Restore "Add new hashing and "hash with state" infrastructure"

This reverts commit e6a172f358c0f48c4b744dbd5e9ef6ff0b4ff289,
which was a revert of a3bf60fbb1f05cd2c69d4ff0a2ef99537afdaba7.

Add new hashing and "hash with state" infrastructure

This adds support for three new hash functions: StadtX, Zaphod32 and SBOX,
and reworks some of our hash internals infrastructure to do so.

SBOX is special in that it is designed to be used in conjuction with any
other hash function for hashing short strings very efficiently and very
securely. It features compile time options on how much memory and startup
time are traded off to control the length of keys that SBOX hashes.

This also adds support for caching the hash values of single byte characters
which can be used in conjuction with any other hash, including SBOX, although
SBOX itself is as fast as the lookup cache, so typically you wouldnt use both
at the same time.

This also *removes* support for Jenkins One-At-A-Time. It has served us
well, but it's day is done.

This patch adds three new files: zaphod32_hash.h, stadtx_hash.h,
sbox32_hash.h

1 files changed, 221 insertions, 269 deletions

diff --git a/hv_func.h b/hv_func.h
index f0afe27dbb..b05eb87c67 100644
--- a/hv_func.h
+++ b/hv_func.h
@@ -12,140 +12,228 @@
 #ifndef PERL_SEEN_HV_FUNC_H /* compile once */
 #define PERL_SEEN_HV_FUNC_H
 
-#if IVSZIE == 8
+#if IVSIZE == 8
 #define CAN64BITHASH
 #endif
 
-#if !( 0 \
-        || defined(PERL_HASH_FUNC_SIPHASH) \
-        || defined(PERL_HASH_FUNC_SIPHASH13) \
-        || defined(PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13) \
-        || defined(PERL_HASH_FUNC_ONE_AT_A_TIME_HARD) \
-    )
-#ifdef CAN64BITHASH
-#define PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13
-#else
-#define PERL_HASH_FUNC_ONE_AT_A_TIME_HARD
-#endif
-#endif
-
-#if defined(PERL_HASH_FUNC_SIPHASH)
-#   define PERL_HASH_FUNC "SIPHASH_2_4"
-#   define PERL_HASH_SEED_BYTES 16
-#   define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_siphash_2_4((seed),(U8*)(str),(len))
-#elif defined(PERL_HASH_FUNC_SIPHASH13)
-#   define PERL_HASH_FUNC "SIPHASH_1_3"
-#   define PERL_HASH_SEED_BYTES 16
-#   define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_siphash_1_3((seed),(U8*)(str),(len))
-#elif defined(PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13)
-#   define PERL_HASH_FUNC "HYBRID_OAATHU_SIPHASH_1_3"
-#   define PERL_HASH_SEED_BYTES 24
-#   define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_oaathu_siphash_1_3((seed),(U8*)(str),(len))
-#elif defined(PERL_HASH_FUNC_ONE_AT_A_TIME_HARD)
-#   define PERL_HASH_FUNC "ONE_AT_A_TIME_HARD"
-#   define PERL_HASH_SEED_BYTES 8
-#   define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_one_at_a_time_hard((seed),(U8*)(str),(len))
-#endif
-
-#ifndef PERL_HASH_WITH_SEED
-#error "No hash function defined!"
-#endif
-#ifndef PERL_HASH_SEED_BYTES
-#error "PERL_HASH_SEED_BYTES not defined"
-#endif
-#ifndef PERL_HASH_FUNC
-#error "PERL_HASH_FUNC not defined"
-#endif
-
-#ifndef PERL_HASH_SEED
-#   if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT)
-#       define PERL_HASH_SEED PL_hash_seed
-#   elif PERL_HASH_SEED_BYTES == 4
-#       define PERL_HASH_SEED ((const U8 *)"PeRl")
-#   elif PERL_HASH_SEED_BYTES == 8
-#       define PERL_HASH_SEED ((const U8 *)"PeRlHaSh")
-#   elif PERL_HASH_SEED_BYTES == 16
-#       define PERL_HASH_SEED ((const U8 *)"PeRlHaShhAcKpErl")
-#   else
-#       error "No PERL_HASH_SEED definition for " PERL_HASH_FUNC
-#   endif
-#endif
-
-#define PERL_HASH(hash,str,len) PERL_HASH_WITH_SEED(PERL_HASH_SEED,hash,str,len)
-
-/* legacy - only mod_perl should be doing this.  */
-#ifdef PERL_HASH_INTERNAL_ACCESS
-#define PERL_HASH_INTERNAL(hash,str,len) PERL_HASH(hash,str,len)
-#endif
-
 /*-----------------------------------------------------------------------------
  * Endianess, misalignment capabilities and util macros
  *
  * The following 3 macros are defined in this section. The other macros defined
  * are only needed to help derive these 3.
  *
+ * U8TO16_LE(x)   Read a little endian unsigned 32-bit int
  * U8TO32_LE(x)   Read a little endian unsigned 32-bit int
- * UNALIGNED_SAFE   Defined if unaligned access is safe
+ * U8TO28_LE(x)   Read a little endian unsigned 32-bit int
  * ROTL32(x,r)      Rotate x left by r bits
+ * ROTL64(x,r)      Rotate x left by r bits
+ * ROTR32(x,r)      Rotate x right by r bits
+ * ROTR64(x,r)      Rotate x right by r bits
  */
 
