xnu-2050.9.2.tar.gz

[apple/xnu.git] / libkern / zlib / adler32.c

diff --git a/libkern/zlib/adler32.c b/libkern/zlib/adler32.c
index c94fde18702ee0957c3b2fbe020d00c01b29f177..00214cd2e351f19131c2286132a64575a833edd6 100644 (file)
--- a/libkern/zlib/adler32.c
+++ b/libkern/zlib/adler32.c
@@ -32,6 +32,7 @@
 
 /* @(#) $Id$ */
 
+
 #define ZLIB_INTERNAL
 #if KERNEL
     #include <libkern/zlib.h>
@@ -39,6 +40,11 @@
     #include "zlib.h"
 #endif /* KERNEL */
 
+#if defined __x86_64__ || defined __i386__ || defined _ARM_ARCH_6
+#include <stdint.h> // For uintptr_t.
+    extern uLong adler32_vec(uLong adler, uLong sum2, const Bytef *buf, uInt len);
+#endif
+
 #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 */
@@ -124,6 +130,23 @@ uLong ZEXPORT adler32(adler, buf, len)
         return adler | (sum2 << 16);
     }
 
+#if defined __x86_64__ || defined __i386__ || defined _ARM_ARCH_6
+
+       if (len>=32000) {       /* use vector code only if len is sufficiently large to compensate registers save/restore */
+       /* align buf to 16-byte boundary */
+    while (((uintptr_t)buf)&15) { /* not on a 16-byte boundary */
+        len--;
+        adler += *buf++;
+        sum2 += adler;
+        if (adler >= BASE) adler -= BASE;
+        MOD4(sum2);             /* only added so many BASE's */
+    }
+
+    return adler32_vec(adler, sum2, buf, len);      // x86_64 or i386 (up to SSE3) or armv6 or up
+       }
+
+#endif // defined __x86_64__ || defined __i386__ || defined _ARM_ARCH_6
+
     /* do length NMAX blocks -- requires just one modulo operation */
     while (len >= NMAX) {
         len -= NMAX;