X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/75bce3ad347a1ea870058391e624cccc159737d3..cc9a39576ab6edb139c9bb77d01f4118853e04d2:/src/zlib/adler32.c

diff --git a/src/zlib/adler32.c b/src/zlib/adler32.c
index ce12383f4b..624a1696eb 100644
--- a/src/zlib/adler32.c
+++ b/src/zlib/adler32.c
@@ -1,13 +1,14 @@
 /* adler32.c -- compute the Adler-32 checksum of a data stream
- * Copyright (C) 1995-1998 Mark Adler
+ * Copyright (C) 1995-2003 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /* @(#) $Id$ */
 
-#include "../zlib/zlib.h"
+#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 */
 
@@ -17,15 +18,36 @@
 #define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
 #define DO16(buf)   DO8(buf,0); DO8(buf,8);
 
-/* ========================================================================= */
-#if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */
-uLong ZEXPORT adler32 (uLong adler, const Bytef* buf, uInt len)
+#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;
     const Bytef *buf;
     uInt len;
-#endif
 {
     unsigned long s1 = adler & 0xffff;
     unsigned long s2 = (adler >> 16) & 0xffff;
@@ -34,19 +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;
 }