Line data    Source code

       1             : #ifndef HEADER_fd_src_util_fd_hash32_h
       2             : #define HEADER_fd_src_util_fd_hash32_h
       3             : 
       4             : #include "bits/fd_bits.h"
       5             : 
       6             : #if FD_HAS_INT128
       7             : 
       8             : static inline ulong
       9   879748920 : fd_xxh3_mul128_fold64( ulong lhs, ulong rhs ) {
      10             : #if defined(FD_USING_GCC) && defined(__BMI2__)
      11             :   ulong lo, hi;
      12             :   __asm__( "mulx %3,%0,%1" : "=r"(lo), "=r"(hi) : "d"(lhs), "rm"(rhs) );
      13             :   return lo ^ hi;
      14             : #else
      15   879748920 :   uint128 product = (uint128)lhs * (uint128)rhs;
      16   879748920 :   return (ulong)product ^ (ulong)( product>>64 );
      17   879748920 : #endif
      18   879748920 : }
      19             : 
      20             : static inline ulong
      21             : fd_xxh3_mix16b( ulong i0, ulong i1,
      22             :                 ulong s0, ulong s1,
      23   879748914 :                 ulong seed ) {
      24   879748914 :   return fd_xxh3_mul128_fold64( i0 ^ (s0 + seed), i1 ^ (s1 - seed) );
      25   879748914 : }
      26             : 
      27             : FD_FN_PURE static inline ulong
      28             : fd_hash32( uchar const key[ 32 ],
      29   439865390 :            ulong       seed ) {
      30   439865390 :   ulong k0 = FD_LOAD( ulong, key+ 0 );
      31   439865390 :   ulong k1 = FD_LOAD( ulong, key+ 8 );
      32   439865390 :   ulong k2 = FD_LOAD( ulong, key+16 );
      33   439865390 :   ulong k3 = FD_LOAD( ulong, key+24 );
      34   439865390 :   ulong acc = 32 * 0x9E3779B185EBCA87ULL;
      35   439865390 :   acc += fd_xxh3_mix16b( k0, k1, 0xbe4ba423396cfeb8UL, 0x1cad21f72c81017cUL, seed );
      36   439865390 :   acc += fd_xxh3_mix16b( k2, k3, 0xdb979083e96dd4deUL, 0x1f67b3b7a4a44072UL, seed );
      37   439865390 :   acc = acc ^ (acc >> 37);
      38   439865390 :   acc *= 0x165667919E3779F9ULL;
      39   439865390 :   acc = acc ^ (acc >> 32);
      40   439865390 :   return acc;
      41   439865390 : }
      42             : 
      43             : #else
      44             : 
      45             : /* If the target does not support xxHash3, fallback to the 'old' key
      46             :    hash function.
      47             : 
      48             :    FIXME This version is vulnerable to HashDoS */
      49             : 
      50             : FD_FN_PURE static inline ulong
      51             : fd_hash32( uchar const key[ 32 ],
      52             :            ulong       seed ) {
      53             :   /* tons of ILP */
      54             :   return (fd_ulong_hash( seed ^ (1UL<<0) ^ FD_LOAD( ulong, key+ 0 ) )   ^
      55             :           fd_ulong_hash( seed ^ (1UL<<1) ^ FD_LOAD( ulong, key+ 8 ) ) ) ^
      56             :          (fd_ulong_hash( seed ^ (1UL<<2) ^ FD_LOAD( ulong, key+16 ) ) ^
      57             :           fd_ulong_hash( seed ^ (1UL<<3) ^ FD_LOAD( ulong, key+24 ) ) );
      58             : }
      59             : 
      60             : #endif /* FD_HAS_INT128 */
      61             : 
      62             : #endif /* HEADER_fd_src_util_fd_hash32_h */