+++ /dev/null
---- a/include/linux/jhash.h
-+++ b/include/linux/jhash.h
-@@ -3,80 +3,95 @@
-
- /* jhash.h: Jenkins hash support.
- *
-- * Copyright (C) 1996 Bob Jenkins (bob_jenkins@burtleburtle.net)
-+ * Copyright (C) 2006. Bob Jenkins (bob_jenkins@burtleburtle.net)
- *
- * http://burtleburtle.net/bob/hash/
- *
- * These are the credits from Bob's sources:
- *
-- * lookup2.c, by Bob Jenkins, December 1996, Public Domain.
-- * hash(), hash2(), hash3, and mix() are externally useful functions.
-- * Routines to test the hash are included if SELF_TEST is defined.
-- * You can use this free for any purpose. It has no warranty.
-+ * lookup3.c, by Bob Jenkins, May 2006, Public Domain.
- *
-- * Copyright (C) 2003 David S. Miller (davem@redhat.com)
-+ * These are functions for producing 32-bit hashes for hash table lookup.
-+ * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
-+ * are externally useful functions. Routines to test the hash are included
-+ * if SELF_TEST is defined. You can use this free for any purpose. It's in
-+ * the public domain. It has no warranty.
-+ *
-+ * Copyright (C) 2009 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu)
- *
- * I've modified Bob's hash to be useful in the Linux kernel, and
-- * any bugs present are surely my fault. -DaveM
-+ * any bugs present are my fault. Jozsef
- */
-
--/* NOTE: Arguments are modified. */
--#define __jhash_mix(a, b, c) \
-+#define __rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
-+
-+/* __jhash_mix - mix 3 32-bit values reversibly. */
-+#define __jhash_mix(a,b,c) \
-+{ \
-+ a -= c; a ^= __rot(c, 4); c += b; \
-+ b -= a; b ^= __rot(a, 6); a += c; \
-+ c -= b; c ^= __rot(b, 8); b += a; \
-+ a -= c; a ^= __rot(c,16); c += b; \
-+ b -= a; b ^= __rot(a,19); a += c; \
-+ c -= b; c ^= __rot(b, 4); b += a; \
-+}
-+
-+/* __jhash_final - final mixing of 3 32-bit values (a,b,c) into c */
-+#define __jhash_final(a,b,c) \
- { \
-- a -= b; a -= c; a ^= (c>>13); \
-- b -= c; b -= a; b ^= (a<<8); \
-- c -= a; c -= b; c ^= (b>>13); \
-- a -= b; a -= c; a ^= (c>>12); \
-- b -= c; b -= a; b ^= (a<<16); \
-- c -= a; c -= b; c ^= (b>>5); \
-- a -= b; a -= c; a ^= (c>>3); \
-- b -= c; b -= a; b ^= (a<<10); \
-- c -= a; c -= b; c ^= (b>>15); \
-+ c ^= b; c -= __rot(b,14); \
-+ a ^= c; a -= __rot(c,11); \
-+ b ^= a; b -= __rot(a,25); \
-+ c ^= b; c -= __rot(b,16); \
-+ a ^= c; a -= __rot(c,4); \
-+ b ^= a; b -= __rot(a,14); \
-+ c ^= b; c -= __rot(b,24); \
- }
-
--/* The golden ration: an arbitrary value */
--#define JHASH_GOLDEN_RATIO 0x9e3779b9
-+/* An arbitrary initial parameter */
-+#define JHASH_GOLDEN_RATIO 0xdeadbeef
-
- /* The most generic version, hashes an arbitrary sequence
- * of bytes. No alignment or length assumptions are made about
-- * the input key.
-+ * the input key. The result depends on endianness.