-#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \
-  || defined(_MSC_VER) || defined (__TURBOC__)
-#define U8TO16_LE(d) (*((const U16 *) (d)))
-#endif
-
-#if !defined (U8TO16_LE)
-#define U8TO16_LE(d) ((((const U8 *)(d))[1] << 8)\
-                      +((const U8 *)(d))[0])
+#ifndef U32_ALIGNMENT_REQUIRED
+  #if (BYTEORDER == 0x1234 || BYTEORDER == 0x12345678)
+    #define U8TO16_LE(ptr)   (*((const U16*)(ptr)))
+    #define U8TO32_LE(ptr)   (*((const U32*)(ptr)))
+    #define U8TO64_LE(ptr)   (*((const U64*)(ptr)))
+  #elif (BYTEORDER == 0x4321 || BYTEORDER == 0x87654321)
+    #if defined(__GNUC__) && (__GNUC__>4 || (__GNUC__==4 && __GNUC_MINOR__>=3))
+      #define U8TO16_LE(ptr)   (__builtin_bswap16(*((U16*)(ptr))))
+      #define U8TO32_LE(ptr)   (__builtin_bswap32(*((U32*)(ptr))))
+      #define U8TO64_LE(ptr)   (__builtin_bswap64(*((U64*)(ptr))))
+    #endif
+  #endif
 #endif
 
-#if (BYTEORDER == 0x1234 || BYTEORDER == 0x12345678) && U32SIZE == 4
-  /* CPU endian matches murmurhash algorithm, so read 32-bit word directly */
-  #define U8TO32_LE(ptr)   (*((const U32*)(ptr)))
-#elif BYTEORDER == 0x4321 || BYTEORDER == 0x87654321
-  /* TODO: Add additional cases below where a compiler provided bswap32 is available */
-  #if defined(__GNUC__) && (__GNUC__>4 || (__GNUC__==4 && __GNUC_MINOR__>=3))
-    #define U8TO32_LE(ptr)   (__builtin_bswap32(*((U32*)(ptr))))
-  #else
+#ifndef U8TO16_LE
     /* Without a known fast bswap32 we're just as well off doing this */
-    #define U8TO32_LE(ptr)   (ptr[0]|ptr[1]<<8|ptr[2]<<16|ptr[3]<<24)
-    #define UNALIGNED_SAFE
-  #endif
-#else
-  /* Unknown endianess so last resort is to read individual bytes */
-  #define U8TO32_LE(ptr)   (ptr[0]|ptr[1]<<8|ptr[2]<<16|ptr[3]<<24)
-  /* Since we're not doing word-reads we can skip the messing about with realignment */
-  #define UNALIGNED_SAFE
+  #define U8TO16_LE(ptr)   ((U32)(ptr)[0]|(U32)(ptr)[1]<<8)
+  #define U8TO32_LE(ptr)   ((U32)(ptr)[0]|(U32)(ptr)[1]<<8|(U32)(ptr)[2]<<16|(U32)(ptr)[3]<<24)
+  #define U8TO64_LE(ptr)   ((U64)(ptr)[0]|(U64)(ptr)[1]<<8|(U64)(ptr)[2]<<16|(U64)(ptr)[3]<<24|\
+                            (U64)(ptr)[4]<<32|(U64)(ptr)[5]<<40|\
+                            (U64)(ptr)[6]<<48|(U64)(ptr)[7]<<56)
 #endif
 
