Line data    Source code

       1             : #ifndef HEADER_fd_src_ballet_murmur3_fd_murmur3_h
       2             : #define HEADER_fd_src_ballet_murmur3_fd_murmur3_h
       3             : 
       4             : /* fd_murmur3 provides APIs for Murmur3 hashing of messages. */
       5             : 
       6             : #include "../fd_ballet_base.h"
       7             : 
       8             : FD_PROTOTYPES_BEGIN
       9             : 
      10             : /* fd_murmur3_32 computes the Murmur3-32 hash given a hash seed and a
      11             :    contiguous memory region to serve as input of size sz.  data points
      12             :    to the first byte of the input and may be freed on return.  Returns
      13             :    the hash digest as a 32-bit integer.  Is idempotent (Guaranteed to
      14             :    return the same hash given the same seed and input byte stream) */
      15             : 
      16             : FD_FN_PURE uint
      17             : fd_murmur3_32( void const * data,
      18             :                ulong        sz,
      19             :                uint         seed );
      20             : 
      21             : /* fd_pchash computes the hash of a program counter suitable for use as
      22             :    the call instruction immediate.  Equivalent to fd_murmur3_32 with
      23             :    zero seed and pc serialized to little-endian ulong. */
      24             : 
      25             : static inline uint
      26   337848348 : fd_pchash( uint pc ) {
      27   337848348 :   uint x = pc;
      28   337848348 :   x *= 0xcc9e2d51U;
      29   337848348 :   x  = fd_uint_rotate_left( x, 15 );
      30   337848348 :   x *= 0x1b873593U;
      31   337848348 :   x  = fd_uint_rotate_left( x, 13 );
      32   337848348 :   x *= 5;
      33   337848348 :   x += 0xe6546b64U;
      34   337848348 :   x  = fd_uint_rotate_left( x, 13 );
      35   337848348 :   x *= 5;
      36   337848348 :   x += 0xe6546b64U;
      37   337848348 :   x ^= 8;
      38   337848348 :   x ^= x >> 16;
      39   337848348 :   x *= 0x85ebca6bU;
      40   337848348 :   x ^= x >> 13;
      41   337848348 :   x *= 0xc2b2ae35U;
      42   337848348 :   x ^= x >> 16;
      43   337848348 :   return x;
      44   337848348 : }
      45             : 
      46             : /* Inverse of the above.  E.g.:
      47             :      fd_pchash_inverse( fd_pchash( (uint)x ) )==(uint)x
      48             :    and:
      49             :      fd_pchash( fd_pchash_inverse( (uint)x ) )==(uint)x */
      50             : 
      51             : static inline uint
      52   304595976 : fd_pchash_inverse( uint hash ) {
      53   304595976 :   uint x = hash;
      54   304595976 :   x ^= x >> 16;
      55   304595976 :   x *= 0x7ed1b41dU;
      56   304595976 :   x ^= (x >> 13) ^ (x >> 26);
      57   304595976 :   x *= 0xa5cb9243U;
      58   304595976 :   x ^= x >> 16;
      59   304595976 :   x ^= 8;
      60   304595976 :   x -= 0xe6546b64U;
      61   304595976 :   x *= 0xcccccccdU;
      62   304595976 :   x  = fd_uint_rotate_right( x, 13 );
      63   304595976 :   x -= 0xe6546b64U;
      64   304595976 :   x *= 0xcccccccdU;
      65   304595976 :   x  = fd_uint_rotate_right( x, 13 );
      66   304595976 :   x *= 0x56ed309bU;
      67   304595976 :   x  = fd_uint_rotate_right( x, 15 );
      68   304595976 :   x *= 0xdee13bb1U;
      69   304595976 :   return x;
      70   304595976 : }
      71             : 
      72             : FD_PROTOTYPES_END
      73             : 
      74             : #endif /* HEADER_fd_src_ballet_murmur3_fd_murmur3_h */