- */
- static inline u32 jhash(const void *key, u32 length, u32 initval)
- {
-- u32 a, b, c, len;
-+ u32 a,b,c;
- const u8 *k = key;
-
-- len = length;
-- a = b = JHASH_GOLDEN_RATIO;
-- c = initval;
--
-- while (len >= 12) {
-- a += (k[0] +((u32)k[1]<<8) +((u32)k[2]<<16) +((u32)k[3]<<24));
-- b += (k[4] +((u32)k[5]<<8) +((u32)k[6]<<16) +((u32)k[7]<<24));
-- c += (k[8] +((u32)k[9]<<8) +((u32)k[10]<<16)+((u32)k[11]<<24));
--
-- __jhash_mix(a,b,c);
-+ /* Set up the internal state */
-+ a = b = c = JHASH_GOLDEN_RATIO + length + initval;
-
-+ /* all but the last block: affect some 32 bits of (a,b,c) */
-+ while (length > 12) {
-+ a += (k[0] + ((u32)k[1]<<8) + ((u32)k[2]<<16) + ((u32)k[3]<<24));
-+ b += (k[4] + ((u32)k[5]<<8) + ((u32)k[6]<<16) + ((u32)k[7]<<24));
-+ c += (k[8] + ((u32)k[9]<<8) + ((u32)k[10]<<16) + ((u32)k[11]<<24));
-+ __jhash_mix(a, b, c);
-+ length -= 12;
- k += 12;
-- len -= 12;
- }
-
-- c += length;
-- switch (len) {
-- case 11: c += ((u32)k[10]<<24);
-- case 10: c += ((u32)k[9]<<16);
-- case 9 : c += ((u32)k[8]<<8);
-- case 8 : b += ((u32)k[7]<<24);
-- case 7 : b += ((u32)k[6]<<16);
-- case 6 : b += ((u32)k[5]<<8);
-+ /* last block: affect all 32 bits of (c) */
-+ /* all the case statements fall through */
-+ switch (length) {
-+ case 12: c += (u32)k[11]<<24;
-+ case 11: c += (u32)k[10]<<16;
-+ case 10: c += (u32)k[9]<<8;
-+ case 9 : c += k[8];
-+ case 8 : b += (u32)k[7]<<24;
-+ case 7 : b += (u32)k[6]<<16;
-+ case 6 : b += (u32)k[5]<<8;
- case 5 : b += k[4];
-- case 4 : a += ((u32)k[3]<<24);
-- case 3 : a += ((u32)k[2]<<16);
-- case 2 : a += ((u32)k[1]<<8);
-+ case 4 : a += (u32)k[3]<<24;
-+ case 3 : a += (u32)k[2]<<16;
-+ case 2 : a += (u32)k[1]<<8;
- case 1 : a += k[0];
-- };
--
-- __jhash_mix(a,b,c);
-+ __jhash_final(a, b, c);
-+ case 0 :
-+ break;
-+ }
-
- return c;
- }
-@@ -86,58 +101,57 @@ static inline u32 jhash(const void *key,
- */
- static inline u32 jhash2(const u32 *k, u32 length, u32 initval)
- {
-- u32 a, b, c, len;
-+ u32 a, b, c;
-
-- a = b = JHASH_GOLDEN_RATIO;
-- c = initval;
-- len = length;
-+ /* Set up the internal state */
-+ a = b = c = JHASH_GOLDEN_RATIO + (length<<2) + initval;
-
-- while (len >= 3) {
-+ /* handle most of the key */
-+ while (length > 3) {
- a += k[0];
- b += k[1];
- c += k[2];
- __jhash_mix(a, b, c);
-- k += 3; len -= 3;
-+ length -= 3;
-+ k += 3;
- }
-
-- c += length * 4;
--
-- switch (len) {
-- case 2 : b += k[1];
-- case 1 : a += k[0];
-- };
--
-- __jhash_mix(a,b,c);
-+ /* handle the last 3 u32's */
-+ /* all the case statements fall through */
-+ switch (length) {
-+ case 3: c += k[2];
-+ case 2: b += k[1];
-+ case 1: a += k[0];
-+ __jhash_final(a, b, c);
-+ case 0: /* case 0: nothing left to add */
-+ break;
-+ }
-
- return c;
- }
-
--
- /* A special ultra-optimized versions that knows they are hashing exactly
- * 3, 2 or 1 word(s).
-- *
-- * NOTE: In partilar the "c += length; __jhash_mix(a,b,c);" normally
-- * done at the end is not done here.
- */
- static inline u32 jhash_3words(u32 a, u32 b, u32 c, u32 initval)
- {
-- a += JHASH_GOLDEN_RATIO;
-- b += JHASH_GOLDEN_RATIO;
-- c += initval;
-+ a += JHASH_GOLDEN_RATIO + initval;
-+ b += JHASH_GOLDEN_RATIO + initval;
-+ c += JHASH_GOLDEN_RATIO + initval;
-
-- __jhash_mix(a, b, c);
-+ __jhash_final(a, b, c);
-
- return c;
- }
-
- static inline u32 jhash_2words(u32 a, u32 b, u32 initval)
- {
-- return jhash_3words(a, b, 0, initval);
-+ return jhash_3words(0, a, b, initval);
- }
-
- static inline u32 jhash_1word(u32 a, u32 initval)
- {
-- return jhash_3words(a, 0, 0, initval);
-+ return jhash_3words(0, 0, a, initval);
- }
-
- #endif /* _LINUX_JHASH_H */
projects / openwrt / openwrt.git / blobdiff