 #ifdef CAN64BITHASH
-#ifndef U64TYPE
-/* This probably isn't going to work, but failing with a compiler error due to
+  #ifndef U64TYPE
+  /* This probably isn't going to work, but failing with a compiler error due to
    lack of uint64_t is no worse than failing right now with an #error.  */
-#define U64 uint64_t
-#endif
+  #define U64 uint64_t
+  #endif
 #endif
 
 /* Find best way to ROTL32/ROTL64 */
 #if defined(_MSC_VER)
   #include <stdlib.h>  /* Microsoft put _rotl declaration in here */
   #define ROTL32(x,r)  _rotl(x,r)
-  #ifdef CAN64BITHASH
-    #define ROTL64(x,r)  _rotl64(x,r)
-  #endif
+  #define ROTR32(x,r)  _rotr(x,r)
+  #define ROTL64(x,r)  _rotl64(x,r)
+  #define ROTR64(x,r)  _rotr64(x,r)
 #else
   /* gcc recognises this code and generates a rotate instruction for CPUs with one */
-  #define ROTL32(x,r)  (((U32)x << r) | ((U32)x >> (32 - r)))
-  #ifdef CAN64BITHASH
-    #define ROTL64(x,r)  (((U64)x << r) | ((U64)x >> (64 - r)))
-  #endif
+  #define ROTL32(x,r)  (((U32)(x) << (r)) | ((U32)(x) >> (32 - (r))))
+  #define ROTR32(x,r)  (((U32)(x) << (32 - (r))) | ((U32)(x) >> (r)))
+  #define ROTL64(x,r)  ( ( (U64)(x) << (r) ) | ( (U64)(x) >> ( 64 - (r) ) ) )
+  #define ROTR64(x,r)  ( ( (U64)(x) << ( 64 - (r) ) ) | ( (U64)(x) >> (r) ) )
 #endif
 
