcb5a5b30593543268acbcbcb94f60d24a2 (patch)
treed78dc96223ec34a63cbfdd92e3fc6dc5037f3eac /cpukit/zlib/adler32.c
parentbsps/amd64: add a new EFI-based variant of AMD64 BSP (diff)
downloadrtems-1f00afcb5a5b30593543268acbcbcb94f60d24a2.tar.bz2
zlib: Update from 1.2.5 to 1.2.13
The updated files were extracted from: https://www.zlib.net/zlib-1.2.13.tar.xz The archive had an SHA-256 hash value of: d14c38e313afc35a9a8760dadf26042f51ea0f5d154b0630a31da0540107fb98 Close #4902.
Diffstat (limited to 'cpukit/zlib/adler32.c')
-rw-r--r--cpukit/zlib/adler32.c87
1 files changed, 53 insertions, 34 deletions
diff --git a/cpukit/zlib/adler32.c b/cpukit/zlib/adler32.c
index 172de60321..d0be4380a3 100644
--- a/cpukit/zlib/adler32.c
+++ b/cpukit/zlib/adler32.c
@@ -1,15 +1,15 @@
/* adler32.c -- compute the Adler-32 checksum of a data stream
- * Copyright (C) 1995-2007 Mark Adler
+ * Copyright (C) 1995-2011, 2016 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
-#include "zutil.h"
+/* @(#) $Id$ */
-#define local static
+#include "zutil.h"
-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 65521U /* 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 */
@@ -19,46 +19,51 @@ local uLong adler32_combine_(uLong adler1, uLong adler2, z_off64_t len2);
#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 */
+/* use NO_DIVIDE if your processor does not do division in hardware --
+ try it both ways to see which is faster */
#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 { \
+ unsigned long tmp = a >> 16; \
+ a &= 0xffffUL; \
+ a += (tmp << 4) - tmp; \
+ } while (0)
+# define MOD28(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); \
+ CHOP(a); \
if (a >= BASE) a -= BASE; \
} while (0)
-# define MOD4(a) \
+# define MOD(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); \
+ CHOP(a); \
+ MOD28(a); \
+ } while (0)
+# 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; \
} while (0)
#else
# define MOD(a) a %= BASE
-# define MOD4(a) a %= BASE
+# define MOD28(a) a %= BASE
+# define MOD63(a) a %= BASE
#endif
/* ========================================================================= */
-uLong ZEXPORT adler32(adler, buf, len)
+uLong ZEXPORT adler32_z(adler, buf, len)
uLong adler;
const Bytef *buf;
- uInt len;
+ z_size_t len;
{
unsigned long sum2;
unsigned n;
@@ -90,7 +95,7 @@ uLong ZEXPORT adler32(adler, buf, len)
}
if (adler >= BASE)
adler -= BASE;
- MOD4(sum2); /* only added so many BASE's */
+ MOD28(sum2); /* only added so many BASE's */
return adler | (sum2 << 16);
}
@@ -126,6 +131,15 @@ uLong ZEXPORT adler32(adler, buf, len)
}
/* ========================================================================= */
+uLong ZEXPORT adler32(adler, buf, len)
+ uLong adler;
+ const Bytef *buf;
+ uInt len;
+{
+ return adler32_z(adler, buf, len);
+}
+
+/* ========================================================================= */
local uLong adler32_combine_(adler1, adler2, len2)
uLong adler1;
uLong adler2;
@@ -135,8 +149,13 @@ local uLong adler32_combine_(adler1, adler2, len2)
unsigned long sum2;
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 */
- rem = (unsigned)(len2 % BASE);
+ MOD63(len2); /* assumes len2 >= 0 */
+ rem = (unsigned)len2;
sum1 = adler1 & 0xffff;
sum2 = rem * sum1;
MOD(sum2);
@@ -144,7 +163,7 @@ local uLong adler32_combine_(adler1, adler2, len2)
sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;
if (sum1 >= BASE) sum1 -= BASE;
if (sum1 >= BASE) sum1 -= BASE;
- if (sum2 >= (BASE << 1)) sum2 -= (BASE << 1);
+ if (sum2 >= ((unsigned long)BASE << 1)) sum2 -= ((unsigned long)BASE << 1);
if (sum2 >= BASE) sum2 -= BASE;
return sum1 | (sum2 << 16);
}