 
 #ifdef UV_IS_QUAD
 #define ROTL_UV(x,r) ROTL64(x,r)
+#define ROTR_UV(x,r) ROTL64(x,r)
 #else
 #define ROTL_UV(x,r) ROTL32(x,r)
+#define ROTR_UV(x,r) ROTR32(x,r)
+#endif
+
+/*-----------------------------------------------------------------------------*
+ * And now set up the actual hashing macros
+ *-----------------------------------------------------------------------------*/
+#define PERL_HASH_FUNC_ZAPHOD32
+
+#if !( 0 \
+        || defined(PERL_HASH_FUNC_SIPHASH) \
+        || defined(PERL_HASH_FUNC_SIPHASH13) \
+        || defined(PERL_HASH_FUNC_STADTX) \
+        || defined(PERL_HASH_FUNC_ZAPHOD32) \
+    )
+#   ifdef CAN64BITHASH
+#       define PERL_HASH_FUNC_STADTX
+#   else
+#       define PERL_HASH_FUNC_ZAPHOD32
+#   endif
+#endif
+
+#ifndef PERL_HASH_USE_SBOX32_ALSO
+#define PERL_HASH_USE_SBOX32_ALSO 1
+#endif
+
+#ifndef SBOX32_MAX_LEN
+#define SBOX32_MAX_LEN 24
+#endif
+
+/* this must be after the SBOX32_MAX_LEN define */
+#include "sbox32_hash.h"
+
+#if defined(PERL_HASH_FUNC_SIPHASH)
+# define __PERL_HASH_FUNC "SIPHASH_2_4"
+# define __PERL_HASH_SEED_BYTES 16
+# define __PERL_HASH_STATE_BYTES 32
+# define __PERL_HASH_SEED_STATE(seed,state) S_perl_siphash_seed_state(seed,state)
+# define __PERL_HASH_WITH_STATE(state,str,len) S_perl_hash_siphash_2_4_with_state((state),(U8*)(str),(len))
+#elif defined(PERL_HASH_FUNC_SIPHASH13)
+# define __PERL_HASH_FUNC "SIPHASH_1_3"
+# define __PERL_HASH_SEED_BYTES 16
+# define __PERL_HASH_STATE_BYTES 32
+# define __PERL_HASH_SEED_STATE(seed,state) S_perl_siphash_seed_state(seed,state)
+# define __PERL_HASH_WITH_STATE(state,str,len) S_perl_hash_siphash_1_3_with_state((state),(U8*)(str),(len))
+#elif defined(PERL_HASH_FUNC_STADTX)
+# define __PERL_HASH_FUNC "STATDX"
+# define __PERL_HASH_SEED_BYTES 16
+# define __PERL_HASH_STATE_BYTES 32
+# define __PERL_HASH_SEED_STATE(seed,state) stadtx_seed_state(seed,state)
+# define __PERL_HASH_WITH_STATE(state,str,len) (U32)stadtx_hash_with_state((state),(U8*)(str),(len))
+# include "stadtx_hash.h"
+#elif defined(PERL_HASH_FUNC_ZAPHOD32)
+# define __PERL_HASH_FUNC "ZAPHOD32"
+# define __PERL_HASH_SEED_BYTES 12
+# define __PERL_HASH_STATE_BYTES 12
+# define __PERL_HASH_SEED_STATE(seed,state) zaphod32_seed_state(seed,state)
+# define __PERL_HASH_WITH_STATE(state,str,len) (U32)zaphod32_hash_with_state((state),(U8*)(str),(len))
+# include "zaphod32_hash.h"
+#endif
+
+#ifndef __PERL_HASH_WITH_STATE
+#error "No hash function defined!"
+#endif
+#ifndef __PERL_HASH_SEED_BYTES
+#error "__PERL_HASH_SEED_BYTES not defined"
+#endif
+#ifndef __PERL_HASH_FUNC
+#error "__PERL_HASH_FUNC not defined"
+#endif
+
+
+#if PERL_HASH_USE_SBOX32_ALSO == 1
+# define _PERL_HASH_FUNC                        __PERL_HASH_FUNC
+# define _PERL_HASH_SEED_BYTES                  __PERL_HASH_SEED_BYTES
+# define _PERL_HASH_STATE_BYTES                 __PERL_HASH_STATE_BYTES
+# define _PERL_HASH_SEED_STATE(seed,state)      __PERL_HASH_SEED_STATE(seed,state)
+# define _PERL_HASH_WITH_STATE(state,str,len)   __PERL_HASH_WITH_STATE(state,str,len)
+#else
+
+#define _PERL_HASH_FUNC         "SBOX32_WITH_" __PERL_HASH_FUNC
+
+#define _PERL_HASH_SEED_BYTES   ( __PERL_HASH_SEED_BYTES + ( 3 * sizeof(U32) ) )
+
+#define _PERL_HASH_STATE_BYTES  \
+    ( __PERL_HASH_SEED_BYTES + ( ( 1 + ( 256 * SBOX32_MAX_LEN ) ) * sizeof(U32) ) )
+
+#define _PERL_HASH_SEED_STATE(seed,state) STMT_START {                                      \
+    __PERL_HASH_SEED_STATE(seed,state);                                                     \
+    sbox32_seed_state96(seed + __PERL_HASH_SEED_BYTES , state + __PERL_HASH_STATE_BYTES);   \
+} STMT_END
+
+#define _PERL_HASH_WITH_STATE(state,str,len)                                                \
+    ((len <= SBOX32_MAX_LEN)                                                                \
+        ? sbox32_hash_with_state((state + __PERL_HASH_STATE_BYTES),(U8*)(str),(len))        \
+        : __PERL_HASH_WITH_STATE((state),(str),(len)))
+
+#endif
+
+PERL_STATIC_INLINE
+U32 S_perl_hash_with_seed(const U8 * const seed, const U8 * const str, const STRLEN len)
+{
+    U8 state[_PERL_HASH_STATE_BYTES];
+    _PERL_HASH_SEED_STATE(seed,state);
+    return _PERL_HASH_WITH_STATE(state,str,len);
+}
+
+#define PERL_HASH_WITH_SEED(seed,hash,str,len) \
+    (hash) = S_perl_hash_with_seed(seed,str,len)
+#define PERL_HASH_WITH_STATE(state,hash,str,len) \
+    (hash) = _PERL_HASH_WITH_STATE((state),(U8*)(str),(len))
+#define PERL_HASH_SEED_STATE(seed,state) _PERL_HASH_SEED_STATE(seed,state)
+#define PERL_HASH_SEED_BYTES _PERL_HASH_SEED_BYTES
+#define PERL_HASH_STATE_BYTES _PERL_HASH_STATE_BYTES
+#define PERL_HASH_FUNC        _PERL_HASH_FUNC
+
+#ifdef PERL_USE_SINGLE_CHAR_HASH_CACHE
+#define PERL_HASH(state,str,len) \
+    (hash) = ((len) < 2 ? ( (len) == 0 ? PL_hash_chars[256] : PL_hash_chars[(U8)(str)[0]] ) \
+                       : _PERL_HASH_WITH_STATE(PL_hash_state,(U8*)(str),(len)))
+#else
+#define PERL_HASH(hash,str,len) \
+    PERL_HASH_WITH_STATE(PL_hash_state,hash,(U8*)(str),(len))
+#endif
+
+/* Setup the hash seed, either we do things dynamically at start up,
+ * including reading from the environment, or we randomly setup the
+ * seed. The seed will be passed into the PERL_HASH_SEED_STATE() function
+ * defined for the configuration defined for this perl, which will then
+ * initialze whatever state it might need later in hashing. */
+
+#ifndef PERL_HASH_SEED
+#   if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT)
+#       define PERL_HASH_SEED PL_hash_seed
+#   else
+       /* this is a 512 bit seed, which should be more than enough for the
+        * configuration of any of our hash functions (with or without sbox).
+        * If you actually use a hard coded seed, you are strongly encouraged
+        * to replace this with something else of the correct length
+        * for the hash function you are using (24-32 bytes depending on build
+        * options). Repeat, you are *STRONGLY* encouraged not to use the value
+        * provided here.
+        */
+#       define PERL_HASH_SEED \
+           ((const U8 *)"A long string of pseudorandomly "  \
+                        "chosen bytes for hashing in Perl")
+#   endif
+#endif
+
+/* legacy - only mod_perl should be doing this.  */
+#ifdef PERL_HASH_INTERNAL_ACCESS
+#define PERL_HASH_INTERNAL(hash,str,len) PERL_HASH(hash,str,len)
 #endif
 
 /* This is SipHash by Jean-Philippe Aumasson and Daniel J. Bernstein.
@@ -164,16 +252,6 @@
 
 #ifdef CAN64BITHASH
 
-#define U8TO64_LE(p) \
-  (((U64)((p)[0])      ) | \
-   ((U64)((p)[1]) <<  8) | \
-   ((U64)((p)[2]) << 16) | \
-   ((U64)((p)[3]) << 24) | \
-   ((U64)((p)[4]) << 32) | \
-   ((U64)((p)[5]) << 40) | \
-   ((U64)((p)[6]) << 48) | \
-   ((U64)((p)[7]) << 56))
-
 #define SIPROUND            \
   STMT_START {              \
     v0 += v1; v1=ROTL64(v1,13); v1 ^= v0; v0=ROTL64(v0,32); \
@@ -182,30 +260,37 @@
     v2 += v1; v1=ROTL64(v1,17); v1 ^= v2; v2=ROTL64(v2,32); \
   } STMT_END
 
-/* SipHash-2-4 */
-
+#define SIPHASH_SEED_STATE(key,v0,v1,v2,v3) \
+do {                                    \
+    v0 = v2 = U8TO64_LE(key + 0);       \
+    v1 = v3 = U8TO64_LE(key + 8);       \
+  /* "somepseudorandomlygeneratedbytes" */  \
+    v0 ^= 0x736f6d6570736575ull;        \
+    v1 ^= 0x646f72616e646f6dull;        \
+    v2 ^= 0x6c7967656e657261ull;        \
+    v3 ^= 0x7465646279746573ull;        \
+} while (0)
+
+PERL_STATIC_INLINE
+void S_perl_siphash_seed_state(const unsigned char * const seed_buf, unsigned char * state_buf) {
+    U64 *v= (U64*) state_buf;
+    SIPHASH_SEED_STATE(seed_buf, v[0],v[1],v[2],v[3]);
+}
 
 #define PERL_SIPHASH_FNC(FNC,SIP_ROUNDS,SIP_FINAL_ROUNDS) \
 PERL_STATIC_INLINE U32 \
-FNC(const unsigned char * const seed, const unsigned char *in, const STRLEN inlen) { \
-  /* "somepseudorandomlygeneratedbytes" */  \
-  U64 v0 = UINT64_C(0x736f6d6570736575);    \
-  U64 v1 = UINT64_C(0x646f72616e646f6d);    \
-  U64 v2 = UINT64_C(0x6c7967656e657261);    \
-  U64 v3 = UINT64_C(0x7465646279746573);    \
-                                            \
-  U64 b;                                    \
-  U64 k0 = ((const U64*)seed)[0];           \
-  U64 k1 = ((const U64*)seed)[1];           \
-  U64 m;                                    \
+FNC ## _with_state \
+  (const unsigned char * const state, const unsigned char *in, const STRLEN inlen) \
+{                                           \
   const int left = inlen & 7;               \
   const U8 *end = in + inlen - left;        \
                                             \
-  b = ( ( U64 )(inlen) ) << 56;             \
-  v3 ^= k1;                                 \
-  v2 ^= k0;                                 \
-  v1 ^= k1;                                 \
-  v0 ^= k0;                                 \
+  U64 b = ( ( U64 )(inlen) ) << 56;         \
+  U64 m;                                    \
+  U64 v0 = U8TO64_LE(state);                \
+  U64 v1 = U8TO64_LE(state+8);              \
+  U64 v2 = U8TO64_LE(state+16);             \
+  U64 v3 = U8TO64_LE(state+24);             \
                                             \
   for ( ; in != end; in += 8 )              \
   {                                         \
@@ -241,8 +326,17 @@ FNC(const unsigned char * const seed, const unsigned char *in, const STRLEN inle
                                             \
   b = v0 ^ v1 ^ v2  ^ v3;                   \
   return (U32)(b & U32_MAX);                \
+}                                           \
+                                            \
+PERL_STATIC_INLINE U32                      \
+FNC (const unsigned char * const seed, const unsigned char *in, const STRLEN inlen) \
+{                                                                   \
+    U64 state[4];                                                   \
+    SIPHASH_SEED_STATE(seed,state[0],state[1],state[2],state[3]);   \
+    return FNC ## _with_state((U8*)state,in,inlen);                 \
 }
 
+
 PERL_SIPHASH_FNC(
     S_perl_hash_siphash_1_3
     ,SIPROUND;
@@ -254,152 +348,10 @@ PERL_SIPHASH_FNC(
     ,SIPROUND;SIPROUND;
     ,SIPROUND;SIPROUND;SIPROUND;SIPROUND;
 )
-
 #endif /* defined(CAN64BITHASH) */
 
-/* - ONE_AT_A_TIME_HARD is the 5.17+ recommend ONE_AT_A_TIME variant */
 
-/* This is derived from the "One-at-a-Time" algorithm by Bob Jenkins
- * from requirements by Colin Plumb.
- * (http://burtleburtle.net/bob/hash/doobs.html)
- * Modified by Yves Orton to increase security for Perl 5.17 and later.
- */
-PERL_STATIC_INLINE U32
-S_perl_hash_one_at_a_time_hard(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
-    const unsigned char * const end = (const unsigned char *)str + len;
-    U32 hash = *((const U32*)seed) + (U32)len;
-    
-    while (str < end) {
-        hash += (hash << 10);
-        hash ^= (hash >> 6);
-        hash += *str++;
-    }
-    
-    hash += (hash << 10);
-    hash ^= (hash >> 6);
-    hash += seed[4];
-    
-    hash += (hash << 10);
-    hash ^= (hash >> 6);
-    hash += seed[5];
-    
-    hash += (hash << 10);
-    hash ^= (hash >> 6);
-    hash += seed[6];
-    
-    hash += (hash << 10);
-    hash ^= (hash >> 6);
-    hash += seed[7];
-    
-    hash += (hash << 10);
-    hash ^= (hash >> 6);
-
-    hash += (hash << 3);
-    hash ^= (hash >> 11);
-    return (hash + (hash << 15));
-}
 
-#ifdef CAN64BITHASH
-
-/* Hybrid hash function
- *
- * For short strings, 16 bytes or shorter, we use an optimised variant
- * of One At A Time Hard, and for longer strings, we use siphash_1_3.
- *
- * The optimisation of One At A Time Hard means we read the key in
- * reverse from normal, but by doing so we avoid the loop overhead.
- */
-PERL_STATIC_INLINE U32
-S_perl_hash_oaathu_siphash_1_3(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
-    U32 hash = *((const U32*)seed) + (U32)len;
-    switch (len) {
-        case 16:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[15];
-        case 15:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[14];
-        case 14:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[13];
-        case 13:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[12];
-        case 12:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[11];
-        case 11:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[10];
-        case 10:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[9];
-        case 9:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[8];
-        case 8:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[7];
-        case 7:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[6];
-        case 6:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[5];
-        case 5:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[4];
-        case 4:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[3];
-        case 3:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[2];
-        case 2:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[1];
-        case 1:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += str[0];
-        case 0:
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += seed[4];
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += seed[5];
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += seed[6];
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-            hash += seed[7];
-            hash += (hash << 10);
-            hash ^= (hash >> 6);
-
-            hash += (hash << 3);
-            hash ^= (hash >> 11);
-            return (hash + (hash << 15));
-    }
-    return S_perl_hash_siphash_1_3(seed+8, str, len);
-}
-#endif /* defined(CAN64BITHASH) */
 
 
 #endif /*compile once*/